set_value_range_to_value (vr, build_int_cst (type, 0), vr->equiv);
}
-
-/* If abs (min) < abs (max), set VR to [-max, max], if
- abs (min) >= abs (max), set VR to [-min, min]. */
-
-static void
-abs_extent_range (value_range *vr, tree min, tree max)
-{
- int cmp;
-
- gcc_assert (TREE_CODE (min) == INTEGER_CST);
- gcc_assert (TREE_CODE (max) == INTEGER_CST);
- gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min)));
- gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min)));
- min = fold_unary (ABS_EXPR, TREE_TYPE (min), min);
- max = fold_unary (ABS_EXPR, TREE_TYPE (max), max);
- if (TREE_OVERFLOW (min) || TREE_OVERFLOW (max))
- {
- set_value_range_to_varying (vr);
- return;
- }
- cmp = compare_values (min, max);
- if (cmp == -1)
- min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), max);
- else if (cmp == 0 || cmp == 1)
- {
- max = min;
- min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), min);
- }
- else
- {
- set_value_range_to_varying (vr);
- return;
- }
- set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL);
-}
-
/* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
bool
vr0->type = VR_UNDEFINED;
vr1->type = VR_UNDEFINED;
+ /* As a future improvement, we could handle ~[0, A] as: [-INF, -1] U
+ [A+1, +INF]. Not sure if this helps in practice, though. */
+
if (ar->type != VR_ANTI_RANGE
|| TREE_CODE (ar->min) != INTEGER_CST
|| TREE_CODE (ar->max) != INTEGER_CST
static void inline
extract_range_into_wide_ints (value_range *vr,
signop sign, unsigned prec,
- wide_int *wmin, wide_int *wmax)
+ wide_int &wmin, wide_int &wmax)
{
if (range_int_cst_p (vr))
{
- *wmin = wi::to_wide (vr->min);
- *wmax = wi::to_wide (vr->max);
+ wmin = wi::to_wide (vr->min);
+ wmax = wi::to_wide (vr->max);
}
else
{
- *wmin = wi::min_value (prec, sign);
- *wmax = wi::max_value (prec, sign);
+ wmin = wi::min_value (prec, sign);
+ wmax = wi::max_value (prec, sign);
}
}
wide_int wmin, wmax;
wide_int vr0_min, vr0_max;
wide_int vr1_min, vr1_max;
- extract_range_into_wide_ints (&vr0, sign, prec, &vr0_min, &vr0_max);
- extract_range_into_wide_ints (&vr1, sign, prec, &vr1_min, &vr1_max);
+ extract_range_into_wide_ints (&vr0, sign, prec, vr0_min, vr0_max);
+ extract_range_into_wide_ints (&vr1, sign, prec, vr1_min, vr1_max);
if (wide_int_range_min_max (wmin, wmax, code, sign, prec,
vr0_min, vr0_max, vr1_min, vr1_max))
set_value_range (vr, VR_RANGE,
|| code == EXACT_DIV_EXPR
|| code == ROUND_DIV_EXPR)
{
- if (vr0.type != VR_RANGE || symbolic_range_p (&vr0))
+ wide_int dividend_min, dividend_max, divisor_min, divisor_max;
+ wide_int wmin, wmax, extra_min, extra_max;
+ bool extra_range_p;
+
+ /* Special case explicit division by zero as undefined. */
+ if (range_is_null (&vr1))
{
- /* For division, if op1 has VR_RANGE but op0 does not, something
- can be deduced just from that range. Say [min, max] / [4, max]
- gives [min / 4, max / 4] range. */
- if (vr1.type == VR_RANGE
- && !symbolic_range_p (&vr1)
- && range_includes_zero_p (vr1.min, vr1.max) == 0)
- {
- vr0.type = type = VR_RANGE;
- vr0.min = vrp_val_min (expr_type);
- vr0.max = vrp_val_max (expr_type);
- }
+ /* However, we must not eliminate a division by zero if
+ flag_non_call_exceptions. */
+ if (cfun->can_throw_non_call_exceptions)
+ set_value_range_to_varying (vr);
else
- {
- set_value_range_to_varying (vr);
- return;
- }
+ set_value_range_to_undefined (vr);
+ return;
}
- /* For divisions, if flag_non_call_exceptions is true, we must
- not eliminate a division by zero. */
- if (cfun->can_throw_non_call_exceptions
- && (vr1.type != VR_RANGE
- || range_includes_zero_p (vr1.min, vr1.max) != 0))
+ /* First, normalize ranges into constants we can handle. Note
+ that VR_ANTI_RANGE's of constants were already normalized
+ before arriving here.
