mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-22 15:02:32 +00:00
a6d689632c
While improving access path analysis a typo happened. Now it can happen that gcc misscompiles. The patch is fixing the issue. However, also other gcc versions 10.2+ are affected. They also should be bumped or the fix should be backported. For more bug information have a look at: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109585 Signed-off-by: Nick Hainke <vincent@systemli.org>
70 lines
1.8 KiB
Diff
70 lines
1.8 KiB
Diff
From bb406a6aea336966681927a27f54ee89c4fd4ea1 Mon Sep 17 00:00:00 2001
|
|
From: Richard Biener <rguenther@suse.de>
|
|
Date: Mon, 24 Apr 2023 13:31:07 +0200
|
|
Subject: [PATCH] rtl-optimization/109585 - alias analysis typo
|
|
|
|
When r10-514-gc6b84edb6110dd2b4fb improved access path analysis
|
|
it introduced a typo that triggers when there's an access to a
|
|
trailing array in the first access path leading to false
|
|
disambiguation.
|
|
|
|
PR rtl-optimization/109585
|
|
* tree-ssa-alias.cc (aliasing_component_refs_p): Fix typo.
|
|
|
|
* gcc.dg/torture/pr109585.c: New testcase.
|
|
|
|
(cherry picked from commit 6d4bd27a60447c7505cb4783e675e98a191a8904)
|
|
---
|
|
gcc/testsuite/gcc.dg/torture/pr109585.c | 33 +++++++++++++++++++++++++
|
|
gcc/tree-ssa-alias.cc | 2 +-
|
|
2 files changed, 34 insertions(+), 1 deletion(-)
|
|
create mode 100644 gcc/testsuite/gcc.dg/torture/pr109585.c
|
|
|
|
--- /dev/null
|
|
+++ b/gcc/testsuite/gcc.dg/torture/pr109585.c
|
|
@@ -0,0 +1,33 @@
|
|
+/* { dg-do run } */
|
|
+
|
|
+#include <stdlib.h>
|
|
+
|
|
+struct P {
|
|
+ long v;
|
|
+ struct P *n;
|
|
+};
|
|
+
|
|
+struct F {
|
|
+ long x;
|
|
+ struct P fam[];
|
|
+};
|
|
+
|
|
+int __attribute__((noipa))
|
|
+f(struct F *f, int i)
|
|
+{
|
|
+ struct P *p = f->fam;
|
|
+ asm("" : "+r"(f): "r"(p));
|
|
+ p->v = 0;
|
|
+ p->n = 0;
|
|
+ return f->fam->n != 0;
|
|
+}
|
|
+
|
|
+int
|
|
+main()
|
|
+{
|
|
+ struct F *m = malloc (sizeof (long) + 2 * sizeof (struct P));
|
|
+ m->fam[0].n = &m->fam[1];
|
|
+ if (f (m, 0))
|
|
+ abort ();
|
|
+ return 0;
|
|
+}
|
|
--- a/gcc/tree-ssa-alias.cc
|
|
+++ b/gcc/tree-ssa-alias.cc
|
|
@@ -1330,7 +1330,7 @@ aliasing_component_refs_p (tree ref1,
|
|
/* If we didn't find a common base, try the other way around. */
|
|
if (cmp_outer <= 0
|
|
|| (end_struct_ref1
|
|
- && compare_type_sizes (TREE_TYPE (end_struct_ref1), type1) <= 0))
|
|
+ && compare_type_sizes (TREE_TYPE (end_struct_ref1), type2) <= 0))
|
|
{
|
|
int res = aliasing_component_refs_walk (ref2, type2, base2,
|
|
offset2, max_size2,
|