fix regression with MEM commoning

This fixes a regression when canonicalizing refs for LIM PR84362.
This possibly unshares and rewrites the refs in the internal data
and thus pointer equality no longer works in ref_always_accessed
computation.

2020-04-29  Richard Biener  <rguenther@suse.de>

	* tree-ssa-loop-im.c (ref_always_accessed::operator ()):
	Just check whether the stmt stores.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b7ec1386740a8cbfb3fa086a3100aaf9e28a2023..c4afdb053f72f69cee486eb85c9abaf3769946e5 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-29  Richard Biener  <rguenther@suse.de>
+
+       * tree-ssa-loop-im.c (ref_always_accessed::operator ()):
+       Just check whether the stmt stores.
+
 2020-04-28  Alexandre Oliva <oliva@adacore.com>
 
        PR target/94812

diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c
index 273a58038bd87a46948f94e6afb481bfc078b5ae..abd5f702b91ad80f7038e69be7f1f71d19c20098 100644 (file)
--- a/gcc/tree-ssa-loop-im.c
+++ b/gcc/tree-ssa-loop-im.c
@@ -2179,20 +2179,21 @@ ref_always_accessed::operator () (mem_ref_loc *loc)
 {
   class loop *must_exec;
 
-  if (!get_lim_data (loc->stmt))
+  struct lim_aux_data *lim_data = get_lim_data (loc->stmt);
+  if (!lim_data)
     return false;
 
   /* If we require an always executed store make sure the statement
-     stores to the reference.  */
+     is a store.  */
   if (stored_p)
     {
       tree lhs = gimple_get_lhs (loc->stmt);
       if (!lhs
-         || lhs != *loc->ref)
+         || !(DECL_P (lhs) || REFERENCE_CLASS_P (lhs)))
        return false;
     }
 
-  must_exec = get_lim_data (loc->stmt)->always_executed_in;
+  must_exec = lim_data->always_executed_in;
   if (!must_exec)
     return false;