1 /* Support routines for Value Range Propagation (VRP).
2 Copyright (C) 2005-2015 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
29 #include "fold-const.h"
30 #include "stor-layout.h"
33 #include "hard-reg-set.h"
35 #include "dominance.h"
38 #include "basic-block.h"
39 #include "tree-ssa-alias.h"
40 #include "internal-fn.h"
41 #include "gimple-fold.h"
43 #include "gimple-expr.h"
45 #include "gimple-iterator.h"
46 #include "gimple-walk.h"
47 #include "gimple-ssa.h"
49 #include "tree-phinodes.h"
50 #include "ssa-iterators.h"
51 #include "stringpool.h"
52 #include "tree-ssanames.h"
53 #include "tree-ssa-loop-manip.h"
54 #include "tree-ssa-loop-niter.h"
55 #include "tree-ssa-loop.h"
56 #include "tree-into-ssa.h"
58 #include "tree-pass.h"
59 #include "tree-dump.h"
60 #include "gimple-pretty-print.h"
61 #include "diagnostic-core.h"
64 #include "tree-scalar-evolution.h"
65 #include "tree-ssa-propagate.h"
66 #include "tree-chrec.h"
67 #include "tree-ssa-threadupdate.h"
69 #include "insn-config.h"
77 #include "insn-codes.h"
79 #include "tree-ssa-scopedtables.h"
80 #include "tree-ssa-threadedge.h"
84 /* Range of values that can be associated with an SSA_NAME after VRP
88 /* Lattice value represented by this range. */
89 enum value_range_type type;
91 /* Minimum and maximum values represented by this range. These
92 values should be interpreted as follows:
94 - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
97 - If TYPE == VR_RANGE then MIN holds the minimum value and
98 MAX holds the maximum value of the range [MIN, MAX].
100 - If TYPE == ANTI_RANGE the variable is known to NOT
101 take any values in the range [MIN, MAX]. */
105 /* Set of SSA names whose value ranges are equivalent to this one.
106 This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */
110 typedef struct value_range_d value_range_t;
112 #define VR_INITIALIZER { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL }
114 /* Set of SSA names found live during the RPO traversal of the function
115 for still active basic-blocks. */
116 static sbitmap *live;
118 /* Return true if the SSA name NAME is live on the edge E. */
121 live_on_edge (edge e, tree name)
123 return (live[e->dest->index]
124 && bitmap_bit_p (live[e->dest->index], SSA_NAME_VERSION (name)));
127 /* Local functions. */
128 static int compare_values (tree val1, tree val2);
129 static int compare_values_warnv (tree val1, tree val2, bool *);
130 static void vrp_meet (value_range_t *, value_range_t *);
131 static void vrp_intersect_ranges (value_range_t *, value_range_t *);
132 static tree vrp_evaluate_conditional_warnv_with_ops (enum tree_code,
133 tree, tree, bool, bool *,
136 /* Location information for ASSERT_EXPRs. Each instance of this
137 structure describes an ASSERT_EXPR for an SSA name. Since a single
138 SSA name may have more than one assertion associated with it, these
139 locations are kept in a linked list attached to the corresponding
141 struct assert_locus_d
143 /* Basic block where the assertion would be inserted. */
146 /* Some assertions need to be inserted on an edge (e.g., assertions
147 generated by COND_EXPRs). In those cases, BB will be NULL. */
150 /* Pointer to the statement that generated this assertion. */
151 gimple_stmt_iterator si;
153 /* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */
154 enum tree_code comp_code;
156 /* Value being compared against. */
159 /* Expression to compare. */
162 /* Next node in the linked list. */
163 struct assert_locus_d *next;
166 typedef struct assert_locus_d *assert_locus_t;
168 /* If bit I is present, it means that SSA name N_i has a list of
169 assertions that should be inserted in the IL. */
170 static bitmap need_assert_for;
172 /* Array of locations lists where to insert assertions. ASSERTS_FOR[I]
173 holds a list of ASSERT_LOCUS_T nodes that describe where
174 ASSERT_EXPRs for SSA name N_I should be inserted. */
175 static assert_locus_t *asserts_for;
177 /* Value range array. After propagation, VR_VALUE[I] holds the range
178 of values that SSA name N_I may take. */
179 static unsigned num_vr_values;
180 static value_range_t **vr_value;
181 static bool values_propagated;
183 /* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
184 number of executable edges we saw the last time we visited the
186 static int *vr_phi_edge_counts;
193 static vec<edge> to_remove_edges;
194 static vec<switch_update> to_update_switch_stmts;
197 /* Return the maximum value for TYPE. */
200 vrp_val_max (const_tree type)
202 if (!INTEGRAL_TYPE_P (type))
205 return TYPE_MAX_VALUE (type);
208 /* Return the minimum value for TYPE. */
211 vrp_val_min (const_tree type)
213 if (!INTEGRAL_TYPE_P (type))
216 return TYPE_MIN_VALUE (type);
219 /* Return whether VAL is equal to the maximum value of its type. This
220 will be true for a positive overflow infinity. We can't do a
221 simple equality comparison with TYPE_MAX_VALUE because C typedefs
222 and Ada subtypes can produce types whose TYPE_MAX_VALUE is not ==
223 to the integer constant with the same value in the type. */
226 vrp_val_is_max (const_tree val)
228 tree type_max = vrp_val_max (TREE_TYPE (val));
229 return (val == type_max
230 || (type_max != NULL_TREE
231 && operand_equal_p (val, type_max, 0)));
234 /* Return whether VAL is equal to the minimum value of its type. This
235 will be true for a negative overflow infinity. */
238 vrp_val_is_min (const_tree val)
240 tree type_min = vrp_val_min (TREE_TYPE (val));
241 return (val == type_min
242 || (type_min != NULL_TREE
243 && operand_equal_p (val, type_min, 0)));
247 /* Return whether TYPE should use an overflow infinity distinct from
248 TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to
249 represent a signed overflow during VRP computations. An infinity
250 is distinct from a half-range, which will go from some number to
251 TYPE_{MIN,MAX}_VALUE. */
254 needs_overflow_infinity (const_tree type)
256 return INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type);
259 /* Return whether TYPE can support our overflow infinity
260 representation: we use the TREE_OVERFLOW flag, which only exists
261 for constants. If TYPE doesn't support this, we don't optimize
262 cases which would require signed overflow--we drop them to
266 supports_overflow_infinity (const_tree type)
268 tree min = vrp_val_min (type), max = vrp_val_max (type);
269 #ifdef ENABLE_CHECKING
270 gcc_assert (needs_overflow_infinity (type));
272 return (min != NULL_TREE
273 && CONSTANT_CLASS_P (min)
275 && CONSTANT_CLASS_P (max));
278 /* VAL is the maximum or minimum value of a type. Return a
279 corresponding overflow infinity. */
282 make_overflow_infinity (tree val)
284 gcc_checking_assert (val != NULL_TREE && CONSTANT_CLASS_P (val));
285 val = copy_node (val);
286 TREE_OVERFLOW (val) = 1;
290 /* Return a negative overflow infinity for TYPE. */
293 negative_overflow_infinity (tree type)
295 gcc_checking_assert (supports_overflow_infinity (type));
296 return make_overflow_infinity (vrp_val_min (type));
299 /* Return a positive overflow infinity for TYPE. */
302 positive_overflow_infinity (tree type)
304 gcc_checking_assert (supports_overflow_infinity (type));
305 return make_overflow_infinity (vrp_val_max (type));
308 /* Return whether VAL is a negative overflow infinity. */
311 is_negative_overflow_infinity (const_tree val)
313 return (TREE_OVERFLOW_P (val)
314 && needs_overflow_infinity (TREE_TYPE (val))
315 && vrp_val_is_min (val));
318 /* Return whether VAL is a positive overflow infinity. */
321 is_positive_overflow_infinity (const_tree val)
323 return (TREE_OVERFLOW_P (val)
324 && needs_overflow_infinity (TREE_TYPE (val))
325 && vrp_val_is_max (val));
328 /* Return whether VAL is a positive or negative overflow infinity. */
331 is_overflow_infinity (const_tree val)
333 return (TREE_OVERFLOW_P (val)
334 && needs_overflow_infinity (TREE_TYPE (val))
335 && (vrp_val_is_min (val) || vrp_val_is_max (val)));
338 /* Return whether STMT has a constant rhs that is_overflow_infinity. */
341 stmt_overflow_infinity (gimple stmt)
343 if (is_gimple_assign (stmt)
344 && get_gimple_rhs_class (gimple_assign_rhs_code (stmt)) ==
346 return is_overflow_infinity (gimple_assign_rhs1 (stmt));
350 /* If VAL is now an overflow infinity, return VAL. Otherwise, return
351 the same value with TREE_OVERFLOW clear. This can be used to avoid
352 confusing a regular value with an overflow value. */
355 avoid_overflow_infinity (tree val)
357 if (!is_overflow_infinity (val))
360 if (vrp_val_is_max (val))
361 return vrp_val_max (TREE_TYPE (val));
364 gcc_checking_assert (vrp_val_is_min (val));
365 return vrp_val_min (TREE_TYPE (val));
370 /* Return true if ARG is marked with the nonnull attribute in the
371 current function signature. */
374 nonnull_arg_p (const_tree arg)
376 tree t, attrs, fntype;
377 unsigned HOST_WIDE_INT arg_num;
379 gcc_assert (TREE_CODE (arg) == PARM_DECL && POINTER_TYPE_P (TREE_TYPE (arg)));
381 /* The static chain decl is always non null. */
382 if (arg == cfun->static_chain_decl)
385 /* THIS argument of method is always non-NULL. */
386 if (TREE_CODE (TREE_TYPE (current_function_decl)) == METHOD_TYPE
387 && arg == DECL_ARGUMENTS (current_function_decl)
388 && flag_delete_null_pointer_checks)
391 /* Values passed by reference are always non-NULL. */
392 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE
393 && flag_delete_null_pointer_checks)
396 fntype = TREE_TYPE (current_function_decl);
397 for (attrs = TYPE_ATTRIBUTES (fntype); attrs; attrs = TREE_CHAIN (attrs))
399 attrs = lookup_attribute ("nonnull", attrs);
401 /* If "nonnull" wasn't specified, we know nothing about the argument. */
402 if (attrs == NULL_TREE)
405 /* If "nonnull" applies to all the arguments, then ARG is non-null. */
406 if (TREE_VALUE (attrs) == NULL_TREE)
409 /* Get the position number for ARG in the function signature. */
410 for (arg_num = 1, t = DECL_ARGUMENTS (current_function_decl);
412 t = DECL_CHAIN (t), arg_num++)
418 gcc_assert (t == arg);
420 /* Now see if ARG_NUM is mentioned in the nonnull list. */
421 for (t = TREE_VALUE (attrs); t; t = TREE_CHAIN (t))
423 if (compare_tree_int (TREE_VALUE (t), arg_num) == 0)
432 /* Set value range VR to VR_UNDEFINED. */
435 set_value_range_to_undefined (value_range_t *vr)
437 vr->type = VR_UNDEFINED;
438 vr->min = vr->max = NULL_TREE;
440 bitmap_clear (vr->equiv);
444 /* Set value range VR to VR_VARYING. */
447 set_value_range_to_varying (value_range_t *vr)
449 vr->type = VR_VARYING;
450 vr->min = vr->max = NULL_TREE;
452 bitmap_clear (vr->equiv);
456 /* Set value range VR to {T, MIN, MAX, EQUIV}. */
459 set_value_range (value_range_t *vr, enum value_range_type t, tree min,
460 tree max, bitmap equiv)
462 #if defined ENABLE_CHECKING
463 /* Check the validity of the range. */
464 if (t == VR_RANGE || t == VR_ANTI_RANGE)
468 gcc_assert (min && max);
470 gcc_assert ((!TREE_OVERFLOW_P (min) || is_overflow_infinity (min))
471 && (!TREE_OVERFLOW_P (max) || is_overflow_infinity (max)));
473 if (INTEGRAL_TYPE_P (TREE_TYPE (min)) && t == VR_ANTI_RANGE)
474 gcc_assert (!vrp_val_is_min (min) || !vrp_val_is_max (max));
476 cmp = compare_values (min, max);
477 gcc_assert (cmp == 0 || cmp == -1 || cmp == -2);
479 if (needs_overflow_infinity (TREE_TYPE (min)))
480 gcc_assert (!is_overflow_infinity (min)
481 || !is_overflow_infinity (max));
484 if (t == VR_UNDEFINED || t == VR_VARYING)
485 gcc_assert (min == NULL_TREE && max == NULL_TREE);
487 if (t == VR_UNDEFINED || t == VR_VARYING)
488 gcc_assert (equiv == NULL || bitmap_empty_p (equiv));
495 /* Since updating the equivalence set involves deep copying the
496 bitmaps, only do it if absolutely necessary. */
497 if (vr->equiv == NULL
499 vr->equiv = BITMAP_ALLOC (NULL);
501 if (equiv != vr->equiv)
503 if (equiv && !bitmap_empty_p (equiv))
504 bitmap_copy (vr->equiv, equiv);
506 bitmap_clear (vr->equiv);
511 /* Set value range VR to the canonical form of {T, MIN, MAX, EQUIV}.
512 This means adjusting T, MIN and MAX representing the case of a
513 wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX]
514 as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges.
515 In corner cases where MAX+1 or MIN-1 wraps this will fall back
517 This routine exists to ease canonicalization in the case where we
518 extract ranges from var + CST op limit. */
521 set_and_canonicalize_value_range (value_range_t *vr, enum value_range_type t,
522 tree min, tree max, bitmap equiv)
524 /* Use the canonical setters for VR_UNDEFINED and VR_VARYING. */
525 if (t == VR_UNDEFINED)
527 set_value_range_to_undefined (vr);
530 else if (t == VR_VARYING)
532 set_value_range_to_varying (vr);
536 /* Nothing to canonicalize for symbolic ranges. */
537 if (TREE_CODE (min) != INTEGER_CST
538 || TREE_CODE (max) != INTEGER_CST)
540 set_value_range (vr, t, min, max, equiv);
544 /* Wrong order for min and max, to swap them and the VR type we need
546 if (tree_int_cst_lt (max, min))
550 /* For one bit precision if max < min, then the swapped
551 range covers all values, so for VR_RANGE it is varying and
552 for VR_ANTI_RANGE empty range, so drop to varying as well. */
553 if (TYPE_PRECISION (TREE_TYPE (min)) == 1)
555 set_value_range_to_varying (vr);
559 one = build_int_cst (TREE_TYPE (min), 1);
560 tmp = int_const_binop (PLUS_EXPR, max, one);
561 max = int_const_binop (MINUS_EXPR, min, one);
564 /* There's one corner case, if we had [C+1, C] before we now have
565 that again. But this represents an empty value range, so drop
566 to varying in this case. */
567 if (tree_int_cst_lt (max, min))
569 set_value_range_to_varying (vr);
573 t = t == VR_RANGE ? VR_ANTI_RANGE : VR_RANGE;
576 /* Anti-ranges that can be represented as ranges should be so. */
577 if (t == VR_ANTI_RANGE)
579 bool is_min = vrp_val_is_min (min);
580 bool is_max = vrp_val_is_max (max);
582 if (is_min && is_max)
584 /* We cannot deal with empty ranges, drop to varying.
585 ??? This could be VR_UNDEFINED instead. */
586 set_value_range_to_varying (vr);
589 else if (TYPE_PRECISION (TREE_TYPE (min)) == 1
590 && (is_min || is_max))
592 /* Non-empty boolean ranges can always be represented
593 as a singleton range. */
595 min = max = vrp_val_max (TREE_TYPE (min));
597 min = max = vrp_val_min (TREE_TYPE (min));
601 /* As a special exception preserve non-null ranges. */
602 && !(TYPE_UNSIGNED (TREE_TYPE (min))
603 && integer_zerop (max)))
605 tree one = build_int_cst (TREE_TYPE (max), 1);
606 min = int_const_binop (PLUS_EXPR, max, one);
607 max = vrp_val_max (TREE_TYPE (max));
612 tree one = build_int_cst (TREE_TYPE (min), 1);
613 max = int_const_binop (MINUS_EXPR, min, one);
614 min = vrp_val_min (TREE_TYPE (min));
619 /* Drop [-INF(OVF), +INF(OVF)] to varying. */
620 if (needs_overflow_infinity (TREE_TYPE (min))
621 && is_overflow_infinity (min)
622 && is_overflow_infinity (max))
624 set_value_range_to_varying (vr);
628 set_value_range (vr, t, min, max, equiv);
631 /* Copy value range FROM into value range TO. */
634 copy_value_range (value_range_t *to, value_range_t *from)
636 set_value_range (to, from->type, from->min, from->max, from->equiv);
639 /* Set value range VR to a single value. This function is only called
640 with values we get from statements, and exists to clear the
641 TREE_OVERFLOW flag so that we don't think we have an overflow
642 infinity when we shouldn't. */
645 set_value_range_to_value (value_range_t *vr, tree val, bitmap equiv)
647 gcc_assert (is_gimple_min_invariant (val));
648 if (TREE_OVERFLOW_P (val))
649 val = drop_tree_overflow (val);
650 set_value_range (vr, VR_RANGE, val, val, equiv);
653 /* Set value range VR to a non-negative range of type TYPE.
654 OVERFLOW_INFINITY indicates whether to use an overflow infinity
655 rather than TYPE_MAX_VALUE; this should be true if we determine
656 that the range is nonnegative based on the assumption that signed
657 overflow does not occur. */
660 set_value_range_to_nonnegative (value_range_t *vr, tree type,
661 bool overflow_infinity)
665 if (overflow_infinity && !supports_overflow_infinity (type))
667 set_value_range_to_varying (vr);
671 zero = build_int_cst (type, 0);
672 set_value_range (vr, VR_RANGE, zero,
674 ? positive_overflow_infinity (type)
675 : TYPE_MAX_VALUE (type)),
679 /* Set value range VR to a non-NULL range of type TYPE. */
682 set_value_range_to_nonnull (value_range_t *vr, tree type)
684 tree zero = build_int_cst (type, 0);
685 set_value_range (vr, VR_ANTI_RANGE, zero, zero, vr->equiv);
689 /* Set value range VR to a NULL range of type TYPE. */
692 set_value_range_to_null (value_range_t *vr, tree type)
694 set_value_range_to_value (vr, build_int_cst (type, 0), vr->equiv);
698 /* Set value range VR to a range of a truthvalue of type TYPE. */
701 set_value_range_to_truthvalue (value_range_t *vr, tree type)
703 if (TYPE_PRECISION (type) == 1)
704 set_value_range_to_varying (vr);
706 set_value_range (vr, VR_RANGE,
707 build_int_cst (type, 0), build_int_cst (type, 1),
712 /* If abs (min) < abs (max), set VR to [-max, max], if
713 abs (min) >= abs (max), set VR to [-min, min]. */
716 abs_extent_range (value_range_t *vr, tree min, tree max)
720 gcc_assert (TREE_CODE (min) == INTEGER_CST);
721 gcc_assert (TREE_CODE (max) == INTEGER_CST);
722 gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min)));
723 gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min)));
724 min = fold_unary (ABS_EXPR, TREE_TYPE (min), min);
725 max = fold_unary (ABS_EXPR, TREE_TYPE (max), max);
726 if (TREE_OVERFLOW (min) || TREE_OVERFLOW (max))
728 set_value_range_to_varying (vr);
731 cmp = compare_values (min, max);
733 min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), max);
734 else if (cmp == 0 || cmp == 1)
737 min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), min);
741 set_value_range_to_varying (vr);
744 set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL);
748 /* Return value range information for VAR.
750 If we have no values ranges recorded (ie, VRP is not running), then
751 return NULL. Otherwise create an empty range if none existed for VAR. */
753 static value_range_t *
754 get_value_range (const_tree var)
756 static const struct value_range_d vr_const_varying
757 = { VR_VARYING, NULL_TREE, NULL_TREE, NULL };
760 unsigned ver = SSA_NAME_VERSION (var);
762 /* If we have no recorded ranges, then return NULL. */
766 /* If we query the range for a new SSA name return an unmodifiable VARYING.
767 We should get here at most from the substitute-and-fold stage which
768 will never try to change values. */
769 if (ver >= num_vr_values)
770 return CONST_CAST (value_range_t *, &vr_const_varying);
776 /* After propagation finished do not allocate new value-ranges. */
777 if (values_propagated)
778 return CONST_CAST (value_range_t *, &vr_const_varying);
780 /* Create a default value range. */
781 vr_value[ver] = vr = XCNEW (value_range_t);
783 /* Defer allocating the equivalence set. */
786 /* If VAR is a default definition of a parameter, the variable can
787 take any value in VAR's type. */
788 if (SSA_NAME_IS_DEFAULT_DEF (var))
790 sym = SSA_NAME_VAR (var);
791 if (TREE_CODE (sym) == PARM_DECL)
793 /* Try to use the "nonnull" attribute to create ~[0, 0]
794 anti-ranges for pointers. Note that this is only valid with
795 default definitions of PARM_DECLs. */
796 if (POINTER_TYPE_P (TREE_TYPE (sym))
797 && nonnull_arg_p (sym))
798 set_value_range_to_nonnull (vr, TREE_TYPE (sym));
800 set_value_range_to_varying (vr);
802 else if (TREE_CODE (sym) == RESULT_DECL
803 && DECL_BY_REFERENCE (sym))
804 set_value_range_to_nonnull (vr, TREE_TYPE (sym));
810 /* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
813 vrp_operand_equal_p (const_tree val1, const_tree val2)
817 if (!val1 || !val2 || !operand_equal_p (val1, val2, 0))
819 return is_overflow_infinity (val1) == is_overflow_infinity (val2);
822 /* Return true, if the bitmaps B1 and B2 are equal. */
825 vrp_bitmap_equal_p (const_bitmap b1, const_bitmap b2)
828 || ((!b1 || bitmap_empty_p (b1))
829 && (!b2 || bitmap_empty_p (b2)))
831 && bitmap_equal_p (b1, b2)));
834 /* Update the value range and equivalence set for variable VAR to
835 NEW_VR. Return true if NEW_VR is different from VAR's previous
838 NOTE: This function assumes that NEW_VR is a temporary value range
839 object created for the sole purpose of updating VAR's range. The
840 storage used by the equivalence set from NEW_VR will be freed by
841 this function. Do not call update_value_range when NEW_VR
842 is the range object associated with another SSA name. */
845 update_value_range (const_tree var, value_range_t *new_vr)
847 value_range_t *old_vr;
850 /* If there is a value-range on the SSA name from earlier analysis
852 if (INTEGRAL_TYPE_P (TREE_TYPE (var)))
855 value_range_type rtype = get_range_info (var, &min, &max);
856 if (rtype == VR_RANGE || rtype == VR_ANTI_RANGE)
860 nr.min = wide_int_to_tree (TREE_TYPE (var), min);
861 nr.max = wide_int_to_tree (TREE_TYPE (var), max);
863 vrp_intersect_ranges (new_vr, &nr);
867 /* Update the value range, if necessary. */
868 old_vr = get_value_range (var);
869 is_new = old_vr->type != new_vr->type
870 || !vrp_operand_equal_p (old_vr->min, new_vr->min)
871 || !vrp_operand_equal_p (old_vr->max, new_vr->max)
872 || !vrp_bitmap_equal_p (old_vr->equiv, new_vr->equiv);
876 /* Do not allow transitions up the lattice. The following
877 is slightly more awkward than just new_vr->type < old_vr->type
878 because VR_RANGE and VR_ANTI_RANGE need to be considered
879 the same. We may not have is_new when transitioning to
880 UNDEFINED. If old_vr->type is VARYING, we shouldn't be
882 if (new_vr->type == VR_UNDEFINED)
884 BITMAP_FREE (new_vr->equiv);
885 set_value_range_to_varying (old_vr);
886 set_value_range_to_varying (new_vr);
890 set_value_range (old_vr, new_vr->type, new_vr->min, new_vr->max,
894 BITMAP_FREE (new_vr->equiv);
900 /* Add VAR and VAR's equivalence set to EQUIV. This is the central
901 point where equivalence processing can be turned on/off. */
904 add_equivalence (bitmap *equiv, const_tree var)
906 unsigned ver = SSA_NAME_VERSION (var);
907 value_range_t *vr = vr_value[ver];
910 *equiv = BITMAP_ALLOC (NULL);
911 bitmap_set_bit (*equiv, ver);
913 bitmap_ior_into (*equiv, vr->equiv);
917 /* Return true if VR is ~[0, 0]. */
920 range_is_nonnull (value_range_t *vr)
922 return vr->type == VR_ANTI_RANGE
923 && integer_zerop (vr->min)
924 && integer_zerop (vr->max);
928 /* Return true if VR is [0, 0]. */
931 range_is_null (value_range_t *vr)
933 return vr->type == VR_RANGE
934 && integer_zerop (vr->min)
935 && integer_zerop (vr->max);
938 /* Return true if max and min of VR are INTEGER_CST. It's not necessary
942 range_int_cst_p (value_range_t *vr)
944 return (vr->type == VR_RANGE
945 && TREE_CODE (vr->max) == INTEGER_CST
946 && TREE_CODE (vr->min) == INTEGER_CST);
949 /* Return true if VR is a INTEGER_CST singleton. */
952 range_int_cst_singleton_p (value_range_t *vr)
954 return (range_int_cst_p (vr)
955 && !is_overflow_infinity (vr->min)
956 && !is_overflow_infinity (vr->max)
957 && tree_int_cst_equal (vr->min, vr->max));
960 /* Return true if value range VR involves at least one symbol. */
963 symbolic_range_p (value_range_t *vr)
965 return (!is_gimple_min_invariant (vr->min)
966 || !is_gimple_min_invariant (vr->max));
969 /* Return the single symbol (an SSA_NAME) contained in T if any, or NULL_TREE
970 otherwise. We only handle additive operations and set NEG to true if the
971 symbol is negated and INV to the invariant part, if any. */
974 get_single_symbol (tree t, bool *neg, tree *inv)
979 if (TREE_CODE (t) == PLUS_EXPR
980 || TREE_CODE (t) == POINTER_PLUS_EXPR
981 || TREE_CODE (t) == MINUS_EXPR)
983 if (is_gimple_min_invariant (TREE_OPERAND (t, 0)))
985 neg_ = (TREE_CODE (t) == MINUS_EXPR);
986 inv_ = TREE_OPERAND (t, 0);
987 t = TREE_OPERAND (t, 1);
989 else if (is_gimple_min_invariant (TREE_OPERAND (t, 1)))
992 inv_ = TREE_OPERAND (t, 1);
993 t = TREE_OPERAND (t, 0);
1004 if (TREE_CODE (t) == NEGATE_EXPR)
1006 t = TREE_OPERAND (t, 0);
1010 if (TREE_CODE (t) != SSA_NAME)
1018 /* The reverse operation: build a symbolic expression with TYPE
1019 from symbol SYM, negated according to NEG, and invariant INV. */
1022 build_symbolic_expr (tree type, tree sym, bool neg, tree inv)
1024 const bool pointer_p = POINTER_TYPE_P (type);
1028 t = build1 (NEGATE_EXPR, type, t);
1030 if (integer_zerop (inv))
1033 return build2 (pointer_p ? POINTER_PLUS_EXPR : PLUS_EXPR, type, t, inv);
1036 /* Return true if value range VR involves exactly one symbol SYM. */
1039 symbolic_range_based_on_p (value_range_t *vr, const_tree sym)
1041 bool neg, min_has_symbol, max_has_symbol;
1044 if (is_gimple_min_invariant (vr->min))
1045 min_has_symbol = false;
1046 else if (get_single_symbol (vr->min, &neg, &inv) == sym)
1047 min_has_symbol = true;
1051 if (is_gimple_min_invariant (vr->max))
1052 max_has_symbol = false;
1053 else if (get_single_symbol (vr->max, &neg, &inv) == sym)
1054 max_has_symbol = true;
1058 return (min_has_symbol || max_has_symbol);
1061 /* Return true if value range VR uses an overflow infinity. */
1064 overflow_infinity_range_p (value_range_t *vr)
1066 return (vr->type == VR_RANGE
1067 && (is_overflow_infinity (vr->min)
1068 || is_overflow_infinity (vr->max)));
1071 /* Return false if we can not make a valid comparison based on VR;
1072 this will be the case if it uses an overflow infinity and overflow
1073 is not undefined (i.e., -fno-strict-overflow is in effect).
1074 Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR
1075 uses an overflow infinity. */
1078 usable_range_p (value_range_t *vr, bool *strict_overflow_p)
1080 gcc_assert (vr->type == VR_RANGE);
1081 if (is_overflow_infinity (vr->min))
1083 *strict_overflow_p = true;
1084 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr->min)))
1087 if (is_overflow_infinity (vr->max))
1089 *strict_overflow_p = true;
1090 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr->max)))
1097 /* Return true if the result of assignment STMT is know to be non-negative.
1098 If the return value is based on the assumption that signed overflow is
1099 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1100 *STRICT_OVERFLOW_P.*/
1103 gimple_assign_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p)
1105 enum tree_code code = gimple_assign_rhs_code (stmt);
1106 switch (get_gimple_rhs_class (code))
1108 case GIMPLE_UNARY_RHS:
1109 return tree_unary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt),
1110 gimple_expr_type (stmt),
1111 gimple_assign_rhs1 (stmt),
1113 case GIMPLE_BINARY_RHS:
1114 return tree_binary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt),
1115 gimple_expr_type (stmt),
1116 gimple_assign_rhs1 (stmt),
1117 gimple_assign_rhs2 (stmt),
1119 case GIMPLE_TERNARY_RHS:
1121 case GIMPLE_SINGLE_RHS:
1122 return tree_single_nonnegative_warnv_p (gimple_assign_rhs1 (stmt),
1124 case GIMPLE_INVALID_RHS:
1131 /* Return true if return value of call STMT is know to be non-negative.
1132 If the return value is based on the assumption that signed overflow is
1133 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1134 *STRICT_OVERFLOW_P.*/
1137 gimple_call_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p)
1139 tree arg0 = gimple_call_num_args (stmt) > 0 ?
1140 gimple_call_arg (stmt, 0) : NULL_TREE;
1141 tree arg1 = gimple_call_num_args (stmt) > 1 ?
1142 gimple_call_arg (stmt, 1) : NULL_TREE;
1144 return tree_call_nonnegative_warnv_p (gimple_expr_type (stmt),
1145 gimple_call_fndecl (stmt),
1151 /* Return true if STMT is know to to compute a non-negative value.
1152 If the return value is based on the assumption that signed overflow is
1153 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1154 *STRICT_OVERFLOW_P.*/
1157 gimple_stmt_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p)
1159 switch (gimple_code (stmt))
1162 return gimple_assign_nonnegative_warnv_p (stmt, strict_overflow_p);
1164 return gimple_call_nonnegative_warnv_p (stmt, strict_overflow_p);
1170 /* Return true if the result of assignment STMT is know to be non-zero.
1171 If the return value is based on the assumption that signed overflow is
1172 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1173 *STRICT_OVERFLOW_P.*/
1176 gimple_assign_nonzero_warnv_p (gimple stmt, bool *strict_overflow_p)
1178 enum tree_code code = gimple_assign_rhs_code (stmt);
1179 switch (get_gimple_rhs_class (code))
1181 case GIMPLE_UNARY_RHS:
1182 return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt),
1183 gimple_expr_type (stmt),
1184 gimple_assign_rhs1 (stmt),
1186 case GIMPLE_BINARY_RHS:
1187 return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt),
1188 gimple_expr_type (stmt),
1189 gimple_assign_rhs1 (stmt),
1190 gimple_assign_rhs2 (stmt),
1192 case GIMPLE_TERNARY_RHS:
1194 case GIMPLE_SINGLE_RHS:
1195 return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt),
1197 case GIMPLE_INVALID_RHS:
1204 /* Return true if STMT is known to compute a non-zero value.
1205 If the return value is based on the assumption that signed overflow is
1206 undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
1207 *STRICT_OVERFLOW_P.*/
1210 gimple_stmt_nonzero_warnv_p (gimple stmt, bool *strict_overflow_p)
1212 switch (gimple_code (stmt))
1215 return gimple_assign_nonzero_warnv_p (stmt, strict_overflow_p);
1218 tree fndecl = gimple_call_fndecl (stmt);
1219 if (!fndecl) return false;
1220 if (flag_delete_null_pointer_checks && !flag_check_new
1221 && DECL_IS_OPERATOR_NEW (fndecl)
1222 && !TREE_NOTHROW (fndecl))
1224 /* References are always non-NULL. */
1225 if (flag_delete_null_pointer_checks
1226 && TREE_CODE (TREE_TYPE (fndecl)) == REFERENCE_TYPE)
1228 if (flag_delete_null_pointer_checks &&
1229 lookup_attribute ("returns_nonnull",
1230 TYPE_ATTRIBUTES (gimple_call_fntype (stmt))))
1232 return gimple_alloca_call_p (stmt);
1239 /* Like tree_expr_nonzero_warnv_p, but this function uses value ranges
1243 vrp_stmt_computes_nonzero (gimple stmt, bool *strict_overflow_p)
1245 if (gimple_stmt_nonzero_warnv_p (stmt, strict_overflow_p))
1248 /* If we have an expression of the form &X->a, then the expression
1249 is nonnull if X is nonnull. */
1250 if (is_gimple_assign (stmt)
1251 && gimple_assign_rhs_code (stmt) == ADDR_EXPR)
1253 tree expr = gimple_assign_rhs1 (stmt);
1254 tree base = get_base_address (TREE_OPERAND (expr, 0));
1256 if (base != NULL_TREE
1257 && TREE_CODE (base) == MEM_REF
1258 && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
1260 value_range_t *vr = get_value_range (TREE_OPERAND (base, 0));
1261 if (range_is_nonnull (vr))
1269 /* Returns true if EXPR is a valid value (as expected by compare_values) --
1270 a gimple invariant, or SSA_NAME +- CST. */
1273 valid_value_p (tree expr)
1275 if (TREE_CODE (expr) == SSA_NAME)
1278 if (TREE_CODE (expr) == PLUS_EXPR
1279 || TREE_CODE (expr) == MINUS_EXPR)
1280 return (TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME
1281 && TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST);
1283 return is_gimple_min_invariant (expr);
1289 -2 if those are incomparable. */
1291 operand_less_p (tree val, tree val2)
1293 /* LT is folded faster than GE and others. Inline the common case. */
1294 if (TREE_CODE (val) == INTEGER_CST && TREE_CODE (val2) == INTEGER_CST)
1295 return tree_int_cst_lt (val, val2);
1300 fold_defer_overflow_warnings ();
1302 tcmp = fold_binary_to_constant (LT_EXPR, boolean_type_node, val, val2);
1304 fold_undefer_and_ignore_overflow_warnings ();
1307 || TREE_CODE (tcmp) != INTEGER_CST)
1310 if (!integer_zerop (tcmp))
1314 /* val >= val2, not considering overflow infinity. */
1315 if (is_negative_overflow_infinity (val))
1316 return is_negative_overflow_infinity (val2) ? 0 : 1;
1317 else if (is_positive_overflow_infinity (val2))
1318 return is_positive_overflow_infinity (val) ? 0 : 1;
1323 /* Compare two values VAL1 and VAL2. Return
1325 -2 if VAL1 and VAL2 cannot be compared at compile-time,
1328 +1 if VAL1 > VAL2, and
1331 This is similar to tree_int_cst_compare but supports pointer values
1332 and values that cannot be compared at compile time.
1334 If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
1335 true if the return value is only valid if we assume that signed
1336 overflow is undefined. */
1339 compare_values_warnv (tree val1, tree val2, bool *strict_overflow_p)
1344 /* Below we rely on the fact that VAL1 and VAL2 are both pointers or
1346 gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1))
1347 == POINTER_TYPE_P (TREE_TYPE (val2)));
1349 /* Convert the two values into the same type. This is needed because
1350 sizetype causes sign extension even for unsigned types. */
1351 val2 = fold_convert (TREE_TYPE (val1), val2);
1352 STRIP_USELESS_TYPE_CONVERSION (val2);
1354 if ((TREE_CODE (val1) == SSA_NAME
1355 || (TREE_CODE (val1) == NEGATE_EXPR
1356 && TREE_CODE (TREE_OPERAND (val1, 0)) == SSA_NAME)
1357 || TREE_CODE (val1) == PLUS_EXPR
1358 || TREE_CODE (val1) == MINUS_EXPR)
1359 && (TREE_CODE (val2) == SSA_NAME
1360 || (TREE_CODE (val2) == NEGATE_EXPR
1361 && TREE_CODE (TREE_OPERAND (val2, 0)) == SSA_NAME)
1362 || TREE_CODE (val2) == PLUS_EXPR
1363 || TREE_CODE (val2) == MINUS_EXPR))
1365 tree n1, c1, n2, c2;
1366 enum tree_code code1, code2;
1368 /* If VAL1 and VAL2 are of the form '[-]NAME [+-] CST' or 'NAME',
1369 return -1 or +1 accordingly. If VAL1 and VAL2 don't use the
1370 same name, return -2. */
1371 if (TREE_CODE (val1) == SSA_NAME || TREE_CODE (val1) == NEGATE_EXPR)
1379 code1 = TREE_CODE (val1);
1380 n1 = TREE_OPERAND (val1, 0);
1381 c1 = TREE_OPERAND (val1, 1);
1382 if (tree_int_cst_sgn (c1) == -1)
1384 if (is_negative_overflow_infinity (c1))
1386 c1 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c1), c1);
1389 code1 = code1 == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR;
1393 if (TREE_CODE (val2) == SSA_NAME || TREE_CODE (val2) == NEGATE_EXPR)
1401 code2 = TREE_CODE (val2);
1402 n2 = TREE_OPERAND (val2, 0);
1403 c2 = TREE_OPERAND (val2, 1);
1404 if (tree_int_cst_sgn (c2) == -1)
1406 if (is_negative_overflow_infinity (c2))
1408 c2 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c2), c2);
1411 code2 = code2 == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR;
1415 /* Both values must use the same name. */
1416 if (TREE_CODE (n1) == NEGATE_EXPR && TREE_CODE (n2) == NEGATE_EXPR)
1418 n1 = TREE_OPERAND (n1, 0);
1419 n2 = TREE_OPERAND (n2, 0);
1424 if (code1 == SSA_NAME && code2 == SSA_NAME)
1428 /* If overflow is defined we cannot simplify more. */
1429 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1)))
1432 if (strict_overflow_p != NULL
1433 && (code1 == SSA_NAME || !TREE_NO_WARNING (val1))
1434 && (code2 == SSA_NAME || !TREE_NO_WARNING (val2)))
1435 *strict_overflow_p = true;
1437 if (code1 == SSA_NAME)
1439 if (code2 == PLUS_EXPR)
1440 /* NAME < NAME + CST */
1442 else if (code2 == MINUS_EXPR)
1443 /* NAME > NAME - CST */
1446 else if (code1 == PLUS_EXPR)
1448 if (code2 == SSA_NAME)
1449 /* NAME + CST > NAME */
1451 else if (code2 == PLUS_EXPR)
1452 /* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
1453 return compare_values_warnv (c1, c2, strict_overflow_p);
1454 else if (code2 == MINUS_EXPR)
1455 /* NAME + CST1 > NAME - CST2 */
1458 else if (code1 == MINUS_EXPR)
1460 if (code2 == SSA_NAME)
1461 /* NAME - CST < NAME */
1463 else if (code2 == PLUS_EXPR)
1464 /* NAME - CST1 < NAME + CST2 */
1466 else if (code2 == MINUS_EXPR)
1467 /* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
1468 C1 and C2 are swapped in the call to compare_values. */
1469 return compare_values_warnv (c2, c1, strict_overflow_p);
1475 /* We cannot compare non-constants. */
1476 if (!is_gimple_min_invariant (val1) || !is_gimple_min_invariant (val2))
1479 if (!POINTER_TYPE_P (TREE_TYPE (val1)))
1481 /* We cannot compare overflowed values, except for overflow
1483 if (TREE_OVERFLOW (val1) || TREE_OVERFLOW (val2))
1485 if (strict_overflow_p != NULL)
1486 *strict_overflow_p = true;
1487 if (is_negative_overflow_infinity (val1))
1488 return is_negative_overflow_infinity (val2) ? 0 : -1;
1489 else if (is_negative_overflow_infinity (val2))
1491 else if (is_positive_overflow_infinity (val1))
1492 return is_positive_overflow_infinity (val2) ? 0 : 1;
1493 else if (is_positive_overflow_infinity (val2))
1498 return tree_int_cst_compare (val1, val2);
1504 /* First see if VAL1 and VAL2 are not the same. */
1505 if (val1 == val2 || operand_equal_p (val1, val2, 0))
1508 /* If VAL1 is a lower address than VAL2, return -1. */
1509 if (operand_less_p (val1, val2) == 1)
1512 /* If VAL1 is a higher address than VAL2, return +1. */
1513 if (operand_less_p (val2, val1) == 1)
1516 /* If VAL1 is different than VAL2, return +2.
