From: kelefth <konstantinos.elefther...@vrull.eu>

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 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 b1fa1678dc3..1b8c35bc6cb 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 00000000000..6a9fc5fa141
--- /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);
+}
-- 
2.47.0

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