https://gcc.gnu.org/g:6d4e8847f74d3c7f8e36f64d009dd0d856826533
commit r16-692-g6d4e8847f74d3c7f8e36f64d009dd0d856826533
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date: Mon Apr 21 13:00:19 2025 -0700
forwprop: Add alias walk limit to optimize_memcpy_to_memset.
As sugguested in
https://gcc.gnu.org/pipermail/gcc-patches/2025-April/681507.html,
this adds the aliasing walk limit.
gcc/ChangeLog:
* tree-ssa-forwprop.cc (optimize_memcpy_to_memset): Add a limit on
the alias walk.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
Diff:
---
gcc/tree-ssa-forwprop.cc | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 71de99f46ffe..0f52e8fe6efc 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -1216,13 +1216,15 @@ optimize_memcpy_to_memset (gimple_stmt_iterator *gsip,
tree dest, tree src, tree
ao_ref_init (&read, src);
tree vuse = gimple_vuse (stmt);
gimple *defstmt;
+ unsigned limit = param_sccvn_max_alias_queries_per_access;
do {
if (vuse == NULL || TREE_CODE (vuse) != SSA_NAME)
return false;
defstmt = SSA_NAME_DEF_STMT (vuse);
if (is_a <gphi*>(defstmt))
return false;
-
+ if (limit-- == 0)
+ return false;
/* If the len was null, then we can use TBBA. */
if (stmt_may_clobber_ref_p_1 (defstmt, &read,
/* tbaa_p = */ len_was_null))
