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:
* 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>
---
gcc/loop-invariant.cc | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/gcc/loop-invariant.cc b/gcc/loop-invariant.cc
index bcb52bb9c76..79a4c39dfb0 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 trap. */
+ if (!always_reached && asm_noperands (PATTERN (insn)) >= 0)
+ return;
+
depends_on = BITMAP_ALLOC (NULL);
if (!check_dependencies (insn, depends_on))
{
--
2.43.0
