Re: [PATCH] match.pd: Add 2 TYPE_OVERFLOW_SANITIZED checks [PR106990]

[Richard Biener <rguenther@suse.de>]

> Am 19.10.2022 um 10:02 schrieb Jakub Jelinek <jakub@redhat.com>:
> 
> 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?

Ok.

Thanks,
Richard 

> 2022-10-19  Jakub Jelinek  <jakub@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
>