1517 For integer constants we either have already returned -1 or 1
1518 or they are equivalent. We still might succeed in proving
1519 something about non-trivial operands. */
1520 if (TREE_CODE (val1) != INTEGER_CST
1521 || TREE_CODE (val2) != INTEGER_CST)
1523 t = fold_binary_to_constant (NE_EXPR, boolean_type_node, val1, val2);
1524 if (t && integer_onep (t))
1532 /* Compare values like compare_values_warnv, but treat comparisons of
1533 nonconstants which rely on undefined overflow as incomparable. */
1536 compare_values (tree val1, tree val2)
1542 ret = compare_values_warnv (val1, val2, &sop);
1544 && (!is_gimple_min_invariant (val1) || !is_gimple_min_invariant (val2)))
1550 /* Return 1 if VAL is inside value range MIN <= VAL <= MAX,
1551 0 if VAL is not inside [MIN, MAX],
1552 -2 if we cannot tell either way.
1554 Benchmark compile/20001226-1.c compilation time after changing this
1558 value_inside_range (tree val, tree min, tree max)
1562 cmp1 = operand_less_p (val, min);
1568 cmp2 = operand_less_p (max, val);
1576 /* Return true if value ranges VR0 and VR1 have a non-empty
1579 Benchmark compile/20001226-1.c compilation time after changing this
1584 value_ranges_intersect_p (value_range_t *vr0, value_range_t *vr1)
1586 /* The value ranges do not intersect if the maximum of the first range is
1587 less than the minimum of the second range or vice versa.
1588 When those relations are unknown, we can't do any better. */
1589 if (operand_less_p (vr0->max, vr1->min) != 0)
1591 if (operand_less_p (vr1->max, vr0->min) != 0)
1597 /* Return 1 if [MIN, MAX] includes the value zero, 0 if it does not
1598 include the value zero, -2 if we cannot tell. */
1601 range_includes_zero_p (tree min, tree max)
1603 tree zero = build_int_cst (TREE_TYPE (min), 0);
1604 return value_inside_range (zero, min, max);
1607 /* Return true if *VR is know to only contain nonnegative values. */
1610 value_range_nonnegative_p (value_range_t *vr)
1612 /* Testing for VR_ANTI_RANGE is not useful here as any anti-range
1613 which would return a useful value should be encoded as a
1615 if (vr->type == VR_RANGE)
1617 int result = compare_values (vr->min, integer_zero_node);
1618 return (result == 0 || result == 1);
1624 /* If *VR has a value rante that is a single constant value return that,
1625 otherwise return NULL_TREE. */
1628 value_range_constant_singleton (value_range_t *vr)
1630 if (vr->type == VR_RANGE
1631 && operand_equal_p (vr->min, vr->max, 0)
1632 && is_gimple_min_invariant (vr->min))
1638 /* If OP has a value range with a single constant value return that,
1639 otherwise return NULL_TREE. This returns OP itself if OP is a
1643 op_with_constant_singleton_value_range (tree op)
1645 if (is_gimple_min_invariant (op))
1648 if (TREE_CODE (op) != SSA_NAME)
1651 return value_range_constant_singleton (get_value_range (op));
1654 /* Return true if op is in a boolean [0, 1] value-range. */
1657 op_with_boolean_value_range_p (tree op)
1661 if (TYPE_PRECISION (TREE_TYPE (op)) == 1)
1664 if (integer_zerop (op)
1665 || integer_onep (op))
1668 if (TREE_CODE (op) != SSA_NAME)
1671 vr = get_value_range (op);
1672 return (vr->type == VR_RANGE
1673 && integer_zerop (vr->min)
1674 && integer_onep (vr->max));
1677 /* Extract value range information from an ASSERT_EXPR EXPR and store
1681 extract_range_from_assert (value_range_t *vr_p, tree expr)
1683 tree var, cond, limit, min, max, type;
1684 value_range_t *limit_vr;
1685 enum tree_code cond_code;
1687 var = ASSERT_EXPR_VAR (expr);
1688 cond = ASSERT_EXPR_COND (expr);
1690 gcc_assert (COMPARISON_CLASS_P (cond));
1692 /* Find VAR in the ASSERT_EXPR conditional. */
1693 if (var == TREE_OPERAND (cond, 0)
1694 || TREE_CODE (TREE_OPERAND (cond, 0)) == PLUS_EXPR
1695 || TREE_CODE (TREE_OPERAND (cond, 0)) == NOP_EXPR)
1697 /* If the predicate is of the form VAR COMP LIMIT, then we just
1698 take LIMIT from the RHS and use the same comparison code. */
1699 cond_code = TREE_CODE (cond);
1700 limit = TREE_OPERAND (cond, 1);
1701 cond = TREE_OPERAND (cond, 0);
1705 /* If the predicate is of the form LIMIT COMP VAR, then we need
1706 to flip around the comparison code to create the proper range
1708 cond_code = swap_tree_comparison (TREE_CODE (cond));
1709 limit = TREE_OPERAND (cond, 0);
1710 cond = TREE_OPERAND (cond, 1);
1713 limit = avoid_overflow_infinity (limit);
1715 type = TREE_TYPE (var);
1716 gcc_assert (limit != var);
1718 /* For pointer arithmetic, we only keep track of pointer equality
1720 if (POINTER_TYPE_P (type) && cond_code != NE_EXPR && cond_code != EQ_EXPR)
1722 set_value_range_to_varying (vr_p);
1726 /* If LIMIT is another SSA name and LIMIT has a range of its own,
1727 try to use LIMIT's range to avoid creating symbolic ranges
1729 limit_vr = (TREE_CODE (limit) == SSA_NAME) ? get_value_range (limit) : NULL;
1731 /* LIMIT's range is only interesting if it has any useful information. */
1733 && (limit_vr->type == VR_UNDEFINED
1734 || limit_vr->type == VR_VARYING
1735 || symbolic_range_p (limit_vr)))
1738 /* Initially, the new range has the same set of equivalences of
1739 VAR's range. This will be revised before returning the final
1740 value. Since assertions may be chained via mutually exclusive
1741 predicates, we will need to trim the set of equivalences before
1743 gcc_assert (vr_p->equiv == NULL);
1744 add_equivalence (&vr_p->equiv, var);
1746 /* Extract a new range based on the asserted comparison for VAR and
1747 LIMIT's value range. Notice that if LIMIT has an anti-range, we
1748 will only use it for equality comparisons (EQ_EXPR). For any
1749 other kind of assertion, we cannot derive a range from LIMIT's
1750 anti-range that can be used to describe the new range. For
1751 instance, ASSERT_EXPR <x_2, x_2 <= b_4>. If b_4 is ~[2, 10],
1752 then b_4 takes on the ranges [-INF, 1] and [11, +INF]. There is
1753 no single range for x_2 that could describe LE_EXPR, so we might
1754 as well build the range [b_4, +INF] for it.
1755 One special case we handle is extracting a range from a
1756 range test encoded as (unsigned)var + CST <= limit. */
1757 if (TREE_CODE (cond) == NOP_EXPR
1758 || TREE_CODE (cond) == PLUS_EXPR)
1760 if (TREE_CODE (cond) == PLUS_EXPR)
1762 min = fold_build1 (NEGATE_EXPR, TREE_TYPE (TREE_OPERAND (cond, 1)),
1763 TREE_OPERAND (cond, 1));
1764 max = int_const_binop (PLUS_EXPR, limit, min);
1765 cond = TREE_OPERAND (cond, 0);
1769 min = build_int_cst (TREE_TYPE (var), 0);
1773 /* Make sure to not set TREE_OVERFLOW on the final type
1774 conversion. We are willingly interpreting large positive
1775 unsigned values as negative signed values here. */
1776 min = force_fit_type (TREE_TYPE (var), wi::to_widest (min), 0, false);
1777 max = force_fit_type (TREE_TYPE (var), wi::to_widest (max), 0, false);
1779 /* We can transform a max, min range to an anti-range or
1780 vice-versa. Use set_and_canonicalize_value_range which does
1782 if (cond_code == LE_EXPR)
1783 set_and_canonicalize_value_range (vr_p, VR_RANGE,
1784 min, max, vr_p->equiv);
1785 else if (cond_code == GT_EXPR)
1786 set_and_canonicalize_value_range (vr_p, VR_ANTI_RANGE,
1787 min, max, vr_p->equiv);
1791 else if (cond_code == EQ_EXPR)
1793 enum value_range_type range_type;
1797 range_type = limit_vr->type;
1798 min = limit_vr->min;
1799 max = limit_vr->max;
1803 range_type = VR_RANGE;
1808 set_value_range (vr_p, range_type, min, max, vr_p->equiv);
1810 /* When asserting the equality VAR == LIMIT and LIMIT is another
1811 SSA name, the new range will also inherit the equivalence set
1813 if (TREE_CODE (limit) == SSA_NAME)
1814 add_equivalence (&vr_p->equiv, limit);
1816 else if (cond_code == NE_EXPR)
1818 /* As described above, when LIMIT's range is an anti-range and
1819 this assertion is an inequality (NE_EXPR), then we cannot
1820 derive anything from the anti-range. For instance, if
1821 LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does
1822 not imply that VAR's range is [0, 0]. So, in the case of
1823 anti-ranges, we just assert the inequality using LIMIT and
1826 If LIMIT_VR is a range, we can only use it to build a new
1827 anti-range if LIMIT_VR is a single-valued range. For
1828 instance, if LIMIT_VR is [0, 1], the predicate
1829 VAR != [0, 1] does not mean that VAR's range is ~[0, 1].
1830 Rather, it means that for value 0 VAR should be ~[0, 0]
1831 and for value 1, VAR should be ~[1, 1]. We cannot
1832 represent these ranges.
1834 The only situation in which we can build a valid
1835 anti-range is when LIMIT_VR is a single-valued range
1836 (i.e., LIMIT_VR->MIN == LIMIT_VR->MAX). In that case,
1837 build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX]. */
1839 && limit_vr->type == VR_RANGE
1840 && compare_values (limit_vr->min, limit_vr->max) == 0)
1842 min = limit_vr->min;
1843 max = limit_vr->max;
1847 /* In any other case, we cannot use LIMIT's range to build a
1848 valid anti-range. */
1852 /* If MIN and MAX cover the whole range for their type, then
1853 just use the original LIMIT. */
1854 if (INTEGRAL_TYPE_P (type)
1855 && vrp_val_is_min (min)
1856 && vrp_val_is_max (max))
1859 set_and_canonicalize_value_range (vr_p, VR_ANTI_RANGE,
1860 min, max, vr_p->equiv);
1862 else if (cond_code == LE_EXPR || cond_code == LT_EXPR)
1864 min = TYPE_MIN_VALUE (type);
1866 if (limit_vr == NULL || limit_vr->type == VR_ANTI_RANGE)
1870 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1871 range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for
1873 max = limit_vr->max;
1876 /* If the maximum value forces us to be out of bounds, simply punt.
1877 It would be pointless to try and do anything more since this
1878 all should be optimized away above us. */
1879 if ((cond_code == LT_EXPR
1880 && compare_values (max, min) == 0)
1881 || is_overflow_infinity (max))
1882 set_value_range_to_varying (vr_p);
1885 /* For LT_EXPR, we create the range [MIN, MAX - 1]. */
1886 if (cond_code == LT_EXPR)
1888 if (TYPE_PRECISION (TREE_TYPE (max)) == 1
1889 && !TYPE_UNSIGNED (TREE_TYPE (max)))
1890 max = fold_build2 (PLUS_EXPR, TREE_TYPE (max), max,
1891 build_int_cst (TREE_TYPE (max), -1));
1893 max = fold_build2 (MINUS_EXPR, TREE_TYPE (max), max,
1894 build_int_cst (TREE_TYPE (max), 1));
1896 TREE_NO_WARNING (max) = 1;
1899 set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
1902 else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
1904 max = TYPE_MAX_VALUE (type);
1906 if (limit_vr == NULL || limit_vr->type == VR_ANTI_RANGE)
1910 /* If LIMIT_VR is of the form [N1, N2], we need to build the
1911 range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for
1913 min = limit_vr->min;
1916 /* If the minimum value forces us to be out of bounds, simply punt.
1917 It would be pointless to try and do anything more since this
1918 all should be optimized away above us. */
1919 if ((cond_code == GT_EXPR
1920 && compare_values (min, max) == 0)
1921 || is_overflow_infinity (min))
1922 set_value_range_to_varying (vr_p);
1925 /* For GT_EXPR, we create the range [MIN + 1, MAX]. */
1926 if (cond_code == GT_EXPR)
1928 if (TYPE_PRECISION (TREE_TYPE (min)) == 1
1929 && !TYPE_UNSIGNED (TREE_TYPE (min)))
1930 min = fold_build2 (MINUS_EXPR, TREE_TYPE (min), min,
1931 build_int_cst (TREE_TYPE (min), -1));
1933 min = fold_build2 (PLUS_EXPR, TREE_TYPE (min), min,
1934 build_int_cst (TREE_TYPE (min), 1));
1936 TREE_NO_WARNING (min) = 1;
1939 set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
1945 /* Finally intersect the new range with what we already know about var. */
1946 vrp_intersect_ranges (vr_p, get_value_range (var));
1950 /* Extract range information from SSA name VAR and store it in VR. If
1951 VAR has an interesting range, use it. Otherwise, create the
1952 range [VAR, VAR] and return it. This is useful in situations where
1953 we may have conditionals testing values of VARYING names. For
1960 Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is
1964 extract_range_from_ssa_name (value_range_t *vr, tree var)
1966 value_range_t *var_vr = get_value_range (var);
1968 if (var_vr->type != VR_VARYING)
1969 copy_value_range (vr, var_vr);
1971 set_value_range (vr, VR_RANGE, var, var, NULL);
1973 add_equivalence (&vr->equiv, var);
1977 /* Wrapper around int_const_binop. If the operation overflows and we
1978 are not using wrapping arithmetic, then adjust the result to be
1979 -INF or +INF depending on CODE, VAL1 and VAL2. This can return
1980 NULL_TREE if we need to use an overflow infinity representation but
1981 the type does not support it. */
1984 vrp_int_const_binop (enum tree_code code, tree val1, tree val2)
1988 res = int_const_binop (code, val1, val2);
1990 /* If we are using unsigned arithmetic, operate symbolically
1991 on -INF and +INF as int_const_binop only handles signed overflow. */
1992 if (TYPE_UNSIGNED (TREE_TYPE (val1)))
1994 int checkz = compare_values (res, val1);
1995 bool overflow = false;
1997 /* Ensure that res = val1 [+*] val2 >= val1
1998 or that res = val1 - val2 <= val1. */
1999 if ((code == PLUS_EXPR
2000 && !(checkz == 1 || checkz == 0))
2001 || (code == MINUS_EXPR
2002 && !(checkz == 0 || checkz == -1)))
2006 /* Checking for multiplication overflow is done by dividing the
2007 output of the multiplication by the first input of the
2008 multiplication. If the result of that division operation is
2009 not equal to the second input of the multiplication, then the
2010 multiplication overflowed. */
2011 else if (code == MULT_EXPR && !integer_zerop (val1))
2013 tree tmp = int_const_binop (TRUNC_DIV_EXPR,
2016 int check = compare_values (tmp, val2);
2024 res = copy_node (res);
2025 TREE_OVERFLOW (res) = 1;
2029 else if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1)))
2030 /* If the singed operation wraps then int_const_binop has done
2031 everything we want. */
2033 /* Signed division of -1/0 overflows and by the time it gets here
2034 returns NULL_TREE. */
2037 else if ((TREE_OVERFLOW (res)
2038 && !TREE_OVERFLOW (val1)
2039 && !TREE_OVERFLOW (val2))
2040 || is_overflow_infinity (val1)
2041 || is_overflow_infinity (val2))
2043 /* If the operation overflowed but neither VAL1 nor VAL2 are
2044 overflown, return -INF or +INF depending on the operation
2045 and the combination of signs of the operands. */
2046 int sgn1 = tree_int_cst_sgn (val1);
2047 int sgn2 = tree_int_cst_sgn (val2);
2049 if (needs_overflow_infinity (TREE_TYPE (res))
2050 && !supports_overflow_infinity (TREE_TYPE (res)))
2053 /* We have to punt on adding infinities of different signs,
2054 since we can't tell what the sign of the result should be.
2055 Likewise for subtracting infinities of the same sign. */
2056 if (((code == PLUS_EXPR && sgn1 != sgn2)
2057 || (code == MINUS_EXPR && sgn1 == sgn2))
2058 && is_overflow_infinity (val1)
2059 && is_overflow_infinity (val2))
2062 /* Don't try to handle division or shifting of infinities. */
2063 if ((code == TRUNC_DIV_EXPR
2064 || code == FLOOR_DIV_EXPR
2065 || code == CEIL_DIV_EXPR
2066 || code == EXACT_DIV_EXPR
2067 || code == ROUND_DIV_EXPR
2068 || code == RSHIFT_EXPR)
2069 && (is_overflow_infinity (val1)
2070 || is_overflow_infinity (val2)))
2073 /* Notice that we only need to handle the restricted set of
2074 operations handled by extract_range_from_binary_expr.
2075 Among them, only multiplication, addition and subtraction
2076 can yield overflow without overflown operands because we
2077 are working with integral types only... except in the
2078 case VAL1 = -INF and VAL2 = -1 which overflows to +INF
2079 for division too. */
2081 /* For multiplication, the sign of the overflow is given
2082 by the comparison of the signs of the operands. */
2083 if ((code == MULT_EXPR && sgn1 == sgn2)
2084 /* For addition, the operands must be of the same sign
2085 to yield an overflow. Its sign is therefore that
2086 of one of the operands, for example the first. For
2087 infinite operands X + -INF is negative, not positive. */
2088 || (code == PLUS_EXPR
2090 ? !is_negative_overflow_infinity (val2)
2091 : is_positive_overflow_infinity (val2)))
2092 /* For subtraction, non-infinite operands must be of
2093 different signs to yield an overflow. Its sign is
2094 therefore that of the first operand or the opposite of
2095 that of the second operand. A first operand of 0 counts
2096 as positive here, for the corner case 0 - (-INF), which
2097 overflows, but must yield +INF. For infinite operands 0
2098 - INF is negative, not positive. */
2099 || (code == MINUS_EXPR
2101 ? !is_positive_overflow_infinity (val2)
2102 : is_negative_overflow_infinity (val2)))
2103 /* We only get in here with positive shift count, so the
2104 overflow direction is the same as the sign of val1.
2105 Actually rshift does not overflow at all, but we only
2106 handle the case of shifting overflowed -INF and +INF. */
2107 || (code == RSHIFT_EXPR
2109 /* For division, the only case is -INF / -1 = +INF. */
2110 || code == TRUNC_DIV_EXPR
2111 || code == FLOOR_DIV_EXPR
2112 || code == CEIL_DIV_EXPR
2113 || code == EXACT_DIV_EXPR
2114 || code == ROUND_DIV_EXPR)
2115 return (needs_overflow_infinity (TREE_TYPE (res))
2116 ? positive_overflow_infinity (TREE_TYPE (res))
2117 : TYPE_MAX_VALUE (TREE_TYPE (res)));
2119 return (needs_overflow_infinity (TREE_TYPE (res))
2120 ? negative_overflow_infinity (TREE_TYPE (res))
2121 : TYPE_MIN_VALUE (TREE_TYPE (res)));
2128 /* For range VR compute two wide_int bitmasks. In *MAY_BE_NONZERO
2129 bitmask if some bit is unset, it means for all numbers in the range
2130 the bit is 0, otherwise it might be 0 or 1. In *MUST_BE_NONZERO
2131 bitmask if some bit is set, it means for all numbers in the range
2132 the bit is 1, otherwise it might be 0 or 1. */
2135 zero_nonzero_bits_from_vr (const tree expr_type,
2137 wide_int *may_be_nonzero,
2138 wide_int *must_be_nonzero)
2140 *may_be_nonzero = wi::minus_one (TYPE_PRECISION (expr_type));
2141 *must_be_nonzero = wi::zero (TYPE_PRECISION (expr_type));
2142 if (!range_int_cst_p (vr)
2143 || is_overflow_infinity (vr->min)
2144 || is_overflow_infinity (vr->max))
2147 if (range_int_cst_singleton_p (vr))
2149 *may_be_nonzero = vr->min;
2150 *must_be_nonzero = *may_be_nonzero;
2152 else if (tree_int_cst_sgn (vr->min) >= 0
2153 || tree_int_cst_sgn (vr->max) < 0)
2155 wide_int xor_mask = wi::bit_xor (vr->min, vr->max);
2156 *may_be_nonzero = wi::bit_or (vr->min, vr->max);
2157 *must_be_nonzero = wi::bit_and (vr->min, vr->max);
2160 wide_int mask = wi::mask (wi::floor_log2 (xor_mask), false,
2161 may_be_nonzero->get_precision ());
2162 *may_be_nonzero = *may_be_nonzero | mask;
2163 *must_be_nonzero = must_be_nonzero->and_not (mask);
2170 /* Create two value-ranges in *VR0 and *VR1 from the anti-range *AR
2171 so that *VR0 U *VR1 == *AR. Returns true if that is possible,
2172 false otherwise. If *AR can be represented with a single range
2173 *VR1 will be VR_UNDEFINED. */
2176 ranges_from_anti_range (value_range_t *ar,
2177 value_range_t *vr0, value_range_t *vr1)
2179 tree type = TREE_TYPE (ar->min);
2181 vr0->type = VR_UNDEFINED;
2182 vr1->type = VR_UNDEFINED;
2184 if (ar->type != VR_ANTI_RANGE
2185 || TREE_CODE (ar->min) != INTEGER_CST
2186 || TREE_CODE (ar->max) != INTEGER_CST
2187 || !vrp_val_min (type)
2188 || !vrp_val_max (type))
2191 if (!vrp_val_is_min (ar->min))
2193 vr0->type = VR_RANGE;
2194 vr0->min = vrp_val_min (type);
2195 vr0->max = wide_int_to_tree (type, wi::sub (ar->min, 1));
2197 if (!vrp_val_is_max (ar->max))
2199 vr1->type = VR_RANGE;
2200 vr1->min = wide_int_to_tree (type, wi::add (ar->max, 1));
2201 vr1->max = vrp_val_max (type);
2203 if (vr0->type == VR_UNDEFINED)
2206 vr1->type = VR_UNDEFINED;
2209 return vr0->type != VR_UNDEFINED;
2212 /* Helper to extract a value-range *VR for a multiplicative operation
2216 extract_range_from_multiplicative_op_1 (value_range_t *vr,
2217 enum tree_code code,
2218 value_range_t *vr0, value_range_t *vr1)
2220 enum value_range_type type;
2227 /* Multiplications, divisions and shifts are a bit tricky to handle,
2228 depending on the mix of signs we have in the two ranges, we
2229 need to operate on different values to get the minimum and
2230 maximum values for the new range. One approach is to figure
2231 out all the variations of range combinations and do the
2234 However, this involves several calls to compare_values and it
2235 is pretty convoluted. It's simpler to do the 4 operations
2236 (MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
2237 MAX1) and then figure the smallest and largest values to form
2239 gcc_assert (code == MULT_EXPR
2240 || code == TRUNC_DIV_EXPR
2241 || code == FLOOR_DIV_EXPR
2242 || code == CEIL_DIV_EXPR
2243 || code == EXACT_DIV_EXPR
2244 || code == ROUND_DIV_EXPR
2245 || code == RSHIFT_EXPR
2246 || code == LSHIFT_EXPR);
2247 gcc_assert ((vr0->type == VR_RANGE
2248 || (code == MULT_EXPR && vr0->type == VR_ANTI_RANGE))
2249 && vr0->type == vr1->type);
2253 /* Compute the 4 cross operations. */
2255 val[0] = vrp_int_const_binop (code, vr0->min, vr1->min);
2256 if (val[0] == NULL_TREE)
2259 if (vr1->max == vr1->min)
2263 val[1] = vrp_int_const_binop (code, vr0->min, vr1->max);
2264 if (val[1] == NULL_TREE)
2268 if (vr0->max == vr0->min)
2272 val[2] = vrp_int_const_binop (code, vr0->max, vr1->min);
2273 if (val[2] == NULL_TREE)
2277 if (vr0->min == vr0->max || vr1->min == vr1->max)
2281 val[3] = vrp_int_const_binop (code, vr0->max, vr1->max);
2282 if (val[3] == NULL_TREE)
2288 set_value_range_to_varying (vr);
2292 /* Set MIN to the minimum of VAL[i] and MAX to the maximum
2296 for (i = 1; i < 4; i++)
2298 if (!is_gimple_min_invariant (min)
2299 || (TREE_OVERFLOW (min) && !is_overflow_infinity (min))
2300 || !is_gimple_min_invariant (max)
2301 || (TREE_OVERFLOW (max) && !is_overflow_infinity (max)))
2306 if (!is_gimple_min_invariant (val[i])
2307 || (TREE_OVERFLOW (val[i])
2308 && !is_overflow_infinity (val[i])))
2310 /* If we found an overflowed value, set MIN and MAX
2311 to it so that we set the resulting range to
2317 if (compare_values (val[i], min) == -1)
2320 if (compare_values (val[i], max) == 1)
2325 /* If either MIN or MAX overflowed, then set the resulting range to
2326 VARYING. But we do accept an overflow infinity
2328 if (min == NULL_TREE
2329 || !is_gimple_min_invariant (min)
2330 || (TREE_OVERFLOW (min) && !is_overflow_infinity (min))
2332 || !is_gimple_min_invariant (max)
2333 || (TREE_OVERFLOW (max) && !is_overflow_infinity (max)))
2335 set_value_range_to_varying (vr);
2341 2) [-INF, +-INF(OVF)]
2342 3) [+-INF(OVF), +INF]
2343 4) [+-INF(OVF), +-INF(OVF)]
2344 We learn nothing when we have INF and INF(OVF) on both sides.
2345 Note that we do accept [-INF, -INF] and [+INF, +INF] without
2347 if ((vrp_val_is_min (min) || is_overflow_infinity (min))
2348 && (vrp_val_is_max (max) || is_overflow_infinity (max)))
2350 set_value_range_to_varying (vr);
2354 cmp = compare_values (min, max);
2355 if (cmp == -2 || cmp == 1)
2357 /* If the new range has its limits swapped around (MIN > MAX),
2358 then the operation caused one of them to wrap around, mark
2359 the new range VARYING. */
2360 set_value_range_to_varying (vr);
2363 set_value_range (vr, type, min, max, NULL);
2366 /* Extract range information from a binary operation CODE based on
2367 the ranges of each of its operands *VR0 and *VR1 with resulting
2368 type EXPR_TYPE. The resulting range is stored in *VR. */
2371 extract_range_from_binary_expr_1 (value_range_t *vr,
2372 enum tree_code code, tree expr_type,
2373 value_range_t *vr0_, value_range_t *vr1_)
2375 value_range_t vr0 = *vr0_, vr1 = *vr1_;
2376 value_range_t vrtem0 = VR_INITIALIZER, vrtem1 = VR_INITIALIZER;
2377 enum value_range_type type;
2378 tree min = NULL_TREE, max = NULL_TREE;
2381 if (!INTEGRAL_TYPE_P (expr_type)
2382 && !POINTER_TYPE_P (expr_type))
2384 set_value_range_to_varying (vr);
2388 /* Not all binary expressions can be applied to ranges in a
2389 meaningful way. Handle only arithmetic operations. */
2390 if (code != PLUS_EXPR
2391 && code != MINUS_EXPR
2392 && code != POINTER_PLUS_EXPR
2393 && code != MULT_EXPR
2394 && code != TRUNC_DIV_EXPR
2395 && code != FLOOR_DIV_EXPR
2396 && code != CEIL_DIV_EXPR
2397 && code != EXACT_DIV_EXPR
2398 && code != ROUND_DIV_EXPR
2399 && code != TRUNC_MOD_EXPR
2400 && code != RSHIFT_EXPR
2401 && code != LSHIFT_EXPR
2404 && code != BIT_AND_EXPR
2405 && code != BIT_IOR_EXPR
2406 && code != BIT_XOR_EXPR)
2408 set_value_range_to_varying (vr);
2412 /* If both ranges are UNDEFINED, so is the result. */
2413 if (vr0.type == VR_UNDEFINED && vr1.type == VR_UNDEFINED)
2415 set_value_range_to_undefined (vr);
2418 /* If one of the ranges is UNDEFINED drop it to VARYING for the following
2419 code. At some point we may want to special-case operations that
2420 have UNDEFINED result for all or some value-ranges of the not UNDEFINED
2422 else if (vr0.type == VR_UNDEFINED)
2423 set_value_range_to_varying (&vr0);
2424 else if (vr1.type == VR_UNDEFINED)
2425 set_value_range_to_varying (&vr1);
2427 /* Now canonicalize anti-ranges to ranges when they are not symbolic
2428 and express ~[] op X as ([]' op X) U ([]'' op X). */
2429 if (vr0.type == VR_ANTI_RANGE
2430 && ranges_from_anti_range (&vr0, &vrtem0, &vrtem1))
2432 extract_range_from_binary_expr_1 (vr, code, expr_type, &vrtem0, vr1_);
2433 if (vrtem1.type != VR_UNDEFINED)
2435 value_range_t vrres = VR_INITIALIZER;
2436 extract_range_from_binary_expr_1 (&vrres, code, expr_type,
2438 vrp_meet (vr, &vrres);
2442 /* Likewise for X op ~[]. */
2443 if (vr1.type == VR_ANTI_RANGE
2444 && ranges_from_anti_range (&vr1, &vrtem0, &vrtem1))
2446 extract_range_from_binary_expr_1 (vr, code, expr_type, vr0_, &vrtem0);
2447 if (vrtem1.type != VR_UNDEFINED)
2449 value_range_t vrres = VR_INITIALIZER;
2450 extract_range_from_binary_expr_1 (&vrres, code, expr_type,
2452 vrp_meet (vr, &vrres);
2457 /* The type of the resulting value range defaults to VR0.TYPE. */
2460 /* Refuse to operate on VARYING ranges, ranges of different kinds
2461 and symbolic ranges. As an exception, we allow BIT_{AND,IOR}
2462 because we may be able to derive a useful range even if one of
2463 the operands is VR_VARYING or symbolic range. Similarly for
2464 divisions, MIN/MAX and PLUS/MINUS.
2466 TODO, we may be able to derive anti-ranges in some cases. */
2467 if (code != BIT_AND_EXPR
2468 && code != BIT_IOR_EXPR
2469 && code != TRUNC_DIV_EXPR
2470 && code != FLOOR_DIV_EXPR
2471 && code != CEIL_DIV_EXPR
2472 && code != EXACT_DIV_EXPR
2473 && code != ROUND_DIV_EXPR
2474 && code != TRUNC_MOD_EXPR
2477 && code != PLUS_EXPR
2478 && code != MINUS_EXPR
2479 && code != RSHIFT_EXPR
2480 && (vr0.type == VR_VARYING
2481 || vr1.type == VR_VARYING
2482 || vr0.type != vr1.type
2483 || symbolic_range_p (&vr0)
2484 || symbolic_range_p (&vr1)))
2486 set_value_range_to_varying (vr);
2490 /* Now evaluate the expression to determine the new range. */
2491 if (POINTER_TYPE_P (expr_type))
2493 if (code == MIN_EXPR || code == MAX_EXPR)
2495 /* For MIN/MAX expressions with pointers, we only care about
2496 nullness, if both are non null, then the result is nonnull.
2497 If both are null, then the result is null. Otherwise they
2499 if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1))
2500 set_value_range_to_nonnull (vr, expr_type);
2501 else if (range_is_null (&vr0) && range_is_null (&vr1))
2502 set_value_range_to_null (vr, expr_type);
2504 set_value_range_to_varying (vr);
2506 else if (code == POINTER_PLUS_EXPR)
2508 /* For pointer types, we are really only interested in asserting
2509 whether the expression evaluates to non-NULL. */
2510 if (range_is_nonnull (&vr0) || range_is_nonnull (&vr1))
2511 set_value_range_to_nonnull (vr, expr_type);
2512 else if (range_is_null (&vr0) && range_is_null (&vr1))
2513 set_value_range_to_null (vr, expr_type);
2515 set_value_range_to_varying (vr);
2517 else if (code == BIT_AND_EXPR)
2519 /* For pointer types, we are really only interested in asserting
2520 whether the expression evaluates to non-NULL. */
2521 if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1))
2522 set_value_range_to_nonnull (vr, expr_type);
2523 else if (range_is_null (&vr0) || range_is_null (&vr1))
2524 set_value_range_to_null (vr, expr_type);
2526 set_value_range_to_varying (vr);
2529 set_value_range_to_varying (vr);
2534 /* For integer ranges, apply the operation to each end of the
2535 range and see what we end up with. */
2536 if (code == PLUS_EXPR || code == MINUS_EXPR)
2538 const bool minus_p = (code == MINUS_EXPR);
2539 tree min_op0 = vr0.min;
2540 tree min_op1 = minus_p ? vr1.max : vr1.min;
2541 tree max_op0 = vr0.max;
2542 tree max_op1 = minus_p ? vr1.min : vr1.max;
2543 tree sym_min_op0 = NULL_TREE;
2544 tree sym_min_op1 = NULL_TREE;
2545 tree sym_max_op0 = NULL_TREE;
2546 tree sym_max_op1 = NULL_TREE;
2547 bool neg_min_op0, neg_min_op1, neg_max_op0, neg_max_op1;
2549 /* If we have a PLUS or MINUS with two VR_RANGEs, either constant or
2550 single-symbolic ranges, try to compute the precise resulting range,
2551 but only if we know that this resulting range will also be constant
2552 or single-symbolic. */
2553 if (vr0.type == VR_RANGE && vr1.type == VR_RANGE
2554 && (TREE_CODE (min_op0) == INTEGER_CST
2556 = get_single_symbol (min_op0, &neg_min_op0, &min_op0)))
2557 && (TREE_CODE (min_op1) == INTEGER_CST
2559 = get_single_symbol (min_op1, &neg_min_op1, &min_op1)))
2560 && (!(sym_min_op0 && sym_min_op1)
2561 || (sym_min_op0 == sym_min_op1
2562 && neg_min_op0 == (minus_p ? neg_min_op1 : !neg_min_op1)))
2563 && (TREE_CODE (max_op0) == INTEGER_CST
2565 = get_single_symbol (max_op0, &neg_max_op0, &max_op0)))
2566 && (TREE_CODE (max_op1) == INTEGER_CST
2568 = get_single_symbol (max_op1, &neg_max_op1, &max_op1)))
2569 && (!(sym_max_op0 && sym_max_op1)
2570 || (sym_max_op0 == sym_max_op1
2571 && neg_max_op0 == (minus_p ? neg_max_op1 : !neg_max_op1))))
2573 const signop sgn = TYPE_SIGN (expr_type);
2574 const unsigned int prec = TYPE_PRECISION (expr_type);
2575 wide_int type_min, type_max, wmin, wmax;
2579 /* Get the lower and upper bounds of the type. */
2580 if (TYPE_OVERFLOW_WRAPS (expr_type))
2582 type_min = wi::min_value (prec, sgn);
2583 type_max = wi::max_value (prec, sgn);
2587 type_min = vrp_val_min (expr_type);
2588 type_max = vrp_val_max (expr_type);
2591 /* Combine the lower bounds, if any. */
2592 if (min_op0 && min_op1)
2596 wmin = wi::sub (min_op0, min_op1);
2598 /* Check for overflow. */
2599 if (wi::cmp (0, min_op1, sgn)
2600 != wi::cmp (wmin, min_op0, sgn))
2601 min_ovf = wi::cmp (min_op0, min_op1, sgn);
2605 wmin = wi::add (min_op0, min_op1);
2607 /* Check for overflow. */
2608 if (wi::cmp (min_op1, 0, sgn)
2609 != wi::cmp (wmin, min_op0, sgn))
2610 min_ovf = wi::cmp (min_op0, wmin, sgn);
2616 wmin = minus_p ? wi::neg (min_op1) : min_op1;
2618 wmin = wi::shwi (0, prec);
2620 /* Combine the upper bounds, if any. */
2621 if (max_op0 && max_op1)
2625 wmax = wi::sub (max_op0, max_op1);
2627 /* Check for overflow. */
2628 if (wi::cmp (0, max_op1, sgn)
2629 != wi::cmp (wmax, max_op0, sgn))
2630 max_ovf = wi::cmp (max_op0, max_op1, sgn);
2634 wmax = wi::add (max_op0, max_op1);
2636 if (wi::cmp (max_op1, 0, sgn)
2637 != wi::cmp (wmax, max_op0, sgn))
2638 max_ovf = wi::cmp (max_op0, wmax, sgn);
2644 wmax = minus_p ? wi::neg (max_op1) : max_op1;
2646 wmax = wi::shwi (0, prec);
2648 /* Check for type overflow. */
2651 if (wi::cmp (wmin, type_min, sgn) == -1)
2653 else if (wi::cmp (wmin, type_max, sgn) == 1)
2658 if (wi::cmp (wmax, type_min, sgn) == -1)
2660 else if (wi::cmp (wmax, type_max, sgn) == 1)
2664 /* If we have overflow for the constant part and the resulting
2665 range will be symbolic, drop to VR_VARYING. */
2666 if ((min_ovf && sym_min_op0 != sym_min_op1)
2667 || (max_ovf && sym_max_op0 != sym_max_op1))
2669 set_value_range_to_varying (vr);
2673 if (TYPE_OVERFLOW_WRAPS (expr_type))
2675 /* If overflow wraps, truncate the values and adjust the
2676 range kind and bounds appropriately. */
2677 wide_int tmin = wide_int::from (wmin, prec, sgn);
2678 wide_int tmax = wide_int::from (wmax, prec, sgn);
2679 if (min_ovf == max_ovf)
2681 /* No overflow or both overflow or underflow. The
2682 range kind stays VR_RANGE. */
2683 min = wide_int_to_tree (expr_type, tmin);
2684 max = wide_int_to_tree (expr_type, tmax);
2686 else if (min_ovf == -1 && max_ovf == 1)
2688 /* Underflow and overflow, drop to VR_VARYING. */
2689 set_value_range_to_varying (vr);
2694 /* Min underflow or max overflow. The range kind
2695 changes to VR_ANTI_RANGE. */
2696 bool covers = false;
2697 wide_int tem = tmin;
2698 gcc_assert ((min_ovf == -1 && max_ovf == 0)
2699 || (max_ovf == 1 && min_ovf == 0));
2700 type = VR_ANTI_RANGE;
2702 if (wi::cmp (tmin, tmax, sgn) < 0)
2705 if (wi::cmp (tmax, tem, sgn) > 0)
2707 /* If the anti-range would cover nothing, drop to varying.
