re PR rtl-optimization/80491 (Compiler regression for long-add case.)

	PR rtl-optimization/80491
	* alias.c (memory_modified_in_insn_p): Return true for CALL_INSNs.

From-SVN: r247409

gcc/ChangeLog

+2017-04-29  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/80491
+	* alias.c (memory_modified_in_insn_p): Return true for CALL_INSNs.
+
 2017-04-29  Marc Glisse  <marc.glisse@inria.fr>
 
 	PR tree-optimization/80487

gcc/alias.c

@@ -3221,6 +3221,10 @@ memory_modified_in_insn_p (const_rtx mem, const_rtx insn)
 {
   if (!INSN_P (insn))
     return false;
+  /* Conservatively assume all non-readonly MEMs might be modified in
+     calls.  */
+  if (CALL_P (insn))
+    return true;
   memory_modified = false;
   note_stores (PATTERN (insn), memory_modified_1, CONST_CAST_RTX(mem));
   return memory_modified;