+
+ NOTE: As a future improvement, we may be able to do better
+ with mixed symbolic (anti-)ranges like [0, A]. See note in
+ ranges_from_anti_range. */
+ extract_range_into_wide_ints (&vr0, sign, prec,
+ dividend_min, dividend_max);
+ extract_range_into_wide_ints (&vr1, sign, prec,
+ divisor_min, divisor_max);
+ if (!wide_int_range_div (wmin, wmax, code, sign, prec,
+ dividend_min, dividend_max,
+ divisor_min, divisor_max,
+ TYPE_OVERFLOW_UNDEFINED (expr_type),
+ TYPE_OVERFLOW_WRAPS (expr_type),
+ extra_range_p, extra_min, extra_max))
{
set_value_range_to_varying (vr);
return;
}
-
- /* For divisions, if op0 is VR_RANGE, we can deduce a range
- even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
- include 0. */
- if (vr0.type == VR_RANGE
- && (vr1.type != VR_RANGE
- || range_includes_zero_p (vr1.min, vr1.max) != 0))
- {
- tree zero = build_int_cst (TREE_TYPE (vr0.min), 0);
- int cmp;
-
- min = NULL_TREE;
- max = NULL_TREE;
- if (TYPE_UNSIGNED (expr_type)
- || value_range_nonnegative_p (&vr1))
- {
- /* For unsigned division or when divisor is known
- to be non-negative, the range has to cover
- all numbers from 0 to max for positive max
- and all numbers from min to 0 for negative min. */
- cmp = compare_values (vr0.max, zero);
- if (cmp == -1)
- {
- /* When vr0.max < 0, vr1.min != 0 and value
- ranges for dividend and divisor are available. */
- if (vr1.type == VR_RANGE
- && !symbolic_range_p (&vr0)
- && !symbolic_range_p (&vr1)
- && compare_values (vr1.min, zero) != 0)
- max = int_const_binop (code, vr0.max, vr1.min);
- else
- max = zero;
- }
- else if (cmp == 0 || cmp == 1)
- max = vr0.max;
- else
- type = VR_VARYING;
- cmp = compare_values (vr0.min, zero);
- if (cmp == 1)
- {
- /* For unsigned division when value ranges for dividend
- and divisor are available. */
- if (vr1.type == VR_RANGE
- && !symbolic_range_p (&vr0)
- && !symbolic_range_p (&vr1)
- && compare_values (vr1.max, zero) != 0)
- min = int_const_binop (code, vr0.min, vr1.max);
- else
- min = zero;
- }
- else if (cmp == 0 || cmp == -1)
- min = vr0.min;
- else
- type = VR_VARYING;
- }
- else
- {
- /* Otherwise the range is -max .. max or min .. -min
- depending on which bound is bigger in absolute value,
- as the division can change the sign. */
- abs_extent_range (vr, vr0.min, vr0.max);
- return;
- }
- if (type == VR_VARYING)
- {
- set_value_range_to_varying (vr);
- return;
- }
- }
- else if (range_int_cst_p (&vr0) && range_int_cst_p (&vr1))
+ set_value_range (vr, VR_RANGE,
+ wide_int_to_tree (expr_type, wmin),
+ wide_int_to_tree (expr_type, wmax), NULL);
+ if (extra_range_p)
{
- extract_range_from_multiplicative_op (vr, code, &vr0, &vr1);
- return;
+ value_range extra_range = VR_INITIALIZER;
+ set_value_range (&extra_range, VR_RANGE,
+ wide_int_to_tree (expr_type, extra_min),
+ wide_int_to_tree (expr_type, extra_max), NULL);
+ vrp_meet (vr, &extra_range);
}
+ return;
}
else if (code == TRUNC_MOD_EXPR)
{
}
wide_int wmin, wmax, tmp;
wide_int vr0_min, vr0_max, vr1_min, vr1_max;
- extract_range_into_wide_ints (&vr0, sign, prec, &vr0_min, &vr0_max);
- extract_range_into_wide_ints (&vr1, sign, prec, &vr1_min, &vr1_max);
+ extract_range_into_wide_ints (&vr0, sign, prec, vr0_min, vr0_max);
+ extract_range_into_wide_ints (&vr1, sign, prec, vr1_min, vr1_max);