2708 Likewise if the anti-range bounds are outside of the
2710 if (covers || wi::cmp (tmin, tmax, sgn) > 0)
2712 set_value_range_to_varying (vr);
2715 min = wide_int_to_tree (expr_type, tmin);
2716 max = wide_int_to_tree (expr_type, tmax);
2721 /* If overflow does not wrap, saturate to the types min/max
2725 if (needs_overflow_infinity (expr_type)
2726 && supports_overflow_infinity (expr_type))
2727 min = negative_overflow_infinity (expr_type);
2729 min = wide_int_to_tree (expr_type, type_min);
2731 else if (min_ovf == 1)
2733 if (needs_overflow_infinity (expr_type)
2734 && supports_overflow_infinity (expr_type))
2735 min = positive_overflow_infinity (expr_type);
2737 min = wide_int_to_tree (expr_type, type_max);
2740 min = wide_int_to_tree (expr_type, wmin);
2744 if (needs_overflow_infinity (expr_type)
2745 && supports_overflow_infinity (expr_type))
2746 max = negative_overflow_infinity (expr_type);
2748 max = wide_int_to_tree (expr_type, type_min);
2750 else if (max_ovf == 1)
2752 if (needs_overflow_infinity (expr_type)
2753 && supports_overflow_infinity (expr_type))
2754 max = positive_overflow_infinity (expr_type);
2756 max = wide_int_to_tree (expr_type, type_max);
2759 max = wide_int_to_tree (expr_type, wmax);
2762 if (needs_overflow_infinity (expr_type)
2763 && supports_overflow_infinity (expr_type))
2765 if ((min_op0 && is_negative_overflow_infinity (min_op0))
2768 ? is_positive_overflow_infinity (min_op1)
2769 : is_negative_overflow_infinity (min_op1))))
2770 min = negative_overflow_infinity (expr_type);
2771 if ((max_op0 && is_positive_overflow_infinity (max_op0))
2774 ? is_negative_overflow_infinity (max_op1)
2775 : is_positive_overflow_infinity (max_op1))))
2776 max = positive_overflow_infinity (expr_type);
2779 /* If the result lower bound is constant, we're done;
2780 otherwise, build the symbolic lower bound. */
2781 if (sym_min_op0 == sym_min_op1)
2783 else if (sym_min_op0)
2784 min = build_symbolic_expr (expr_type, sym_min_op0,
2786 else if (sym_min_op1)
2787 min = build_symbolic_expr (expr_type, sym_min_op1,
2788 neg_min_op1 ^ minus_p, min);
2790 /* Likewise for the upper bound. */
2791 if (sym_max_op0 == sym_max_op1)
2793 else if (sym_max_op0)
2794 max = build_symbolic_expr (expr_type, sym_max_op0,
2796 else if (sym_max_op1)
2797 max = build_symbolic_expr (expr_type, sym_max_op1,
2798 neg_max_op1 ^ minus_p, max);
2802 /* For other cases, for example if we have a PLUS_EXPR with two
2803 VR_ANTI_RANGEs, drop to VR_VARYING. It would take more effort
2804 to compute a precise range for such a case.
2805 ??? General even mixed range kind operations can be expressed
2806 by for example transforming ~[3, 5] + [1, 2] to range-only
2807 operations and a union primitive:
2808 [-INF, 2] + [1, 2] U [5, +INF] + [1, 2]
2809 [-INF+1, 4] U [6, +INF(OVF)]
2810 though usually the union is not exactly representable with
2811 a single range or anti-range as the above is
2812 [-INF+1, +INF(OVF)] intersected with ~[5, 5]
2813 but one could use a scheme similar to equivalences for this. */
2814 set_value_range_to_varying (vr);
2818 else if (code == MIN_EXPR
2819 || code == MAX_EXPR)
2821 if (vr0.type == VR_RANGE
2822 && !symbolic_range_p (&vr0))
2825 if (vr1.type == VR_RANGE
2826 && !symbolic_range_p (&vr1))
2828 /* For operations that make the resulting range directly
2829 proportional to the original ranges, apply the operation to
2830 the same end of each range. */
2831 min = vrp_int_const_binop (code, vr0.min, vr1.min);
2832 max = vrp_int_const_binop (code, vr0.max, vr1.max);
2834 else if (code == MIN_EXPR)
2836 min = vrp_val_min (expr_type);
2839 else if (code == MAX_EXPR)
2842 max = vrp_val_max (expr_type);
2845 else if (vr1.type == VR_RANGE
2846 && !symbolic_range_p (&vr1))
2849 if (code == MIN_EXPR)
2851 min = vrp_val_min (expr_type);
2854 else if (code == MAX_EXPR)
2857 max = vrp_val_max (expr_type);
2862 set_value_range_to_varying (vr);
2866 else if (code == MULT_EXPR)
2868 /* Fancy code so that with unsigned, [-3,-1]*[-3,-1] does not
2869 drop to varying. This test requires 2*prec bits if both
2870 operands are signed and 2*prec + 2 bits if either is not. */
2872 signop sign = TYPE_SIGN (expr_type);
2873 unsigned int prec = TYPE_PRECISION (expr_type);
2875 if (range_int_cst_p (&vr0)
2876 && range_int_cst_p (&vr1)
2877 && TYPE_OVERFLOW_WRAPS (expr_type))
2879 typedef FIXED_WIDE_INT (WIDE_INT_MAX_PRECISION * 2) vrp_int;
2880 typedef generic_wide_int
2881 <wi::extended_tree <WIDE_INT_MAX_PRECISION * 2> > vrp_int_cst;
2882 vrp_int sizem1 = wi::mask <vrp_int> (prec, false);
2883 vrp_int size = sizem1 + 1;
2885 /* Extend the values using the sign of the result to PREC2.
2886 From here on out, everthing is just signed math no matter
2887 what the input types were. */
2888 vrp_int min0 = vrp_int_cst (vr0.min);
2889 vrp_int max0 = vrp_int_cst (vr0.max);
2890 vrp_int min1 = vrp_int_cst (vr1.min);
2891 vrp_int max1 = vrp_int_cst (vr1.max);
2892 /* Canonicalize the intervals. */
2893 if (sign == UNSIGNED)
2895 if (wi::ltu_p (size, min0 + max0))
2901 if (wi::ltu_p (size, min1 + max1))
2908 vrp_int prod0 = min0 * min1;
2909 vrp_int prod1 = min0 * max1;
2910 vrp_int prod2 = max0 * min1;
2911 vrp_int prod3 = max0 * max1;
2913 /* Sort the 4 products so that min is in prod0 and max is in
2915 /* min0min1 > max0max1 */
2916 if (wi::gts_p (prod0, prod3))
2918 vrp_int tmp = prod3;
2923 /* min0max1 > max0min1 */
2924 if (wi::gts_p (prod1, prod2))
2926 vrp_int tmp = prod2;
2931 if (wi::gts_p (prod0, prod1))
2933 vrp_int tmp = prod1;
2938 if (wi::gts_p (prod2, prod3))
2940 vrp_int tmp = prod3;
2945 /* diff = max - min. */
2946 prod2 = prod3 - prod0;
2947 if (wi::geu_p (prod2, sizem1))
2949 /* the range covers all values. */
2950 set_value_range_to_varying (vr);
2954 /* The following should handle the wrapping and selecting
2955 VR_ANTI_RANGE for us. */
2956 min = wide_int_to_tree (expr_type, prod0);
2957 max = wide_int_to_tree (expr_type, prod3);
2958 set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL);
2962 /* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
2963 drop to VR_VARYING. It would take more effort to compute a
2964 precise range for such a case. For example, if we have
2965 op0 == 65536 and op1 == 65536 with their ranges both being
2966 ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so
2967 we cannot claim that the product is in ~[0,0]. Note that we
2968 are guaranteed to have vr0.type == vr1.type at this
2970 if (vr0.type == VR_ANTI_RANGE
2971 && !TYPE_OVERFLOW_UNDEFINED (expr_type))
2973 set_value_range_to_varying (vr);
2977 extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
2980 else if (code == RSHIFT_EXPR
2981 || code == LSHIFT_EXPR)
2983 /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
2984 then drop to VR_VARYING. Outside of this range we get undefined
2985 behavior from the shift operation. We cannot even trust
2986 SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
2987 shifts, and the operation at the tree level may be widened. */
2988 if (range_int_cst_p (&vr1)
2989 && compare_tree_int (vr1.min, 0) >= 0
2990 && compare_tree_int (vr1.max, TYPE_PRECISION (expr_type)) == -1)
2992 if (code == RSHIFT_EXPR)
2994 /* Even if vr0 is VARYING or otherwise not usable, we can derive
2995 useful ranges just from the shift count. E.g.
2996 x >> 63 for signed 64-bit x is always [-1, 0]. */
2997 if (vr0.type != VR_RANGE || symbolic_range_p (&vr0))
2999 vr0.type = type = VR_RANGE;
3000 vr0.min = vrp_val_min (expr_type);
3001 vr0.max = vrp_val_max (expr_type);
3003 extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
3006 /* We can map lshifts by constants to MULT_EXPR handling. */
3007 else if (code == LSHIFT_EXPR
3008 && range_int_cst_singleton_p (&vr1))
3010 bool saved_flag_wrapv;
3011 value_range_t vr1p = VR_INITIALIZER;
3012 vr1p.type = VR_RANGE;
3013 vr1p.min = (wide_int_to_tree
3015 wi::set_bit_in_zero (tree_to_shwi (vr1.min),
3016 TYPE_PRECISION (expr_type))));
3017 vr1p.max = vr1p.min;
3018 /* We have to use a wrapping multiply though as signed overflow
3019 on lshifts is implementation defined in C89. */
3020 saved_flag_wrapv = flag_wrapv;
3022 extract_range_from_binary_expr_1 (vr, MULT_EXPR, expr_type,
3024 flag_wrapv = saved_flag_wrapv;
3027 else if (code == LSHIFT_EXPR
3028 && range_int_cst_p (&vr0))
3030 int prec = TYPE_PRECISION (expr_type);
3031 int overflow_pos = prec;
3033 wide_int low_bound, high_bound;
3034 bool uns = TYPE_UNSIGNED (expr_type);
3035 bool in_bounds = false;
3040 bound_shift = overflow_pos - tree_to_shwi (vr1.max);
3041 /* If bound_shift == HOST_BITS_PER_WIDE_INT, the llshift can
3042 overflow. However, for that to happen, vr1.max needs to be
3043 zero, which means vr1 is a singleton range of zero, which
3044 means it should be handled by the previous LSHIFT_EXPR
3046 wide_int bound = wi::set_bit_in_zero (bound_shift, prec);
3047 wide_int complement = ~(bound - 1);
3052 high_bound = complement;
3053 if (wi::ltu_p (vr0.max, low_bound))
3055 /* [5, 6] << [1, 2] == [10, 24]. */
3056 /* We're shifting out only zeroes, the value increases
3060 else if (wi::ltu_p (high_bound, vr0.min))
3062 /* [0xffffff00, 0xffffffff] << [1, 2]
3063 == [0xfffffc00, 0xfffffffe]. */
3064 /* We're shifting out only ones, the value decreases
3071 /* [-1, 1] << [1, 2] == [-4, 4]. */
3072 low_bound = complement;
3074 if (wi::lts_p (vr0.max, high_bound)
3075 && wi::lts_p (low_bound, vr0.min))
3077 /* For non-negative numbers, we're shifting out only
3078 zeroes, the value increases monotonically.
3079 For negative numbers, we're shifting out only ones, the
3080 value decreases monotomically. */
3087 extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
3092 set_value_range_to_varying (vr);
3095 else if (code == TRUNC_DIV_EXPR
3096 || code == FLOOR_DIV_EXPR
3097 || code == CEIL_DIV_EXPR
3098 || code == EXACT_DIV_EXPR
3099 || code == ROUND_DIV_EXPR)
3101 if (vr0.type != VR_RANGE || symbolic_range_p (&vr0))
3103 /* For division, if op1 has VR_RANGE but op0 does not, something
3104 can be deduced just from that range. Say [min, max] / [4, max]
3105 gives [min / 4, max / 4] range. */
3106 if (vr1.type == VR_RANGE
3107 && !symbolic_range_p (&vr1)
3108 && range_includes_zero_p (vr1.min, vr1.max) == 0)
3110 vr0.type = type = VR_RANGE;
3111 vr0.min = vrp_val_min (expr_type);
3112 vr0.max = vrp_val_max (expr_type);
3116 set_value_range_to_varying (vr);
3121 /* For divisions, if flag_non_call_exceptions is true, we must
3122 not eliminate a division by zero. */
3123 if (cfun->can_throw_non_call_exceptions
3124 && (vr1.type != VR_RANGE
3125 || range_includes_zero_p (vr1.min, vr1.max) != 0))
3127 set_value_range_to_varying (vr);
3131 /* For divisions, if op0 is VR_RANGE, we can deduce a range
3132 even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
3134 if (vr0.type == VR_RANGE
3135 && (vr1.type != VR_RANGE
3136 || range_includes_zero_p (vr1.min, vr1.max) != 0))
3138 tree zero = build_int_cst (TREE_TYPE (vr0.min), 0);
3143 if (TYPE_UNSIGNED (expr_type)
3144 || value_range_nonnegative_p (&vr1))
3146 /* For unsigned division or when divisor is known
3147 to be non-negative, the range has to cover
3148 all numbers from 0 to max for positive max
3149 and all numbers from min to 0 for negative min. */
3150 cmp = compare_values (vr0.max, zero);
3153 else if (cmp == 0 || cmp == 1)
3157 cmp = compare_values (vr0.min, zero);
3160 else if (cmp == 0 || cmp == -1)
3167 /* Otherwise the range is -max .. max or min .. -min
3168 depending on which bound is bigger in absolute value,
3169 as the division can change the sign. */
3170 abs_extent_range (vr, vr0.min, vr0.max);
3173 if (type == VR_VARYING)
3175 set_value_range_to_varying (vr);
3181 extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
3185 else if (code == TRUNC_MOD_EXPR)
3187 if (range_is_null (&vr1))
3189 set_value_range_to_undefined (vr);
3192 /* ABS (A % B) < ABS (B) and either
3193 0 <= A % B <= A or A <= A % B <= 0. */
3195 signop sgn = TYPE_SIGN (expr_type);
3196 unsigned int prec = TYPE_PRECISION (expr_type);
3197 wide_int wmin, wmax, tmp;
3198 wide_int zero = wi::zero (prec);
3199 wide_int one = wi::one (prec);
3200 if (vr1.type == VR_RANGE && !symbolic_range_p (&vr1))
3202 wmax = wi::sub (vr1.max, one);
3205 tmp = wi::sub (wi::minus_one (prec), vr1.min);
3206 wmax = wi::smax (wmax, tmp);
3211 wmax = wi::max_value (prec, sgn);
3212 /* X % INT_MIN may be INT_MAX. */
3213 if (sgn == UNSIGNED)
3217 if (sgn == UNSIGNED)
3222 if (vr0.type == VR_RANGE && TREE_CODE (vr0.min) == INTEGER_CST)
3225 if (wi::gts_p (tmp, zero))
3227 wmin = wi::smax (wmin, tmp);
3231 if (vr0.type == VR_RANGE && TREE_CODE (vr0.max) == INTEGER_CST)
3234 if (sgn == SIGNED && wi::neg_p (tmp))
3236 wmax = wi::min (wmax, tmp, sgn);
3239 min = wide_int_to_tree (expr_type, wmin);
3240 max = wide_int_to_tree (expr_type, wmax);
3242 else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR)
3244 bool int_cst_range0, int_cst_range1;
3245 wide_int may_be_nonzero0, may_be_nonzero1;
3246 wide_int must_be_nonzero0, must_be_nonzero1;
3248 int_cst_range0 = zero_nonzero_bits_from_vr (expr_type, &vr0,
3251 int_cst_range1 = zero_nonzero_bits_from_vr (expr_type, &vr1,
3256 if (code == BIT_AND_EXPR)
3258 min = wide_int_to_tree (expr_type,
3259 must_be_nonzero0 & must_be_nonzero1);
3260 wide_int wmax = may_be_nonzero0 & may_be_nonzero1;
3261 /* If both input ranges contain only negative values we can
3262 truncate the result range maximum to the minimum of the
3263 input range maxima. */
3264 if (int_cst_range0 && int_cst_range1
3265 && tree_int_cst_sgn (vr0.max) < 0
3266 && tree_int_cst_sgn (vr1.max) < 0)
3268 wmax = wi::min (wmax, vr0.max, TYPE_SIGN (expr_type));
3269 wmax = wi::min (wmax, vr1.max, TYPE_SIGN (expr_type));
3271 /* If either input range contains only non-negative values
3272 we can truncate the result range maximum to the respective
3273 maximum of the input range. */
3274 if (int_cst_range0 && tree_int_cst_sgn (vr0.min) >= 0)
3275 wmax = wi::min (wmax, vr0.max, TYPE_SIGN (expr_type));
3276 if (int_cst_range1 && tree_int_cst_sgn (vr1.min) >= 0)
3277 wmax = wi::min (wmax, vr1.max, TYPE_SIGN (expr_type));
3278 max = wide_int_to_tree (expr_type, wmax);
3280 else if (code == BIT_IOR_EXPR)
3282 max = wide_int_to_tree (expr_type,
3283 may_be_nonzero0 | may_be_nonzero1);
3284 wide_int wmin = must_be_nonzero0 | must_be_nonzero1;
3285 /* If the input ranges contain only positive values we can
3286 truncate the minimum of the result range to the maximum
3287 of the input range minima. */
3288 if (int_cst_range0 && int_cst_range1
3289 && tree_int_cst_sgn (vr0.min) >= 0
3290 && tree_int_cst_sgn (vr1.min) >= 0)
3292 wmin = wi::max (wmin, vr0.min, TYPE_SIGN (expr_type));
3293 wmin = wi::max (wmin, vr1.min, TYPE_SIGN (expr_type));
3295 /* If either input range contains only negative values
3296 we can truncate the minimum of the result range to the
3297 respective minimum range. */
3298 if (int_cst_range0 && tree_int_cst_sgn (vr0.max) < 0)
3299 wmin = wi::max (wmin, vr0.min, TYPE_SIGN (expr_type));
3300 if (int_cst_range1 && tree_int_cst_sgn (vr1.max) < 0)
3301 wmin = wi::max (wmin, vr1.min, TYPE_SIGN (expr_type));
3302 min = wide_int_to_tree (expr_type, wmin);
3304 else if (code == BIT_XOR_EXPR)
3306 wide_int result_zero_bits = ((must_be_nonzero0 & must_be_nonzero1)
3307 | ~(may_be_nonzero0 | may_be_nonzero1));
3308 wide_int result_one_bits
3309 = (must_be_nonzero0.and_not (may_be_nonzero1)
3310 | must_be_nonzero1.and_not (may_be_nonzero0));
3311 max = wide_int_to_tree (expr_type, ~result_zero_bits);
3312 min = wide_int_to_tree (expr_type, result_one_bits);
3313 /* If the range has all positive or all negative values the
3314 result is better than VARYING. */
3315 if (tree_int_cst_sgn (min) < 0
3316 || tree_int_cst_sgn (max) >= 0)
3319 max = min = NULL_TREE;
3325 /* If either MIN or MAX overflowed, then set the resulting range to
3326 VARYING. But we do accept an overflow infinity representation. */
3327 if (min == NULL_TREE
3328 || (TREE_OVERFLOW_P (min) && !is_overflow_infinity (min))
3330 || (TREE_OVERFLOW_P (max) && !is_overflow_infinity (max)))
3332 set_value_range_to_varying (vr);
3338 2) [-INF, +-INF(OVF)]
3339 3) [+-INF(OVF), +INF]
3340 4) [+-INF(OVF), +-INF(OVF)]
3341 We learn nothing when we have INF and INF(OVF) on both sides.
3342 Note that we do accept [-INF, -INF] and [+INF, +INF] without
3344 if ((vrp_val_is_min (min) || is_overflow_infinity (min))
3345 && (vrp_val_is_max (max) || is_overflow_infinity (max)))
3347 set_value_range_to_varying (vr);
3351 cmp = compare_values (min, max);
3352 if (cmp == -2 || cmp == 1)
3354 /* If the new range has its limits swapped around (MIN > MAX),
3355 then the operation caused one of them to wrap around, mark
3356 the new range VARYING. */
3357 set_value_range_to_varying (vr);
3360 set_value_range (vr, type, min, max, NULL);
3363 /* Extract range information from a binary expression OP0 CODE OP1 based on
3364 the ranges of each of its operands with resulting type EXPR_TYPE.
3365 The resulting range is stored in *VR. */
3368 extract_range_from_binary_expr (value_range_t *vr,
3369 enum tree_code code,
3370 tree expr_type, tree op0, tree op1)
3372 value_range_t vr0 = VR_INITIALIZER;
3373 value_range_t vr1 = VR_INITIALIZER;
3375 /* Get value ranges for each operand. For constant operands, create
3376 a new value range with the operand to simplify processing. */
3377 if (TREE_CODE (op0) == SSA_NAME)
3378 vr0 = *(get_value_range (op0));
3379 else if (is_gimple_min_invariant (op0))
3380 set_value_range_to_value (&vr0, op0, NULL);
3382 set_value_range_to_varying (&vr0);
3384 if (TREE_CODE (op1) == SSA_NAME)
3385 vr1 = *(get_value_range (op1));
3386 else if (is_gimple_min_invariant (op1))
3387 set_value_range_to_value (&vr1, op1, NULL);
3389 set_value_range_to_varying (&vr1);
3391 extract_range_from_binary_expr_1 (vr, code, expr_type, &vr0, &vr1);
3393 /* Try harder for PLUS and MINUS if the range of one operand is symbolic
3394 and based on the other operand, for example if it was deduced from a
3395 symbolic comparison. When a bound of the range of the first operand
3396 is invariant, we set the corresponding bound of the new range to INF
3397 in order to avoid recursing on the range of the second operand. */
3398 if (vr->type == VR_VARYING
3399 && (code == PLUS_EXPR || code == MINUS_EXPR)
3400 && TREE_CODE (op1) == SSA_NAME
3401 && vr0.type == VR_RANGE
3402 && symbolic_range_based_on_p (&vr0, op1))
3404 const bool minus_p = (code == MINUS_EXPR);
3405 value_range_t n_vr1 = VR_INITIALIZER;
3407 /* Try with VR0 and [-INF, OP1]. */
3408 if (is_gimple_min_invariant (minus_p ? vr0.max : vr0.min))
3409 set_value_range (&n_vr1, VR_RANGE, vrp_val_min (expr_type), op1, NULL);
3411 /* Try with VR0 and [OP1, +INF]. */
3412 else if (is_gimple_min_invariant (minus_p ? vr0.min : vr0.max))
3413 set_value_range (&n_vr1, VR_RANGE, op1, vrp_val_max (expr_type), NULL);
3415 /* Try with VR0 and [OP1, OP1]. */
3417 set_value_range (&n_vr1, VR_RANGE, op1, op1, NULL);
3419 extract_range_from_binary_expr_1 (vr, code, expr_type, &vr0, &n_vr1);
3422 if (vr->type == VR_VARYING
3423 && (code == PLUS_EXPR || code == MINUS_EXPR)
3424 && TREE_CODE (op0) == SSA_NAME
3425 && vr1.type == VR_RANGE
3426 && symbolic_range_based_on_p (&vr1, op0))
3428 const bool minus_p = (code == MINUS_EXPR);
3429 value_range_t n_vr0 = VR_INITIALIZER;
3431 /* Try with [-INF, OP0] and VR1. */
3432 if (is_gimple_min_invariant (minus_p ? vr1.max : vr1.min))
3433 set_value_range (&n_vr0, VR_RANGE, vrp_val_min (expr_type), op0, NULL);
3435 /* Try with [OP0, +INF] and VR1. */
3436 else if (is_gimple_min_invariant (minus_p ? vr1.min : vr1.max))
3437 set_value_range (&n_vr0, VR_RANGE, op0, vrp_val_max (expr_type), NULL);
3439 /* Try with [OP0, OP0] and VR1. */
3441 set_value_range (&n_vr0, VR_RANGE, op0, op0, NULL);
3443 extract_range_from_binary_expr_1 (vr, code, expr_type, &n_vr0, &vr1);
3447 /* Extract range information from a unary operation CODE based on
3448 the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
3449 The The resulting range is stored in *VR. */
3452 extract_range_from_unary_expr_1 (value_range_t *vr,
3453 enum tree_code code, tree type,
3454 value_range_t *vr0_, tree op0_type)
3456 value_range_t vr0 = *vr0_, vrtem0 = VR_INITIALIZER, vrtem1 = VR_INITIALIZER;
3458 /* VRP only operates on integral and pointer types. */
3459 if (!(INTEGRAL_TYPE_P (op0_type)
3460 || POINTER_TYPE_P (op0_type))
3461 || !(INTEGRAL_TYPE_P (type)
3462 || POINTER_TYPE_P (type)))
3464 set_value_range_to_varying (vr);
3468 /* If VR0 is UNDEFINED, so is the result. */
3469 if (vr0.type == VR_UNDEFINED)
3471 set_value_range_to_undefined (vr);
3475 /* Handle operations that we express in terms of others. */
3476 if (code == PAREN_EXPR || code == OBJ_TYPE_REF)
3478 /* PAREN_EXPR and OBJ_TYPE_REF are simple copies. */
3479 copy_value_range (vr, &vr0);
3482 else if (code == NEGATE_EXPR)
3484 /* -X is simply 0 - X, so re-use existing code that also handles
3485 anti-ranges fine. */
3486 value_range_t zero = VR_INITIALIZER;
3487 set_value_range_to_value (&zero, build_int_cst (type, 0), NULL);
3488 extract_range_from_binary_expr_1 (vr, MINUS_EXPR, type, &zero, &vr0);
3491 else if (code == BIT_NOT_EXPR)
3493 /* ~X is simply -1 - X, so re-use existing code that also handles
3494 anti-ranges fine. */
3495 value_range_t minusone = VR_INITIALIZER;
3496 set_value_range_to_value (&minusone, build_int_cst (type, -1), NULL);
3497 extract_range_from_binary_expr_1 (vr, MINUS_EXPR,
3498 type, &minusone, &vr0);
3502 /* Now canonicalize anti-ranges to ranges when they are not symbolic
3503 and express op ~[] as (op []') U (op []''). */
3504 if (vr0.type == VR_ANTI_RANGE
3505 && ranges_from_anti_range (&vr0, &vrtem0, &vrtem1))
3507 extract_range_from_unary_expr_1 (vr, code, type, &vrtem0, op0_type);
3508 if (vrtem1.type != VR_UNDEFINED)
3510 value_range_t vrres = VR_INITIALIZER;
3511 extract_range_from_unary_expr_1 (&vrres, code, type,
3513 vrp_meet (vr, &vrres);
3518 if (CONVERT_EXPR_CODE_P (code))
3520 tree inner_type = op0_type;
3521 tree outer_type = type;
3523 /* If the expression evaluates to a pointer, we are only interested in
3524 determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
3525 if (POINTER_TYPE_P (type))
3527 if (range_is_nonnull (&vr0))
3528 set_value_range_to_nonnull (vr, type);
3529 else if (range_is_null (&vr0))
3530 set_value_range_to_null (vr, type);
3532 set_value_range_to_varying (vr);
3536 /* If VR0 is varying and we increase the type precision, assume
3537 a full range for the following transformation. */
3538 if (vr0.type == VR_VARYING
3539 && INTEGRAL_TYPE_P (inner_type)
3540 && TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type))
3542 vr0.type = VR_RANGE;
3543 vr0.min = TYPE_MIN_VALUE (inner_type);
3544 vr0.max = TYPE_MAX_VALUE (inner_type);
3547 /* If VR0 is a constant range or anti-range and the conversion is
3548 not truncating we can convert the min and max values and
3549 canonicalize the resulting range. Otherwise we can do the
3550 conversion if the size of the range is less than what the
3551 precision of the target type can represent and the range is
3552 not an anti-range. */
3553 if ((vr0.type == VR_RANGE
3554 || vr0.type == VR_ANTI_RANGE)
3555 && TREE_CODE (vr0.min) == INTEGER_CST
3556 && TREE_CODE (vr0.max) == INTEGER_CST
3557 && (!is_overflow_infinity (vr0.min)
3558 || (vr0.type == VR_RANGE
3559 && TYPE_PRECISION (outer_type) > TYPE_PRECISION (inner_type)
3560 && needs_overflow_infinity (outer_type)
3561 && supports_overflow_infinity (outer_type)))
3562 && (!is_overflow_infinity (vr0.max)
3563 || (vr0.type == VR_RANGE
3564 && TYPE_PRECISION (outer_type) > TYPE_PRECISION (inner_type)
3565 && needs_overflow_infinity (outer_type)
3566 && supports_overflow_infinity (outer_type)))
3567 && (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
3568 || (vr0.type == VR_RANGE
3569 && integer_zerop (int_const_binop (RSHIFT_EXPR,
3570 int_const_binop (MINUS_EXPR, vr0.max, vr0.min),
3571 size_int (TYPE_PRECISION (outer_type)))))))
3573 tree new_min, new_max;
3574 if (is_overflow_infinity (vr0.min))
3575 new_min = negative_overflow_infinity (outer_type);
3577 new_min = force_fit_type (outer_type, wi::to_widest (vr0.min),
3579 if (is_overflow_infinity (vr0.max))
3580 new_max = positive_overflow_infinity (outer_type);
3582 new_max = force_fit_type (outer_type, wi::to_widest (vr0.max),
3584 set_and_canonicalize_value_range (vr, vr0.type,
3585 new_min, new_max, NULL);
3589 set_value_range_to_varying (vr);
3592 else if (code == ABS_EXPR)
3597 /* Pass through vr0 in the easy cases. */
3598 if (TYPE_UNSIGNED (type)
3599 || value_range_nonnegative_p (&vr0))
3601 copy_value_range (vr, &vr0);
3605 /* For the remaining varying or symbolic ranges we can't do anything
3607 if (vr0.type == VR_VARYING
3608 || symbolic_range_p (&vr0))
3610 set_value_range_to_varying (vr);
3614 /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
3616 if (!TYPE_OVERFLOW_UNDEFINED (type)
3617 && ((vr0.type == VR_RANGE
3618 && vrp_val_is_min (vr0.min))
3619 || (vr0.type == VR_ANTI_RANGE
3620 && !vrp_val_is_min (vr0.min))))
3622 set_value_range_to_varying (vr);
3626 /* ABS_EXPR may flip the range around, if the original range
3627 included negative values. */
3628 if (is_overflow_infinity (vr0.min))
3629 min = positive_overflow_infinity (type);
3630 else if (!vrp_val_is_min (vr0.min))
3631 min = fold_unary_to_constant (code, type, vr0.min);
3632 else if (!needs_overflow_infinity (type))
3633 min = TYPE_MAX_VALUE (type);
3634 else if (supports_overflow_infinity (type))
3635 min = positive_overflow_infinity (type);
3638 set_value_range_to_varying (vr);
3642 if (is_overflow_infinity (vr0.max))
3643 max = positive_overflow_infinity (type);
3644 else if (!vrp_val_is_min (vr0.max))
3645 max = fold_unary_to_constant (code, type, vr0.max);
3646 else if (!needs_overflow_infinity (type))
3647 max = TYPE_MAX_VALUE (type);
3648 else if (supports_overflow_infinity (type)
3649 /* We shouldn't generate [+INF, +INF] as set_value_range
3650 doesn't like this and ICEs. */
3651 && !is_positive_overflow_infinity (min))
3652 max = positive_overflow_infinity (type);
3655 set_value_range_to_varying (vr);
3659 cmp = compare_values (min, max);
3661 /* If a VR_ANTI_RANGEs contains zero, then we have
3662 ~[-INF, min(MIN, MAX)]. */
3663 if (vr0.type == VR_ANTI_RANGE)
3665 if (range_includes_zero_p (vr0.min, vr0.max) == 1)
3667 /* Take the lower of the two values. */
3671 /* Create ~[-INF, min (abs(MIN), abs(MAX))]
3672 or ~[-INF + 1, min (abs(MIN), abs(MAX))] when
3673 flag_wrapv is set and the original anti-range doesn't include
3674 TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */
3675 if (TYPE_OVERFLOW_WRAPS (type))
3677 tree type_min_value = TYPE_MIN_VALUE (type);
3679 min = (vr0.min != type_min_value
3680 ? int_const_binop (PLUS_EXPR, type_min_value,
3681 build_int_cst (TREE_TYPE (type_min_value), 1))
3686 if (overflow_infinity_range_p (&vr0))
3687 min = negative_overflow_infinity (type);
3689 min = TYPE_MIN_VALUE (type);
3694 /* All else has failed, so create the range [0, INF], even for
3695 flag_wrapv since TYPE_MIN_VALUE is in the original
3697 vr0.type = VR_RANGE;
3698 min = build_int_cst (type, 0);
3699 if (needs_overflow_infinity (type))
3701 if (supports_overflow_infinity (type))
3702 max = positive_overflow_infinity (type);
3705 set_value_range_to_varying (vr);
3710 max = TYPE_MAX_VALUE (type);
3714 /* If the range contains zero then we know that the minimum value in the
3715 range will be zero. */
3716 else if (range_includes_zero_p (vr0.min, vr0.max) == 1)
3720 min = build_int_cst (type, 0);
3724 /* If the range was reversed, swap MIN and MAX. */
3733 cmp = compare_values (min, max);
3734 if (cmp == -2 || cmp == 1)
3736 /* If the new range has its limits swapped around (MIN > MAX),
3737 then the operation caused one of them to wrap around, mark
3738 the new range VARYING. */
3739 set_value_range_to_varying (vr);
3742 set_value_range (vr, vr0.type, min, max, NULL);
3746 /* For unhandled operations fall back to varying. */
3747 set_value_range_to_varying (vr);
3752 /* Extract range information from a unary expression CODE OP0 based on
3753 the range of its operand with resulting type TYPE.
3754 The resulting range is stored in *VR. */
3757 extract_range_from_unary_expr (value_range_t *vr, enum tree_code code,
3758 tree type, tree op0)
3760 value_range_t vr0 = VR_INITIALIZER;
3762 /* Get value ranges for the operand. For constant operands, create
3763 a new value range with the operand to simplify processing. */
3764 if (TREE_CODE (op0) == SSA_NAME)
3765 vr0 = *(get_value_range (op0));
3766 else if (is_gimple_min_invariant (op0))
3767 set_value_range_to_value (&vr0, op0, NULL);
3769 set_value_range_to_varying (&vr0);
3771 extract_range_from_unary_expr_1 (vr, code, type, &vr0, TREE_TYPE (op0));
3775 /* Extract range information from a conditional expression STMT based on
3776 the ranges of each of its operands and the expression code. */
3779 extract_range_from_cond_expr (value_range_t *vr, gassign *stmt)
3782 value_range_t vr0 = VR_INITIALIZER;
3783 value_range_t vr1 = VR_INITIALIZER;
3785 /* Get value ranges for each operand. For constant operands, create
3786 a new value range with the operand to simplify processing. */
3787 op0 = gimple_assign_rhs2 (stmt);
3788 if (TREE_CODE (op0) == SSA_NAME)
3789 vr0 = *(get_value_range (op0));
3790 else if (is_gimple_min_invariant (op0))
3791 set_value_range_to_value (&vr0, op0, NULL);
3793 set_value_range_to_varying (&vr0);
3795 op1 = gimple_assign_rhs3 (stmt);
3796 if (TREE_CODE (op1) == SSA_NAME)
3797 vr1 = *(get_value_range (op1));
3798 else if (is_gimple_min_invariant (op1))
3799 set_value_range_to_value (&vr1, op1, NULL);
3801 set_value_range_to_varying (&vr1);
3803 /* The resulting value range is the union of the operand ranges */
3804 copy_value_range (vr, &vr0);
3805 vrp_meet (vr, &vr1);
3809 /* Extract range information from a comparison expression EXPR based
3810 on the range of its operand and the expression code. */
3813 extract_range_from_comparison (value_range_t *vr, enum tree_code code,
3814 tree type, tree op0, tree op1)
3819 val = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, false, &sop,
3822 /* A disadvantage of using a special infinity as an overflow
3823 representation is that we lose the ability to record overflow
3824 when we don't have an infinity. So we have to ignore a result
3825 which relies on overflow. */
3827 if (val && !is_overflow_infinity (val) && !sop)
3829 /* Since this expression was found on the RHS of an assignment,
3830 its type may be different from _Bool. Convert VAL to EXPR's
3832 val = fold_convert (type, val);
3833 if (is_gimple_min_invariant (val))
3834 set_value_range_to_value (vr, val, vr->equiv);
3836 set_value_range (vr, VR_RANGE, val, val, vr->equiv);
3839 /* The result of a comparison is always true or false. */
3840 set_value_range_to_truthvalue (vr, type);
3843 /* Helper function for simplify_internal_call_using_ranges and
3844 extract_range_basic. Return true if OP0 SUBCODE OP1 for
3845 SUBCODE {PLUS,MINUS,MULT}_EXPR is known to never overflow or
3846 always overflow. Set *OVF to true if it is known to always
3850 check_for_binary_op_overflow (enum tree_code subcode, tree type,
3851 tree op0, tree op1, bool *ovf)
3853 value_range_t vr0 = VR_INITIALIZER;
3854 value_range_t vr1 = VR_INITIALIZER;
3855 if (TREE_CODE (op0) == SSA_NAME)
3856 vr0 = *get_value_range (op0);
3857 else if (TREE_CODE (op0) == INTEGER_CST)
3858 set_value_range_to_value (&vr0, op0, NULL);
3860 set_value_range_to_varying (&vr0);
3862 if (TREE_CODE (op1) == SSA_NAME)
3863 vr1 = *get_value_range (op1);
3864 else if (TREE_CODE (op1) == INTEGER_CST)
3865 set_value_range_to_value (&vr1, op1, NULL);
3867 set_value_range_to_varying (&vr1);
3869 if (!range_int_cst_p (&vr0)
3870 || TREE_OVERFLOW (vr0.min)
3871 || TREE_OVERFLOW (vr0.max))
3873 vr0.min = vrp_val_min (TREE_TYPE (op0));
3874 vr0.max = vrp_val_max (TREE_TYPE (op0));
3876 if (!range_int_cst_p (&vr1)
3877 || TREE_OVERFLOW (vr1.min)
3878 || TREE_OVERFLOW (vr1.max))
3880 vr1.min = vrp_val_min (TREE_TYPE (op1));
3881 vr1.max = vrp_val_max (TREE_TYPE (op1));
3883 *ovf = arith_overflowed_p (subcode, type, vr0.min,
3884 subcode == MINUS_EXPR ? vr1.max : vr1.min);
3885 if (arith_overflowed_p (subcode, type, vr0.max,
3886 subcode == MINUS_EXPR ? vr1.min : vr1.max) != *ovf)
3888 if (subcode == MULT_EXPR)
3890 if (arith_overflowed_p (subcode, type, vr0.min, vr1.max) != *ovf
3891 || arith_overflowed_p (subcode, type, vr0.max, vr1.min) != *ovf)
3896 /* So far we found that there is an overflow on the boundaries.
3897 That doesn't prove that there is an overflow even for all values
3898 in between the boundaries. For that compute widest_int range
3899 of the result and see if it doesn't overlap the range of
3901 widest_int wmin, wmax;
3904 w[0] = wi::to_widest (vr0.min);
3905 w[1] = wi::to_widest (vr0.max);
3906 w[2] = wi::to_widest (vr1.min);
3907 w[3] = wi::to_widest (vr1.max);
3908 for (i = 0; i < 4; i++)
3914 wt = wi::add (w[i & 1], w[2 + (i & 2) / 2]);
3917 wt = wi::sub (w[i & 1], w[2 + (i & 2) / 2]);
3920 wt = wi::mul (w[i & 1], w[2 + (i & 2) / 2]);
3932 wmin = wi::smin (wmin, wt);
3933 wmax = wi::smax (wmax, wt);
3936 /* The result of op0 CODE op1 is known to be in range
3938 widest_int wtmin = wi::to_widest (vrp_val_min (type));
3939 widest_int wtmax = wi::to_widest (vrp_val_max (type));
3940 /* If all values in [wmin, wmax] are smaller than
3941 [wtmin, wtmax] or all are larger than [wtmin, wtmax],
3942 the arithmetic operation will always overflow. */
3943 if (wi::lts_p (wmax, wtmin) || wi::gts_p (wmin, wtmax))
3950 /* Try to derive a nonnegative or nonzero range out of STMT relying
3951 primarily on generic routines in fold in conjunction with range data.
