[PATCH] gcc: do not apply store motion on loop with no exits. The temporary variable will not be wrote back to memory as there is no exit of inifinite loop, so we prohibit applying store motion on loops with no exits.

[Xin Wang via Gcc]

Signed-off-by: Xin Wang <yw987194...@gmail.com>

---
 gcc/tree-ssa-loop-im.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/tree-ssa-loop-im.cc b/gcc/tree-ssa-loop-im.cc
index 225964c6215..de0450f5192 100644
--- a/gcc/tree-ssa-loop-im.cc
+++ b/gcc/tree-ssa-loop-im.cc
@@ -3355,6 +3355,9 @@ loop_suitable_for_sm (class loop *loop ATTRIBUTE_UNUSED,
   unsigned i;
   edge ex;
 
+  if (exits.is_empty())
+    return false;
+
   FOR_EACH_VEC_ELT (exits, i, ex)
     if (ex->flags & (EDGE_ABNORMAL | EDGE_EH))
       return false;
-- 
2.25.1