gcc:
2018-07-23 Bernd Edlinger <bernd.edlinger@hotmail.de>
PR c/86617
* genmatch.c (dt_operand::gen_match_op): Avoid folding volatile values.
testsuite:
2018-07-23 Bernd Edlinger <bernd.edlinger@hotmail.de>
PR c/86617
* gcc.dg/pr86617.c: New test.
===================================================================
@@ -2748,12 +2748,14 @@ dt_operand::gen_match_op (FILE *f, int indent, con
char match_opname[20];
match_dop->get_name (match_opname);
if (value_match)
- fprintf_indent (f, indent, "if (%s == %s || operand_equal_p (%s, %s, 0))\n",
- opname, match_opname, opname, match_opname);
+ fprintf_indent (f, indent, "if ((%s == %s && ! TREE_SIDE_EFFECTS (%s)) "
+ "|| operand_equal_p (%s, %s, 0))\n",
+ opname, match_opname, opname, opname, match_opname);
else
- fprintf_indent (f, indent, "if (%s == %s || (operand_equal_p (%s, %s, 0) "
+ fprintf_indent (f, indent, "if ((%s == %s && ! TREE_SIDE_EFFECTS (%s)) "
+ "|| (operand_equal_p (%s, %s, 0) "
"&& types_match (%s, %s)))\n",
- opname, match_opname, opname, match_opname,
+ opname, match_opname, opname, opname, match_opname,
opname, match_opname);
fprintf_indent (f, indent + 2, "{\n");
return 1;
===================================================================
@@ -0,0 +1,11 @@
+/* { dg-options "-Os -fdump-rtl-final" } */
+
+volatile unsigned char u8;
+
+void test (void)
+{
+ u8 = u8 + u8;
+ u8 = u8 - u8;
+}
+
+/* { dg-final { scan-rtl-dump-times "mem/v" 6 "final" } } */