3952 Store the result in *VR */
3955 extract_range_basic (value_range_t *vr, gimple stmt)
3958 tree type = gimple_expr_type (stmt);
3960 if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
3962 tree fndecl = gimple_call_fndecl (stmt), arg;
3963 int mini, maxi, zerov = 0, prec;
3965 switch (DECL_FUNCTION_CODE (fndecl))
3967 case BUILT_IN_CONSTANT_P:
3968 /* If the call is __builtin_constant_p and the argument is a
3969 function parameter resolve it to false. This avoids bogus
3970 array bound warnings.
3971 ??? We could do this as early as inlining is finished. */
3972 arg = gimple_call_arg (stmt, 0);
3973 if (TREE_CODE (arg) == SSA_NAME
3974 && SSA_NAME_IS_DEFAULT_DEF (arg)
3975 && TREE_CODE (SSA_NAME_VAR (arg)) == PARM_DECL)
3977 set_value_range_to_null (vr, type);
3981 /* Both __builtin_ffs* and __builtin_popcount return
3983 CASE_INT_FN (BUILT_IN_FFS):
3984 CASE_INT_FN (BUILT_IN_POPCOUNT):
3985 arg = gimple_call_arg (stmt, 0);
3986 prec = TYPE_PRECISION (TREE_TYPE (arg));
3989 if (TREE_CODE (arg) == SSA_NAME)
3991 value_range_t *vr0 = get_value_range (arg);
3992 /* If arg is non-zero, then ffs or popcount
3994 if (((vr0->type == VR_RANGE
3995 && range_includes_zero_p (vr0->min, vr0->max) == 0)
3996 || (vr0->type == VR_ANTI_RANGE
3997 && range_includes_zero_p (vr0->min, vr0->max) == 1))
3998 && !is_overflow_infinity (vr0->min)
3999 && !is_overflow_infinity (vr0->max))
4001 /* If some high bits are known to be zero,
4002 we can decrease the maximum. */
4003 if (vr0->type == VR_RANGE
4004 && TREE_CODE (vr0->max) == INTEGER_CST
4005 && !operand_less_p (vr0->min,
4006 build_zero_cst (TREE_TYPE (vr0->min)))
4007 && !is_overflow_infinity (vr0->max))
4008 maxi = tree_floor_log2 (vr0->max) + 1;
4011 /* __builtin_parity* returns [0, 1]. */
4012 CASE_INT_FN (BUILT_IN_PARITY):
4016 /* __builtin_c[lt]z* return [0, prec-1], except for
4017 when the argument is 0, but that is undefined behavior.
4018 On many targets where the CLZ RTL or optab value is defined
4019 for 0 the value is prec, so include that in the range
4021 CASE_INT_FN (BUILT_IN_CLZ):
4022 arg = gimple_call_arg (stmt, 0);
4023 prec = TYPE_PRECISION (TREE_TYPE (arg));
4026 if (optab_handler (clz_optab, TYPE_MODE (TREE_TYPE (arg)))
4028 && CLZ_DEFINED_VALUE_AT_ZERO (TYPE_MODE (TREE_TYPE (arg)),
4030 /* Handle only the single common value. */
4032 /* Magic value to give up, unless vr0 proves
4035 if (TREE_CODE (arg) == SSA_NAME)
4037 value_range_t *vr0 = get_value_range (arg);
4038 /* From clz of VR_RANGE minimum we can compute
4040 if (vr0->type == VR_RANGE
4041 && TREE_CODE (vr0->min) == INTEGER_CST
4042 && !is_overflow_infinity (vr0->min))
4044 maxi = prec - 1 - tree_floor_log2 (vr0->min);
4048 else if (vr0->type == VR_ANTI_RANGE
4049 && integer_zerop (vr0->min)
4050 && !is_overflow_infinity (vr0->min))
4057 /* From clz of VR_RANGE maximum we can compute
4059 if (vr0->type == VR_RANGE
4060 && TREE_CODE (vr0->max) == INTEGER_CST
4061 && !is_overflow_infinity (vr0->max))
4063 mini = prec - 1 - tree_floor_log2 (vr0->max);
4071 /* __builtin_ctz* return [0, prec-1], except for
4072 when the argument is 0, but that is undefined behavior.
4073 If there is a ctz optab for this mode and
4074 CTZ_DEFINED_VALUE_AT_ZERO, include that in the range,
4075 otherwise just assume 0 won't be seen. */
4076 CASE_INT_FN (BUILT_IN_CTZ):
4077 arg = gimple_call_arg (stmt, 0);
4078 prec = TYPE_PRECISION (TREE_TYPE (arg));
4081 if (optab_handler (ctz_optab, TYPE_MODE (TREE_TYPE (arg)))
4083 && CTZ_DEFINED_VALUE_AT_ZERO (TYPE_MODE (TREE_TYPE (arg)),
4086 /* Handle only the two common values. */
4089 else if (zerov == prec)
4092 /* Magic value to give up, unless vr0 proves
4096 if (TREE_CODE (arg) == SSA_NAME)
4098 value_range_t *vr0 = get_value_range (arg);
4099 /* If arg is non-zero, then use [0, prec - 1]. */
4100 if (((vr0->type == VR_RANGE
4101 && integer_nonzerop (vr0->min))
4102 || (vr0->type == VR_ANTI_RANGE
4103 && integer_zerop (vr0->min)))
4104 && !is_overflow_infinity (vr0->min))
4109 /* If some high bits are known to be zero,
4110 we can decrease the result maximum. */
4111 if (vr0->type == VR_RANGE
4112 && TREE_CODE (vr0->max) == INTEGER_CST
4113 && !is_overflow_infinity (vr0->max))
4115 maxi = tree_floor_log2 (vr0->max);
4116 /* For vr0 [0, 0] give up. */
4124 /* __builtin_clrsb* returns [0, prec-1]. */
4125 CASE_INT_FN (BUILT_IN_CLRSB):
4126 arg = gimple_call_arg (stmt, 0);
4127 prec = TYPE_PRECISION (TREE_TYPE (arg));
4132 set_value_range (vr, VR_RANGE, build_int_cst (type, mini),
4133 build_int_cst (type, maxi), NULL);
4139 else if (is_gimple_call (stmt) && gimple_call_internal_p (stmt))
4141 enum tree_code subcode = ERROR_MARK;
4142 switch (gimple_call_internal_fn (stmt))
4144 case IFN_UBSAN_CHECK_ADD:
4145 subcode = PLUS_EXPR;
4147 case IFN_UBSAN_CHECK_SUB:
4148 subcode = MINUS_EXPR;
4150 case IFN_UBSAN_CHECK_MUL:
4151 subcode = MULT_EXPR;
4156 if (subcode != ERROR_MARK)
4158 bool saved_flag_wrapv = flag_wrapv;
4159 /* Pretend the arithmetics is wrapping. If there is
4160 any overflow, we'll complain, but will actually do
4161 wrapping operation. */
4163 extract_range_from_binary_expr (vr, subcode, type,
4164 gimple_call_arg (stmt, 0),
4165 gimple_call_arg (stmt, 1));
4166 flag_wrapv = saved_flag_wrapv;
4168 /* If for both arguments vrp_valueize returned non-NULL,
4169 this should have been already folded and if not, it
4170 wasn't folded because of overflow. Avoid removing the
4171 UBSAN_CHECK_* calls in that case. */
4172 if (vr->type == VR_RANGE
4173 && (vr->min == vr->max
4174 || operand_equal_p (vr->min, vr->max, 0)))
4175 set_value_range_to_varying (vr);
4179 /* Handle extraction of the two results (result of arithmetics and
4180 a flag whether arithmetics overflowed) from {ADD,SUB,MUL}_OVERFLOW
4181 internal function. */
4182 else if (is_gimple_assign (stmt)
4183 && (gimple_assign_rhs_code (stmt) == REALPART_EXPR
4184 || gimple_assign_rhs_code (stmt) == IMAGPART_EXPR)
4185 && INTEGRAL_TYPE_P (type))
4187 enum tree_code code = gimple_assign_rhs_code (stmt);
4188 tree op = gimple_assign_rhs1 (stmt);
4189 if (TREE_CODE (op) == code && TREE_CODE (TREE_OPERAND (op, 0)) == SSA_NAME)
4191 gimple g = SSA_NAME_DEF_STMT (TREE_OPERAND (op, 0));
4192 if (is_gimple_call (g) && gimple_call_internal_p (g))
4194 enum tree_code subcode = ERROR_MARK;
4195 switch (gimple_call_internal_fn (g))
4197 case IFN_ADD_OVERFLOW:
4198 subcode = PLUS_EXPR;
4200 case IFN_SUB_OVERFLOW:
4201 subcode = MINUS_EXPR;
4203 case IFN_MUL_OVERFLOW:
4204 subcode = MULT_EXPR;
4209 if (subcode != ERROR_MARK)
4211 tree op0 = gimple_call_arg (g, 0);
4212 tree op1 = gimple_call_arg (g, 1);
4213 if (code == IMAGPART_EXPR)
4216 if (check_for_binary_op_overflow (subcode, type,
4218 set_value_range_to_value (vr,
4219 build_int_cst (type, ovf),
4222 set_value_range (vr, VR_RANGE, build_int_cst (type, 0),
4223 build_int_cst (type, 1), NULL);
4225 else if (types_compatible_p (type, TREE_TYPE (op0))
4226 && types_compatible_p (type, TREE_TYPE (op1)))
4228 bool saved_flag_wrapv = flag_wrapv;
4229 /* Pretend the arithmetics is wrapping. If there is
4230 any overflow, IMAGPART_EXPR will be set. */
4232 extract_range_from_binary_expr (vr, subcode, type,
4234 flag_wrapv = saved_flag_wrapv;
4238 value_range_t vr0 = VR_INITIALIZER;
4239 value_range_t vr1 = VR_INITIALIZER;
4240 bool saved_flag_wrapv = flag_wrapv;
4241 /* Pretend the arithmetics is wrapping. If there is
4242 any overflow, IMAGPART_EXPR will be set. */
4244 extract_range_from_unary_expr (&vr0, NOP_EXPR,
4246 extract_range_from_unary_expr (&vr1, NOP_EXPR,
4248 extract_range_from_binary_expr_1 (vr, subcode, type,
4250 flag_wrapv = saved_flag_wrapv;
4257 if (INTEGRAL_TYPE_P (type)
4258 && gimple_stmt_nonnegative_warnv_p (stmt, &sop))
4259 set_value_range_to_nonnegative (vr, type,
4260 sop || stmt_overflow_infinity (stmt));
4261 else if (vrp_stmt_computes_nonzero (stmt, &sop)
4263 set_value_range_to_nonnull (vr, type);
4265 set_value_range_to_varying (vr);
4269 /* Try to compute a useful range out of assignment STMT and store it
4273 extract_range_from_assignment (value_range_t *vr, gassign *stmt)
4275 enum tree_code code = gimple_assign_rhs_code (stmt);
4277 if (code == ASSERT_EXPR)
4278 extract_range_from_assert (vr, gimple_assign_rhs1 (stmt));
4279 else if (code == SSA_NAME)
4280 extract_range_from_ssa_name (vr, gimple_assign_rhs1 (stmt));
4281 else if (TREE_CODE_CLASS (code) == tcc_binary)
4282 extract_range_from_binary_expr (vr, gimple_assign_rhs_code (stmt),
4283 gimple_expr_type (stmt),
4284 gimple_assign_rhs1 (stmt),
4285 gimple_assign_rhs2 (stmt));
4286 else if (TREE_CODE_CLASS (code) == tcc_unary)
4287 extract_range_from_unary_expr (vr, gimple_assign_rhs_code (stmt),
4288 gimple_expr_type (stmt),
4289 gimple_assign_rhs1 (stmt));
4290 else if (code == COND_EXPR)
4291 extract_range_from_cond_expr (vr, stmt);
4292 else if (TREE_CODE_CLASS (code) == tcc_comparison)
4293 extract_range_from_comparison (vr, gimple_assign_rhs_code (stmt),
4294 gimple_expr_type (stmt),
4295 gimple_assign_rhs1 (stmt),
4296 gimple_assign_rhs2 (stmt));
4297 else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
4298 && is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
4299 set_value_range_to_value (vr, gimple_assign_rhs1 (stmt), NULL);
4301 set_value_range_to_varying (vr);
4303 if (vr->type == VR_VARYING)
4304 extract_range_basic (vr, stmt);
4307 /* Given a range VR, a LOOP and a variable VAR, determine whether it
4308 would be profitable to adjust VR using scalar evolution information
4309 for VAR. If so, update VR with the new limits. */
4312 adjust_range_with_scev (value_range_t *vr, struct loop *loop,
4313 gimple stmt, tree var)
4315 tree init, step, chrec, tmin, tmax, min, max, type, tem;
4316 enum ev_direction dir;
4318 /* TODO. Don't adjust anti-ranges. An anti-range may provide
4319 better opportunities than a regular range, but I'm not sure. */
4320 if (vr->type == VR_ANTI_RANGE)
4323 chrec = instantiate_parameters (loop, analyze_scalar_evolution (loop, var));
4325 /* Like in PR19590, scev can return a constant function. */
4326 if (is_gimple_min_invariant (chrec))
4328 set_value_range_to_value (vr, chrec, vr->equiv);
4332 if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
4335 init = initial_condition_in_loop_num (chrec, loop->num);
4336 tem = op_with_constant_singleton_value_range (init);
4339 step = evolution_part_in_loop_num (chrec, loop->num);
4340 tem = op_with_constant_singleton_value_range (step);
4344 /* If STEP is symbolic, we can't know whether INIT will be the
4345 minimum or maximum value in the range. Also, unless INIT is
4346 a simple expression, compare_values and possibly other functions
4347 in tree-vrp won't be able to handle it. */
4348 if (step == NULL_TREE
4349 || !is_gimple_min_invariant (step)
4350 || !valid_value_p (init))
4353 dir = scev_direction (chrec);
4354 if (/* Do not adjust ranges if we do not know whether the iv increases
4355 or decreases, ... */
4356 dir == EV_DIR_UNKNOWN
4357 /* ... or if it may wrap. */
4358 || scev_probably_wraps_p (init, step, stmt, get_chrec_loop (chrec),
4362 /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
4363 negative_overflow_infinity and positive_overflow_infinity,
4364 because we have concluded that the loop probably does not
4367 type = TREE_TYPE (var);
4368 if (POINTER_TYPE_P (type) || !TYPE_MIN_VALUE (type))
4369 tmin = lower_bound_in_type (type, type);
4371 tmin = TYPE_MIN_VALUE (type);
4372 if (POINTER_TYPE_P (type) || !TYPE_MAX_VALUE (type))
4373 tmax = upper_bound_in_type (type, type);
4375 tmax = TYPE_MAX_VALUE (type);
4377 /* Try to use estimated number of iterations for the loop to constrain the
4378 final value in the evolution. */
4379 if (TREE_CODE (step) == INTEGER_CST
4380 && is_gimple_val (init)
4381 && (TREE_CODE (init) != SSA_NAME
4382 || get_value_range (init)->type == VR_RANGE))
4386 /* We are only entering here for loop header PHI nodes, so using
4387 the number of latch executions is the correct thing to use. */
4388 if (max_loop_iterations (loop, &nit))
4390 value_range_t maxvr = VR_INITIALIZER;
4391 signop sgn = TYPE_SIGN (TREE_TYPE (step));
4394 widest_int wtmp = wi::mul (wi::to_widest (step), nit, sgn,
4396 /* If the multiplication overflowed we can't do a meaningful
4397 adjustment. Likewise if the result doesn't fit in the type
4398 of the induction variable. For a signed type we have to
4399 check whether the result has the expected signedness which
4400 is that of the step as number of iterations is unsigned. */
4402 && wi::fits_to_tree_p (wtmp, TREE_TYPE (init))
4404 || wi::gts_p (wtmp, 0) == wi::gts_p (step, 0)))
4406 tem = wide_int_to_tree (TREE_TYPE (init), wtmp);
4407 extract_range_from_binary_expr (&maxvr, PLUS_EXPR,
4408 TREE_TYPE (init), init, tem);
4409 /* Likewise if the addition did. */
4410 if (maxvr.type == VR_RANGE)
4419 if (vr->type == VR_VARYING || vr->type == VR_UNDEFINED)
4424 /* For VARYING or UNDEFINED ranges, just about anything we get
4425 from scalar evolutions should be better. */
4427 if (dir == EV_DIR_DECREASES)
4432 else if (vr->type == VR_RANGE)
4437 if (dir == EV_DIR_DECREASES)
4439 /* INIT is the maximum value. If INIT is lower than VR->MAX
4440 but no smaller than VR->MIN, set VR->MAX to INIT. */
4441 if (compare_values (init, max) == -1)
4444 /* According to the loop information, the variable does not
4445 overflow. If we think it does, probably because of an
4446 overflow due to arithmetic on a different INF value,
4448 if (is_negative_overflow_infinity (min)
4449 || compare_values (min, tmin) == -1)
4455 /* If INIT is bigger than VR->MIN, set VR->MIN to INIT. */
4456 if (compare_values (init, min) == 1)
4459 if (is_positive_overflow_infinity (max)
4460 || compare_values (tmax, max) == -1)
4467 /* If we just created an invalid range with the minimum
4468 greater than the maximum, we fail conservatively.
4469 This should happen only in unreachable
4470 parts of code, or for invalid programs. */
4471 if (compare_values (min, max) == 1
4472 || (is_negative_overflow_infinity (min)
4473 && is_positive_overflow_infinity (max)))
4476 set_value_range (vr, VR_RANGE, min, max, vr->equiv);
4480 /* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
4482 - Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for
4483 all the values in the ranges.
4485 - Return BOOLEAN_FALSE_NODE if the comparison always returns false.
4487 - Return NULL_TREE if it is not always possible to determine the
4488 value of the comparison.
4490 Also set *STRICT_OVERFLOW_P to indicate whether a range with an
4491 overflow infinity was used in the test. */
4495 compare_ranges (enum tree_code comp, value_range_t *vr0, value_range_t *vr1,
4496 bool *strict_overflow_p)
4498 /* VARYING or UNDEFINED ranges cannot be compared. */
4499 if (vr0->type == VR_VARYING
4500 || vr0->type == VR_UNDEFINED
4501 || vr1->type == VR_VARYING
4502 || vr1->type == VR_UNDEFINED)
4505 /* Anti-ranges need to be handled separately. */
4506 if (vr0->type == VR_ANTI_RANGE || vr1->type == VR_ANTI_RANGE)
4508 /* If both are anti-ranges, then we cannot compute any
4510 if (vr0->type == VR_ANTI_RANGE && vr1->type == VR_ANTI_RANGE)
4513 /* These comparisons are never statically computable. */
4520 /* Equality can be computed only between a range and an
4521 anti-range. ~[VAL1, VAL2] == [VAL1, VAL2] is always false. */
4522 if (vr0->type == VR_RANGE)
4524 /* To simplify processing, make VR0 the anti-range. */
4525 value_range_t *tmp = vr0;
4530 gcc_assert (comp == NE_EXPR || comp == EQ_EXPR);
4532 if (compare_values_warnv (vr0->min, vr1->min, strict_overflow_p) == 0
4533 && compare_values_warnv (vr0->max, vr1->max, strict_overflow_p) == 0)
4534 return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node;
4539 if (!usable_range_p (vr0, strict_overflow_p)
4540 || !usable_range_p (vr1, strict_overflow_p))
4543 /* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the
4544 operands around and change the comparison code. */
4545 if (comp == GT_EXPR || comp == GE_EXPR)
4547 comp = (comp == GT_EXPR) ? LT_EXPR : LE_EXPR;
4548 std::swap (vr0, vr1);
4551 if (comp == EQ_EXPR)
4553 /* Equality may only be computed if both ranges represent
4554 exactly one value. */
4555 if (compare_values_warnv (vr0->min, vr0->max, strict_overflow_p) == 0
4556 && compare_values_warnv (vr1->min, vr1->max, strict_overflow_p) == 0)
4558 int cmp_min = compare_values_warnv (vr0->min, vr1->min,
4560 int cmp_max = compare_values_warnv (vr0->max, vr1->max,
4562 if (cmp_min == 0 && cmp_max == 0)
4563 return boolean_true_node;
4564 else if (cmp_min != -2 && cmp_max != -2)
4565 return boolean_false_node;
4567 /* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */
4568 else if (compare_values_warnv (vr0->min, vr1->max,
4569 strict_overflow_p) == 1
4570 || compare_values_warnv (vr1->min, vr0->max,
4571 strict_overflow_p) == 1)
4572 return boolean_false_node;
4576 else if (comp == NE_EXPR)
4580 /* If VR0 is completely to the left or completely to the right
4581 of VR1, they are always different. Notice that we need to
4582 make sure that both comparisons yield similar results to
4583 avoid comparing values that cannot be compared at
4585 cmp1 = compare_values_warnv (vr0->max, vr1->min, strict_overflow_p);
4586 cmp2 = compare_values_warnv (vr0->min, vr1->max, strict_overflow_p);
4587 if ((cmp1 == -1 && cmp2 == -1) || (cmp1 == 1 && cmp2 == 1))
4588 return boolean_true_node;
4590 /* If VR0 and VR1 represent a single value and are identical,
4592 else if (compare_values_warnv (vr0->min, vr0->max,
4593 strict_overflow_p) == 0
4594 && compare_values_warnv (vr1->min, vr1->max,
4595 strict_overflow_p) == 0
4596 && compare_values_warnv (vr0->min, vr1->min,
4597 strict_overflow_p) == 0
4598 && compare_values_warnv (vr0->max, vr1->max,
4599 strict_overflow_p) == 0)
4600 return boolean_false_node;
4602 /* Otherwise, they may or may not be different. */
4606 else if (comp == LT_EXPR || comp == LE_EXPR)
4610 /* If VR0 is to the left of VR1, return true. */
4611 tst = compare_values_warnv (vr0->max, vr1->min, strict_overflow_p);
4612 if ((comp == LT_EXPR && tst == -1)
4613 || (comp == LE_EXPR && (tst == -1 || tst == 0)))
4615 if (overflow_infinity_range_p (vr0)
4616 || overflow_infinity_range_p (vr1))
4617 *strict_overflow_p = true;
4618 return boolean_true_node;
4621 /* If VR0 is to the right of VR1, return false. */
4622 tst = compare_values_warnv (vr0->min, vr1->max, strict_overflow_p);
4623 if ((comp == LT_EXPR && (tst == 0 || tst == 1))
4624 || (comp == LE_EXPR && tst == 1))
4626 if (overflow_infinity_range_p (vr0)
4627 || overflow_infinity_range_p (vr1))
4628 *strict_overflow_p = true;
4629 return boolean_false_node;
4632 /* Otherwise, we don't know. */
4640 /* Given a value range VR, a value VAL and a comparison code COMP, return
4641 BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
4642 values in VR. Return BOOLEAN_FALSE_NODE if the comparison
4643 always returns false. Return NULL_TREE if it is not always
4644 possible to determine the value of the comparison. Also set
4645 *STRICT_OVERFLOW_P to indicate whether a range with an overflow
4646 infinity was used in the test. */
4649 compare_range_with_value (enum tree_code comp, value_range_t *vr, tree val,
4650 bool *strict_overflow_p)
4652 if (vr->type == VR_VARYING || vr->type == VR_UNDEFINED)
4655 /* Anti-ranges need to be handled separately. */
4656 if (vr->type == VR_ANTI_RANGE)
4658 /* For anti-ranges, the only predicates that we can compute at
4659 compile time are equality and inequality. */
4666 /* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */
4667 if (value_inside_range (val, vr->min, vr->max) == 1)
4668 return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node;
4673 if (!usable_range_p (vr, strict_overflow_p))
4676 if (comp == EQ_EXPR)
4678 /* EQ_EXPR may only be computed if VR represents exactly
4680 if (compare_values_warnv (vr->min, vr->max, strict_overflow_p) == 0)
4682 int cmp = compare_values_warnv (vr->min, val, strict_overflow_p);
4684 return boolean_true_node;
4685 else if (cmp == -1 || cmp == 1 || cmp == 2)
4686 return boolean_false_node;
4688 else if (compare_values_warnv (val, vr->min, strict_overflow_p) == -1
4689 || compare_values_warnv (vr->max, val, strict_overflow_p) == -1)
4690 return boolean_false_node;
4694 else if (comp == NE_EXPR)
4696 /* If VAL is not inside VR, then they are always different. */
4697 if (compare_values_warnv (vr->max, val, strict_overflow_p) == -1
4698 || compare_values_warnv (vr->min, val, strict_overflow_p) == 1)
4699 return boolean_true_node;
4701 /* If VR represents exactly one value equal to VAL, then return
4703 if (compare_values_warnv (vr->min, vr->max, strict_overflow_p) == 0
4704 && compare_values_warnv (vr->min, val, strict_overflow_p) == 0)
4705 return boolean_false_node;
4707 /* Otherwise, they may or may not be different. */
4710 else if (comp == LT_EXPR || comp == LE_EXPR)
4714 /* If VR is to the left of VAL, return true. */
4715 tst = compare_values_warnv (vr->max, val, strict_overflow_p);
4716 if ((comp == LT_EXPR && tst == -1)
4717 || (comp == LE_EXPR && (tst == -1 || tst == 0)))
4719 if (overflow_infinity_range_p (vr))
4720 *strict_overflow_p = true;
4721 return boolean_true_node;
4724 /* If VR is to the right of VAL, return false. */
4725 tst = compare_values_warnv (vr->min, val, strict_overflow_p);
4726 if ((comp == LT_EXPR && (tst == 0 || tst == 1))
4727 || (comp == LE_EXPR && tst == 1))
4729 if (overflow_infinity_range_p (vr))
4730 *strict_overflow_p = true;
4731 return boolean_false_node;
4734 /* Otherwise, we don't know. */
4737 else if (comp == GT_EXPR || comp == GE_EXPR)
4741 /* If VR is to the right of VAL, return true. */
4742 tst = compare_values_warnv (vr->min, val, strict_overflow_p);
4743 if ((comp == GT_EXPR && tst == 1)
4744 || (comp == GE_EXPR && (tst == 0 || tst == 1)))
4746 if (overflow_infinity_range_p (vr))
4747 *strict_overflow_p = true;
4748 return boolean_true_node;
4751 /* If VR is to the left of VAL, return false. */
4752 tst = compare_values_warnv (vr->max, val, strict_overflow_p);
4753 if ((comp == GT_EXPR && (tst == -1 || tst == 0))
4754 || (comp == GE_EXPR && tst == -1))
4756 if (overflow_infinity_range_p (vr))
4757 *strict_overflow_p = true;
4758 return boolean_false_node;
4761 /* Otherwise, we don't know. */
4769 /* Debugging dumps. */
4771 void dump_value_range (FILE *, value_range_t *);
4772 void debug_value_range (value_range_t *);
4773 void dump_all_value_ranges (FILE *);
4774 void debug_all_value_ranges (void);
4775 void dump_vr_equiv (FILE *, bitmap);
4776 void debug_vr_equiv (bitmap);
4779 /* Dump value range VR to FILE. */
4782 dump_value_range (FILE *file, value_range_t *vr)
4785 fprintf (file, "[]");
4786 else if (vr->type == VR_UNDEFINED)
4787 fprintf (file, "UNDEFINED");
4788 else if (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE)
4790 tree type = TREE_TYPE (vr->min);
4792 fprintf (file, "%s[", (vr->type == VR_ANTI_RANGE) ? "~" : "");
4794 if (is_negative_overflow_infinity (vr->min))
4795 fprintf (file, "-INF(OVF)");
4796 else if (INTEGRAL_TYPE_P (type)
4797 && !TYPE_UNSIGNED (type)
4798 && vrp_val_is_min (vr->min))
4799 fprintf (file, "-INF");
4801 print_generic_expr (file, vr->min, 0);
4803 fprintf (file, ", ");
4805 if (is_positive_overflow_infinity (vr->max))
4806 fprintf (file, "+INF(OVF)");
4807 else if (INTEGRAL_TYPE_P (type)
4808 && vrp_val_is_max (vr->max))
4809 fprintf (file, "+INF");
4811 print_generic_expr (file, vr->max, 0);
4813 fprintf (file, "]");
4820 fprintf (file, " EQUIVALENCES: { ");
4822 EXECUTE_IF_SET_IN_BITMAP (vr->equiv, 0, i, bi)
4824 print_generic_expr (file, ssa_name (i), 0);
4825 fprintf (file, " ");
4829 fprintf (file, "} (%u elements)", c);
4832 else if (vr->type == VR_VARYING)
4833 fprintf (file, "VARYING");
4835 fprintf (file, "INVALID RANGE");
4839 /* Dump value range VR to stderr. */
4842 debug_value_range (value_range_t *vr)
4844 dump_value_range (stderr, vr);
4845 fprintf (stderr, "\n");
4849 /* Dump value ranges of all SSA_NAMEs to FILE. */
4852 dump_all_value_ranges (FILE *file)
4856 for (i = 0; i < num_vr_values; i++)
4860 print_generic_expr (file, ssa_name (i), 0);
4861 fprintf (file, ": ");
4862 dump_value_range (file, vr_value[i]);
4863 fprintf (file, "\n");
4867 fprintf (file, "\n");
4871 /* Dump all value ranges to stderr. */
4874 debug_all_value_ranges (void)
4876 dump_all_value_ranges (stderr);
4880 /* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
4881 create a new SSA name N and return the assertion assignment
4882 'N = ASSERT_EXPR <V, V OP W>'. */
4885 build_assert_expr_for (tree cond, tree v)
4890 gcc_assert (TREE_CODE (v) == SSA_NAME
4891 && COMPARISON_CLASS_P (cond));
4893 a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond);
4894 assertion = gimple_build_assign (NULL_TREE, a);
4896 /* The new ASSERT_EXPR, creates a new SSA name that replaces the
4897 operand of the ASSERT_EXPR. Create it so the new name and the old one
4898 are registered in the replacement table so that we can fix the SSA web
4899 after adding all the ASSERT_EXPRs. */
4900 create_new_def_for (v, assertion, NULL);
4906 /* Return false if EXPR is a predicate expression involving floating
4910 fp_predicate (gimple stmt)
4912 GIMPLE_CHECK (stmt, GIMPLE_COND);
4914 return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt)));
4917 /* If the range of values taken by OP can be inferred after STMT executes,
4918 return the comparison code (COMP_CODE_P) and value (VAL_P) that
4919 describes the inferred range. Return true if a range could be
4923 infer_value_range (gimple stmt, tree op, enum tree_code *comp_code_p, tree *val_p)
4926 *comp_code_p = ERROR_MARK;
4928 /* Do not attempt to infer anything in names that flow through
4930 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op))
4933 /* Similarly, don't infer anything from statements that may throw
4934 exceptions. ??? Relax this requirement? */
4935 if (stmt_could_throw_p (stmt))
4938 /* If STMT is the last statement of a basic block with no normal
4939 successors, there is no point inferring anything about any of its
4940 operands. We would not be able to find a proper insertion point
4941 for the assertion, anyway. */
4942 if (stmt_ends_bb_p (stmt))
4947 FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->succs)
4948 if (!(e->flags & EDGE_ABNORMAL))
4954 if (infer_nonnull_range (stmt, op, true, true))
4956 *val_p = build_int_cst (TREE_TYPE (op), 0);
4957 *comp_code_p = NE_EXPR;
4965 void dump_asserts_for (FILE *, tree);
4966 void debug_asserts_for (tree);
4967 void dump_all_asserts (FILE *);
4968 void debug_all_asserts (void);
4970 /* Dump all the registered assertions for NAME to FILE. */
4973 dump_asserts_for (FILE *file, tree name)
4977 fprintf (file, "Assertions to be inserted for ");
4978 print_generic_expr (file, name, 0);
4979 fprintf (file, "\n");
4981 loc = asserts_for[SSA_NAME_VERSION (name)];
4984 fprintf (file, "\t");
4985 print_gimple_stmt (file, gsi_stmt (loc->si), 0, 0);
4986 fprintf (file, "\n\tBB #%d", loc->bb->index);
4989 fprintf (file, "\n\tEDGE %d->%d", loc->e->src->index,
4990 loc->e->dest->index);
4991 dump_edge_info (file, loc->e, dump_flags, 0);
4993 fprintf (file, "\n\tPREDICATE: ");
4994 print_generic_expr (file, name, 0);
4995 fprintf (file, " %s ", get_tree_code_name (loc->comp_code));
4996 print_generic_expr (file, loc->val, 0);
4997 fprintf (file, "\n\n");
5001 fprintf (file, "\n");
5005 /* Dump all the registered assertions for NAME to stderr. */
5008 debug_asserts_for (tree name)
5010 dump_asserts_for (stderr, name);
5014 /* Dump all the registered assertions for all the names to FILE. */
5017 dump_all_asserts (FILE *file)
5022 fprintf (file, "\nASSERT_EXPRs to be inserted\n\n");
5023 EXECUTE_IF_SET_IN_BITMAP (need_assert_for, 0, i, bi)
5024 dump_asserts_for (file, ssa_name (i));
5025 fprintf (file, "\n");
5029 /* Dump all the registered assertions for all the names to stderr. */
5032 debug_all_asserts (void)
5034 dump_all_asserts (stderr);
5038 /* If NAME doesn't have an ASSERT_EXPR registered for asserting
5039 'EXPR COMP_CODE VAL' at a location that dominates block BB or
5040 E->DEST, then register this location as a possible insertion point
5041 for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>.
5043 BB, E and SI provide the exact insertion point for the new
5044 ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted
5045 on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on
5046 BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E
5047 must not be NULL. */
5050 register_new_assert_for (tree name, tree expr,
5051 enum tree_code comp_code,
5055 gimple_stmt_iterator si)
5057 assert_locus_t n, loc, last_loc;
5058 basic_block dest_bb;
5060 gcc_checking_assert (bb == NULL || e == NULL);
5063 gcc_checking_assert (gimple_code (gsi_stmt (si)) != GIMPLE_COND
5064 && gimple_code (gsi_stmt (si)) != GIMPLE_SWITCH);
5066 /* Never build an assert comparing against an integer constant with
5067 TREE_OVERFLOW set. This confuses our undefined overflow warning
5069 if (TREE_OVERFLOW_P (val))
5070 val = drop_tree_overflow (val);
5072 /* The new assertion A will be inserted at BB or E. We need to
5073 determine if the new location is dominated by a previously
5074 registered location for A. If we are doing an edge insertion,
5075 assume that A will be inserted at E->DEST. Note that this is not
5078 If E is a critical edge, it will be split. But even if E is
5079 split, the new block will dominate the same set of blocks that
5082 The reverse, however, is not true, blocks dominated by E->DEST
5083 will not be dominated by the new block created to split E. So,
5084 if the insertion location is on a critical edge, we will not use
5085 the new location to move another assertion previously registered
5086 at a block dominated by E->DEST. */
5087 dest_bb = (bb) ? bb : e->dest;
5089 /* If NAME already has an ASSERT_EXPR registered for COMP_CODE and
5090 VAL at a block dominating DEST_BB, then we don't need to insert a new
5091 one. Similarly, if the same assertion already exists at a block
5092 dominated by DEST_BB and the new location is not on a critical
5093 edge, then update the existing location for the assertion (i.e.,
5094 move the assertion up in the dominance tree).
5096 Note, this is implemented as a simple linked list because there
5097 should not be more than a handful of assertions registered per
5098 name. If this becomes a performance problem, a table hashed by
5099 COMP_CODE and VAL could be implemented. */
5100 loc = asserts_for[SSA_NAME_VERSION (name)];
5104 if (loc->comp_code == comp_code
5106 || operand_equal_p (loc->val, val, 0))
5107 && (loc->expr == expr
5108 || operand_equal_p (loc->expr, expr, 0)))
5110 /* If E is not a critical edge and DEST_BB
5111 dominates the existing location for the assertion, move
5112 the assertion up in the dominance tree by updating its
5113 location information. */
5114 if ((e == NULL || !EDGE_CRITICAL_P (e))
5115 && dominated_by_p (CDI_DOMINATORS, loc->bb, dest_bb))
5124 /* Update the last node of the list and move to the next one. */
5129 /* If we didn't find an assertion already registered for
5130 NAME COMP_CODE VAL, add a new one at the end of the list of
5131 assertions associated with NAME. */
5132 n = XNEW (struct assert_locus_d);
5136 n->comp_code = comp_code;
5144 asserts_for[SSA_NAME_VERSION (name)] = n;
5146 bitmap_set_bit (need_assert_for, SSA_NAME_VERSION (name));
5149 /* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME.
5150 Extract a suitable test code and value and store them into *CODE_P and
5151 *VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P.
5153 If no extraction was possible, return FALSE, otherwise return TRUE.
5155 If INVERT is true, then we invert the result stored into *CODE_P. */
5158 extract_code_and_val_from_cond_with_ops (tree name, enum tree_code cond_code,
5159 tree cond_op0, tree cond_op1,
5160 bool invert, enum tree_code *code_p,
5163 enum tree_code comp_code;
5166 /* Otherwise, we have a comparison of the form NAME COMP VAL
5167 or VAL COMP NAME. */
5168 if (name == cond_op1)
5170 /* If the predicate is of the form VAL COMP NAME, flip
5171 COMP around because we need to register NAME as the
5172 first operand in the predicate. */
5173 comp_code = swap_tree_comparison (cond_code);
5178 /* The comparison is of the form NAME COMP VAL, so the
5179 comparison code remains unchanged. */
5180 comp_code = cond_code;
5184 /* Invert the comparison code as necessary. */
5186 comp_code = invert_tree_comparison (comp_code, 0);
5188 /* VRP does not handle float types. */
5189 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (val)))
5192 /* Do not register always-false predicates.
5193 FIXME: this works around a limitation in fold() when dealing with
5194 enumerations. Given 'enum { N1, N2 } x;', fold will not
5195 fold 'if (x > N2)' to 'if (0)'. */
5196 if ((comp_code == GT_EXPR || comp_code == LT_EXPR)
5197 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
5199 tree min = TYPE_MIN_VALUE (TREE_TYPE (val));
5200 tree max = TYPE_MAX_VALUE (TREE_TYPE (val));
5202 if (comp_code == GT_EXPR
5204 || compare_values (val, max) == 0))
5207 if (comp_code == LT_EXPR
5209 || compare_values (val, min) == 0))
5212 *code_p = comp_code;
5217 /* Find out smallest RES where RES > VAL && (RES & MASK) == RES, if any
5218 (otherwise return VAL). VAL and MASK must be zero-extended for
5219 precision PREC. If SGNBIT is non-zero, first xor VAL with SGNBIT
5220 (to transform signed values into unsigned) and at the end xor
5224 masked_increment (const wide_int &val_in, const wide_int &mask,
5225 const wide_int &sgnbit, unsigned int prec)
5227 wide_int bit = wi::one (prec), res;
5230 wide_int val = val_in ^ sgnbit;
5231 for (i = 0; i < prec; i++, bit += bit)
5234 if ((res & bit) == 0)
5237 res = (val + bit).and_not (res);
5239 if (wi::gtu_p (res, val))
5240 return res ^ sgnbit;
5242 return val ^ sgnbit;
5245 /* Try to register an edge assertion for SSA name NAME on edge E for
5246 the condition COND contributing to the conditional jump pointed to by BSI.
