From: Richard Biener <rguenther@suse.de>
To: gcc-patches@gcc.gnu.org
Subject: [PATCH] tree-optimization/89317 - another pattern for &p->x != p + 4
Date: Mon, 12 Dec 2022 08:54:40 +0100 (CET) [thread overview]
Message-ID: <20221212075441.50129138F3@imap2.suse-dmz.suse.de> (raw)
As seen in the original testcase for PR89317 we are missing
comparison simplification patterns for &p->x != p + 4. Fixed
by making an existing one apply. To make the pattern apply
during CCP we need to simplify ccp_fold to not use GENERIC
folding of conditions but also use GIMPLE folding.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/89317
* tree-ssa-ccp.cc (ccp_fold): Handle GIMPLE_COND via
gimple_fold_stmt_to_constant_1.
* match.pd (&a != &a + c): Apply to pointer_plus with non-ADDR_EXPR
base as well.
* gcc.dg/tree-ssa/pr89317.c: Amend.
---
gcc/match.pd | 2 +-
gcc/testsuite/gcc.dg/tree-ssa/pr89317.c | 17 +++++++++++++++++
gcc/tree-ssa-ccp.cc | 11 +----------
3 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index ba83c69734f..3517605c04d 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2263,7 +2263,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
/* (&a + b) !=/== (&a[1] + c) -> (&a[0] - &a[1]) + b !=/== c */
(for neeq (ne eq)
(simplify
- (neeq:c ADDR_EXPR@0 (pointer_plus ADDR_EXPR@2 @3))
+ (neeq:c ADDR_EXPR@0 (pointer_plus @2 @3))
(with { poly_int64 diff; tree inner_type = TREE_TYPE (@3);}
(if (ptr_difference_const (@0, @2, &diff))
(neeq { build_int_cst_type (inner_type, diff); } @3))))
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr89317.c b/gcc/testsuite/gcc.dg/tree-ssa/pr89317.c
index 0d0a049454f..0c8f2f53a45 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr89317.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr89317.c
@@ -10,4 +10,21 @@ int foo (struct b *x)
return b - a;
}
+int bar (struct b *x)
+{
+ int *a = x->data;
+ int *b = ((int*)x) + 4;
+ if (a != b)
+ return 1;
+ return 0;
+}
+
+int baz (struct b *x)
+{
+ int *a = x->data;
+ int *b = ((int*)x) + 4;
+ return (a != b);
+}
+
/* { dg-final { scan-tree-dump "return 4;" "ccp1" } } */
+/* { dg-final { scan-tree-dump-times "return 1;" 2 "ccp1" } } */
diff --git a/gcc/tree-ssa-ccp.cc b/gcc/tree-ssa-ccp.cc
index 69fd7f1d11d..68e69bfe129 100644
--- a/gcc/tree-ssa-ccp.cc
+++ b/gcc/tree-ssa-ccp.cc
@@ -1271,24 +1271,15 @@ valueize_op_1 (tree op)
static tree
ccp_fold (gimple *stmt)
{
- location_t loc = gimple_location (stmt);
switch (gimple_code (stmt))
{
- case GIMPLE_COND:
- {
- /* Handle comparison operators that can appear in GIMPLE form. */
- tree op0 = valueize_op (gimple_cond_lhs (stmt));
- tree op1 = valueize_op (gimple_cond_rhs (stmt));
- enum tree_code code = gimple_cond_code (stmt);
- return fold_binary_loc (loc, code, boolean_type_node, op0, op1);
- }
-
case GIMPLE_SWITCH:
{
/* Return the constant switch index. */
return valueize_op (gimple_switch_index (as_a <gswitch *> (stmt)));
}
+ case GIMPLE_COND:
case GIMPLE_ASSIGN:
case GIMPLE_CALL:
return gimple_fold_stmt_to_constant_1 (stmt,
--
2.35.3
reply other threads:[~2022-12-12 7:54 UTC|newest]
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