From b317dca04e3ffb31144f79cb804ff6835c2a9af8 Mon Sep 17 00:00:00 2001
From: kelefth <konstantinos.eleftheriou@vrull.eu>
Date: Thu, 5 Dec 2024 11:11:27 +0100
Subject: [PATCH] avoid-store-forwarding: bail when an instruction may throw
[PR117816]
Avoid-store-forwarding doesn't handle the case where an instruction in
the store-load sequence contains a REG_EH_REGION note, leading to the
insertion of instructions after it, while it should be the last
instruction in the basic block. This causes an ICE when compiling
using `-O -fnon-call-exceptions -favoid-store-forwarding
-fno-forward-propagate -finstrument-functions`.
This patch rejects the transformation when there are instructions in
the sequence that may throw an exeption.
PR rtl-optimization/117816
gcc/ChangeLog:
* avoid-store-forwarding.cc (store_forwarding_analyzer::avoid_store_forwarding):
Reject the transformation when having instructions that may
throw exceptions in the sequence.
gcc/testsuite/ChangeLog:
* gcc.dg/pr117816.c: New test.
---
gcc/avoid-store-forwarding.cc | 2 +-
gcc/testsuite/gcc.dg/pr117816.c | 11 +++++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/pr117816.c
diff --git a/gcc/avoid-store-forwarding.cc b/gcc/avoid-store-forwarding.cc
index b1fa1678dc30..1b8c35bc6cb7 100644
--- a/gcc/avoid-store-forwarding.cc
+++ b/gcc/avoid-store-forwarding.cc
@@ -429,7 +429,7 @@ store_forwarding_analyzer::avoid_store_forwarding (basic_block bb)
rtx set = single_set (insn);
- if (!set)
+ if (!set || insn_could_throw_p (insn))
{
store_exprs.truncate (0);
continue;
diff --git a/gcc/testsuite/gcc.dg/pr117816.c b/gcc/testsuite/gcc.dg/pr117816.c
new file mode 100644
index 000000000000..6a9fc5fa1415
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr117816.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fnon-call-exceptions -favoid-store-forwarding -fno-forward-propagate -finstrument-functions" } */
+
+char *p;
+int y;
+long x;
+
+void foo()
+{
+ x /= *(int *)__builtin_memmove(&y, 4 + p, 3);
+}
--
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