Hi!
As requested in the PR, this adds 2 TYPE_OVERFLOW_SANITIZED checks
and corresponding testcase.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2022-10-19 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/106990
* match.pd ((~X - ~Y) -> Y - X, -x & 1 -> x & 1): Guard with
!TYPE_OVERFLOW_SANITIZED (type).
* c-c++-common/ubsan/pr106990.c: New test.
--- gcc/match.pd.jj 2022-10-13 15:51:08.928071208 +0200
+++ gcc/match.pd 2022-10-18 16:01:12.145705958 +0200
@@ -1331,8 +1331,9 @@ (define_operator_list SYNC_FETCH_AND_AND
/* (~X - ~Y) -> Y - X. */
(simplify
(minus (bit_not @0) (bit_not @1))
- (with { tree utype = unsigned_type_for (type); }
- (convert (minus (convert:utype @1) (convert:utype @0)))))
+ (if (!TYPE_OVERFLOW_SANITIZED (type))
+ (with { tree utype = unsigned_type_for (type); }
+ (convert (minus (convert:utype @1) (convert:utype @0))))))
/* ~(X - Y) -> ~X + Y. */
(simplify
@@ -8176,5 +8177,6 @@ and,
/* -x & 1 -> x & 1. */
(simplify
- (bit_and (negate @0) integer_onep@1)
- (bit_and @0 @1))
+ (bit_and (negate @0) integer_onep@1)
+ (if (!TYPE_OVERFLOW_SANITIZED (type))
+ (bit_and @0 @1)))
--- gcc/testsuite/c-c++-common/ubsan/pr106990.c.jj 2022-10-18
15:56:20.260656260 +0200
+++ gcc/testsuite/c-c++-common/ubsan/pr106990.c 2022-10-18 16:17:37.295403933
+0200
@@ -0,0 +1,29 @@
+/* PR tree-optimization/106990 */
+/* { dg-do run { target int32 } } */
+/* { dg-options "-fsanitize=signed-integer-overflow" } */
+
+__attribute__((noipa)) int
+foo (void)
+{
+ int x = -1956816001;
+ int y = 1999200512;
+ return ~x - ~y;
+}
+
+__attribute__((noipa)) int
+bar (void)
+{
+ int x = -__INT_MAX__ - 1;
+ return -x & 1;
+}
+
+int
+main ()
+{
+ foo ();
+ bar ();
+ return 0;
+}
+
+/* { dg-output "signed integer overflow: 1956816000 - -1999200513 cannot be
represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*negation of -2147483648 cannot be represented in type
'int'; cast to an unsigned type to negate this value to itself" } */
Jakub