wide_int_range_trunc_mod (wmin, wmax, sign, prec,
vr0_min, vr0_max, vr1_min, vr1_max);
min = wide_int_to_tree (expr_type, wmin);
&may_be_nonzero0, &must_be_nonzero0);
vrp_set_zero_nonzero_bits (expr_type, &vr1,
&may_be_nonzero1, &must_be_nonzero1);
- extract_range_into_wide_ints (&vr0, sign, prec, &vr0_min, &vr0_max);
- extract_range_into_wide_ints (&vr1, sign, prec, &vr1_min, &vr1_max);
+ extract_range_into_wide_ints (&vr0, sign, prec, vr0_min, vr0_max);
+ extract_range_into_wide_ints (&vr1, sign, prec, vr1_min, vr1_max);
if (code == BIT_AND_EXPR)
{
if (wide_int_range_bit_and (wmin, wmax, sign, prec,
}
wide_int wmin, wmax;
wide_int vr0_min, vr0_max;
- extract_range_into_wide_ints (&vr0, sign, prec, &vr0_min, &vr0_max);
+ extract_range_into_wide_ints (&vr0, sign, prec, vr0_min, vr0_max);
if (wide_int_range_abs (wmin, wmax, sign, prec, vr0_min, vr0_max,
TYPE_OVERFLOW_UNDEFINED (type)))
set_value_range (vr, VR_RANGE,
#include "system.h"
#include "coretypes.h"
#include "tree.h"
+#include "function.h"
#include "fold-const.h"
#include "wide-int-range.h"
return false;
return true;
}
+
+/* Calculate a division operation on two ranges and store the result in
+ [WMIN, WMAX] U [EXTRA_MIN, EXTRA_MAX].
+
+ If EXTRA_RANGE_P is set upon return, EXTRA_MIN/EXTRA_MAX hold
+ meaningful information, otherwise they should be ignored.
+
+ Return TRUE if we were able to successfully calculate the new range. */
+
+bool
+wide_int_range_div (wide_int &wmin, wide_int &wmax,
+ tree_code code, signop sign, unsigned prec,
+ const wide_int ÷nd_min, const wide_int ÷nd_max,
+ const wide_int &divisor_min, const wide_int &divisor_max,
+ bool overflow_undefined,
+ bool overflow_wraps,
+ bool &extra_range_p,
+ wide_int &extra_min, wide_int &extra_max)
+{
+ extra_range_p = false;
+
+ /* If we know we won't divide by zero, just do the division. */
+ if (!wide_int_range_includes_zero_p (divisor_min, divisor_max, sign))
+ {
+ wide_int_range_multiplicative_op (wmin, wmax, code, sign, prec,
+ dividend_min, dividend_max,
+ divisor_min, divisor_max,
+ overflow_undefined,
+ overflow_wraps);
+ return true;
+ }
+
+ /* If flag_non_call_exceptions, we must not eliminate a division
+ by zero. */
+ if (cfun->can_throw_non_call_exceptions)
+ return false;
+
+ /* If we're definitely dividing by zero, there's nothing to do. */
+ if (wide_int_range_zero_p (divisor_min, divisor_max, prec))
+ return false;
+
+ /* Perform the division in 2 parts, [LB, -1] and [1, UB],
+ which will skip any division by zero.
+
+ First divide by the negative numbers, if any. */
+ if (wi::neg_p (divisor_min, sign))
+ {
+ if (!wide_int_range_multiplicative_op (wmin, wmax,
+ code, sign, prec,
+ dividend_min, dividend_max,
+ divisor_min, wi::minus_one (prec),
+ overflow_undefined,
+ overflow_wraps))
+ return false;
+ extra_range_p = true;
+ }
+ /* Then divide by the non-zero positive numbers, if any. */
+ if (wi::gt_p (divisor_max, wi::zero (prec), sign))
+ {
+ if (!wide_int_range_multiplicative_op (extra_range_p ? extra_min : wmin,
+ extra_range_p ? extra_max : wmax,
+ code, sign, prec,
+ dividend_min, dividend_max,
+ wi::one (prec), divisor_max,
+ overflow_undefined,
+ overflow_wraps))
+ return false;
+ }
+ else
+ extra_range_p = false;
+ return true;
+}
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