PR tree-optimization/81741
PR tree-optimization/71947
* tree-ssa-dom.c: Include tree-inline.h.
(record_temporary_equivalences): Only record SSA_NAME = SSA_NAME
equivalences if one is more expensive to compute than the other.
* tree-ssa-scopedtables.h (class const_or_copies): Make
record_const_or_copy_raw method private.
(class avail_exprs_stack): New method simplify_binary_operation.
* tree-ssa-scopedtables.c (avail_exprs_stack::lookup_avail_expr): Call
avail_exprs_stack::simplify_binary_operation as needed.
(avail_exprs_stack::simplify_binary_operation): New function.
PR tree-optimization/81741
PR tree-optimization/71947
* gcc.dg/tree-ssa/pr81741.c: New test.
* gcc.dg/tree-ssa/pr71947-7.c: New test.
* gcc.dg/tree-ssa/pr71947-8.c: New test.
* gcc.dg/tree-ssa/pr71947-9.c: New test.
* gcc.dg/tree-ssa/pr71941-1.c: Tweak expected output.
* gcc.dg/tree-ssa/pr71941-2.c: Tweak expected output.
* gcc.dg/tree-ssa/pr71941-3.c: Tweak expected output.
* gcc.dg/tree-ssa/
20030922-2.c: xfail.
From-SVN: r251279
+2017-08-22 Jeff Law <law@redhat.com>
+
+ PR tree-optimization/81741
+ PR tree-optimization/71947
+ * tree-ssa-dom.c: Include tree-inline.h.
+ (record_temporary_equivalences): Only record SSA_NAME = SSA_NAME
+ equivalences if one is more expensive to compute than the other.
+ * tree-ssa-scopedtables.h (class const_or_copies): Make
+ record_const_or_copy_raw method private.
+ (class avail_exprs_stack): New method simplify_binary_operation.
+ * tree-ssa-scopedtables.c (avail_exprs_stack::lookup_avail_expr): Call
+ avail_exprs_stack::simplify_binary_operation as needed.
+ (avail_exprs_stack::simplify_binary_operation): New function.
+
2017-08-22 Sebastian Huber <sebastian.huber@embedded-brains.de>
* config.gcc (powerpc-*-rtems*): Add rs6000/linux64.opt.
+2017-08-22 Jeff Law <law@redhat.com>
+
+ PR tree-optimization/81741
+ PR tree-optimization/71947
+ * gcc.dg/tree-ssa/pr81741.c: New test.
+ * gcc.dg/tree-ssa/pr71947-7.c: New test.
+ * gcc.dg/tree-ssa/pr71947-8.c: New test.
+ * gcc.dg/tree-ssa/pr71947-9.c: New test.
+ * gcc.dg/tree-ssa/pr71941-1.c: Tweak expected output.
+ * gcc.dg/tree-ssa/pr71941-2.c: Tweak expected output.
+ * gcc.dg/tree-ssa/pr71941-3.c: Tweak expected output.
+ * gcc.dg/tree-ssa/20030922-2.c: xfail.