5247 Invert the condition COND if INVERT is true. */
5250 register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
5251 enum tree_code cond_code,
5252 tree cond_op0, tree cond_op1, bool invert)
5255 enum tree_code comp_code;
5257 if (!extract_code_and_val_from_cond_with_ops (name, cond_code,
5260 invert, &comp_code, &val))
5263 /* Only register an ASSERT_EXPR if NAME was found in the sub-graph
5264 reachable from E. */
5265 if (live_on_edge (e, name)
5266 && !has_single_use (name))
5267 register_new_assert_for (name, name, comp_code, val, NULL, e, bsi);
5269 /* In the case of NAME <= CST and NAME being defined as
5270 NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2
5271 and NAME2 <= CST - CST2. We can do the same for NAME > CST.
5272 This catches range and anti-range tests. */
5273 if ((comp_code == LE_EXPR
5274 || comp_code == GT_EXPR)
5275 && TREE_CODE (val) == INTEGER_CST
5276 && TYPE_UNSIGNED (TREE_TYPE (val)))
5278 gimple def_stmt = SSA_NAME_DEF_STMT (name);
5279 tree cst2 = NULL_TREE, name2 = NULL_TREE, name3 = NULL_TREE;
5281 /* Extract CST2 from the (optional) addition. */
5282 if (is_gimple_assign (def_stmt)
5283 && gimple_assign_rhs_code (def_stmt) == PLUS_EXPR)
5285 name2 = gimple_assign_rhs1 (def_stmt);
5286 cst2 = gimple_assign_rhs2 (def_stmt);
5287 if (TREE_CODE (name2) == SSA_NAME
5288 && TREE_CODE (cst2) == INTEGER_CST)
5289 def_stmt = SSA_NAME_DEF_STMT (name2);
5292 /* Extract NAME2 from the (optional) sign-changing cast. */
5293 if (gimple_assign_cast_p (def_stmt))
5295 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))
5296 && ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))
5297 && (TYPE_PRECISION (gimple_expr_type (def_stmt))
5298 == TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))))
5299 name3 = gimple_assign_rhs1 (def_stmt);
5302 /* If name3 is used later, create an ASSERT_EXPR for it. */
5303 if (name3 != NULL_TREE
5304 && TREE_CODE (name3) == SSA_NAME
5305 && (cst2 == NULL_TREE
5306 || TREE_CODE (cst2) == INTEGER_CST)
5307 && INTEGRAL_TYPE_P (TREE_TYPE (name3))
5308 && live_on_edge (e, name3)
5309 && !has_single_use (name3))
5313 /* Build an expression for the range test. */
5314 tmp = build1 (NOP_EXPR, TREE_TYPE (name), name3);
5315 if (cst2 != NULL_TREE)
5316 tmp = build2 (PLUS_EXPR, TREE_TYPE (name), tmp, cst2);
5320 fprintf (dump_file, "Adding assert for ");
5321 print_generic_expr (dump_file, name3, 0);
5322 fprintf (dump_file, " from ");
5323 print_generic_expr (dump_file, tmp, 0);
5324 fprintf (dump_file, "\n");
5327 register_new_assert_for (name3, tmp, comp_code, val, NULL, e, bsi);
5330 /* If name2 is used later, create an ASSERT_EXPR for it. */
5331 if (name2 != NULL_TREE
5332 && TREE_CODE (name2) == SSA_NAME
5333 && TREE_CODE (cst2) == INTEGER_CST
5334 && INTEGRAL_TYPE_P (TREE_TYPE (name2))
5335 && live_on_edge (e, name2)
5336 && !has_single_use (name2))
5340 /* Build an expression for the range test. */
5342 if (TREE_TYPE (name) != TREE_TYPE (name2))
5343 tmp = build1 (NOP_EXPR, TREE_TYPE (name), tmp);
5344 if (cst2 != NULL_TREE)
5345 tmp = build2 (PLUS_EXPR, TREE_TYPE (name), tmp, cst2);
5349 fprintf (dump_file, "Adding assert for ");
5350 print_generic_expr (dump_file, name2, 0);
5351 fprintf (dump_file, " from ");
5352 print_generic_expr (dump_file, tmp, 0);
5353 fprintf (dump_file, "\n");
5356 register_new_assert_for (name2, tmp, comp_code, val, NULL, e, bsi);
5360 /* In the case of post-in/decrement tests like if (i++) ... and uses
5361 of the in/decremented value on the edge the extra name we want to
5362 assert for is not on the def chain of the name compared. Instead
5363 it is in the set of use stmts. */
5364 if ((comp_code == NE_EXPR
5365 || comp_code == EQ_EXPR)
5366 && TREE_CODE (val) == INTEGER_CST)
5368 imm_use_iterator ui;
5370 FOR_EACH_IMM_USE_STMT (use_stmt, ui, name)
5372 /* Cut off to use-stmts that are in the predecessor. */
5373 if (gimple_bb (use_stmt) != e->src)
5376 if (!is_gimple_assign (use_stmt))
5379 enum tree_code code = gimple_assign_rhs_code (use_stmt);
5380 if (code != PLUS_EXPR
5381 && code != MINUS_EXPR)
5384 tree cst = gimple_assign_rhs2 (use_stmt);
5385 if (TREE_CODE (cst) != INTEGER_CST)
5388 tree name2 = gimple_assign_lhs (use_stmt);
5389 if (live_on_edge (e, name2))
5391 cst = int_const_binop (code, val, cst);
5392 register_new_assert_for (name2, name2, comp_code, cst,
5398 if (TREE_CODE_CLASS (comp_code) == tcc_comparison
5399 && TREE_CODE (val) == INTEGER_CST)
5401 gimple def_stmt = SSA_NAME_DEF_STMT (name);
5402 tree name2 = NULL_TREE, names[2], cst2 = NULL_TREE;
5403 tree val2 = NULL_TREE;
5404 unsigned int prec = TYPE_PRECISION (TREE_TYPE (val));
5405 wide_int mask = wi::zero (prec);
5406 unsigned int nprec = prec;
5407 enum tree_code rhs_code = ERROR_MARK;
5409 if (is_gimple_assign (def_stmt))
5410 rhs_code = gimple_assign_rhs_code (def_stmt);
5412 /* Add asserts for NAME cmp CST and NAME being defined
5413 as NAME = (int) NAME2. */
5414 if (!TYPE_UNSIGNED (TREE_TYPE (val))
5415 && (comp_code == LE_EXPR || comp_code == LT_EXPR
5416 || comp_code == GT_EXPR || comp_code == GE_EXPR)
5417 && gimple_assign_cast_p (def_stmt))
5419 name2 = gimple_assign_rhs1 (def_stmt);
5420 if (CONVERT_EXPR_CODE_P (rhs_code)
5421 && INTEGRAL_TYPE_P (TREE_TYPE (name2))
5422 && TYPE_UNSIGNED (TREE_TYPE (name2))
5423 && prec == TYPE_PRECISION (TREE_TYPE (name2))
5424 && (comp_code == LE_EXPR || comp_code == GT_EXPR
5425 || !tree_int_cst_equal (val,
5426 TYPE_MIN_VALUE (TREE_TYPE (val))))
5427 && live_on_edge (e, name2)
5428 && !has_single_use (name2))
5431 enum tree_code new_comp_code = comp_code;
5433 cst = fold_convert (TREE_TYPE (name2),
5434 TYPE_MIN_VALUE (TREE_TYPE (val)));
5435 /* Build an expression for the range test. */
5436 tmp = build2 (PLUS_EXPR, TREE_TYPE (name2), name2, cst);
5437 cst = fold_build2 (PLUS_EXPR, TREE_TYPE (name2), cst,
5438 fold_convert (TREE_TYPE (name2), val));
5439 if (comp_code == LT_EXPR || comp_code == GE_EXPR)
5441 new_comp_code = comp_code == LT_EXPR ? LE_EXPR : GT_EXPR;
5442 cst = fold_build2 (MINUS_EXPR, TREE_TYPE (name2), cst,
5443 build_int_cst (TREE_TYPE (name2), 1));
5448 fprintf (dump_file, "Adding assert for ");
5449 print_generic_expr (dump_file, name2, 0);
5450 fprintf (dump_file, " from ");
5451 print_generic_expr (dump_file, tmp, 0);
5452 fprintf (dump_file, "\n");
5455 register_new_assert_for (name2, tmp, new_comp_code, cst, NULL,
5460 /* Add asserts for NAME cmp CST and NAME being defined as
5461 NAME = NAME2 >> CST2.
5463 Extract CST2 from the right shift. */
5464 if (rhs_code == RSHIFT_EXPR)
5466 name2 = gimple_assign_rhs1 (def_stmt);
5467 cst2 = gimple_assign_rhs2 (def_stmt);
5468 if (TREE_CODE (name2) == SSA_NAME
5469 && tree_fits_uhwi_p (cst2)
5470 && INTEGRAL_TYPE_P (TREE_TYPE (name2))
5471 && IN_RANGE (tree_to_uhwi (cst2), 1, prec - 1)
5472 && prec == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (val)))
5473 && live_on_edge (e, name2)
5474 && !has_single_use (name2))
5476 mask = wi::mask (tree_to_uhwi (cst2), false, prec);
5477 val2 = fold_binary (LSHIFT_EXPR, TREE_TYPE (val), val, cst2);
5480 if (val2 != NULL_TREE
5481 && TREE_CODE (val2) == INTEGER_CST
5482 && simple_cst_equal (fold_build2 (RSHIFT_EXPR,
5486 enum tree_code new_comp_code = comp_code;
5490 if (comp_code == EQ_EXPR || comp_code == NE_EXPR)
5492 if (!TYPE_UNSIGNED (TREE_TYPE (val)))
5494 tree type = build_nonstandard_integer_type (prec, 1);
5495 tmp = build1 (NOP_EXPR, type, name2);
5496 val2 = fold_convert (type, val2);
5498 tmp = fold_build2 (MINUS_EXPR, TREE_TYPE (tmp), tmp, val2);
5499 new_val = wide_int_to_tree (TREE_TYPE (tmp), mask);
5500 new_comp_code = comp_code == EQ_EXPR ? LE_EXPR : GT_EXPR;
5502 else if (comp_code == LT_EXPR || comp_code == GE_EXPR)
5505 = wi::min_value (prec, TYPE_SIGN (TREE_TYPE (val)));
5507 if (minval == new_val)
5508 new_val = NULL_TREE;
5513 = wi::max_value (prec, TYPE_SIGN (TREE_TYPE (val)));
5516 new_val = NULL_TREE;
5518 new_val = wide_int_to_tree (TREE_TYPE (val2), mask);
5525 fprintf (dump_file, "Adding assert for ");
5526 print_generic_expr (dump_file, name2, 0);
5527 fprintf (dump_file, " from ");
5528 print_generic_expr (dump_file, tmp, 0);
5529 fprintf (dump_file, "\n");
5532 register_new_assert_for (name2, tmp, new_comp_code, new_val,
5537 /* Add asserts for NAME cmp CST and NAME being defined as
5538 NAME = NAME2 & CST2.
5540 Extract CST2 from the and.
5543 NAME = (unsigned) NAME2;
5544 casts where NAME's type is unsigned and has smaller precision
5545 than NAME2's type as if it was NAME = NAME2 & MASK. */
5546 names[0] = NULL_TREE;
5547 names[1] = NULL_TREE;
5549 if (rhs_code == BIT_AND_EXPR
5550 || (CONVERT_EXPR_CODE_P (rhs_code)
5551 && TREE_CODE (TREE_TYPE (val)) == INTEGER_TYPE
5552 && TYPE_UNSIGNED (TREE_TYPE (val))
5553 && TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))
5556 name2 = gimple_assign_rhs1 (def_stmt);
5557 if (rhs_code == BIT_AND_EXPR)
5558 cst2 = gimple_assign_rhs2 (def_stmt);
5561 cst2 = TYPE_MAX_VALUE (TREE_TYPE (val));
5562 nprec = TYPE_PRECISION (TREE_TYPE (name2));
5564 if (TREE_CODE (name2) == SSA_NAME
5565 && INTEGRAL_TYPE_P (TREE_TYPE (name2))
5566 && TREE_CODE (cst2) == INTEGER_CST
5567 && !integer_zerop (cst2)
5569 || TYPE_UNSIGNED (TREE_TYPE (val))))
5571 gimple def_stmt2 = SSA_NAME_DEF_STMT (name2);
5572 if (gimple_assign_cast_p (def_stmt2))
5574 names[1] = gimple_assign_rhs1 (def_stmt2);
5575 if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt2))
5576 || !INTEGRAL_TYPE_P (TREE_TYPE (names[1]))
5577 || (TYPE_PRECISION (TREE_TYPE (name2))
5578 != TYPE_PRECISION (TREE_TYPE (names[1])))
5579 || !live_on_edge (e, names[1])
5580 || has_single_use (names[1]))
5581 names[1] = NULL_TREE;
5583 if (live_on_edge (e, name2)
5584 && !has_single_use (name2))
5588 if (names[0] || names[1])
5590 wide_int minv, maxv, valv, cst2v;
5591 wide_int tem, sgnbit;
5592 bool valid_p = false, valn, cst2n;
5593 enum tree_code ccode = comp_code;
5595 valv = wide_int::from (val, nprec, UNSIGNED);
5596 cst2v = wide_int::from (cst2, nprec, UNSIGNED);
5597 valn = wi::neg_p (valv, TYPE_SIGN (TREE_TYPE (val)));
5598 cst2n = wi::neg_p (cst2v, TYPE_SIGN (TREE_TYPE (val)));
5599 /* If CST2 doesn't have most significant bit set,
5600 but VAL is negative, we have comparison like
5601 if ((x & 0x123) > -4) (always true). Just give up. */
5605 sgnbit = wi::set_bit_in_zero (nprec - 1, nprec);
5607 sgnbit = wi::zero (nprec);
5608 minv = valv & cst2v;
5612 /* Minimum unsigned value for equality is VAL & CST2
5613 (should be equal to VAL, otherwise we probably should
5614 have folded the comparison into false) and
5615 maximum unsigned value is VAL | ~CST2. */
5616 maxv = valv | ~cst2v;
5621 tem = valv | ~cst2v;
5622 /* If VAL is 0, handle (X & CST2) != 0 as (X & CST2) > 0U. */
5626 sgnbit = wi::zero (nprec);
5629 /* If (VAL | ~CST2) is all ones, handle it as
5630 (X & CST2) < VAL. */
5635 sgnbit = wi::zero (nprec);
5638 if (!cst2n && wi::neg_p (cst2v))
5639 sgnbit = wi::set_bit_in_zero (nprec - 1, nprec);
5648 if (tem == wi::mask (nprec - 1, false, nprec))
5654 sgnbit = wi::zero (nprec);
5659 /* Minimum unsigned value for >= if (VAL & CST2) == VAL
5660 is VAL and maximum unsigned value is ~0. For signed
5661 comparison, if CST2 doesn't have most significant bit
5662 set, handle it similarly. If CST2 has MSB set,
5663 the minimum is the same, and maximum is ~0U/2. */
5666 /* If (VAL & CST2) != VAL, X & CST2 can't be equal to
5668 minv = masked_increment (valv, cst2v, sgnbit, nprec);
5672 maxv = wi::mask (nprec - (cst2n ? 1 : 0), false, nprec);
5678 /* Find out smallest MINV where MINV > VAL
5679 && (MINV & CST2) == MINV, if any. If VAL is signed and
5680 CST2 has MSB set, compute it biased by 1 << (nprec - 1). */
5681 minv = masked_increment (valv, cst2v, sgnbit, nprec);
5684 maxv = wi::mask (nprec - (cst2n ? 1 : 0), false, nprec);
5689 /* Minimum unsigned value for <= is 0 and maximum
5690 unsigned value is VAL | ~CST2 if (VAL & CST2) == VAL.
5691 Otherwise, find smallest VAL2 where VAL2 > VAL
5692 && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
5694 For signed comparison, if CST2 doesn't have most
5695 significant bit set, handle it similarly. If CST2 has
5696 MSB set, the maximum is the same and minimum is INT_MIN. */
5701 maxv = masked_increment (valv, cst2v, sgnbit, nprec);
5713 /* Minimum unsigned value for < is 0 and maximum
5714 unsigned value is (VAL-1) | ~CST2 if (VAL & CST2) == VAL.
5715 Otherwise, find smallest VAL2 where VAL2 > VAL
5716 && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
5718 For signed comparison, if CST2 doesn't have most
5719 significant bit set, handle it similarly. If CST2 has
5720 MSB set, the maximum is the same and minimum is INT_MIN. */
5729 maxv = masked_increment (valv, cst2v, sgnbit, nprec);
5743 && (maxv - minv) != -1)
5745 tree tmp, new_val, type;
5748 for (i = 0; i < 2; i++)
5751 wide_int maxv2 = maxv;
5753 type = TREE_TYPE (names[i]);
5754 if (!TYPE_UNSIGNED (type))
5756 type = build_nonstandard_integer_type (nprec, 1);
5757 tmp = build1 (NOP_EXPR, type, names[i]);
5761 tmp = build2 (PLUS_EXPR, type, tmp,
5762 wide_int_to_tree (type, -minv));
5763 maxv2 = maxv - minv;
5765 new_val = wide_int_to_tree (type, maxv2);
5769 fprintf (dump_file, "Adding assert for ");
5770 print_generic_expr (dump_file, names[i], 0);
5771 fprintf (dump_file, " from ");
5772 print_generic_expr (dump_file, tmp, 0);
5773 fprintf (dump_file, "\n");
5776 register_new_assert_for (names[i], tmp, LE_EXPR,
5777 new_val, NULL, e, bsi);
5784 /* OP is an operand of a truth value expression which is known to have
5785 a particular value. Register any asserts for OP and for any
5786 operands in OP's defining statement.
5788 If CODE is EQ_EXPR, then we want to register OP is zero (false),
5789 if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
5792 register_edge_assert_for_1 (tree op, enum tree_code code,
5793 edge e, gimple_stmt_iterator bsi)
5797 enum tree_code rhs_code;
5799 /* We only care about SSA_NAMEs. */
5800 if (TREE_CODE (op) != SSA_NAME)
5803 /* We know that OP will have a zero or nonzero value. If OP is used
5804 more than once go ahead and register an assert for OP. */
5805 if (live_on_edge (e, op)
5806 && !has_single_use (op))
5808 val = build_int_cst (TREE_TYPE (op), 0);
5809 register_new_assert_for (op, op, code, val, NULL, e, bsi);
5812 /* Now look at how OP is set. If it's set from a comparison,
5813 a truth operation or some bit operations, then we may be able
5814 to register information about the operands of that assignment. */
5815 op_def = SSA_NAME_DEF_STMT (op);
5816 if (gimple_code (op_def) != GIMPLE_ASSIGN)
5819 rhs_code = gimple_assign_rhs_code (op_def);
5821 if (TREE_CODE_CLASS (rhs_code) == tcc_comparison)
5823 bool invert = (code == EQ_EXPR ? true : false);
5824 tree op0 = gimple_assign_rhs1 (op_def);
5825 tree op1 = gimple_assign_rhs2 (op_def);
5827 if (TREE_CODE (op0) == SSA_NAME)
5828 register_edge_assert_for_2 (op0, e, bsi, rhs_code, op0, op1, invert);
5829 if (TREE_CODE (op1) == SSA_NAME)
5830 register_edge_assert_for_2 (op1, e, bsi, rhs_code, op0, op1, invert);
5832 else if ((code == NE_EXPR
5833 && gimple_assign_rhs_code (op_def) == BIT_AND_EXPR)
5835 && gimple_assign_rhs_code (op_def) == BIT_IOR_EXPR))
5837 /* Recurse on each operand. */
5838 tree op0 = gimple_assign_rhs1 (op_def);
5839 tree op1 = gimple_assign_rhs2 (op_def);
5840 if (TREE_CODE (op0) == SSA_NAME
5841 && has_single_use (op0))
5842 register_edge_assert_for_1 (op0, code, e, bsi);
5843 if (TREE_CODE (op1) == SSA_NAME
5844 && has_single_use (op1))
5845 register_edge_assert_for_1 (op1, code, e, bsi);
5847 else if (gimple_assign_rhs_code (op_def) == BIT_NOT_EXPR
5848 && TYPE_PRECISION (TREE_TYPE (gimple_assign_lhs (op_def))) == 1)
5850 /* Recurse, flipping CODE. */
5851 code = invert_tree_comparison (code, false);
5852 register_edge_assert_for_1 (gimple_assign_rhs1 (op_def), code, e, bsi);
5854 else if (gimple_assign_rhs_code (op_def) == SSA_NAME)
5856 /* Recurse through the copy. */
5857 register_edge_assert_for_1 (gimple_assign_rhs1 (op_def), code, e, bsi);
5859 else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def)))
5861 /* Recurse through the type conversion, unless it is a narrowing
5862 conversion or conversion from non-integral type. */
5863 tree rhs = gimple_assign_rhs1 (op_def);
5864 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs))
5865 && (TYPE_PRECISION (TREE_TYPE (rhs))
5866 <= TYPE_PRECISION (TREE_TYPE (op))))
5867 register_edge_assert_for_1 (rhs, code, e, bsi);
5871 /* Try to register an edge assertion for SSA name NAME on edge E for
5872 the condition COND contributing to the conditional jump pointed to by
5876 register_edge_assert_for (tree name, edge e, gimple_stmt_iterator si,
5877 enum tree_code cond_code, tree cond_op0,
5881 enum tree_code comp_code;
5882 bool is_else_edge = (e->flags & EDGE_FALSE_VALUE) != 0;
5884 /* Do not attempt to infer anything in names that flow through
5886 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
5889 if (!extract_code_and_val_from_cond_with_ops (name, cond_code,
5895 /* Register ASSERT_EXPRs for name. */
5896 register_edge_assert_for_2 (name, e, si, cond_code, cond_op0,
5897 cond_op1, is_else_edge);
5900 /* If COND is effectively an equality test of an SSA_NAME against
5901 the value zero or one, then we may be able to assert values
5902 for SSA_NAMEs which flow into COND. */
5904 /* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining
5905 statement of NAME we can assert both operands of the BIT_AND_EXPR
5906 have nonzero value. */
5907 if (((comp_code == EQ_EXPR && integer_onep (val))
5908 || (comp_code == NE_EXPR && integer_zerop (val))))
5910 gimple def_stmt = SSA_NAME_DEF_STMT (name);
5912 if (is_gimple_assign (def_stmt)
5913 && gimple_assign_rhs_code (def_stmt) == BIT_AND_EXPR)
5915 tree op0 = gimple_assign_rhs1 (def_stmt);
5916 tree op1 = gimple_assign_rhs2 (def_stmt);
5917 register_edge_assert_for_1 (op0, NE_EXPR, e, si);
5918 register_edge_assert_for_1 (op1, NE_EXPR, e, si);
5922 /* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining
5923 statement of NAME we can assert both operands of the BIT_IOR_EXPR
5925 if (((comp_code == EQ_EXPR && integer_zerop (val))
5926 || (comp_code == NE_EXPR && integer_onep (val))))
5928 gimple def_stmt = SSA_NAME_DEF_STMT (name);
5930 /* For BIT_IOR_EXPR only if NAME == 0 both operands have
5931 necessarily zero value, or if type-precision is one. */
5932 if (is_gimple_assign (def_stmt)
5933 && (gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR
5934 && (TYPE_PRECISION (TREE_TYPE (name)) == 1
5935 || comp_code == EQ_EXPR)))
5937 tree op0 = gimple_assign_rhs1 (def_stmt);
5938 tree op1 = gimple_assign_rhs2 (def_stmt);
5939 register_edge_assert_for_1 (op0, EQ_EXPR, e, si);
5940 register_edge_assert_for_1 (op1, EQ_EXPR, e, si);
5946 /* Determine whether the outgoing edges of BB should receive an
5947 ASSERT_EXPR for each of the operands of BB's LAST statement.
5948 The last statement of BB must be a COND_EXPR.
5950 If any of the sub-graphs rooted at BB have an interesting use of
5951 the predicate operands, an assert location node is added to the
5952 list of assertions for the corresponding operands. */
5955 find_conditional_asserts (basic_block bb, gcond *last)
5957 gimple_stmt_iterator bsi;
5963 bsi = gsi_for_stmt (last);
5965 /* Look for uses of the operands in each of the sub-graphs
5966 rooted at BB. We need to check each of the outgoing edges
5967 separately, so that we know what kind of ASSERT_EXPR to
5969 FOR_EACH_EDGE (e, ei, bb->succs)
5974 /* Register the necessary assertions for each operand in the
5975 conditional predicate. */
5976 FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
5977 register_edge_assert_for (op, e, bsi,
5978 gimple_cond_code (last),
5979 gimple_cond_lhs (last),
5980 gimple_cond_rhs (last));
5990 /* Compare two case labels sorting first by the destination bb index
5991 and then by the case value. */
5994 compare_case_labels (const void *p1, const void *p2)
5996 const struct case_info *ci1 = (const struct case_info *) p1;
5997 const struct case_info *ci2 = (const struct case_info *) p2;
5998 int idx1 = ci1->bb->index;
5999 int idx2 = ci2->bb->index;
6003 else if (idx1 == idx2)
6005 /* Make sure the default label is first in a group. */
6006 if (!CASE_LOW (ci1->expr))
6008 else if (!CASE_LOW (ci2->expr))
6011 return tree_int_cst_compare (CASE_LOW (ci1->expr),
6012 CASE_LOW (ci2->expr));
6018 /* Determine whether the outgoing edges of BB should receive an
6019 ASSERT_EXPR for each of the operands of BB's LAST statement.
6020 The last statement of BB must be a SWITCH_EXPR.
6022 If any of the sub-graphs rooted at BB have an interesting use of
6023 the predicate operands, an assert location node is added to the
6024 list of assertions for the corresponding operands. */
6027 find_switch_asserts (basic_block bb, gswitch *last)
6029 gimple_stmt_iterator bsi;
6032 struct case_info *ci;
6033 size_t n = gimple_switch_num_labels (last);
6034 #if GCC_VERSION >= 4000
6037 /* Work around GCC 3.4 bug (PR 37086). */
6038 volatile unsigned int idx;
6041 bsi = gsi_for_stmt (last);
6042 op = gimple_switch_index (last);
6043 if (TREE_CODE (op) != SSA_NAME)
6046 /* Build a vector of case labels sorted by destination label. */
6047 ci = XNEWVEC (struct case_info, n);
6048 for (idx = 0; idx < n; ++idx)
6050 ci[idx].expr = gimple_switch_label (last, idx);
6051 ci[idx].bb = label_to_block (CASE_LABEL (ci[idx].expr));
6053 qsort (ci, n, sizeof (struct case_info), compare_case_labels);
6055 for (idx = 0; idx < n; ++idx)
6058 tree cl = ci[idx].expr;
6059 basic_block cbb = ci[idx].bb;
6061 min = CASE_LOW (cl);
6062 max = CASE_HIGH (cl);
6064 /* If there are multiple case labels with the same destination
6065 we need to combine them to a single value range for the edge. */
6066 if (idx + 1 < n && cbb == ci[idx + 1].bb)
6068 /* Skip labels until the last of the group. */
6071 } while (idx < n && cbb == ci[idx].bb);
6074 /* Pick up the maximum of the case label range. */
6075 if (CASE_HIGH (ci[idx].expr))
6076 max = CASE_HIGH (ci[idx].expr);
6078 max = CASE_LOW (ci[idx].expr);
6081 /* Nothing to do if the range includes the default label until we
6082 can register anti-ranges. */
6083 if (min == NULL_TREE)
6086 /* Find the edge to register the assert expr on. */
6087 e = find_edge (bb, cbb);
6089 /* Register the necessary assertions for the operand in the
6091 register_edge_assert_for (op, e, bsi,
6092 max ? GE_EXPR : EQ_EXPR,
6093 op, fold_convert (TREE_TYPE (op), min));
6095 register_edge_assert_for (op, e, bsi, LE_EXPR, op,
6096 fold_convert (TREE_TYPE (op), max));
6103 /* Traverse all the statements in block BB looking for statements that
6104 may generate useful assertions for the SSA names in their operand.
6105 If a statement produces a useful assertion A for name N_i, then the
6106 list of assertions already generated for N_i is scanned to
6107 determine if A is actually needed.
6109 If N_i already had the assertion A at a location dominating the
6110 current location, then nothing needs to be done. Otherwise, the
6111 new location for A is recorded instead.
6113 1- For every statement S in BB, all the variables used by S are
6114 added to bitmap FOUND_IN_SUBGRAPH.
6116 2- If statement S uses an operand N in a way that exposes a known
6117 value range for N, then if N was not already generated by an
6118 ASSERT_EXPR, create a new assert location for N. For instance,
6119 if N is a pointer and the statement dereferences it, we can
6120 assume that N is not NULL.
6122 3- COND_EXPRs are a special case of #2. We can derive range
6123 information from the predicate but need to insert different
6124 ASSERT_EXPRs for each of the sub-graphs rooted at the
6125 conditional block. If the last statement of BB is a conditional
6126 expression of the form 'X op Y', then
6128 a) Remove X and Y from the set FOUND_IN_SUBGRAPH.
6130 b) If the conditional is the only entry point to the sub-graph
6131 corresponding to the THEN_CLAUSE, recurse into it. On
6132 return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then
6133 an ASSERT_EXPR is added for the corresponding variable.
6135 c) Repeat step (b) on the ELSE_CLAUSE.
6137 d) Mark X and Y in FOUND_IN_SUBGRAPH.
6146 In this case, an assertion on the THEN clause is useful to
6147 determine that 'a' is always 9 on that edge. However, an assertion
6148 on the ELSE clause would be unnecessary.
6150 4- If BB does not end in a conditional expression, then we recurse
6151 into BB's dominator children.
6153 At the end of the recursive traversal, every SSA name will have a
6154 list of locations where ASSERT_EXPRs should be added. When a new
6155 location for name N is found, it is registered by calling
6156 register_new_assert_for. That function keeps track of all the
6157 registered assertions to prevent adding unnecessary assertions.
6158 For instance, if a pointer P_4 is dereferenced more than once in a
6159 dominator tree, only the location dominating all the dereference of
6160 P_4 will receive an ASSERT_EXPR. */
6163 find_assert_locations_1 (basic_block bb, sbitmap live)
6167 last = last_stmt (bb);
6169 /* If BB's last statement is a conditional statement involving integer
6170 operands, determine if we need to add ASSERT_EXPRs. */
6172 && gimple_code (last) == GIMPLE_COND
6173 && !fp_predicate (last)
6174 && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
6175 find_conditional_asserts (bb, as_a <gcond *> (last));
6177 /* If BB's last statement is a switch statement involving integer
6178 operands, determine if we need to add ASSERT_EXPRs. */
6180 && gimple_code (last) == GIMPLE_SWITCH
6181 && !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
6182 find_switch_asserts (bb, as_a <gswitch *> (last));
6184 /* Traverse all the statements in BB marking used names and looking
6185 for statements that may infer assertions for their used operands. */
6186 for (gimple_stmt_iterator si = gsi_last_bb (bb); !gsi_end_p (si);
6193 stmt = gsi_stmt (si);
6195 if (is_gimple_debug (stmt))
6198 /* See if we can derive an assertion for any of STMT's operands. */
6199 FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
6202 enum tree_code comp_code;
6204 /* If op is not live beyond this stmt, do not bother to insert
6206 if (!bitmap_bit_p (live, SSA_NAME_VERSION (op)))
6209 /* If OP is used in such a way that we can infer a value
6210 range for it, and we don't find a previous assertion for
6211 it, create a new assertion location node for OP. */
6212 if (infer_value_range (stmt, op, &comp_code, &value))
6214 /* If we are able to infer a nonzero value range for OP,
6215 then walk backwards through the use-def chain to see if OP
6216 was set via a typecast.
6218 If so, then we can also infer a nonzero value range
6219 for the operand of the NOP_EXPR. */
6220 if (comp_code == NE_EXPR && integer_zerop (value))
6223 gimple def_stmt = SSA_NAME_DEF_STMT (t);
6225 while (is_gimple_assign (def_stmt)
6226 && CONVERT_EXPR_CODE_P
6227 (gimple_assign_rhs_code (def_stmt))
6229 (gimple_assign_rhs1 (def_stmt)) == SSA_NAME
6231 (TREE_TYPE (gimple_assign_rhs1 (def_stmt))))
6233 t = gimple_assign_rhs1 (def_stmt);
6234 def_stmt = SSA_NAME_DEF_STMT (t);
6236 /* Note we want to register the assert for the
6237 operand of the NOP_EXPR after SI, not after the
6239 if (! has_single_use (t))
6240 register_new_assert_for (t, t, comp_code, value,
6245 register_new_assert_for (op, op, comp_code, value, bb, NULL, si);
6250 FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
6251 bitmap_set_bit (live, SSA_NAME_VERSION (op));
6252 FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF)
6253 bitmap_clear_bit (live, SSA_NAME_VERSION (op));
6256 /* Traverse all PHI nodes in BB, updating live. */
6257 for (gphi_iterator si = gsi_start_phis (bb); !gsi_end_p (si);
6260 use_operand_p arg_p;
6262 gphi *phi = si.phi ();
6263 tree res = gimple_phi_result (phi);
6265 if (virtual_operand_p (res))
6268 FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_USE)
6270 tree arg = USE_FROM_PTR (arg_p);
6271 if (TREE_CODE (arg) == SSA_NAME)
6272 bitmap_set_bit (live, SSA_NAME_VERSION (arg));
6275 bitmap_clear_bit (live, SSA_NAME_VERSION (res));
6279 /* Do an RPO walk over the function computing SSA name liveness
6280 on-the-fly and deciding on assert expressions to insert. */
6283 find_assert_locations (void)
6285 int *rpo = XNEWVEC (int, last_basic_block_for_fn (cfun));
6286 int *bb_rpo = XNEWVEC (int, last_basic_block_for_fn (cfun));
6287 int *last_rpo = XCNEWVEC (int, last_basic_block_for_fn (cfun));
6290 live = XCNEWVEC (sbitmap, last_basic_block_for_fn (cfun));
6291 rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false);
6292 for (i = 0; i < rpo_cnt; ++i)
6295 /* Pre-seed loop latch liveness from loop header PHI nodes. Due to
6296 the order we compute liveness and insert asserts we otherwise
6297 fail to insert asserts into the loop latch. */
6299 FOR_EACH_LOOP (loop, 0)
6301 i = loop->latch->index;
6302 unsigned int j = single_succ_edge (loop->latch)->dest_idx;
6303 for (gphi_iterator gsi = gsi_start_phis (loop->header);
6304 !gsi_end_p (gsi); gsi_next (&gsi))
6306 gphi *phi = gsi.phi ();
6307 if (virtual_operand_p (gimple_phi_result (phi)))
6309 tree arg = gimple_phi_arg_def (phi, j);
6310 if (TREE_CODE (arg) == SSA_NAME)
6312 if (live[i] == NULL)
6314 live[i] = sbitmap_alloc (num_ssa_names);
6315 bitmap_clear (live[i]);
6317 bitmap_set_bit (live[i], SSA_NAME_VERSION (arg));
6322 for (i = rpo_cnt - 1; i >= 0; --i)
6324 basic_block bb = BASIC_BLOCK_FOR_FN (cfun, rpo[i]);
6330 live[rpo[i]] = sbitmap_alloc (num_ssa_names);
6331 bitmap_clear (live[rpo[i]]);
6334 /* Process BB and update the live information with uses in
6336 find_assert_locations_1 (bb, live[rpo[i]]);
6338 /* Merge liveness into the predecessor blocks and free it. */
6339 if (!bitmap_empty_p (live[rpo[i]]))
6342 FOR_EACH_EDGE (e, ei, bb->preds)
6344 int pred = e->src->index;
6345 if ((e->flags & EDGE_DFS_BACK) || pred == ENTRY_BLOCK)
6350 live[pred] = sbitmap_alloc (num_ssa_names);
6351 bitmap_clear (live[pred]);
6353 bitmap_ior (live[pred], live[pred], live[rpo[i]]);
6355 if (bb_rpo[pred] < pred_rpo)
6356 pred_rpo = bb_rpo[pred];
6359 /* Record the RPO number of the last visited block that needs
6360 live information from this block. */
6361 last_rpo[rpo[i]] = pred_rpo;
6365 sbitmap_free (live[rpo[i]]);
6366 live[rpo[i]] = NULL;
6369 /* We can free all successors live bitmaps if all their
6370 predecessors have been visited already. */
6371 FOR_EACH_EDGE (e, ei, bb->succs)
6372 if (last_rpo[e->dest->index] == i
6373 && live[e->dest->index])
6375 sbitmap_free (live[e->dest->index]);
6376 live[e->dest->index] = NULL;
6381 XDELETEVEC (bb_rpo);
6382 XDELETEVEC (last_rpo);
6383 for (i = 0; i < last_basic_block_for_fn (cfun); ++i)
6385 sbitmap_free (live[i]);
6389 /* Create an ASSERT_EXPR for NAME and insert it in the location
6390 indicated by LOC. Return true if we made any edge insertions. */
6393 process_assert_insertions_for (tree name, assert_locus_t loc)
6395 /* Build the comparison expression NAME_i COMP_CODE VAL. */
6402 /* If we have X <=> X do not insert an assert expr for that. */
6403 if (loc->expr == loc->val)
6406 cond = build2 (loc->comp_code, boolean_type_node, loc->expr, loc->val);
6407 assert_stmt = build_assert_expr_for (cond, name);
6410 /* We have been asked to insert the assertion on an edge. This
6411 is used only by COND_EXPR and SWITCH_EXPR assertions. */
6412 gcc_checking_assert (gimple_code (gsi_stmt (loc->si)) == GIMPLE_COND
6413 || (gimple_code (gsi_stmt (loc->si))
6416 gsi_insert_on_edge (loc->e, assert_stmt);
6420 /* Otherwise, we can insert right after LOC->SI iff the
6421 statement must not be the last statement in the block. */
6422 stmt = gsi_stmt (loc->si);
6423 if (!stmt_ends_bb_p (stmt))
6425 gsi_insert_after (&loc->si, assert_stmt, GSI_SAME_STMT);
6429 /* If STMT must be the last statement in BB, we can only insert new
6430 assertions on the non-abnormal edge out of BB. Note that since
6431 STMT is not control flow, there may only be one non-abnormal edge
6433 FOR_EACH_EDGE (e, ei, loc->bb->succs)
6434 if (!(e->flags & EDGE_ABNORMAL))
6436 gsi_insert_on_edge (e, assert_stmt);
6444 /* Process all the insertions registered for every name N_i registered
6445 in NEED_ASSERT_FOR. The list of assertions to be inserted are
6446 found in ASSERTS_FOR[i]. */
6449 process_assert_insertions (void)
6453 bool update_edges_p = false;
6454 int num_asserts = 0;
6456 if (dump_file && (dump_flags & TDF_DETAILS))
6457 dump_all_asserts (dump_file);
6459 EXECUTE_IF_SET_IN_BITMAP (need_assert_for, 0, i, bi)
6461 assert_locus_t loc = asserts_for[i];
6466 assert_locus_t next = loc->next;
6467 update_edges_p |= process_assert_insertions_for (ssa_name (i), loc);
6475 gsi_commit_edge_inserts ();
6477 statistics_counter_event (cfun, "Number of ASSERT_EXPR expressions inserted",
6482 /* Traverse the flowgraph looking for conditional jumps to insert range
6483 expressions. These range expressions are meant to provide information
6484 to optimizations that need to reason in terms of value ranges. They
6485 will not be expanded into RTL. For instance, given:
6494 this pass will transform the code into:
6500 x = ASSERT_EXPR <x, x < y>
6505 y = ASSERT_EXPR <y, x >= y>
6509 The idea is that once copy and constant propagation have run, other
6510 optimizations will be able to determine what ranges of values can 'x'
6511 take in different paths of the code, simply by checking the reaching
6512 definition of 'x'. */
6515 insert_range_assertions (void)
6517 need_assert_for = BITMAP_ALLOC (NULL);
6518 asserts_for = XCNEWVEC (assert_locus_t, num_ssa_names);
6520 calculate_dominance_info (CDI_DOMINATORS);
6522 find_assert_locations ();
6523 if (!bitmap_empty_p (need_assert_for))
6525 process_assert_insertions ();
6526 update_ssa (TODO_update_ssa_no_phi);
6529 if (dump_file && (dump_flags & TDF_DETAILS))
6531 fprintf (dump_file, "\nSSA form after inserting ASSERT_EXPRs\n");
6532 dump_function_to_file (current_function_decl, dump_file, dump_flags);
6536 BITMAP_FREE (need_assert_for);
6539 /* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
6540 and "struct" hacks. If VRP can determine that the
6541 array subscript is a constant, check if it is outside valid
6542 range. If the array subscript is a RANGE, warn if it is
6543 non-overlapping with valid range.
