https://gcc.gnu.org/g:8598a84bf5ca91ddd26f3bf6f944b0235cfa06b4
commit r15-7496-g8598a84bf5ca91ddd26f3bf6f944b0235cfa06b4
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date: Tue Feb 11 21:00:06 2025 -0800
loop-invariant: Treat inline-asm conditional trapping [PR102150]
So inline-asm is known not to trap BUT it can have undefined behavior
if made executed speculatively. This fixes the loop invariant pass to
treat it similarly as trapping cases. If the inline-asm could be executed
always, then it will be pulled out of the loop; otherwise it will be kept
inside the loop.
Bootstrapped and tested on x86_64-linux-gnu.
gcc/ChangeLog:
PR rtl-optimization/102150
* loop-invariant.cc (find_invariant_insn): Treat inline-asm similar
to
trapping instruction and only move them if always executed.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
Diff:
---
gcc/loop-invariant.cc | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/gcc/loop-invariant.cc b/gcc/loop-invariant.cc
index bcb52bb9c76e..236d5ee70eee 100644
--- a/gcc/loop-invariant.cc
+++ b/gcc/loop-invariant.cc
@@ -1123,6 +1123,11 @@ find_invariant_insn (rtx_insn *insn, bool
always_reached, bool always_executed)
if (may_trap_or_fault_p (PATTERN (insn)) && !always_reached)
return;
+ /* inline-asm that is not always executed cannot be moved
+ as it might conditionally trap. */
+ if (!always_reached && asm_noperands (PATTERN (insn)) >= 0)
+ return;
+
depends_on = BITMAP_ALLOC (NULL);
if (!check_dependencies (insn, depends_on))
{