+
2017-08-22 Yvan Roux <yvan.roux@linaro.org>
PR c++/80287
}
/* There should be two IF conditionals. */
-/* { dg-final { scan-tree-dump-times "if " 2 "dom2" } } */
+/* We no longer record the conditional equivalence by design, thus we
+ are unable to simplify the 3rd conditional at compile time. */
+/* { dg-final { scan-tree-dump-times "if " 2 "dom2" { xfail *-*-* } } } */
return ret;
}
-/* { dg-final { scan-tree-dump "Folded to: ret_\[0-9\]+ = 0;" "dom2" } } */
+/* { dg-final { scan-tree-dump "Replaced redundant expr \[^\r\n\]* with .0." "dom2" } } */
return ret;
}
-/* { dg-final { scan-tree-dump "Folded to: ret_\[0-9\]+ = 0;" "dom2" } } */
+/* { dg-final { scan-tree-dump "Replaced redundant expr \[^\r\n\]* with .0." "dom2" } } */
return ret;
}
-/* { dg-final { scan-tree-dump "Folded to: ret_\[0-9\]+ = 0;" "dom2" } } */
+/* { dg-final { scan-tree-dump "Replaced redundant expr \[^\r\n\]* with .0." "dom2" } } */
+
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-vrp -fdump-tree-dom-details" } */
+
+
+int f(int x, int y)
+{
+ int ret;
+ if (x == y)
+ ret = x % y;
+ else
+ ret = 1;
+
+ return ret;
+}
+/* { dg-final { scan-tree-dump "Replaced redundant expr \[^\r\n\]* with .0." "dom2" } } */
+
+
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-vrp -fdump-tree-dom-details" } */
+
+
+int f(int x, int y)
+{
+ int ret;
+ if (x == y)
+ ret = x / y;
+ else
+ ret = 0;
+
+ return ret;
+}
+/* { dg-final { scan-tree-dump "Replaced redundant expr \[^\r\n\]* with .1." "dom2" } } */
+
+
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-vrp -fdump-tree-dom-details" } */
+
+
+int f(int x, int y)
+{
+ int ret;
+ if (x == y)
+ ret = x & y;
+ else
+ ret = 0;
+
+ return ret;
+}
+/* { dg-final { scan-tree-dump "Replaced redundant expr \[^\r\n\]* with .\(x|y\)." "dom2" } } */
+
+
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O2 -w -fdump-tree-dom2-details" } */
+
+#include <string.h>
+
+typedef struct string_s {
+ unsigned long size, alloc;
+ char *ptr;
+} string_t[1];
+
+# define M_ASSUME(x) \
+ (! __builtin_constant_p (!!(x) || !(x)) || (x) ? \
+ (void) 0 : __builtin_unreachable())
+
+int f(string_t s)
+{
+ M_ASSUME(strlen(s->ptr) == s->size);
+ return s->size;
+}
+
+/* { dg-final { scan-assembler-not "strlen" } } */
+
#include "cfgloop.h"
#include "gimple-fold.h"
#include "tree-eh.h"
+#include "tree-inline.h"
#include "gimple-iterator.h"
#include "tree-cfg.h"
#include "tree-into-ssa.h"
/* Record the simple NAME = VALUE equivalence. */
tree rhs = edge_info->rhs;
- record_equality (lhs, rhs, const_and_copies);
- /* We already recorded that LHS = RHS, with canonicalization,
- value chain following, etc.
+ /* If this is a SSA_NAME = SSA_NAME equivalence and one operand is
+ cheaper to compute than the other, then set up the equivalence
+ such that we replace the expensive one with the cheap one.
- We also want to record RHS = LHS, but without any canonicalization
- or value chain following. */
- if (TREE_CODE (rhs) == SSA_NAME)
- const_and_copies->record_const_or_copy_raw (rhs, lhs,
- SSA_NAME_VALUE (rhs));
+ If they are the same cost to compute, then do not record anything. */
+ if (TREE_CODE (lhs) == SSA_NAME && TREE_CODE (rhs) == SSA_NAME)
+ {
+ gimple *rhs_def = SSA_NAME_DEF_STMT (rhs);
+ int rhs_cost = estimate_num_insns (rhs_def, &eni_size_weights);
+
+ gimple *lhs_def = SSA_NAME_DEF_STMT (lhs);
+ int lhs_cost = estimate_num_insns (lhs_def, &eni_size_weights);
+
+ if (rhs_cost > lhs_cost)
+ record_equality (rhs, lhs, const_and_copies);
+ else if (rhs_cost < lhs_cost)
+ record_equality (lhs, rhs, const_and_copies);
+ }
+ else
+ record_equality (lhs, rhs, const_and_copies);
/* If LHS is an SSA_NAME and RHS is a constant integer and LHS was
set via a widening type conversion, then we may be able to record
return NULL;
}
+/* We looked for STMT in the hash table, but did not find it.