6544 IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
6547 check_array_ref (location_t location, tree ref, bool ignore_off_by_one)
6549 value_range_t* vr = NULL;
6550 tree low_sub, up_sub;
6551 tree low_bound, up_bound, up_bound_p1;
6554 if (TREE_NO_WARNING (ref))
6557 low_sub = up_sub = TREE_OPERAND (ref, 1);
6558 up_bound = array_ref_up_bound (ref);
6560 /* Can not check flexible arrays. */
6562 || TREE_CODE (up_bound) != INTEGER_CST)
6565 /* Accesses to trailing arrays via pointers may access storage
6566 beyond the types array bounds. */
6567 base = get_base_address (ref);
6568 if ((warn_array_bounds < 2)
6569 && base && TREE_CODE (base) == MEM_REF)
6571 tree cref, next = NULL_TREE;
6573 if (TREE_CODE (TREE_OPERAND (ref, 0)) != COMPONENT_REF)
6576 cref = TREE_OPERAND (ref, 0);
6577 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (cref, 0))) == RECORD_TYPE)
6578 for (next = DECL_CHAIN (TREE_OPERAND (cref, 1));
6579 next && TREE_CODE (next) != FIELD_DECL;
6580 next = DECL_CHAIN (next))
6583 /* If this is the last field in a struct type or a field in a
6584 union type do not warn. */
6589 low_bound = array_ref_low_bound (ref);
6590 up_bound_p1 = int_const_binop (PLUS_EXPR, up_bound,
6591 build_int_cst (TREE_TYPE (up_bound), 1));
6594 if (tree_int_cst_equal (low_bound, up_bound_p1))
6596 warning_at (location, OPT_Warray_bounds,
6597 "array subscript is above array bounds");
6598 TREE_NO_WARNING (ref) = 1;
6601 if (TREE_CODE (low_sub) == SSA_NAME)
6603 vr = get_value_range (low_sub);
6604 if (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE)
6606 low_sub = vr->type == VR_RANGE ? vr->max : vr->min;
6607 up_sub = vr->type == VR_RANGE ? vr->min : vr->max;
6611 if (vr && vr->type == VR_ANTI_RANGE)
6613 if (TREE_CODE (up_sub) == INTEGER_CST
6614 && (ignore_off_by_one
6615 ? tree_int_cst_lt (up_bound, up_sub)
6616 : tree_int_cst_le (up_bound, up_sub))
6617 && TREE_CODE (low_sub) == INTEGER_CST
6618 && tree_int_cst_le (low_sub, low_bound))
6620 warning_at (location, OPT_Warray_bounds,
6621 "array subscript is outside array bounds");
6622 TREE_NO_WARNING (ref) = 1;
6625 else if (TREE_CODE (up_sub) == INTEGER_CST
6626 && (ignore_off_by_one
6627 ? !tree_int_cst_le (up_sub, up_bound_p1)
6628 : !tree_int_cst_le (up_sub, up_bound)))
6630 if (dump_file && (dump_flags & TDF_DETAILS))
6632 fprintf (dump_file, "Array bound warning for ");
6633 dump_generic_expr (MSG_NOTE, TDF_SLIM, ref);
6634 fprintf (dump_file, "\n");
6636 warning_at (location, OPT_Warray_bounds,
6637 "array subscript is above array bounds");
6638 TREE_NO_WARNING (ref) = 1;
6640 else if (TREE_CODE (low_sub) == INTEGER_CST
6641 && tree_int_cst_lt (low_sub, low_bound))
6643 if (dump_file && (dump_flags & TDF_DETAILS))
6645 fprintf (dump_file, "Array bound warning for ");
6646 dump_generic_expr (MSG_NOTE, TDF_SLIM, ref);
6647 fprintf (dump_file, "\n");
6649 warning_at (location, OPT_Warray_bounds,
6650 "array subscript is below array bounds");
6651 TREE_NO_WARNING (ref) = 1;
6655 /* Searches if the expr T, located at LOCATION computes
6656 address of an ARRAY_REF, and call check_array_ref on it. */
6659 search_for_addr_array (tree t, location_t location)
6661 /* Check each ARRAY_REFs in the reference chain. */
6664 if (TREE_CODE (t) == ARRAY_REF)
6665 check_array_ref (location, t, true /*ignore_off_by_one*/);
6667 t = TREE_OPERAND (t, 0);
6669 while (handled_component_p (t));
6671 if (TREE_CODE (t) == MEM_REF
6672 && TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
6673 && !TREE_NO_WARNING (t))
6675 tree tem = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
6676 tree low_bound, up_bound, el_sz;
6678 if (TREE_CODE (TREE_TYPE (tem)) != ARRAY_TYPE
6679 || TREE_CODE (TREE_TYPE (TREE_TYPE (tem))) == ARRAY_TYPE
6680 || !TYPE_DOMAIN (TREE_TYPE (tem)))
6683 low_bound = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem)));
6684 up_bound = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem)));
6685 el_sz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem)));
6687 || TREE_CODE (low_bound) != INTEGER_CST
6689 || TREE_CODE (up_bound) != INTEGER_CST
6691 || TREE_CODE (el_sz) != INTEGER_CST)
6694 idx = mem_ref_offset (t);
6695 idx = wi::sdiv_trunc (idx, wi::to_offset (el_sz));
6696 if (wi::lts_p (idx, 0))
6698 if (dump_file && (dump_flags & TDF_DETAILS))
6700 fprintf (dump_file, "Array bound warning for ");
6701 dump_generic_expr (MSG_NOTE, TDF_SLIM, t);
6702 fprintf (dump_file, "\n");
6704 warning_at (location, OPT_Warray_bounds,
6705 "array subscript is below array bounds");
6706 TREE_NO_WARNING (t) = 1;
6708 else if (wi::gts_p (idx, (wi::to_offset (up_bound)
6709 - wi::to_offset (low_bound) + 1)))
6711 if (dump_file && (dump_flags & TDF_DETAILS))
6713 fprintf (dump_file, "Array bound warning for ");
6714 dump_generic_expr (MSG_NOTE, TDF_SLIM, t);
6715 fprintf (dump_file, "\n");
6717 warning_at (location, OPT_Warray_bounds,
6718 "array subscript is above array bounds");
6719 TREE_NO_WARNING (t) = 1;
6724 /* walk_tree() callback that checks if *TP is
6725 an ARRAY_REF inside an ADDR_EXPR (in which an array
6726 subscript one outside the valid range is allowed). Call
6727 check_array_ref for each ARRAY_REF found. The location is
6731 check_array_bounds (tree *tp, int *walk_subtree, void *data)
6734 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
6735 location_t location;
6737 if (EXPR_HAS_LOCATION (t))
6738 location = EXPR_LOCATION (t);
6741 location_t *locp = (location_t *) wi->info;
6745 *walk_subtree = TRUE;
6747 if (TREE_CODE (t) == ARRAY_REF)
6748 check_array_ref (location, t, false /*ignore_off_by_one*/);
6750 else if (TREE_CODE (t) == ADDR_EXPR)
6752 search_for_addr_array (t, location);
6753 *walk_subtree = FALSE;
6759 /* Walk over all statements of all reachable BBs and call check_array_bounds
6763 check_all_array_refs (void)
6766 gimple_stmt_iterator si;
6768 FOR_EACH_BB_FN (bb, cfun)
6772 bool executable = false;
6774 /* Skip blocks that were found to be unreachable. */
6775 FOR_EACH_EDGE (e, ei, bb->preds)
6776 executable |= !!(e->flags & EDGE_EXECUTABLE);
6780 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
6782 gimple stmt = gsi_stmt (si);
6783 struct walk_stmt_info wi;
6784 if (!gimple_has_location (stmt)
6785 || is_gimple_debug (stmt))
6788 memset (&wi, 0, sizeof (wi));
6789 wi.info = CONST_CAST (void *, (const void *)
6790 gimple_location_ptr (stmt));
6792 walk_gimple_op (gsi_stmt (si),
6799 /* Return true if all imm uses of VAR are either in STMT, or
6800 feed (optionally through a chain of single imm uses) GIMPLE_COND
6801 in basic block COND_BB. */
6804 all_imm_uses_in_stmt_or_feed_cond (tree var, gimple stmt, basic_block cond_bb)
6806 use_operand_p use_p, use2_p;
6807 imm_use_iterator iter;
6809 FOR_EACH_IMM_USE_FAST (use_p, iter, var)
6810 if (USE_STMT (use_p) != stmt)
6812 gimple use_stmt = USE_STMT (use_p), use_stmt2;
6813 if (is_gimple_debug (use_stmt))
6815 while (is_gimple_assign (use_stmt)
6816 && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME
6817 && single_imm_use (gimple_assign_lhs (use_stmt),
6818 &use2_p, &use_stmt2))
6819 use_stmt = use_stmt2;
6820 if (gimple_code (use_stmt) != GIMPLE_COND
6821 || gimple_bb (use_stmt) != cond_bb)
6834 __builtin_unreachable ();
6836 x_5 = ASSERT_EXPR <x_3, ...>;
6837 If x_3 has no other immediate uses (checked by caller),
6838 var is the x_3 var from ASSERT_EXPR, we can clear low 5 bits
6839 from the non-zero bitmask. */
6842 maybe_set_nonzero_bits (basic_block bb, tree var)
6844 edge e = single_pred_edge (bb);
6845 basic_block cond_bb = e->src;
6846 gimple stmt = last_stmt (cond_bb);
6850 || gimple_code (stmt) != GIMPLE_COND
6851 || gimple_cond_code (stmt) != ((e->flags & EDGE_TRUE_VALUE)
6852 ? EQ_EXPR : NE_EXPR)
6853 || TREE_CODE (gimple_cond_lhs (stmt)) != SSA_NAME
6854 || !integer_zerop (gimple_cond_rhs (stmt)))
6857 stmt = SSA_NAME_DEF_STMT (gimple_cond_lhs (stmt));
6858 if (!is_gimple_assign (stmt)
6859 || gimple_assign_rhs_code (stmt) != BIT_AND_EXPR
6860 || TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST)
6862 if (gimple_assign_rhs1 (stmt) != var)
6866 if (TREE_CODE (gimple_assign_rhs1 (stmt)) != SSA_NAME)
6868 stmt2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
6869 if (!gimple_assign_cast_p (stmt2)
6870 || gimple_assign_rhs1 (stmt2) != var
6871 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt2))
6872 || (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (stmt)))
6873 != TYPE_PRECISION (TREE_TYPE (var))))
6876 cst = gimple_assign_rhs2 (stmt);
6877 set_nonzero_bits (var, wi::bit_and_not (get_nonzero_bits (var), cst));
6880 /* Convert range assertion expressions into the implied copies and
6881 copy propagate away the copies. Doing the trivial copy propagation
6882 here avoids the need to run the full copy propagation pass after
6885 FIXME, this will eventually lead to copy propagation removing the
6886 names that had useful range information attached to them. For
6887 instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>,
6888 then N_i will have the range [3, +INF].
6890 However, by converting the assertion into the implied copy
6891 operation N_i = N_j, we will then copy-propagate N_j into the uses
6892 of N_i and lose the range information. We may want to hold on to
6893 ASSERT_EXPRs a little while longer as the ranges could be used in
6894 things like jump threading.
6896 The problem with keeping ASSERT_EXPRs around is that passes after
6897 VRP need to handle them appropriately.
6899 Another approach would be to make the range information a first
6900 class property of the SSA_NAME so that it can be queried from
6901 any pass. This is made somewhat more complex by the need for
6902 multiple ranges to be associated with one SSA_NAME. */
6905 remove_range_assertions (void)
6908 gimple_stmt_iterator si;
6909 /* 1 if looking at ASSERT_EXPRs immediately at the beginning of
6910 a basic block preceeded by GIMPLE_COND branching to it and
6911 __builtin_trap, -1 if not yet checked, 0 otherwise. */
6914 /* Note that the BSI iterator bump happens at the bottom of the
6915 loop and no bump is necessary if we're removing the statement
6916 referenced by the current BSI. */
6917 FOR_EACH_BB_FN (bb, cfun)
6918 for (si = gsi_after_labels (bb), is_unreachable = -1; !gsi_end_p (si);)
6920 gimple stmt = gsi_stmt (si);
6923 if (is_gimple_assign (stmt)
6924 && gimple_assign_rhs_code (stmt) == ASSERT_EXPR)
6926 tree lhs = gimple_assign_lhs (stmt);
6927 tree rhs = gimple_assign_rhs1 (stmt);
6929 tree cond = fold (ASSERT_EXPR_COND (rhs));
6930 use_operand_p use_p;
6931 imm_use_iterator iter;
6933 gcc_assert (cond != boolean_false_node);
6935 var = ASSERT_EXPR_VAR (rhs);
6936 gcc_assert (TREE_CODE (var) == SSA_NAME);
6938 if (!POINTER_TYPE_P (TREE_TYPE (lhs))
6939 && SSA_NAME_RANGE_INFO (lhs))
6941 if (is_unreachable == -1)
6944 if (single_pred_p (bb)
6945 && assert_unreachable_fallthru_edge_p
6946 (single_pred_edge (bb)))
6950 if (x_7 >= 10 && x_7 < 20)
6951 __builtin_unreachable ();
6952 x_8 = ASSERT_EXPR <x_7, ...>;
6953 if the only uses of x_7 are in the ASSERT_EXPR and
6954 in the condition. In that case, we can copy the
6955 range info from x_8 computed in this pass also
6958 && all_imm_uses_in_stmt_or_feed_cond (var, stmt,
6961 set_range_info (var, SSA_NAME_RANGE_TYPE (lhs),
6962 SSA_NAME_RANGE_INFO (lhs)->get_min (),
6963 SSA_NAME_RANGE_INFO (lhs)->get_max ());
6964 maybe_set_nonzero_bits (bb, var);
6968 /* Propagate the RHS into every use of the LHS. */
6969 FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
6970 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
6971 SET_USE (use_p, var);
6973 /* And finally, remove the copy, it is not needed. */
6974 gsi_remove (&si, true);
6975 release_defs (stmt);
6979 if (!is_gimple_debug (gsi_stmt (si)))
6987 /* Return true if STMT is interesting for VRP. */
6990 stmt_interesting_for_vrp (gimple stmt)
6992 if (gimple_code (stmt) == GIMPLE_PHI)
6994 tree res = gimple_phi_result (stmt);
6995 return (!virtual_operand_p (res)
6996 && (INTEGRAL_TYPE_P (TREE_TYPE (res))
6997 || POINTER_TYPE_P (TREE_TYPE (res))));
6999 else if (is_gimple_assign (stmt) || is_gimple_call (stmt))
7001 tree lhs = gimple_get_lhs (stmt);
7003 /* In general, assignments with virtual operands are not useful
7004 for deriving ranges, with the obvious exception of calls to
7005 builtin functions. */
7006 if (lhs && TREE_CODE (lhs) == SSA_NAME
7007 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
7008 || POINTER_TYPE_P (TREE_TYPE (lhs)))
7009 && (is_gimple_call (stmt)
7010 || !gimple_vuse (stmt)))
7012 else if (is_gimple_call (stmt) && gimple_call_internal_p (stmt))
7013 switch (gimple_call_internal_fn (stmt))
7015 case IFN_ADD_OVERFLOW:
7016 case IFN_SUB_OVERFLOW:
7017 case IFN_MUL_OVERFLOW:
7018 /* These internal calls return _Complex integer type,
7019 but are interesting to VRP nevertheless. */
7020 if (lhs && TREE_CODE (lhs) == SSA_NAME)
7027 else if (gimple_code (stmt) == GIMPLE_COND
7028 || gimple_code (stmt) == GIMPLE_SWITCH)
7035 /* Initialize local data structures for VRP. */
7038 vrp_initialize (void)
7042 values_propagated = false;
7043 num_vr_values = num_ssa_names;
7044 vr_value = XCNEWVEC (value_range_t *, num_vr_values);
7045 vr_phi_edge_counts = XCNEWVEC (int, num_ssa_names);
7047 FOR_EACH_BB_FN (bb, cfun)
7049 for (gphi_iterator si = gsi_start_phis (bb); !gsi_end_p (si);
7052 gphi *phi = si.phi ();
7053 if (!stmt_interesting_for_vrp (phi))
7055 tree lhs = PHI_RESULT (phi);
7056 set_value_range_to_varying (get_value_range (lhs));
7057 prop_set_simulate_again (phi, false);
7060 prop_set_simulate_again (phi, true);
7063 for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si);
7066 gimple stmt = gsi_stmt (si);
7068 /* If the statement is a control insn, then we do not
7069 want to avoid simulating the statement once. Failure
7070 to do so means that those edges will never get added. */
7071 if (stmt_ends_bb_p (stmt))
7072 prop_set_simulate_again (stmt, true);
7073 else if (!stmt_interesting_for_vrp (stmt))
7077 FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF)
7078 set_value_range_to_varying (get_value_range (def));
7079 prop_set_simulate_again (stmt, false);
7082 prop_set_simulate_again (stmt, true);
7087 /* Return the singleton value-range for NAME or NAME. */
7090 vrp_valueize (tree name)
7092 if (TREE_CODE (name) == SSA_NAME)
7094 value_range_t *vr = get_value_range (name);
7095 if (vr->type == VR_RANGE
7096 && (vr->min == vr->max
7097 || operand_equal_p (vr->min, vr->max, 0)))
7103 /* Return the singleton value-range for NAME if that is a constant
7104 but signal to not follow SSA edges. */
7107 vrp_valueize_1 (tree name)
7109 if (TREE_CODE (name) == SSA_NAME)
7111 /* If the definition may be simulated again we cannot follow
7112 this SSA edge as the SSA propagator does not necessarily
7113 re-visit the use. */
7114 gimple def_stmt = SSA_NAME_DEF_STMT (name);
7115 if (!gimple_nop_p (def_stmt)
7116 && prop_simulate_again_p (def_stmt))
7118 value_range_t *vr = get_value_range (name);
7119 if (range_int_cst_singleton_p (vr))
7125 /* Visit assignment STMT. If it produces an interesting range, record
7126 the SSA name in *OUTPUT_P. */
7128 static enum ssa_prop_result
7129 vrp_visit_assignment_or_call (gimple stmt, tree *output_p)
7133 enum gimple_code code = gimple_code (stmt);
7134 lhs = gimple_get_lhs (stmt);
7136 /* We only keep track of ranges in integral and pointer types. */
7137 if (TREE_CODE (lhs) == SSA_NAME
7138 && ((INTEGRAL_TYPE_P (TREE_TYPE (lhs))
7139 /* It is valid to have NULL MIN/MAX values on a type. See
7140 build_range_type. */
7141 && TYPE_MIN_VALUE (TREE_TYPE (lhs))
7142 && TYPE_MAX_VALUE (TREE_TYPE (lhs)))
7143 || POINTER_TYPE_P (TREE_TYPE (lhs))))
7145 value_range_t new_vr = VR_INITIALIZER;
7147 /* Try folding the statement to a constant first. */
7148 tree tem = gimple_fold_stmt_to_constant_1 (stmt, vrp_valueize,
7150 if (tem && is_gimple_min_invariant (tem))
7151 set_value_range_to_value (&new_vr, tem, NULL);
7152 /* Then dispatch to value-range extracting functions. */
7153 else if (code == GIMPLE_CALL)
7154 extract_range_basic (&new_vr, stmt);
7156 extract_range_from_assignment (&new_vr, as_a <gassign *> (stmt));
7158 if (update_value_range (lhs, &new_vr))
7162 if (dump_file && (dump_flags & TDF_DETAILS))
7164 fprintf (dump_file, "Found new range for ");
7165 print_generic_expr (dump_file, lhs, 0);
7166 fprintf (dump_file, ": ");
7167 dump_value_range (dump_file, &new_vr);
7168 fprintf (dump_file, "\n");
7171 if (new_vr.type == VR_VARYING)
7172 return SSA_PROP_VARYING;
7174 return SSA_PROP_INTERESTING;
7177 return SSA_PROP_NOT_INTERESTING;
7179 else if (is_gimple_call (stmt) && gimple_call_internal_p (stmt))
7180 switch (gimple_call_internal_fn (stmt))
7182 case IFN_ADD_OVERFLOW:
7183 case IFN_SUB_OVERFLOW:
7184 case IFN_MUL_OVERFLOW:
7185 /* These internal calls return _Complex integer type,
7186 which VRP does not track, but the immediate uses
7187 thereof might be interesting. */
7188 if (lhs && TREE_CODE (lhs) == SSA_NAME)
7190 imm_use_iterator iter;
7191 use_operand_p use_p;
7192 enum ssa_prop_result res = SSA_PROP_VARYING;
7194 set_value_range_to_varying (get_value_range (lhs));
7196 FOR_EACH_IMM_USE_FAST (use_p, iter, lhs)
7198 gimple use_stmt = USE_STMT (use_p);
7199 if (!is_gimple_assign (use_stmt))
7201 enum tree_code rhs_code = gimple_assign_rhs_code (use_stmt);
7202 if (rhs_code != REALPART_EXPR && rhs_code != IMAGPART_EXPR)
7204 tree rhs1 = gimple_assign_rhs1 (use_stmt);
7205 tree use_lhs = gimple_assign_lhs (use_stmt);
7206 if (TREE_CODE (rhs1) != rhs_code
7207 || TREE_OPERAND (rhs1, 0) != lhs
7208 || TREE_CODE (use_lhs) != SSA_NAME
7209 || !stmt_interesting_for_vrp (use_stmt)
7210 || (!INTEGRAL_TYPE_P (TREE_TYPE (use_lhs))
7211 || !TYPE_MIN_VALUE (TREE_TYPE (use_lhs))
7212 || !TYPE_MAX_VALUE (TREE_TYPE (use_lhs))))
7215 /* If there is a change in the value range for any of the
7216 REALPART_EXPR/IMAGPART_EXPR immediate uses, return
7217 SSA_PROP_INTERESTING. If there are any REALPART_EXPR
7218 or IMAGPART_EXPR immediate uses, but none of them have
7219 a change in their value ranges, return
7220 SSA_PROP_NOT_INTERESTING. If there are no
7221 {REAL,IMAG}PART_EXPR uses at all,
7222 return SSA_PROP_VARYING. */
7223 value_range_t new_vr = VR_INITIALIZER;
7224 extract_range_basic (&new_vr, use_stmt);
7225 value_range_t *old_vr = get_value_range (use_lhs);
7226 if (old_vr->type != new_vr.type
7227 || !vrp_operand_equal_p (old_vr->min, new_vr.min)
7228 || !vrp_operand_equal_p (old_vr->max, new_vr.max)
7229 || !vrp_bitmap_equal_p (old_vr->equiv, new_vr.equiv))
7230 res = SSA_PROP_INTERESTING;
7232 res = SSA_PROP_NOT_INTERESTING;
7233 BITMAP_FREE (new_vr.equiv);
7234 if (res == SSA_PROP_INTERESTING)
7248 /* Every other statement produces no useful ranges. */
7249 FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
7250 set_value_range_to_varying (get_value_range (def));
7252 return SSA_PROP_VARYING;
7255 /* Helper that gets the value range of the SSA_NAME with version I
7256 or a symbolic range containing the SSA_NAME only if the value range
7257 is varying or undefined. */
7259 static inline value_range_t
7260 get_vr_for_comparison (int i)
7262 value_range_t vr = *get_value_range (ssa_name (i));
7264 /* If name N_i does not have a valid range, use N_i as its own
7265 range. This allows us to compare against names that may
7266 have N_i in their ranges. */
7267 if (vr.type == VR_VARYING || vr.type == VR_UNDEFINED)
7270 vr.min = ssa_name (i);
7271 vr.max = ssa_name (i);
7277 /* Compare all the value ranges for names equivalent to VAR with VAL
7278 using comparison code COMP. Return the same value returned by
7279 compare_range_with_value, including the setting of
7280 *STRICT_OVERFLOW_P. */
7283 compare_name_with_value (enum tree_code comp, tree var, tree val,
7284 bool *strict_overflow_p)
7290 int used_strict_overflow;
7292 value_range_t equiv_vr;
7294 /* Get the set of equivalences for VAR. */
7295 e = get_value_range (var)->equiv;
7297 /* Start at -1. Set it to 0 if we do a comparison without relying
7298 on overflow, or 1 if all comparisons rely on overflow. */
7299 used_strict_overflow = -1;
7301 /* Compare vars' value range with val. */
7302 equiv_vr = get_vr_for_comparison (SSA_NAME_VERSION (var));
7304 retval = compare_range_with_value (comp, &equiv_vr, val, &sop);
7306 used_strict_overflow = sop ? 1 : 0;
7308 /* If the equiv set is empty we have done all work we need to do. */
7312 && used_strict_overflow > 0)
7313 *strict_overflow_p = true;
7317 EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
7319 equiv_vr = get_vr_for_comparison (i);
7321 t = compare_range_with_value (comp, &equiv_vr, val, &sop);
7324 /* If we get different answers from different members
7325 of the equivalence set this check must be in a dead
7326 code region. Folding it to a trap representation
7327 would be correct here. For now just return don't-know. */
7337 used_strict_overflow = 0;
7338 else if (used_strict_overflow < 0)
7339 used_strict_overflow = 1;
7344 && used_strict_overflow > 0)
7345 *strict_overflow_p = true;
7351 /* Given a comparison code COMP and names N1 and N2, compare all the
7352 ranges equivalent to N1 against all the ranges equivalent to N2
7353 to determine the value of N1 COMP N2. Return the same value
7354 returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate
7355 whether we relied on an overflow infinity in the comparison. */
7359 compare_names (enum tree_code comp, tree n1, tree n2,
7360 bool *strict_overflow_p)
7364 bitmap_iterator bi1, bi2;
7366 int used_strict_overflow;
7367 static bitmap_obstack *s_obstack = NULL;
7368 static bitmap s_e1 = NULL, s_e2 = NULL;
7370 /* Compare the ranges of every name equivalent to N1 against the
7371 ranges of every name equivalent to N2. */
7372 e1 = get_value_range (n1)->equiv;
7373 e2 = get_value_range (n2)->equiv;
7375 /* Use the fake bitmaps if e1 or e2 are not available. */
7376 if (s_obstack == NULL)
7378 s_obstack = XNEW (bitmap_obstack);
7379 bitmap_obstack_initialize (s_obstack);
7380 s_e1 = BITMAP_ALLOC (s_obstack);
7381 s_e2 = BITMAP_ALLOC (s_obstack);
7388 /* Add N1 and N2 to their own set of equivalences to avoid
7389 duplicating the body of the loop just to check N1 and N2
7391 bitmap_set_bit (e1, SSA_NAME_VERSION (n1));
7392 bitmap_set_bit (e2, SSA_NAME_VERSION (n2));
7394 /* If the equivalence sets have a common intersection, then the two
7395 names can be compared without checking their ranges. */
7396 if (bitmap_intersect_p (e1, e2))
7398 bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
7399 bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
7401 return (comp == EQ_EXPR || comp == GE_EXPR || comp == LE_EXPR)
7403 : boolean_false_node;
7406 /* Start at -1. Set it to 0 if we do a comparison without relying
7407 on overflow, or 1 if all comparisons rely on overflow. */
7408 used_strict_overflow = -1;
7410 /* Otherwise, compare all the equivalent ranges. First, add N1 and
7411 N2 to their own set of equivalences to avoid duplicating the body
7412 of the loop just to check N1 and N2 ranges. */
7413 EXECUTE_IF_SET_IN_BITMAP (e1, 0, i1, bi1)
7415 value_range_t vr1 = get_vr_for_comparison (i1);
7417 t = retval = NULL_TREE;
7418 EXECUTE_IF_SET_IN_BITMAP (e2, 0, i2, bi2)
7422 value_range_t vr2 = get_vr_for_comparison (i2);
7424 t = compare_ranges (comp, &vr1, &vr2, &sop);
7427 /* If we get different answers from different members
7428 of the equivalence set this check must be in a dead
7429 code region. Folding it to a trap representation
7430 would be correct here. For now just return don't-know. */
7434 bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
7435 bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
7441 used_strict_overflow = 0;
7442 else if (used_strict_overflow < 0)
7443 used_strict_overflow = 1;
7449 bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
7450 bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
7451 if (used_strict_overflow > 0)
7452 *strict_overflow_p = true;
7457 /* None of the equivalent ranges are useful in computing this
7459 bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
7460 bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
7464 /* Helper function for vrp_evaluate_conditional_warnv. */
7467 vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code,
7469 bool * strict_overflow_p)
7471 value_range_t *vr0, *vr1;
7473 vr0 = (TREE_CODE (op0) == SSA_NAME) ? get_value_range (op0) : NULL;
7474 vr1 = (TREE_CODE (op1) == SSA_NAME) ? get_value_range (op1) : NULL;
7476 tree res = NULL_TREE;
7478 res = compare_ranges (code, vr0, vr1, strict_overflow_p);
7480 res = compare_range_with_value (code, vr0, op1, strict_overflow_p);
7482 res = (compare_range_with_value
7483 (swap_tree_comparison (code), vr1, op0, strict_overflow_p));
7487 /* Helper function for vrp_evaluate_conditional_warnv. */
7490 vrp_evaluate_conditional_warnv_with_ops (enum tree_code code, tree op0,
7491 tree op1, bool use_equiv_p,
7492 bool *strict_overflow_p, bool *only_ranges)
7496 *only_ranges = true;
7498 /* We only deal with integral and pointer types. */
7499 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
7500 && !POINTER_TYPE_P (TREE_TYPE (op0)))
7506 && (ret = vrp_evaluate_conditional_warnv_with_ops_using_ranges
7507 (code, op0, op1, strict_overflow_p)))
7509 *only_ranges = false;
7510 if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME)
7511 return compare_names (code, op0, op1, strict_overflow_p);
7512 else if (TREE_CODE (op0) == SSA_NAME)
7513 return compare_name_with_value (code, op0, op1, strict_overflow_p);
7514 else if (TREE_CODE (op1) == SSA_NAME)
7515 return (compare_name_with_value
7516 (swap_tree_comparison (code), op1, op0, strict_overflow_p));
7519 return vrp_evaluate_conditional_warnv_with_ops_using_ranges (code, op0, op1,
7524 /* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range
7525 information. Return NULL if the conditional can not be evaluated.
7526 The ranges of all the names equivalent with the operands in COND
7527 will be used when trying to compute the value. If the result is
7528 based on undefined signed overflow, issue a warning if
7532 vrp_evaluate_conditional (enum tree_code code, tree op0, tree op1, gimple stmt)
7538 /* Some passes and foldings leak constants with overflow flag set
7539 into the IL. Avoid doing wrong things with these and bail out. */
7540 if ((TREE_CODE (op0) == INTEGER_CST
7541 && TREE_OVERFLOW (op0))
7542 || (TREE_CODE (op1) == INTEGER_CST
7543 && TREE_OVERFLOW (op1)))
7547 ret = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, true, &sop,
7552 enum warn_strict_overflow_code wc;
7553 const char* warnmsg;
7555 if (is_gimple_min_invariant (ret))
7557 wc = WARN_STRICT_OVERFLOW_CONDITIONAL;
7558 warnmsg = G_("assuming signed overflow does not occur when "
7559 "simplifying conditional to constant");
7563 wc = WARN_STRICT_OVERFLOW_COMPARISON;
7564 warnmsg = G_("assuming signed overflow does not occur when "
7565 "simplifying conditional");
7568 if (issue_strict_overflow_warning (wc))
7570 location_t location;
7572 if (!gimple_has_location (stmt))
7573 location = input_location;
7575 location = gimple_location (stmt);
7576 warning_at (location, OPT_Wstrict_overflow, "%s", warnmsg);
7580 if (warn_type_limits
7581 && ret && only_ranges
7582 && TREE_CODE_CLASS (code) == tcc_comparison
7583 && TREE_CODE (op0) == SSA_NAME)
7585 /* If the comparison is being folded and the operand on the LHS
7586 is being compared against a constant value that is outside of
7587 the natural range of OP0's type, then the predicate will
7588 always fold regardless of the value of OP0. If -Wtype-limits
7589 was specified, emit a warning. */
7590 tree type = TREE_TYPE (op0);
7591 value_range_t *vr0 = get_value_range (op0);
7593 if (vr0->type == VR_RANGE
7594 && INTEGRAL_TYPE_P (type)
7595 && vrp_val_is_min (vr0->min)
7596 && vrp_val_is_max (vr0->max)
7597 && is_gimple_min_invariant (op1))
7599 location_t location;
7601 if (!gimple_has_location (stmt))
7602 location = input_location;
7604 location = gimple_location (stmt);
7606 warning_at (location, OPT_Wtype_limits,
7608 ? G_("comparison always false "
7609 "due to limited range of data type")
7610 : G_("comparison always true "
7611 "due to limited range of data type"));
7619 /* Visit conditional statement STMT. If we can determine which edge
7620 will be taken out of STMT's basic block, record it in
7621 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
7622 SSA_PROP_VARYING. */
7624 static enum ssa_prop_result
7625 vrp_visit_cond_stmt (gcond *stmt, edge *taken_edge_p)
7630 *taken_edge_p = NULL;
7632 if (dump_file && (dump_flags & TDF_DETAILS))
7637 fprintf (dump_file, "\nVisiting conditional with predicate: ");
7638 print_gimple_stmt (dump_file, stmt, 0, 0);
7639 fprintf (dump_file, "\nWith known ranges\n");
7641 FOR_EACH_SSA_TREE_OPERAND (use, stmt, i, SSA_OP_USE)
7643 fprintf (dump_file, "\t");
7644 print_generic_expr (dump_file, use, 0);
7645 fprintf (dump_file, ": ");
7646 dump_value_range (dump_file, vr_value[SSA_NAME_VERSION (use)]);
7649 fprintf (dump_file, "\n");
7652 /* Compute the value of the predicate COND by checking the known
7653 ranges of each of its operands.
7655 Note that we cannot evaluate all the equivalent ranges here
7656 because those ranges may not yet be final and with the current
7657 propagation strategy, we cannot determine when the value ranges
7658 of the names in the equivalence set have changed.
7660 For instance, given the following code fragment
7664 i_14 = ASSERT_EXPR <i_5, i_5 != 0>
7668 Assume that on the first visit to i_14, i_5 has the temporary
7669 range [8, 8] because the second argument to the PHI function is
7670 not yet executable. We derive the range ~[0, 0] for i_14 and the
7671 equivalence set { i_5 }. So, when we visit 'if (i_14 == 1)' for
7672 the first time, since i_14 is equivalent to the range [8, 8], we
7673 determine that the predicate is always false.
7675 On the next round of propagation, i_13 is determined to be
7676 VARYING, which causes i_5 to drop down to VARYING. So, another
7677 visit to i_14 is scheduled. In this second visit, we compute the
7678 exact same range and equivalence set for i_14, namely ~[0, 0] and
7679 { i_5 }. But we did not have the previous range for i_5
7680 registered, so vrp_visit_assignment thinks that the range for
7681 i_14 has not changed. Therefore, the predicate 'if (i_14 == 1)'
7682 is not visited again, which stops propagation from visiting
7683 statements in the THEN clause of that if().
7685 To properly fix this we would need to keep the previous range
7686 value for the names in the equivalence set. This way we would've
7687 discovered that from one visit to the other i_5 changed from
7688 range [8, 8] to VR_VARYING.
7690 However, fixing this apparent limitation may not be worth the
7691 additional checking. Testing on several code bases (GCC, DLV,
7692 MICO, TRAMP3D and SPEC2000) showed that doing this results in
7693 4 more predicates folded in SPEC. */
7696 val = vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt),
7697 gimple_cond_lhs (stmt),
7698 gimple_cond_rhs (stmt),
7703 *taken_edge_p = find_taken_edge (gimple_bb (stmt), val);
7706 if (dump_file && (dump_flags & TDF_DETAILS))
7708 "\nIgnoring predicate evaluation because "
7709 "it assumes that signed overflow is undefined");
7714 if (dump_file && (dump_flags & TDF_DETAILS))
7716 fprintf (dump_file, "\nPredicate evaluates to: ");
7717 if (val == NULL_TREE)
7718 fprintf (dump_file, "DON'T KNOW\n");
7720 print_generic_stmt (dump_file, val, 0);
7723 return (*taken_edge_p) ? SSA_PROP_INTERESTING : SSA_PROP_VARYING;
7726 /* Searches the case label vector VEC for the index *IDX of the CASE_LABEL
7727 that includes the value VAL. The search is restricted to the range
7728 [START_IDX, n - 1] where n is the size of VEC.
7730 If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
7733 If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
7734 it is placed in IDX and false is returned.
7736 If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
7740 find_case_label_index (gswitch *stmt, size_t start_idx, tree val, size_t *idx)
7742 size_t n = gimple_switch_num_labels (stmt);
7745 /* Find case label for minimum of the value range or the next one.
7746 At each iteration we are searching in [low, high - 1]. */
7748 for (low = start_idx, high = n; high != low; )
7752 /* Note that i != high, so we never ask for n. */
7753 size_t i = (high + low) / 2;
7754 t = gimple_switch_label (stmt, i);
7756 /* Cache the result of comparing CASE_LOW and val. */
7757 cmp = tree_int_cst_compare (CASE_LOW (t), val);
7761 /* Ranges cannot be empty. */
7770 if (CASE_HIGH (t) != NULL
7771 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
7783 /* Searches the case label vector VEC for the range of CASE_LABELs that is used
7784 for values between MIN and MAX. The first index is placed in MIN_IDX. The
7785 last index is placed in MAX_IDX. If the range of CASE_LABELs is empty
7786 then MAX_IDX < MIN_IDX.
7787 Returns true if the default label is not needed. */
7790 find_case_label_range (gswitch *stmt, tree min, tree max, size_t *min_idx,
7794 bool min_take_default = !find_case_label_index (stmt, 1, min, &i);
7795 bool max_take_default = !find_case_label_index (stmt, i, max, &j);
7799 && max_take_default)
7801 /* Only the default case label reached.
