diff mbox series

Improve ptr_derefs_may_alias_p for the case of &STRING_CST

Message ID 20220726100930.C4BE538582B1@sourceware.org
State Committed
Commit 67248ad043b366d30e97cb6c192593057e798805
Headers
Series Improve ptr_derefs_may_alias_p for the case of &STRING_CST |

Commit Message

Richard Biener July 26, 2022, 10:08 a.m. UTC 
  When the first pointer happens to be a pointer to a STRING_CST we
give up too early since the 2nd pointer handling could still end
up with a DECL for example which can disambiguate against a STRING_CST
just fine.

Boostrapped and tested on x86_64-unknown-linux-gnu, pushed.

	* tree-ssa-alias.cc (ptr_derefs_may_alias_p): If ptr1
	points to a constant continue checking ptr2.
---
 gcc/tree-ssa-alias.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/gcc/tree-ssa-alias.cc b/gcc/tree-ssa-alias.cc
index 390cd875074..b4c65da5718 100644
--- a/gcc/tree-ssa-alias.cc
+++ b/gcc/tree-ssa-alias.cc
@@ -349,7 +349,9 @@  ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
       else if (base
 	       && DECL_P (base))
 	return ptr_deref_may_alias_decl_p (ptr2, base);
-      else
+      /* Try ptr2 when ptr1 points to a constant.  */
+      else if (base
+	       && !CONSTANT_CLASS_P (base))
 	return true;
     }
   if (TREE_CODE (ptr2) == ADDR_EXPR)