+
+ If STMT is an assignment from a binary operator, we may know something
+ about the operands relationship to each other which would allow
+ us to derive a constant value for the RHS of STMT. */
+
+tree
+avail_exprs_stack::simplify_binary_operation (gimple *stmt,
+ class expr_hash_elt element)
+{
+ if (is_gimple_assign (stmt))
+ {
+ struct hashable_expr *expr = element.expr ();
+ if (expr->kind == EXPR_BINARY)
+ {
+ enum tree_code code = expr->ops.binary.op;
+
+ switch (code)
+ {
+ /* For these cases, if we know the operands
+ are equal, then we know the result. */
+ case MIN_EXPR:
+ case MAX_EXPR:
+ case BIT_IOR_EXPR:
+ case BIT_AND_EXPR:
+ case BIT_XOR_EXPR:
+ case MINUS_EXPR:
+ case TRUNC_DIV_EXPR:
+ case CEIL_DIV_EXPR:
+ case FLOOR_DIV_EXPR:
+ case ROUND_DIV_EXPR:
+ case EXACT_DIV_EXPR:
+ case TRUNC_MOD_EXPR:
+ case CEIL_MOD_EXPR:
+ case FLOOR_MOD_EXPR:
+ case ROUND_MOD_EXPR:
+ {
+ /* Build a simple equality expr and query the hash table
+ for it. */
+ struct hashable_expr expr;
+ expr.type = boolean_type_node;
+ expr.kind = EXPR_BINARY;
+ expr.ops.binary.op = EQ_EXPR;
+ expr.ops.binary.opnd0 = gimple_assign_rhs1 (stmt);
+ expr.ops.binary.opnd1 = gimple_assign_rhs2 (stmt);
+ class expr_hash_elt element2 (&expr, NULL_TREE);
+ expr_hash_elt **slot
+ = m_avail_exprs->find_slot (&element2, NO_INSERT);
+ tree result_type = TREE_TYPE (gimple_assign_lhs (stmt));
+
+ /* If the query was successful and returned a nonzero
+ result, then we know that the operands of the binary
+ expression are the same. In many cases this allows
+ us to compute a constant result of the expression
+ at compile time, even if we do not know the exact
+ values of the operands. */
+ if (slot && *slot && integer_onep ((*slot)->lhs ()))
+ {
+ switch (code)
+ {
+ case MIN_EXPR:
+ case MAX_EXPR:
+ case BIT_IOR_EXPR:
+ case BIT_AND_EXPR:
+ return gimple_assign_rhs1 (stmt);
+
+ case BIT_XOR_EXPR:
+ case MINUS_EXPR:
+ case TRUNC_MOD_EXPR:
+ case CEIL_MOD_EXPR:
+ case FLOOR_MOD_EXPR:
+ case ROUND_MOD_EXPR:
+ return build_zero_cst (result_type);
+
+ case TRUNC_DIV_EXPR:
+ case CEIL_DIV_EXPR:
+ case FLOOR_DIV_EXPR:
+ case ROUND_DIV_EXPR:
+ case EXACT_DIV_EXPR:
+ return build_one_cst (result_type);
+
+ default:
+ gcc_unreachable ();
+ }
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ }
+ }
+ return NULL_TREE;
+}
+
/* Search for an existing instance of STMT in the AVAIL_EXPRS_STACK table.
If found, return its LHS. Otherwise insert STMT in the table and
return NULL_TREE.
}
else if (*slot == NULL)
{
+ /* If we did not find the expression in the hash table, we may still
+ be able to produce a result for some expressions. */
+ tree alt = avail_exprs_stack::simplify_binary_operation (stmt, element);
+ if (alt)
+ return alt;
+
class expr_hash_elt *element2 = new expr_hash_elt (element);
*slot = element2;
vec<std::pair<expr_hash_elt_t, expr_hash_elt_t> > m_stack;
hash_table<expr_elt_hasher> *m_avail_exprs;
+ /* For some assignments where the RHS is a binary operator, if we know
+ a equality relationship between the operands, we may be able to compute
+ a result, even if we don't know the exact value of the operands. */
+ tree simplify_binary_operation (gimple *, class expr_hash_elt);
+
/* We do not allow copying this object or initializing one
from another. */
avail_exprs_stack& operator= (const avail_exprs_stack&);
may follow the value chain for the RHS. */
void record_const_or_copy (tree, tree);
- /* Record a single const/copy pair that can be unwound. This version
- does not follow the value chain for the RHS. */
- void record_const_or_copy_raw (tree, tree, tree);
-
/* Special entry point when we want to provide an explicit previous
value for the first argument. Try to get rid of this in the future.
void record_const_or_copy (tree, tree, tree);
private:
+ /* Record a single const/copy pair that can be unwound. This version
+ does not follow the value chain for the RHS. */
+ void record_const_or_copy_raw (tree, tree, tree);
+
vec<tree> m_stack;
const_and_copies& operator= (const const_and_copies&);
const_and_copies (class const_and_copies &);
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