7802 Return an empty range. */
7809 bool take_default = min_take_default || max_take_default;
7813 if (max_take_default)
7816 /* If the case label range is continuous, we do not need
7817 the default case label. Verify that. */
7818 high = CASE_LOW (gimple_switch_label (stmt, i));
7819 if (CASE_HIGH (gimple_switch_label (stmt, i)))
7820 high = CASE_HIGH (gimple_switch_label (stmt, i));
7821 for (k = i + 1; k <= j; ++k)
7823 low = CASE_LOW (gimple_switch_label (stmt, k));
7824 if (!integer_onep (int_const_binop (MINUS_EXPR, low, high)))
7826 take_default = true;
7830 if (CASE_HIGH (gimple_switch_label (stmt, k)))
7831 high = CASE_HIGH (gimple_switch_label (stmt, k));
7836 return !take_default;
7840 /* Searches the case label vector VEC for the ranges of CASE_LABELs that are
7841 used in range VR. The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and
7842 MAX_IDX2. If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1.
7843 Returns true if the default label is not needed. */
7846 find_case_label_ranges (gswitch *stmt, value_range_t *vr, size_t *min_idx1,
7847 size_t *max_idx1, size_t *min_idx2,
7851 unsigned int n = gimple_switch_num_labels (stmt);
7853 tree case_low, case_high;
7854 tree min = vr->min, max = vr->max;
7856 gcc_checking_assert (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE);
7858 take_default = !find_case_label_range (stmt, min, max, &i, &j);
7860 /* Set second range to emtpy. */
7864 if (vr->type == VR_RANGE)
7868 return !take_default;
7871 /* Set first range to all case labels. */
7878 /* Make sure all the values of case labels [i , j] are contained in
7879 range [MIN, MAX]. */
7880 case_low = CASE_LOW (gimple_switch_label (stmt, i));
7881 case_high = CASE_HIGH (gimple_switch_label (stmt, j));
7882 if (tree_int_cst_compare (case_low, min) < 0)
7884 if (case_high != NULL_TREE
7885 && tree_int_cst_compare (max, case_high) < 0)
7891 /* If the range spans case labels [i, j], the corresponding anti-range spans
7892 the labels [1, i - 1] and [j + 1, n - 1]. */
7918 /* Visit switch statement STMT. If we can determine which edge
7919 will be taken out of STMT's basic block, record it in
7920 *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
7921 SSA_PROP_VARYING. */
7923 static enum ssa_prop_result
7924 vrp_visit_switch_stmt (gswitch *stmt, edge *taken_edge_p)
7928 size_t i = 0, j = 0, k, l;
7931 *taken_edge_p = NULL;
7932 op = gimple_switch_index (stmt);
7933 if (TREE_CODE (op) != SSA_NAME)
7934 return SSA_PROP_VARYING;
7936 vr = get_value_range (op);
7937 if (dump_file && (dump_flags & TDF_DETAILS))
7939 fprintf (dump_file, "\nVisiting switch expression with operand ");
7940 print_generic_expr (dump_file, op, 0);
7941 fprintf (dump_file, " with known range ");
7942 dump_value_range (dump_file, vr);
7943 fprintf (dump_file, "\n");
7946 if ((vr->type != VR_RANGE
7947 && vr->type != VR_ANTI_RANGE)
7948 || symbolic_range_p (vr))
7949 return SSA_PROP_VARYING;
7951 /* Find the single edge that is taken from the switch expression. */
7952 take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l);
7954 /* Check if the range spans no CASE_LABEL. If so, we only reach the default
7958 gcc_assert (take_default);
7959 val = gimple_switch_default_label (stmt);
7963 /* Check if labels with index i to j and maybe the default label
7964 are all reaching the same label. */
7966 val = gimple_switch_label (stmt, i);
7968 && CASE_LABEL (gimple_switch_default_label (stmt))
7969 != CASE_LABEL (val))
7971 if (dump_file && (dump_flags & TDF_DETAILS))
7972 fprintf (dump_file, " not a single destination for this "
7974 return SSA_PROP_VARYING;
7976 for (++i; i <= j; ++i)
7978 if (CASE_LABEL (gimple_switch_label (stmt, i)) != CASE_LABEL (val))
7980 if (dump_file && (dump_flags & TDF_DETAILS))
7981 fprintf (dump_file, " not a single destination for this "
7983 return SSA_PROP_VARYING;
7988 if (CASE_LABEL (gimple_switch_label (stmt, k)) != CASE_LABEL (val))
7990 if (dump_file && (dump_flags & TDF_DETAILS))
7991 fprintf (dump_file, " not a single destination for this "
7993 return SSA_PROP_VARYING;
7998 *taken_edge_p = find_edge (gimple_bb (stmt),
7999 label_to_block (CASE_LABEL (val)));
8001 if (dump_file && (dump_flags & TDF_DETAILS))
8003 fprintf (dump_file, " will take edge to ");
8004 print_generic_stmt (dump_file, CASE_LABEL (val), 0);
8007 return SSA_PROP_INTERESTING;
8011 /* Evaluate statement STMT. If the statement produces a useful range,
8012 return SSA_PROP_INTERESTING and record the SSA name with the
8013 interesting range into *OUTPUT_P.
8015 If STMT is a conditional branch and we can determine its truth
8016 value, the taken edge is recorded in *TAKEN_EDGE_P.
8018 If STMT produces a varying value, return SSA_PROP_VARYING. */
8020 static enum ssa_prop_result
8021 vrp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p)
8026 if (dump_file && (dump_flags & TDF_DETAILS))
8028 fprintf (dump_file, "\nVisiting statement:\n");
8029 print_gimple_stmt (dump_file, stmt, 0, dump_flags);
8032 if (!stmt_interesting_for_vrp (stmt))
8033 gcc_assert (stmt_ends_bb_p (stmt));
8034 else if (is_gimple_assign (stmt) || is_gimple_call (stmt))
8035 return vrp_visit_assignment_or_call (stmt, output_p);
8036 else if (gimple_code (stmt) == GIMPLE_COND)
8037 return vrp_visit_cond_stmt (as_a <gcond *> (stmt), taken_edge_p);
8038 else if (gimple_code (stmt) == GIMPLE_SWITCH)
8039 return vrp_visit_switch_stmt (as_a <gswitch *> (stmt), taken_edge_p);
8041 /* All other statements produce nothing of interest for VRP, so mark
8042 their outputs varying and prevent further simulation. */
8043 FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
8044 set_value_range_to_varying (get_value_range (def));
8046 return SSA_PROP_VARYING;
8049 /* Union the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
8050 { VR1TYPE, VR0MIN, VR0MAX } and store the result
8051 in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
8052 possible such range. The resulting range is not canonicalized. */
8055 union_ranges (enum value_range_type *vr0type,
8056 tree *vr0min, tree *vr0max,
8057 enum value_range_type vr1type,
8058 tree vr1min, tree vr1max)
8060 bool mineq = operand_equal_p (*vr0min, vr1min, 0);
8061 bool maxeq = operand_equal_p (*vr0max, vr1max, 0);
8063 /* [] is vr0, () is vr1 in the following classification comments. */
8067 if (*vr0type == vr1type)
8068 /* Nothing to do for equal ranges. */
8070 else if ((*vr0type == VR_RANGE
8071 && vr1type == VR_ANTI_RANGE)
8072 || (*vr0type == VR_ANTI_RANGE
8073 && vr1type == VR_RANGE))
8075 /* For anti-range with range union the result is varying. */
8081 else if (operand_less_p (*vr0max, vr1min) == 1
8082 || operand_less_p (vr1max, *vr0min) == 1)
8084 /* [ ] ( ) or ( ) [ ]
8085 If the ranges have an empty intersection, result of the union
8086 operation is the anti-range or if both are anti-ranges
8088 if (*vr0type == VR_ANTI_RANGE
8089 && vr1type == VR_ANTI_RANGE)
8091 else if (*vr0type == VR_ANTI_RANGE
8092 && vr1type == VR_RANGE)
8094 else if (*vr0type == VR_RANGE
8095 && vr1type == VR_ANTI_RANGE)
8101 else if (*vr0type == VR_RANGE
8102 && vr1type == VR_RANGE)
8104 /* The result is the convex hull of both ranges. */
8105 if (operand_less_p (*vr0max, vr1min) == 1)
8107 /* If the result can be an anti-range, create one. */
8108 if (TREE_CODE (*vr0max) == INTEGER_CST
8109 && TREE_CODE (vr1min) == INTEGER_CST
8110 && vrp_val_is_min (*vr0min)
8111 && vrp_val_is_max (vr1max))
8113 tree min = int_const_binop (PLUS_EXPR,
8115 build_int_cst (TREE_TYPE (*vr0max), 1));
8116 tree max = int_const_binop (MINUS_EXPR,
8118 build_int_cst (TREE_TYPE (vr1min), 1));
8119 if (!operand_less_p (max, min))
8121 *vr0type = VR_ANTI_RANGE;
8133 /* If the result can be an anti-range, create one. */
8134 if (TREE_CODE (vr1max) == INTEGER_CST
8135 && TREE_CODE (*vr0min) == INTEGER_CST
8136 && vrp_val_is_min (vr1min)
8137 && vrp_val_is_max (*vr0max))
8139 tree min = int_const_binop (PLUS_EXPR,
8141 build_int_cst (TREE_TYPE (vr1max), 1));
8142 tree max = int_const_binop (MINUS_EXPR,
8144 build_int_cst (TREE_TYPE (*vr0min), 1));
8145 if (!operand_less_p (max, min))
8147 *vr0type = VR_ANTI_RANGE;
8161 else if ((maxeq || operand_less_p (vr1max, *vr0max) == 1)
8162 && (mineq || operand_less_p (*vr0min, vr1min) == 1))
8164 /* [ ( ) ] or [( ) ] or [ ( )] */
8165 if (*vr0type == VR_RANGE
8166 && vr1type == VR_RANGE)
8168 else if (*vr0type == VR_ANTI_RANGE
8169 && vr1type == VR_ANTI_RANGE)
8175 else if (*vr0type == VR_ANTI_RANGE
8176 && vr1type == VR_RANGE)
8178 /* Arbitrarily choose the right or left gap. */
8179 if (!mineq && TREE_CODE (vr1min) == INTEGER_CST)
8180 *vr0max = int_const_binop (MINUS_EXPR, vr1min,
8181 build_int_cst (TREE_TYPE (vr1min), 1));
8182 else if (!maxeq && TREE_CODE (vr1max) == INTEGER_CST)
8183 *vr0min = int_const_binop (PLUS_EXPR, vr1max,
8184 build_int_cst (TREE_TYPE (vr1max), 1));
8188 else if (*vr0type == VR_RANGE
8189 && vr1type == VR_ANTI_RANGE)
8190 /* The result covers everything. */
8195 else if ((maxeq || operand_less_p (*vr0max, vr1max) == 1)
8196 && (mineq || operand_less_p (vr1min, *vr0min) == 1))
8198 /* ( [ ] ) or ([ ] ) or ( [ ]) */
8199 if (*vr0type == VR_RANGE
8200 && vr1type == VR_RANGE)
8206 else if (*vr0type == VR_ANTI_RANGE
8207 && vr1type == VR_ANTI_RANGE)
8209 else if (*vr0type == VR_RANGE
8210 && vr1type == VR_ANTI_RANGE)
8212 *vr0type = VR_ANTI_RANGE;
8213 if (!mineq && TREE_CODE (*vr0min) == INTEGER_CST)
8215 *vr0max = int_const_binop (MINUS_EXPR, *vr0min,
8216 build_int_cst (TREE_TYPE (*vr0min), 1));
8219 else if (!maxeq && TREE_CODE (*vr0max) == INTEGER_CST)
8221 *vr0min = int_const_binop (PLUS_EXPR, *vr0max,
8222 build_int_cst (TREE_TYPE (*vr0max), 1));
8228 else if (*vr0type == VR_ANTI_RANGE
8229 && vr1type == VR_RANGE)
8230 /* The result covers everything. */
8235 else if ((operand_less_p (vr1min, *vr0max) == 1
8236 || operand_equal_p (vr1min, *vr0max, 0))
8237 && operand_less_p (*vr0min, vr1min) == 1
8238 && operand_less_p (*vr0max, vr1max) == 1)
8240 /* [ ( ] ) or [ ]( ) */
8241 if (*vr0type == VR_RANGE
8242 && vr1type == VR_RANGE)
8244 else if (*vr0type == VR_ANTI_RANGE
8245 && vr1type == VR_ANTI_RANGE)
8247 else if (*vr0type == VR_ANTI_RANGE
8248 && vr1type == VR_RANGE)
8250 if (TREE_CODE (vr1min) == INTEGER_CST)
8251 *vr0max = int_const_binop (MINUS_EXPR, vr1min,
8252 build_int_cst (TREE_TYPE (vr1min), 1));
8256 else if (*vr0type == VR_RANGE
8257 && vr1type == VR_ANTI_RANGE)
8259 if (TREE_CODE (*vr0max) == INTEGER_CST)
8262 *vr0min = int_const_binop (PLUS_EXPR, *vr0max,
8263 build_int_cst (TREE_TYPE (*vr0max), 1));
8272 else if ((operand_less_p (*vr0min, vr1max) == 1
8273 || operand_equal_p (*vr0min, vr1max, 0))
8274 && operand_less_p (vr1min, *vr0min) == 1
8275 && operand_less_p (vr1max, *vr0max) == 1)
8277 /* ( [ ) ] or ( )[ ] */
8278 if (*vr0type == VR_RANGE
8279 && vr1type == VR_RANGE)
8281 else if (*vr0type == VR_ANTI_RANGE
8282 && vr1type == VR_ANTI_RANGE)
8284 else if (*vr0type == VR_ANTI_RANGE
8285 && vr1type == VR_RANGE)
8287 if (TREE_CODE (vr1max) == INTEGER_CST)
8288 *vr0min = int_const_binop (PLUS_EXPR, vr1max,
8289 build_int_cst (TREE_TYPE (vr1max), 1));
8293 else if (*vr0type == VR_RANGE
8294 && vr1type == VR_ANTI_RANGE)
8296 if (TREE_CODE (*vr0min) == INTEGER_CST)
8300 *vr0max = int_const_binop (MINUS_EXPR, *vr0min,
8301 build_int_cst (TREE_TYPE (*vr0min), 1));
8315 *vr0type = VR_VARYING;
8316 *vr0min = NULL_TREE;
8317 *vr0max = NULL_TREE;
8320 /* Intersect the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
8321 { VR1TYPE, VR0MIN, VR0MAX } and store the result
8322 in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
8323 possible such range. The resulting range is not canonicalized. */
8326 intersect_ranges (enum value_range_type *vr0type,
8327 tree *vr0min, tree *vr0max,
8328 enum value_range_type vr1type,
8329 tree vr1min, tree vr1max)
8331 bool mineq = operand_equal_p (*vr0min, vr1min, 0);
8332 bool maxeq = operand_equal_p (*vr0max, vr1max, 0);
8334 /* [] is vr0, () is vr1 in the following classification comments. */
8338 if (*vr0type == vr1type)
8339 /* Nothing to do for equal ranges. */
8341 else if ((*vr0type == VR_RANGE
8342 && vr1type == VR_ANTI_RANGE)
8343 || (*vr0type == VR_ANTI_RANGE
8344 && vr1type == VR_RANGE))
8346 /* For anti-range with range intersection the result is empty. */
8347 *vr0type = VR_UNDEFINED;
8348 *vr0min = NULL_TREE;
8349 *vr0max = NULL_TREE;
8354 else if (operand_less_p (*vr0max, vr1min) == 1
8355 || operand_less_p (vr1max, *vr0min) == 1)
8357 /* [ ] ( ) or ( ) [ ]
8358 If the ranges have an empty intersection, the result of the
8359 intersect operation is the range for intersecting an
8360 anti-range with a range or empty when intersecting two ranges. */
8361 if (*vr0type == VR_RANGE
8362 && vr1type == VR_ANTI_RANGE)
8364 else if (*vr0type == VR_ANTI_RANGE
8365 && vr1type == VR_RANGE)
8371 else if (*vr0type == VR_RANGE
8372 && vr1type == VR_RANGE)
8374 *vr0type = VR_UNDEFINED;
8375 *vr0min = NULL_TREE;
8376 *vr0max = NULL_TREE;
8378 else if (*vr0type == VR_ANTI_RANGE
8379 && vr1type == VR_ANTI_RANGE)
8381 /* If the anti-ranges are adjacent to each other merge them. */
8382 if (TREE_CODE (*vr0max) == INTEGER_CST
8383 && TREE_CODE (vr1min) == INTEGER_CST
8384 && operand_less_p (*vr0max, vr1min) == 1
8385 && integer_onep (int_const_binop (MINUS_EXPR,
8388 else if (TREE_CODE (vr1max) == INTEGER_CST
8389 && TREE_CODE (*vr0min) == INTEGER_CST
8390 && operand_less_p (vr1max, *vr0min) == 1
8391 && integer_onep (int_const_binop (MINUS_EXPR,
8394 /* Else arbitrarily take VR0. */
8397 else if ((maxeq || operand_less_p (vr1max, *vr0max) == 1)
8398 && (mineq || operand_less_p (*vr0min, vr1min) == 1))
8400 /* [ ( ) ] or [( ) ] or [ ( )] */
8401 if (*vr0type == VR_RANGE
8402 && vr1type == VR_RANGE)
8404 /* If both are ranges the result is the inner one. */
8409 else if (*vr0type == VR_RANGE
8410 && vr1type == VR_ANTI_RANGE)
8412 /* Choose the right gap if the left one is empty. */
8415 if (TREE_CODE (vr1max) == INTEGER_CST)
8416 *vr0min = int_const_binop (PLUS_EXPR, vr1max,
8417 build_int_cst (TREE_TYPE (vr1max), 1));
8421 /* Choose the left gap if the right one is empty. */
8424 if (TREE_CODE (vr1min) == INTEGER_CST)
8425 *vr0max = int_const_binop (MINUS_EXPR, vr1min,
8426 build_int_cst (TREE_TYPE (vr1min), 1));
8430 /* Choose the anti-range if the range is effectively varying. */
8431 else if (vrp_val_is_min (*vr0min)
8432 && vrp_val_is_max (*vr0max))
8438 /* Else choose the range. */
8440 else if (*vr0type == VR_ANTI_RANGE
8441 && vr1type == VR_ANTI_RANGE)
8442 /* If both are anti-ranges the result is the outer one. */
8444 else if (*vr0type == VR_ANTI_RANGE
8445 && vr1type == VR_RANGE)
8447 /* The intersection is empty. */
8448 *vr0type = VR_UNDEFINED;
8449 *vr0min = NULL_TREE;
8450 *vr0max = NULL_TREE;
8455 else if ((maxeq || operand_less_p (*vr0max, vr1max) == 1)
8456 && (mineq || operand_less_p (vr1min, *vr0min) == 1))
8458 /* ( [ ] ) or ([ ] ) or ( [ ]) */
8459 if (*vr0type == VR_RANGE
8460 && vr1type == VR_RANGE)
8461 /* Choose the inner range. */
8463 else if (*vr0type == VR_ANTI_RANGE
8464 && vr1type == VR_RANGE)
8466 /* Choose the right gap if the left is empty. */
8469 *vr0type = VR_RANGE;
8470 if (TREE_CODE (*vr0max) == INTEGER_CST)
8471 *vr0min = int_const_binop (PLUS_EXPR, *vr0max,
8472 build_int_cst (TREE_TYPE (*vr0max), 1));
8477 /* Choose the left gap if the right is empty. */
8480 *vr0type = VR_RANGE;
8481 if (TREE_CODE (*vr0min) == INTEGER_CST)
8482 *vr0max = int_const_binop (MINUS_EXPR, *vr0min,
8483 build_int_cst (TREE_TYPE (*vr0min), 1));
8488 /* Choose the anti-range if the range is effectively varying. */
8489 else if (vrp_val_is_min (vr1min)
8490 && vrp_val_is_max (vr1max))
8492 /* Else choose the range. */
8500 else if (*vr0type == VR_ANTI_RANGE
8501 && vr1type == VR_ANTI_RANGE)
8503 /* If both are anti-ranges the result is the outer one. */
8508 else if (vr1type == VR_ANTI_RANGE
8509 && *vr0type == VR_RANGE)
8511 /* The intersection is empty. */
8512 *vr0type = VR_UNDEFINED;
8513 *vr0min = NULL_TREE;
8514 *vr0max = NULL_TREE;
8519 else if ((operand_less_p (vr1min, *vr0max) == 1
8520 || operand_equal_p (vr1min, *vr0max, 0))
8521 && operand_less_p (*vr0min, vr1min) == 1)
8523 /* [ ( ] ) or [ ]( ) */
8524 if (*vr0type == VR_ANTI_RANGE
8525 && vr1type == VR_ANTI_RANGE)
8527 else if (*vr0type == VR_RANGE
8528 && vr1type == VR_RANGE)
8530 else if (*vr0type == VR_RANGE
8531 && vr1type == VR_ANTI_RANGE)
8533 if (TREE_CODE (vr1min) == INTEGER_CST)
8534 *vr0max = int_const_binop (MINUS_EXPR, vr1min,
8535 build_int_cst (TREE_TYPE (vr1min), 1));
8539 else if (*vr0type == VR_ANTI_RANGE
8540 && vr1type == VR_RANGE)
8542 *vr0type = VR_RANGE;
8543 if (TREE_CODE (*vr0max) == INTEGER_CST)
8544 *vr0min = int_const_binop (PLUS_EXPR, *vr0max,
8545 build_int_cst (TREE_TYPE (*vr0max), 1));
8553 else if ((operand_less_p (*vr0min, vr1max) == 1
8554 || operand_equal_p (*vr0min, vr1max, 0))
8555 && operand_less_p (vr1min, *vr0min) == 1)
8557 /* ( [ ) ] or ( )[ ] */
8558 if (*vr0type == VR_ANTI_RANGE
8559 && vr1type == VR_ANTI_RANGE)
8561 else if (*vr0type == VR_RANGE
8562 && vr1type == VR_RANGE)
8564 else if (*vr0type == VR_RANGE
8565 && vr1type == VR_ANTI_RANGE)
8567 if (TREE_CODE (vr1max) == INTEGER_CST)
8568 *vr0min = int_const_binop (PLUS_EXPR, vr1max,
8569 build_int_cst (TREE_TYPE (vr1max), 1));
8573 else if (*vr0type == VR_ANTI_RANGE
8574 && vr1type == VR_RANGE)
8576 *vr0type = VR_RANGE;
8577 if (TREE_CODE (*vr0min) == INTEGER_CST)
8578 *vr0max = int_const_binop (MINUS_EXPR, *vr0min,
8579 build_int_cst (TREE_TYPE (*vr0min), 1));
8588 /* As a fallback simply use { *VRTYPE, *VR0MIN, *VR0MAX } as
8589 result for the intersection. That's always a conservative
8590 correct estimate. */
8596 /* Intersect the two value-ranges *VR0 and *VR1 and store the result
8597 in *VR0. This may not be the smallest possible such range. */
8600 vrp_intersect_ranges_1 (value_range_t *vr0, value_range_t *vr1)
8602 value_range_t saved;
8604 /* If either range is VR_VARYING the other one wins. */
8605 if (vr1->type == VR_VARYING)
8607 if (vr0->type == VR_VARYING)
8609 copy_value_range (vr0, vr1);
8613 /* When either range is VR_UNDEFINED the resulting range is
8614 VR_UNDEFINED, too. */
8615 if (vr0->type == VR_UNDEFINED)
8617 if (vr1->type == VR_UNDEFINED)
8619 set_value_range_to_undefined (vr0);
8623 /* Save the original vr0 so we can return it as conservative intersection
8624 result when our worker turns things to varying. */
8626 intersect_ranges (&vr0->type, &vr0->min, &vr0->max,
8627 vr1->type, vr1->min, vr1->max);
8628 /* Make sure to canonicalize the result though as the inversion of a
8629 VR_RANGE can still be a VR_RANGE. */
8630 set_and_canonicalize_value_range (vr0, vr0->type,
8631 vr0->min, vr0->max, vr0->equiv);
8632 /* If that failed, use the saved original VR0. */
8633 if (vr0->type == VR_VARYING)
8638 /* If the result is VR_UNDEFINED there is no need to mess with
8639 the equivalencies. */
8640 if (vr0->type == VR_UNDEFINED)
8643 /* The resulting set of equivalences for range intersection is the union of
8645 if (vr0->equiv && vr1->equiv && vr0->equiv != vr1->equiv)
8646 bitmap_ior_into (vr0->equiv, vr1->equiv);
8647 else if (vr1->equiv && !vr0->equiv)
8648 bitmap_copy (vr0->equiv, vr1->equiv);
8652 vrp_intersect_ranges (value_range_t *vr0, value_range_t *vr1)
8654 if (dump_file && (dump_flags & TDF_DETAILS))
8656 fprintf (dump_file, "Intersecting\n ");
8657 dump_value_range (dump_file, vr0);
8658 fprintf (dump_file, "\nand\n ");
8659 dump_value_range (dump_file, vr1);
8660 fprintf (dump_file, "\n");
8662 vrp_intersect_ranges_1 (vr0, vr1);
8663 if (dump_file && (dump_flags & TDF_DETAILS))
8665 fprintf (dump_file, "to\n ");
8666 dump_value_range (dump_file, vr0);
8667 fprintf (dump_file, "\n");
8671 /* Meet operation for value ranges. Given two value ranges VR0 and
8672 VR1, store in VR0 a range that contains both VR0 and VR1. This
8673 may not be the smallest possible such range. */
8676 vrp_meet_1 (value_range_t *vr0, value_range_t *vr1)
8678 value_range_t saved;
8680 if (vr0->type == VR_UNDEFINED)
8682 set_value_range (vr0, vr1->type, vr1->min, vr1->max, vr1->equiv);
8686 if (vr1->type == VR_UNDEFINED)
8688 /* VR0 already has the resulting range. */
8692 if (vr0->type == VR_VARYING)
8694 /* Nothing to do. VR0 already has the resulting range. */
8698 if (vr1->type == VR_VARYING)
8700 set_value_range_to_varying (vr0);
8705 union_ranges (&vr0->type, &vr0->min, &vr0->max,
8706 vr1->type, vr1->min, vr1->max);
8707 if (vr0->type == VR_VARYING)
8709 /* Failed to find an efficient meet. Before giving up and setting
8710 the result to VARYING, see if we can at least derive a useful
8711 anti-range. FIXME, all this nonsense about distinguishing
8712 anti-ranges from ranges is necessary because of the odd
8713 semantics of range_includes_zero_p and friends. */
8714 if (((saved.type == VR_RANGE
8715 && range_includes_zero_p (saved.min, saved.max) == 0)
8716 || (saved.type == VR_ANTI_RANGE
8717 && range_includes_zero_p (saved.min, saved.max) == 1))
8718 && ((vr1->type == VR_RANGE
8719 && range_includes_zero_p (vr1->min, vr1->max) == 0)
8720 || (vr1->type == VR_ANTI_RANGE
8721 && range_includes_zero_p (vr1->min, vr1->max) == 1)))
8723 set_value_range_to_nonnull (vr0, TREE_TYPE (saved.min));
8725 /* Since this meet operation did not result from the meeting of
8726 two equivalent names, VR0 cannot have any equivalences. */
8728 bitmap_clear (vr0->equiv);
8732 set_value_range_to_varying (vr0);
8735 set_and_canonicalize_value_range (vr0, vr0->type, vr0->min, vr0->max,
8737 if (vr0->type == VR_VARYING)
8740 /* The resulting set of equivalences is always the intersection of
8742 if (vr0->equiv && vr1->equiv && vr0->equiv != vr1->equiv)
8743 bitmap_and_into (vr0->equiv, vr1->equiv);
8744 else if (vr0->equiv && !vr1->equiv)
8745 bitmap_clear (vr0->equiv);
8749 vrp_meet (value_range_t *vr0, value_range_t *vr1)
8751 if (dump_file && (dump_flags & TDF_DETAILS))
8753 fprintf (dump_file, "Meeting\n ");
8754 dump_value_range (dump_file, vr0);
8755 fprintf (dump_file, "\nand\n ");
8756 dump_value_range (dump_file, vr1);
8757 fprintf (dump_file, "\n");
8759 vrp_meet_1 (vr0, vr1);
8760 if (dump_file && (dump_flags & TDF_DETAILS))
8762 fprintf (dump_file, "to\n ");
8763 dump_value_range (dump_file, vr0);
8764 fprintf (dump_file, "\n");
8769 /* Visit all arguments for PHI node PHI that flow through executable
8770 edges. If a valid value range can be derived from all the incoming
8771 value ranges, set a new range for the LHS of PHI. */
8773 static enum ssa_prop_result
8774 vrp_visit_phi_node (gphi *phi)
8777 tree lhs = PHI_RESULT (phi);
8778 value_range_t *lhs_vr = get_value_range (lhs);
8779 value_range_t vr_result = VR_INITIALIZER;
8781 int edges, old_edges;
8784 if (dump_file && (dump_flags & TDF_DETAILS))
8786 fprintf (dump_file, "\nVisiting PHI node: ");
8787 print_gimple_stmt (dump_file, phi, 0, dump_flags);
8791 for (i = 0; i < gimple_phi_num_args (phi); i++)
8793 edge e = gimple_phi_arg_edge (phi, i);
8795 if (dump_file && (dump_flags & TDF_DETAILS))
8798 " Argument #%d (%d -> %d %sexecutable)\n",
8799 (int) i, e->src->index, e->dest->index,
8800 (e->flags & EDGE_EXECUTABLE) ? "" : "not ");
8803 if (e->flags & EDGE_EXECUTABLE)
8805 tree arg = PHI_ARG_DEF (phi, i);
8806 value_range_t vr_arg;
8810 if (TREE_CODE (arg) == SSA_NAME)
8812 vr_arg = *(get_value_range (arg));
8813 /* Do not allow equivalences or symbolic ranges to leak in from
8814 backedges. That creates invalid equivalencies.
8815 See PR53465 and PR54767. */
8816 if (e->flags & EDGE_DFS_BACK)
8818 if (vr_arg.type == VR_RANGE
8819 || vr_arg.type == VR_ANTI_RANGE)
8821 vr_arg.equiv = NULL;
8822 if (symbolic_range_p (&vr_arg))
8824 vr_arg.type = VR_VARYING;
8825 vr_arg.min = NULL_TREE;
8826 vr_arg.max = NULL_TREE;
8832 /* If the non-backedge arguments range is VR_VARYING then
8833 we can still try recording a simple equivalence. */
8834 if (vr_arg.type == VR_VARYING)
8836 vr_arg.type = VR_RANGE;
8839 vr_arg.equiv = NULL;
8845 if (TREE_OVERFLOW_P (arg))
8846 arg = drop_tree_overflow (arg);
8848 vr_arg.type = VR_RANGE;
8851 vr_arg.equiv = NULL;
8854 if (dump_file && (dump_flags & TDF_DETAILS))
8856 fprintf (dump_file, "\t");
8857 print_generic_expr (dump_file, arg, dump_flags);
8858 fprintf (dump_file, ": ");
8859 dump_value_range (dump_file, &vr_arg);
8860 fprintf (dump_file, "\n");
8864 copy_value_range (&vr_result, &vr_arg);
8866 vrp_meet (&vr_result, &vr_arg);
8869 if (vr_result.type == VR_VARYING)
8874 if (vr_result.type == VR_VARYING)
8876 else if (vr_result.type == VR_UNDEFINED)
8879 old_edges = vr_phi_edge_counts[SSA_NAME_VERSION (lhs)];
8880 vr_phi_edge_counts[SSA_NAME_VERSION (lhs)] = edges;
8882 /* To prevent infinite iterations in the algorithm, derive ranges
8883 when the new value is slightly bigger or smaller than the
8884 previous one. We don't do this if we have seen a new executable
8885 edge; this helps us avoid an overflow infinity for conditionals
8886 which are not in a loop. If the old value-range was VR_UNDEFINED
8887 use the updated range and iterate one more time. */
8889 && gimple_phi_num_args (phi) > 1
8890 && edges == old_edges
8891 && lhs_vr->type != VR_UNDEFINED)
8893 /* Compare old and new ranges, fall back to varying if the
8894 values are not comparable. */
8895 int cmp_min = compare_values (lhs_vr->min, vr_result.min);
8898 int cmp_max = compare_values (lhs_vr->max, vr_result.max);
8902 /* For non VR_RANGE or for pointers fall back to varying if
8903 the range changed. */
8904 if ((lhs_vr->type != VR_RANGE || vr_result.type != VR_RANGE
8905 || POINTER_TYPE_P (TREE_TYPE (lhs)))
8906 && (cmp_min != 0 || cmp_max != 0))
8909 /* If the new minimum is larger than than the previous one
8910 retain the old value. If the new minimum value is smaller
8911 than the previous one and not -INF go all the way to -INF + 1.
8912 In the first case, to avoid infinite bouncing between different
8913 minimums, and in the other case to avoid iterating millions of
8914 times to reach -INF. Going to -INF + 1 also lets the following
8915 iteration compute whether there will be any overflow, at the
8916 expense of one additional iteration. */
8918 vr_result.min = lhs_vr->min;
8919 else if (cmp_min > 0
8920 && !vrp_val_is_min (vr_result.min))
8922 = int_const_binop (PLUS_EXPR,
8923 vrp_val_min (TREE_TYPE (vr_result.min)),
8924 build_int_cst (TREE_TYPE (vr_result.min), 1));
8926 /* Similarly for the maximum value. */
8928 vr_result.max = lhs_vr->max;
8929 else if (cmp_max < 0
8930 && !vrp_val_is_max (vr_result.max))
8932 = int_const_binop (MINUS_EXPR,
8933 vrp_val_max (TREE_TYPE (vr_result.min)),
8934 build_int_cst (TREE_TYPE (vr_result.min), 1));
8936 /* If we dropped either bound to +-INF then if this is a loop
8937 PHI node SCEV may known more about its value-range. */
8938 if ((cmp_min > 0 || cmp_min < 0
8939 || cmp_max < 0 || cmp_max > 0)
8940 && (l = loop_containing_stmt (phi))
8941 && l->header == gimple_bb (phi))
8942 adjust_range_with_scev (&vr_result, l, phi, lhs);
8944 /* If we will end up with a (-INF, +INF) range, set it to
8945 VARYING. Same if the previous max value was invalid for
8946 the type and we end up with vr_result.min > vr_result.max. */
8947 if ((vrp_val_is_max (vr_result.max)
8948 && vrp_val_is_min (vr_result.min))
8949 || compare_values (vr_result.min,
8954 /* If the new range is different than the previous value, keep
8957 if (update_value_range (lhs, &vr_result))
8959 if (dump_file && (dump_flags & TDF_DETAILS))
8961 fprintf (dump_file, "Found new range for ");
8962 print_generic_expr (dump_file, lhs, 0);
8963 fprintf (dump_file, ": ");
8964 dump_value_range (dump_file, &vr_result);
8965 fprintf (dump_file, "\n");
8968 if (vr_result.type == VR_VARYING)
8969 return SSA_PROP_VARYING;
8971 return SSA_PROP_INTERESTING;
8974 /* Nothing changed, don't add outgoing edges. */
8975 return SSA_PROP_NOT_INTERESTING;
8977 /* No match found. Set the LHS to VARYING. */
8979 set_value_range_to_varying (lhs_vr);
8980 return SSA_PROP_VARYING;
8983 /* Simplify boolean operations if the source is known
8984 to be already a boolean. */
8986 simplify_truth_ops_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
8988 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
8990 bool need_conversion;
8992 /* We handle only !=/== case here. */
8993 gcc_assert (rhs_code == EQ_EXPR || rhs_code == NE_EXPR);
8995 op0 = gimple_assign_rhs1 (stmt);
8996 if (!op_with_boolean_value_range_p (op0))
8999 op1 = gimple_assign_rhs2 (stmt);
9000 if (!op_with_boolean_value_range_p (op1))
9003 /* Reduce number of cases to handle to NE_EXPR. As there is no
9004 BIT_XNOR_EXPR we cannot replace A == B with a single statement. */
9005 if (rhs_code == EQ_EXPR)
9007 if (TREE_CODE (op1) == INTEGER_CST)
9008 op1 = int_const_binop (BIT_XOR_EXPR, op1,
9009 build_int_cst (TREE_TYPE (op1), 1));
9014 lhs = gimple_assign_lhs (stmt);
9016 = !useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (op0));
9018 /* Make sure to not sign-extend a 1-bit 1 when converting the result. */
9020 && !TYPE_UNSIGNED (TREE_TYPE (op0))
9021 && TYPE_PRECISION (TREE_TYPE (op0)) == 1
9022 && TYPE_PRECISION (TREE_TYPE (lhs)) > 1)
9025 /* For A != 0 we can substitute A itself. */
9026 if (integer_zerop (op1))
9027 gimple_assign_set_rhs_with_ops (gsi,
9029 ? NOP_EXPR : TREE_CODE (op0), op0);
9030 /* For A != B we substitute A ^ B. Either with conversion. */
9031 else if (need_conversion)
9033 tree tem = make_ssa_name (TREE_TYPE (op0));
9035 = gimple_build_assign (tem, BIT_XOR_EXPR, op0, op1);
9036 gsi_insert_before (gsi, newop, GSI_SAME_STMT);
9037 gimple_assign_set_rhs_with_ops (gsi, NOP_EXPR, tem);
9041 gimple_assign_set_rhs_with_ops (gsi, BIT_XOR_EXPR, op0, op1);
9042 update_stmt (gsi_stmt (*gsi));
9047 /* Simplify a division or modulo operator to a right shift or
9048 bitwise and if the first operand is unsigned or is greater
9049 than zero and the second operand is an exact power of two.
9050 For TRUNC_MOD_EXPR op0 % op1 with constant op1, optimize it
9051 into just op0 if op0's range is known to be a subset of
9052 [-op1 + 1, op1 - 1] for signed and [0, op1 - 1] for unsigned
9056 simplify_div_or_mod_using_ranges (gimple stmt)
9058 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
9060 tree op0 = gimple_assign_rhs1 (stmt);
9061 tree op1 = gimple_assign_rhs2 (stmt);
9062 value_range_t *vr = get_value_range (op0);
9064 if (rhs_code == TRUNC_MOD_EXPR
9065 && TREE_CODE (op1) == INTEGER_CST
9066 && tree_int_cst_sgn (op1) == 1
9067 && range_int_cst_p (vr)
9068 && tree_int_cst_lt (vr->max, op1))
9070 if (TYPE_UNSIGNED (TREE_TYPE (op0))
9071 || tree_int_cst_sgn (vr->min) >= 0
9072 || tree_int_cst_lt (fold_unary (NEGATE_EXPR, TREE_TYPE (op1), op1),
9075 /* If op0 already has the range op0 % op1 has,
9076 then TRUNC_MOD_EXPR won't change anything. */
9077 gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
9078 gimple_assign_set_rhs_from_tree (&gsi, op0);
9084 if (!integer_pow2p (op1))
9087 if (TYPE_UNSIGNED (TREE_TYPE (op0)))
9089 val = integer_one_node;
9095 val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
9099 && integer_onep (val)
9100 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
9102 location_t location;
9104 if (!gimple_has_location (stmt))
9105 location = input_location;
9107 location = gimple_location (stmt);
9108 warning_at (location, OPT_Wstrict_overflow,
9109 "assuming signed overflow does not occur when "
9110 "simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
9114 if (val && integer_onep (val))
9118 if (rhs_code == TRUNC_DIV_EXPR)
9120 t = build_int_cst (integer_type_node, tree_log2 (op1));
9121 gimple_assign_set_rhs_code (stmt, RSHIFT_EXPR);
9122 gimple_assign_set_rhs1 (stmt, op0);
9123 gimple_assign_set_rhs2 (stmt, t);
9127 t = build_int_cst (TREE_TYPE (op1), 1);
9128 t = int_const_binop (MINUS_EXPR, op1, t);
9129 t = fold_convert (TREE_TYPE (op0), t);
9131 gimple_assign_set_rhs_code (stmt, BIT_AND_EXPR);
9132 gimple_assign_set_rhs1 (stmt, op0);
9133 gimple_assign_set_rhs2 (stmt, t);
9143 /* If the operand to an ABS_EXPR is >= 0, then eliminate the
9144 ABS_EXPR. If the operand is <= 0, then simplify the
9145 ABS_EXPR into a NEGATE_EXPR. */
9148 simplify_abs_using_ranges (gimple stmt)
9151 tree op = gimple_assign_rhs1 (stmt);
9152 tree type = TREE_TYPE (op);
9153 value_range_t *vr = get_value_range (op);
9155 if (TYPE_UNSIGNED (type))
9157 val = integer_zero_node;
9163 val = compare_range_with_value (LE_EXPR, vr, integer_zero_node, &sop);
9167 val = compare_range_with_value (GE_EXPR, vr, integer_zero_node,
9172 if (integer_zerop (val))
9173 val = integer_one_node;
9174 else if (integer_onep (val))
9175 val = integer_zero_node;
9180 && (integer_onep (val) || integer_zerop (val)))
9182 if (sop && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
9184 location_t location;
9186 if (!gimple_has_location (stmt))
9187 location = input_location;
9189 location = gimple_location (stmt);
9190 warning_at (location, OPT_Wstrict_overflow,
9191 "assuming signed overflow does not occur when "
9192 "simplifying %<abs (X)%> to %<X%> or %<-X%>");
9195 gimple_assign_set_rhs1 (stmt, op);
9196 if (integer_onep (val))
9197 gimple_assign_set_rhs_code (stmt, NEGATE_EXPR);
9199 gimple_assign_set_rhs_code (stmt, SSA_NAME);
9208 /* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR.
9209 If all the bits that are being cleared by & are already
9210 known to be zero from VR, or all the bits that are being
9211 set by | are already known to be one from VR, the bit
9212 operation is redundant. */
9215 simplify_bit_ops_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
9217 tree op0 = gimple_assign_rhs1 (stmt);
9218 tree op1 = gimple_assign_rhs2 (stmt);
9219 tree op = NULL_TREE;
9220 value_range_t vr0 = VR_INITIALIZER;
9221 value_range_t vr1 = VR_INITIALIZER;
9222 wide_int may_be_nonzero0, may_be_nonzero1;
9223 wide_int must_be_nonzero0, must_be_nonzero1;
9226 if (TREE_CODE (op0) == SSA_NAME)
9227 vr0 = *(get_value_range (op0));
9228 else if (is_gimple_min_invariant (op0))
9229 set_value_range_to_value (&vr0, op0, NULL);
9233 if (TREE_CODE (op1) == SSA_NAME)
9234 vr1 = *(get_value_range (op1));
9235 else if (is_gimple_min_invariant (op1))
9236 set_value_range_to_value (&vr1, op1, NULL);
9240 if (!zero_nonzero_bits_from_vr (TREE_TYPE (op0), &vr0, &may_be_nonzero0,
9243 if (!zero_nonzero_bits_from_vr (TREE_TYPE (op1), &vr1, &may_be_nonzero1,
9247 switch (gimple_assign_rhs_code (stmt))
9250 mask = may_be_nonzero0.and_not (must_be_nonzero1);
9256 mask = may_be_nonzero1.and_not (must_be_nonzero0);
9264 mask = may_be_nonzero0.and_not (must_be_nonzero1);
9270 mask = may_be_nonzero1.and_not (must_be_nonzero0);
9281 if (op == NULL_TREE)
9284 gimple_assign_set_rhs_with_ops (gsi, TREE_CODE (op), op);
9285 update_stmt (gsi_stmt (*gsi));
9289 /* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has
9290 a known value range VR.
9292 If there is one and only one value which will satisfy the
9293 conditional, then return that value. Else return NULL.
9295 If signed overflow must be undefined for the value to satisfy
9296 the conditional, then set *STRICT_OVERFLOW_P to true. */
9299 test_for_singularity (enum tree_code cond_code, tree op0,
9300 tree op1, value_range_t *vr,
9301 bool *strict_overflow_p)
9306 /* Extract minimum/maximum values which satisfy the
9307 the conditional as it was written. */
9308 if (cond_code == LE_EXPR || cond_code == LT_EXPR)
9310 /* This should not be negative infinity; there is no overflow
9312 min = TYPE_MIN_VALUE (TREE_TYPE (op0));
9315 if (cond_code == LT_EXPR && !is_overflow_infinity (max))
9317 tree one = build_int_cst (TREE_TYPE (op0), 1);
9318 max = fold_build2 (MINUS_EXPR, TREE_TYPE (op0), max, one);
9320 TREE_NO_WARNING (max) = 1;
9323 else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
9325 /* This should not be positive infinity; there is no overflow
9327 max = TYPE_MAX_VALUE (TREE_TYPE (op0));
9330 if (cond_code == GT_EXPR && !is_overflow_infinity (min))
9332 tree one = build_int_cst (TREE_TYPE (op0), 1);
9333 min = fold_build2 (PLUS_EXPR, TREE_TYPE (op0), min, one);
9335 TREE_NO_WARNING (min) = 1;
9339 /* Now refine the minimum and maximum values using any
9340 value range information we have for op0. */
9343 if (compare_values (vr->min, min) == 1)
9345 if (compare_values (vr->max, max) == -1)
9348 /* If the new min/max values have converged to a single value,
9349 then there is only one value which can satisfy the condition,
9350 return that value. */
9351 if (operand_equal_p (min, max, 0) && is_gimple_min_invariant (min))
9353 if ((cond_code == LE_EXPR || cond_code == LT_EXPR)
9354 && is_overflow_infinity (vr->max))
9355 *strict_overflow_p = true;
9356 if ((cond_code == GE_EXPR || cond_code == GT_EXPR)
9357 && is_overflow_infinity (vr->min))
9358 *strict_overflow_p = true;
9366 /* Return whether the value range *VR fits in an integer type specified
9367 by PRECISION and UNSIGNED_P. */
9370 range_fits_type_p (value_range_t *vr, unsigned dest_precision, signop dest_sgn)
9373 unsigned src_precision;
9377 /* We can only handle integral and pointer types. */
9378 src_type = TREE_TYPE (vr->min);
9379 if (!INTEGRAL_TYPE_P (src_type)
9380 && !POINTER_TYPE_P (src_type))
9383 /* An extension is fine unless VR is SIGNED and dest_sgn is UNSIGNED,
9384 and so is an identity transform. */
9385 src_precision = TYPE_PRECISION (TREE_TYPE (vr->min));
9386 src_sgn = TYPE_SIGN (src_type);
9387 if ((src_precision < dest_precision
9388 && !(dest_sgn == UNSIGNED && src_sgn == SIGNED))
9389 || (src_precision == dest_precision && src_sgn == dest_sgn))
9392 /* Now we can only handle ranges with constant bounds. */
9393 if (vr->type != VR_RANGE
9394 || TREE_CODE (vr->min) != INTEGER_CST
9395 || TREE_CODE (vr->max) != INTEGER_CST)
9398 /* For sign changes, the MSB of the wide_int has to be clear.
9399 An unsigned value with its MSB set cannot be represented by
9400 a signed wide_int, while a negative value cannot be represented
9401 by an unsigned wide_int. */
9402 if (src_sgn != dest_sgn
9403 && (wi::lts_p (vr->min, 0) || wi::lts_p (vr->max, 0)))
9406 /* Then we can perform the conversion on both ends and compare
9407 the result for equality. */
9408 tem = wi::ext (wi::to_widest (vr->min), dest_precision, dest_sgn);
9409 if (tem != wi::to_widest (vr->min))
9411 tem = wi::ext (wi::to_widest (vr->max), dest_precision, dest_sgn);
9412 if (tem != wi::to_widest (vr->max))
9418 /* Simplify a conditional using a relational operator to an equality
9419 test if the range information indicates only one value can satisfy
9420 the original conditional. */
9423 simplify_cond_using_ranges (gcond *stmt)
9425 tree op0 = gimple_cond_lhs (stmt);
9426 tree op1 = gimple_cond_rhs (stmt);
9427 enum tree_code cond_code = gimple_cond_code (stmt);
9429 if (cond_code != NE_EXPR
9430 && cond_code != EQ_EXPR
9431 && TREE_CODE (op0) == SSA_NAME
9432 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
9433 && is_gimple_min_invariant (op1))
9435 value_range_t *vr = get_value_range (op0);
9437 /* If we have range information for OP0, then we might be
9438 able to simplify this conditional. */
9439 if (vr->type == VR_RANGE)
9441 enum warn_strict_overflow_code wc = WARN_STRICT_OVERFLOW_COMPARISON;
9443 tree new_tree = test_for_singularity (cond_code, op0, op1, vr, &sop);
9446 && (!sop || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))))
9450 fprintf (dump_file, "Simplified relational ");
9451 print_gimple_stmt (dump_file, stmt, 0, 0);
9452 fprintf (dump_file, " into ");
9455 gimple_cond_set_code (stmt, EQ_EXPR);
9456 gimple_cond_set_lhs (stmt, op0);
9457 gimple_cond_set_rhs (stmt, new_tree);
9463 print_gimple_stmt (dump_file, stmt, 0, 0);
9464 fprintf (dump_file, "\n");
9467 if (sop && issue_strict_overflow_warning (wc))
9469 location_t location = input_location;
9470 if (gimple_has_location (stmt))
9471 location = gimple_location (stmt);
9473 warning_at (location, OPT_Wstrict_overflow,
9474 "assuming signed overflow does not occur when "
9475 "simplifying conditional");
9481 /* Try again after inverting the condition. We only deal
9482 with integral types here, so no need to worry about
9483 issues with inverting FP comparisons. */
9485 new_tree = test_for_singularity
9486 (invert_tree_comparison (cond_code, false),
9487 op0, op1, vr, &sop);
9490 && (!sop || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))))
9494 fprintf (dump_file, "Simplified relational ");
9495 print_gimple_stmt (dump_file, stmt, 0, 0);
9496 fprintf (dump_file, " into ");
9499 gimple_cond_set_code (stmt, NE_EXPR);
9500 gimple_cond_set_lhs (stmt, op0);
9501 gimple_cond_set_rhs (stmt, new_tree);
9507 print_gimple_stmt (dump_file, stmt, 0, 0);
9508 fprintf (dump_file, "\n");
9511 if (sop && issue_strict_overflow_warning (wc))
9513 location_t location = input_location;
9514 if (gimple_has_location (stmt))
9515 location = gimple_location (stmt);
9517 warning_at (location, OPT_Wstrict_overflow,
9518 "assuming signed overflow does not occur when "
9519 "simplifying conditional");
9527 /* If we have a comparison of an SSA_NAME (OP0) against a constant,
9528 see if OP0 was set by a type conversion where the source of
9529 the conversion is another SSA_NAME with a range that fits
9530 into the range of OP0's type.
9532 If so, the conversion is redundant as the earlier SSA_NAME can be
9533 used for the comparison directly if we just massage the constant in the
9535 if (TREE_CODE (op0) == SSA_NAME
9536 && TREE_CODE (op1) == INTEGER_CST)
9538 gimple def_stmt = SSA_NAME_DEF_STMT (op0);
9541 if (!is_gimple_assign (def_stmt)
9542 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
9545 innerop = gimple_assign_rhs1 (def_stmt);
9547 if (TREE_CODE (innerop) == SSA_NAME
9548 && !POINTER_TYPE_P (TREE_TYPE (innerop)))
9550 value_range_t *vr = get_value_range (innerop);
9552 if (range_int_cst_p (vr)
9553 && range_fits_type_p (vr,
9554 TYPE_PRECISION (TREE_TYPE (op0)),
9555 TYPE_SIGN (TREE_TYPE (op0)))
9556 && int_fits_type_p (op1, TREE_TYPE (innerop))
9557 /* The range must not have overflowed, or if it did overflow
9558 we must not be wrapping/trapping overflow and optimizing
9559 with strict overflow semantics. */
9560 && ((!is_negative_overflow_infinity (vr->min)
9561 && !is_positive_overflow_infinity (vr->max))
9562 || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (innerop))))
9564 /* If the range overflowed and the user has asked for warnings
9565 when strict overflow semantics were used to optimize code,
9566 issue an appropriate warning. */
9567 if (cond_code != EQ_EXPR && cond_code != NE_EXPR
9568 && (is_negative_overflow_infinity (vr->min)
9569 || is_positive_overflow_infinity (vr->max))
9570 && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_CONDITIONAL))
9572 location_t location;
9574 if (!gimple_has_location (stmt))
9575 location = input_location;
9577 location = gimple_location (stmt);
9578 warning_at (location, OPT_Wstrict_overflow,
9579 "assuming signed overflow does not occur when "
9580 "simplifying conditional");
9583 tree newconst = fold_convert (TREE_TYPE (innerop), op1);
9584 gimple_cond_set_lhs (stmt, innerop);
9585 gimple_cond_set_rhs (stmt, newconst);
9594 /* Simplify a switch statement using the value range of the switch
9598 simplify_switch_using_ranges (gswitch *stmt)
9600 tree op = gimple_switch_index (stmt);
9605 size_t i = 0, j = 0, n, n2;
9608 size_t k = 1, l = 0;
9610 if (TREE_CODE (op) == SSA_NAME)
9612 vr = get_value_range (op);
9614 /* We can only handle integer ranges. */
9615 if ((vr->type != VR_RANGE
9616 && vr->type != VR_ANTI_RANGE)
9617 || symbolic_range_p (vr))
9620 /* Find case label for min/max of the value range. */
9621 take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l);
9623 else if (TREE_CODE (op) == INTEGER_CST)
9625 take_default = !find_case_label_index (stmt, 1, op, &i);
9639 n = gimple_switch_num_labels (stmt);
9641 /* Bail out if this is just all edges taken. */
9647 /* Build a new vector of taken case labels. */
9648 vec2 = make_tree_vec (j - i + 1 + l - k + 1 + (int)take_default);
9651 /* Add the default edge, if necessary. */
9653 TREE_VEC_ELT (vec2, n2++) = gimple_switch_default_label (stmt);
9655 for (; i <= j; ++i, ++n2)
9656 TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, i);
9658 for (; k <= l; ++k, ++n2)
9659 TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, k);
9661 /* Mark needed edges. */
9662 for (i = 0; i < n2; ++i)
9664 e = find_edge (gimple_bb (stmt),
9665 label_to_block (CASE_LABEL (TREE_VEC_ELT (vec2, i))));
9666 e->aux = (void *)-1;
9669 /* Queue not needed edges for later removal. */
9670 FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->succs)
9672 if (e->aux == (void *)-1)
9678 if (dump_file && (dump_flags & TDF_DETAILS))
9680 fprintf (dump_file, "removing unreachable case label\n");
9682 to_remove_edges.safe_push (e);
9683 e->flags &= ~EDGE_EXECUTABLE;
9686 /* And queue an update for the stmt. */
9689 to_update_switch_stmts.safe_push (su);
9693 /* Simplify an integral conversion from an SSA name in STMT. */
9696 simplify_conversion_using_ranges (gimple stmt)
9698 tree innerop, middleop, finaltype;
9700 value_range_t *innervr;
9701 signop inner_sgn, middle_sgn, final_sgn;
9702 unsigned inner_prec, middle_prec, final_prec;
9703 widest_int innermin, innermed, innermax, middlemin, middlemed, middlemax;
9705 finaltype = TREE_TYPE (gimple_assign_lhs (stmt));
9706 if (!INTEGRAL_TYPE_P (finaltype))
9708 middleop = gimple_assign_rhs1 (stmt);
9709 def_stmt = SSA_NAME_DEF_STMT (middleop);
9710 if (!is_gimple_assign (def_stmt)
9711 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
9713 innerop = gimple_assign_rhs1 (def_stmt);
9714 if (TREE_CODE (innerop) != SSA_NAME
9715 || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop))
9718 /* Get the value-range of the inner operand. */
9719 innervr = get_value_range (innerop);
9720 if (innervr->type != VR_RANGE
9721 || TREE_CODE (innervr->min) != INTEGER_CST
9722 || TREE_CODE (innervr->max) != INTEGER_CST)
9725 /* Simulate the conversion chain to check if the result is equal if
9726 the middle conversion is removed. */
9727 innermin = wi::to_widest (innervr->min);
9728 innermax = wi::to_widest (innervr->max);
9730 inner_prec = TYPE_PRECISION (TREE_TYPE (innerop));
9731 middle_prec = TYPE_PRECISION (TREE_TYPE (middleop));
9732 final_prec = TYPE_PRECISION (finaltype);
9734 /* If the first conversion is not injective, the second must not
9736 if (wi::gtu_p (innermax - innermin,
9737 wi::mask <widest_int> (middle_prec, false))
9738 && middle_prec < final_prec)
9740 /* We also want a medium value so that we can track the effect that
9741 narrowing conversions with sign change have. */
9742 inner_sgn = TYPE_SIGN (TREE_TYPE (innerop));
9743 if (inner_sgn == UNSIGNED)
9744 innermed = wi::shifted_mask <widest_int> (1, inner_prec - 1, false);
9747 if (wi::cmp (innermin, innermed, inner_sgn) >= 0
9748 || wi::cmp (innermed, innermax, inner_sgn) >= 0)
9749 innermed = innermin;
9751 middle_sgn = TYPE_SIGN (TREE_TYPE (middleop));
9752 middlemin = wi::ext (innermin, middle_prec, middle_sgn);
9753 middlemed = wi::ext (innermed, middle_prec, middle_sgn);
9754 middlemax = wi::ext (innermax, middle_prec, middle_sgn);
9756 /* Require that the final conversion applied to both the original
9757 and the intermediate range produces the same result. */
9758 final_sgn = TYPE_SIGN (finaltype);
9759 if (wi::ext (middlemin, final_prec, final_sgn)
9760 != wi::ext (innermin, final_prec, final_sgn)
9761 || wi::ext (middlemed, final_prec, final_sgn)
9762 != wi::ext (innermed, final_prec, final_sgn)
9763 || wi::ext (middlemax, final_prec, final_sgn)
9764 != wi::ext (innermax, final_prec, final_sgn))
9767 gimple_assign_set_rhs1 (stmt, innerop);
9772 /* Simplify a conversion from integral SSA name to float in STMT. */
9775 simplify_float_conversion_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
9777 tree rhs1 = gimple_assign_rhs1 (stmt);
9778 value_range_t *vr = get_value_range (rhs1);
9779 machine_mode fltmode = TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt)));
9784 /* We can only handle constant ranges. */
9785 if (vr->type != VR_RANGE
9786 || TREE_CODE (vr->min) != INTEGER_CST
9787 || TREE_CODE (vr->max) != INTEGER_CST)
9790 /* First check if we can use a signed type in place of an unsigned. */
9791 if (TYPE_UNSIGNED (TREE_TYPE (rhs1))
9792 && (can_float_p (fltmode, TYPE_MODE (TREE_TYPE (rhs1)), 0)
9793 != CODE_FOR_nothing)
9794 && range_fits_type_p (vr, TYPE_PRECISION (TREE_TYPE (rhs1)), SIGNED))
9795 mode = TYPE_MODE (TREE_TYPE (rhs1));
9796 /* If we can do the conversion in the current input mode do nothing. */
9797 else if (can_float_p (fltmode, TYPE_MODE (TREE_TYPE (rhs1)),
9798 TYPE_UNSIGNED (TREE_TYPE (rhs1))) != CODE_FOR_nothing)
9800 /* Otherwise search for a mode we can use, starting from the narrowest
9801 integer mode available. */
9804 mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
9807 /* If we cannot do a signed conversion to float from mode
9808 or if the value-range does not fit in the signed type
9809 try with a wider mode. */
9810 if (can_float_p (fltmode, mode, 0) != CODE_FOR_nothing
9811 && range_fits_type_p (vr, GET_MODE_PRECISION (mode), SIGNED))
9814 mode = GET_MODE_WIDER_MODE (mode);
9815 /* But do not widen the input. Instead leave that to the
9816 optabs expansion code. */
9817 if (GET_MODE_PRECISION (mode) > TYPE_PRECISION (TREE_TYPE (rhs1)))
9820 while (mode != VOIDmode);
9821 if (mode == VOIDmode)
9825 /* It works, insert a truncation or sign-change before the
9826 float conversion. */
9827 tem = make_ssa_name (build_nonstandard_integer_type
9828 (GET_MODE_PRECISION (mode), 0));
9829 conv = gimple_build_assign (tem, NOP_EXPR, rhs1);
9830 gsi_insert_before (gsi, conv, GSI_SAME_STMT);
9831 gimple_assign_set_rhs1 (stmt, tem);
9837 /* Simplify an internal fn call using ranges if possible. */
9840 simplify_internal_call_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
9842 enum tree_code subcode;
9843 bool is_ubsan = false;
9845 switch (gimple_call_internal_fn (stmt))
9847 case IFN_UBSAN_CHECK_ADD:
9848 subcode = PLUS_EXPR;
9851 case IFN_UBSAN_CHECK_SUB:
9852 subcode = MINUS_EXPR;
9855 case IFN_UBSAN_CHECK_MUL:
9856 subcode = MULT_EXPR;
9859 case IFN_ADD_OVERFLOW:
9860 subcode = PLUS_EXPR;
9862 case IFN_SUB_OVERFLOW:
9863 subcode = MINUS_EXPR;
9865 case IFN_MUL_OVERFLOW:
9866 subcode = MULT_EXPR;
9872 tree op0 = gimple_call_arg (stmt, 0);
9873 tree op1 = gimple_call_arg (stmt, 1);
9876 type = TREE_TYPE (op0);
9877 else if (gimple_call_lhs (stmt) == NULL_TREE)
9880 type = TREE_TYPE (TREE_TYPE (gimple_call_lhs (stmt)));
9881 if (!check_for_binary_op_overflow (subcode, type, op0, op1, &ovf)
9882 || (is_ubsan && ovf))
9886 location_t loc = gimple_location (stmt);
9888 g = gimple_build_assign (gimple_call_lhs (stmt), subcode, op0, op1);
9891 int prec = TYPE_PRECISION (type);
9894 || !useless_type_conversion_p (type, TREE_TYPE (op0))
9895 || !useless_type_conversion_p (type, TREE_TYPE (op1)))
9896 utype = build_nonstandard_integer_type (prec, 1);
9897 if (TREE_CODE (op0) == INTEGER_CST)
9898 op0 = fold_convert (utype, op0);
9899 else if (!useless_type_conversion_p (utype, TREE_TYPE (op0)))
9901 g = gimple_build_assign (make_ssa_name (utype), NOP_EXPR, op0);
9902 gimple_set_location (g, loc);
9903 gsi_insert_before (gsi, g, GSI_SAME_STMT);
9904 op0 = gimple_assign_lhs (g);
9906 if (TREE_CODE (op1) == INTEGER_CST)
9907 op1 = fold_convert (utype, op1);
9908 else if (!useless_type_conversion_p (utype, TREE_TYPE (op1)))
9910 g = gimple_build_assign (make_ssa_name (utype), NOP_EXPR, op1);
9911 gimple_set_location (g, loc);
9912 gsi_insert_before (gsi, g, GSI_SAME_STMT);
9913 op1 = gimple_assign_lhs (g);
9915 g = gimple_build_assign (make_ssa_name (utype), subcode, op0, op1);
9916 gimple_set_location (g, loc);
9917 gsi_insert_before (gsi, g, GSI_SAME_STMT);
9920 g = gimple_build_assign (make_ssa_name (type), NOP_EXPR,
9921 gimple_assign_lhs (g));
9922 gimple_set_location (g, loc);
9923 gsi_insert_before (gsi, g, GSI_SAME_STMT);
9925 g = gimple_build_assign (gimple_call_lhs (stmt), COMPLEX_EXPR,
9926 gimple_assign_lhs (g),
9927 build_int_cst (type, ovf));
9929 gimple_set_location (g, loc);
9930 gsi_replace (gsi, g, false);
9934 /* Simplify STMT using ranges if possible. */
9937 simplify_stmt_using_ranges (gimple_stmt_iterator *gsi)
9939 gimple stmt = gsi_stmt (*gsi);
9940 if (is_gimple_assign (stmt))
9942 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
9943 tree rhs1 = gimple_assign_rhs1 (stmt);
9949 /* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity
9950 if the RHS is zero or one, and the LHS are known to be boolean
9952 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
9953 return simplify_truth_ops_using_ranges (gsi, stmt);
9956 /* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
9957 and BIT_AND_EXPR respectively if the first operand is greater
9958 than zero and the second operand is an exact power of two.
9959 Also optimize TRUNC_MOD_EXPR away if the second operand is
9960 constant and the first operand already has the right value
9962 case TRUNC_DIV_EXPR:
9963 case TRUNC_MOD_EXPR:
9964 if (TREE_CODE (rhs1) == SSA_NAME
9965 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
9966 return simplify_div_or_mod_using_ranges (stmt);
9969 /* Transform ABS (X) into X or -X as appropriate. */
9971 if (TREE_CODE (rhs1) == SSA_NAME
9972 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
9973 return simplify_abs_using_ranges (stmt);
9978 /* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR
9979 if all the bits being cleared are already cleared or
9980 all the bits being set are already set. */
9981 if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
9982 return simplify_bit_ops_using_ranges (gsi, stmt);
9986 if (TREE_CODE (rhs1) == SSA_NAME
9987 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
9988 return simplify_conversion_using_ranges (stmt);
9992 if (TREE_CODE (rhs1) == SSA_NAME
9993 && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
9994 return simplify_float_conversion_using_ranges (gsi, stmt);
10001 else if (gimple_code (stmt) == GIMPLE_COND)
10002 return simplify_cond_using_ranges (as_a <gcond *> (stmt));
10003 else if (gimple_code (stmt) == GIMPLE_SWITCH)
10004 return simplify_switch_using_ranges (as_a <gswitch *> (stmt));
10005 else if (is_gimple_call (stmt)
10006 && gimple_call_internal_p (stmt))
10007 return simplify_internal_call_using_ranges (gsi, stmt);
10012 /* If the statement pointed by SI has a predicate whose value can be
10013 computed using the value range information computed by VRP, compute
10014 its value and return true. Otherwise, return false. */
10017 fold_predicate_in (gimple_stmt_iterator *si)
10019 bool assignment_p = false;
10021 gimple stmt = gsi_stmt (*si);
10023 if (is_gimple_assign (stmt)
10024 && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) == tcc_comparison)
10026 assignment_p = true;
10027 val = vrp_evaluate_conditional (gimple_assign_rhs_code (stmt),
10028 gimple_assign_rhs1 (stmt),
10029 gimple_assign_rhs2 (stmt),
10032 else if (gcond *cond_stmt = dyn_cast <gcond *> (stmt))
10033 val = vrp_evaluate_conditional (gimple_cond_code (cond_stmt),
10034 gimple_cond_lhs (cond_stmt),
10035 gimple_cond_rhs (cond_stmt),
10043 val = fold_convert (gimple_expr_type (stmt), val);
10047 fprintf (dump_file, "Folding predicate ");
10048 print_gimple_expr (dump_file, stmt, 0, 0);
10049 fprintf (dump_file, " to ");
10050 print_generic_expr (dump_file, val, 0);
10051 fprintf (dump_file, "\n");
10054 if (is_gimple_assign (stmt))
10055 gimple_assign_set_rhs_from_tree (si, val);
10058 gcc_assert (gimple_code (stmt) == GIMPLE_COND);
10059 gcond *cond_stmt = as_a <gcond *> (stmt);
10060 if (integer_zerop (val))
10061 gimple_cond_make_false (cond_stmt);
10062 else if (integer_onep (val))
10063 gimple_cond_make_true (cond_stmt);
10065 gcc_unreachable ();
10074 /* Callback for substitute_and_fold folding the stmt at *SI. */
10077 vrp_fold_stmt (gimple_stmt_iterator *si)
10079 if (fold_predicate_in (si))
10082 return simplify_stmt_using_ranges (si);
10085 /* Unwindable const/copy equivalences. */
10086 const_and_copies *equiv_stack;
10088 /* A trivial wrapper so that we can present the generic jump threading
10089 code with a simple API for simplifying statements. STMT is the
10090 statement we want to simplify, WITHIN_STMT provides the location
10091 for any overflow warnings. */
10094 simplify_stmt_for_jump_threading (gimple stmt, gimple within_stmt)
10096 if (gcond *cond_stmt = dyn_cast <gcond *> (stmt))
10097 return vrp_evaluate_conditional (gimple_cond_code (cond_stmt),
10098 gimple_cond_lhs (cond_stmt),
10099 gimple_cond_rhs (cond_stmt),
10102 if (gassign *assign_stmt = dyn_cast <gassign *> (stmt))
10104 value_range_t new_vr = VR_INITIALIZER;
10105 tree lhs = gimple_assign_lhs (assign_stmt);
10107 if (TREE_CODE (lhs) == SSA_NAME
10108 && (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
10109 || POINTER_TYPE_P (TREE_TYPE (lhs))))
10111 extract_range_from_assignment (&new_vr, assign_stmt);
10112 if (range_int_cst_singleton_p (&new_vr))
10120 /* Blocks which have more than one predecessor and more than
10121 one successor present jump threading opportunities, i.e.,
10122 when the block is reached from a specific predecessor, we
10123 may be able to determine which of the outgoing edges will
10124 be traversed. When this optimization applies, we are able
10125 to avoid conditionals at runtime and we may expose secondary
10126 optimization opportunities.
10128 This routine is effectively a driver for the generic jump
10129 threading code. It basically just presents the generic code
10130 with edges that may be suitable for jump threading.
10132 Unlike DOM, we do not iterate VRP if jump threading was successful.
10133 While iterating may expose new opportunities for VRP, it is expected
10134 those opportunities would be very limited and the compile time cost
10135 to expose those opportunities would be significant.
10137 As jump threading opportunities are discovered, they are registered
10138 for later realization. */
10141 identify_jump_threads (void)
10148 /* Ugh. When substituting values earlier in this pass we can
10149 wipe the dominance information. So rebuild the dominator
10150 information as we need it within the jump threading code. */
10151 calculate_dominance_info (CDI_DOMINATORS);
10153 /* We do not allow VRP information to be used for jump threading
10154 across a back edge in the CFG. Otherwise it becomes too
10155 difficult to avoid eliminating loop exit tests. Of course
10156 EDGE_DFS_BACK is not accurate at this time so we have to
10158 mark_dfs_back_edges ();
10160 /* Do not thread across edges we are about to remove. Just marking
10161 them as EDGE_DFS_BACK will do. */
10162 FOR_EACH_VEC_ELT (to_remove_edges, i, e)
10163 e->flags |= EDGE_DFS_BACK;
10165 /* Allocate our unwinder stack to unwind any temporary equivalences
10166 that might be recorded. */
10167 equiv_stack = new const_and_copies (dump_file, dump_flags);
10169 /* To avoid lots of silly node creation, we create a single
10170 conditional and just modify it in-place when attempting to
10172 dummy = gimple_build_cond (EQ_EXPR,
10173 integer_zero_node, integer_zero_node,
10176 /* Walk through all the blocks finding those which present a
10177 potential jump threading opportunity. We could set this up
10178 as a dominator walker and record data during the walk, but
10179 I doubt it's worth the effort for the classes of jump
10180 threading opportunities we are trying to identify at this
10181 point in compilation. */
10182 FOR_EACH_BB_FN (bb, cfun)
10186 /* If the generic jump threading code does not find this block
10187 interesting, then there is nothing to do. */
10188 if (! potentially_threadable_block (bb))
10191 last = last_stmt (bb);
10193 /* We're basically looking for a switch or any kind of conditional with
10194 integral or pointer type arguments. Note the type of the second
10195 argument will be the same as the first argument, so no need to
10196 check it explicitly.
10198 We also handle the case where there are no statements in the
10199 block. This come up with forwarder blocks that are not
10200 optimized away because they lead to a loop header. But we do
10201 want to thread through them as we can sometimes thread to the
10202 loop exit which is obviously profitable. */
10204 || gimple_code (last) == GIMPLE_SWITCH
10205 || (gimple_code (last) == GIMPLE_COND
10206 && TREE_CODE (gimple_cond_lhs (last)) == SSA_NAME
10207 && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (last)))
10208 || POINTER_TYPE_P (TREE_TYPE (gimple_cond_lhs (last))))
10209 && (TREE_CODE (gimple_cond_rhs (last)) == SSA_NAME
10210 || is_gimple_min_invariant (gimple_cond_rhs (last)))))
10214 /* We've got a block with multiple predecessors and multiple
10215 successors which also ends in a suitable conditional or
10216 switch statement. For each predecessor, see if we can thread
10217 it to a specific successor. */
10218 FOR_EACH_EDGE (e, ei, bb->preds)
10220 /* Do not thread across back edges or abnormal edges
10222 if (e->flags & (EDGE_DFS_BACK | EDGE_COMPLEX))
10225 thread_across_edge (dummy, e, true, equiv_stack,
10226 simplify_stmt_for_jump_threading);
10231 /* We do not actually update the CFG or SSA graphs at this point as
10232 ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
10233 handle ASSERT_EXPRs gracefully. */
10236 /* We identified all the jump threading opportunities earlier, but could
10237 not transform the CFG at that time. This routine transforms the
10238 CFG and arranges for the dominator tree to be rebuilt if necessary.
10240 Note the SSA graph update will occur during the normal TODO
10241 processing by the pass manager. */
10243 finalize_jump_threads (void)
10245 thread_through_all_blocks (false);
10246 delete equiv_stack;
10250 /* Traverse all the blocks folding conditionals with known ranges. */
10253 vrp_finalize (void)
10257 values_propagated = true;
10261 fprintf (dump_file, "\nValue ranges after VRP:\n\n");
10262 dump_all_value_ranges (dump_file);
10263 fprintf (dump_file, "\n");
10266 substitute_and_fold (op_with_constant_singleton_value_range,
10267 vrp_fold_stmt, false);
10269 if (warn_array_bounds && first_pass_instance)
10270 check_all_array_refs ();
10272 /* We must identify jump threading opportunities before we release
10273 the datastructures built by VRP. */
10274 identify_jump_threads ();
10276 /* Set value range to non pointer SSA_NAMEs. */
10277 for (i = 0; i < num_vr_values; i++)
10280 tree name = ssa_name (i);
10283 || POINTER_TYPE_P (TREE_TYPE (name))
10284 || (vr_value[i]->type == VR_VARYING)
10285 || (vr_value[i]->type == VR_UNDEFINED))
10288 if ((TREE_CODE (vr_value[i]->min) == INTEGER_CST)
10289 && (TREE_CODE (vr_value[i]->max) == INTEGER_CST)
10290 && (vr_value[i]->type == VR_RANGE
10291 || vr_value[i]->type == VR_ANTI_RANGE))
10292 set_range_info (name, vr_value[i]->type, vr_value[i]->min,
10296 /* Free allocated memory. */
10297 for (i = 0; i < num_vr_values; i++)
10300 BITMAP_FREE (vr_value[i]->equiv);
10301 free (vr_value[i]);
10305 free (vr_phi_edge_counts);
10307 /* So that we can distinguish between VRP data being available
10308 and not available. */
10310 vr_phi_edge_counts = NULL;
10314 /* Main entry point to VRP (Value Range Propagation). This pass is
10315 loosely based on J. R. C. Patterson, ``Accurate Static Branch
10316 Prediction by Value Range Propagation,'' in SIGPLAN Conference on
10317 Programming Language Design and Implementation, pp. 67-78, 1995.
10318 Also available at http://citeseer.ist.psu.edu/patterson95accurate.html
10320 This is essentially an SSA-CCP pass modified to deal with ranges
10321 instead of constants.
10323 While propagating ranges, we may find that two or more SSA name
10324 have equivalent, though distinct ranges. For instance,
10327 2 p_4 = ASSERT_EXPR <p_3, p_3 != 0>
10329 4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>;
10333 In the code above, pointer p_5 has range [q_2, q_2], but from the
10334 code we can also determine that p_5 cannot be NULL and, if q_2 had
10335 a non-varying range, p_5's range should also be compatible with it.
10337 These equivalences are created by two expressions: ASSERT_EXPR and
10338 copy operations. Since p_5 is an assertion on p_4, and p_4 was the
10339 result of another assertion, then we can use the fact that p_5 and
10340 p_4 are equivalent when evaluating p_5's range.
10342 Together with value ranges, we also propagate these equivalences
10343 between names so that we can take advantage of information from
10344 multiple ranges when doing final replacement. Note that this
10345 equivalency relation is transitive but not symmetric.
10347 In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we
10348 cannot assert that q_2 is equivalent to p_5 because q_2 may be used
10349 in contexts where that assertion does not hold (e.g., in line 6).
10351 TODO, the main difference between this pass and Patterson's is that
10352 we do not propagate edge probabilities. We only compute whether
10353 edges can be taken or not. That is, instead of having a spectrum
10354 of jump probabilities between 0 and 1, we only deal with 0, 1 and
10355 DON'T KNOW. In the future, it may be worthwhile to propagate
10356 probabilities to aid branch prediction. */
10358 static unsigned int
10365 loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS);
10366 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
10367 scev_initialize ();
10369 /* ??? This ends up using stale EDGE_DFS_BACK for liveness computation.
10370 Inserting assertions may split edges which will invalidate
10372 insert_range_assertions ();
10374 to_remove_edges.create (10);
10375 to_update_switch_stmts.create (5);
10376 threadedge_initialize_values ();
10378 /* For visiting PHI nodes we need EDGE_DFS_BACK computed. */
10379 mark_dfs_back_edges ();
10382 ssa_propagate (vrp_visit_stmt, vrp_visit_phi_node);
10385 free_numbers_of_iterations_estimates ();
10387 /* ASSERT_EXPRs must be removed before finalizing jump threads
10388 as finalizing jump threads calls the CFG cleanup code which
10389 does not properly handle ASSERT_EXPRs. */
10390 remove_range_assertions ();
10392 /* If we exposed any new variables, go ahead and put them into
10393 SSA form now, before we handle jump threading. This simplifies
10394 interactions between rewriting of _DECL nodes into SSA form
10395 and rewriting SSA_NAME nodes into SSA form after block
10396 duplication and CFG manipulation. */
10397 update_ssa (TODO_update_ssa);
10399 finalize_jump_threads ();
10401 /* Remove dead edges from SWITCH_EXPR optimization. This leaves the
10402 CFG in a broken state and requires a cfg_cleanup run. */
10403 FOR_EACH_VEC_ELT (to_remove_edges, i, e)
10405 /* Update SWITCH_EXPR case label vector. */
10406 FOR_EACH_VEC_ELT (to_update_switch_stmts, i, su)
10409 size_t n = TREE_VEC_LENGTH (su->vec);
10411 gimple_switch_set_num_labels (su->stmt, n);
10412 for (j = 0; j < n; j++)
10413 gimple_switch_set_label (su->stmt, j, TREE_VEC_ELT (su->vec, j));
10414 /* As we may have replaced the default label with a regular one
10415 make sure to make it a real default label again. This ensures
10416 optimal expansion. */
10417 label = gimple_switch_label (su->stmt, 0);
10418 CASE_LOW (label) = NULL_TREE;
10419 CASE_HIGH (label) = NULL_TREE;
10422 if (to_remove_edges.length () > 0)
10424 free_dominance_info (CDI_DOMINATORS);
10425 loops_state_set (LOOPS_NEED_FIXUP);
10428 to_remove_edges.release ();
10429 to_update_switch_stmts.release ();
10430 threadedge_finalize_values ();
10433 loop_optimizer_finalize ();
10439 const pass_data pass_data_vrp =
10441 GIMPLE_PASS, /* type */
10443 OPTGROUP_NONE, /* optinfo_flags */
10444 TV_TREE_VRP, /* tv_id */
10445 PROP_ssa, /* properties_required */
10446 0, /* properties_provided */
10447 0, /* properties_destroyed */
10448 0, /* todo_flags_start */
10449 ( TODO_cleanup_cfg | TODO_update_ssa ), /* todo_flags_finish */
10452 class pass_vrp : public gimple_opt_pass
10455 pass_vrp (gcc::context *ctxt)
10456 : gimple_opt_pass (pass_data_vrp, ctxt)
10459 /* opt_pass methods: */
10460 opt_pass * clone () { return new pass_vrp (m_ctxt); }
10461 virtual bool gate (function *) { return flag_tree_vrp != 0; }
10462 virtual unsigned int execute (function *) { return execute_vrp (); }
10464 }; // class pass_vrp
10466 } // anon namespace
10469 make_pass_vrp (gcc::context *ctxt)
10471 return new pass_vrp (ctxt);