On Tue, 5 Apr 2022, Jakub Jelinek wrote:
> Hi!
>
> In the following testcase sqrt is declared as unprototyped function
> and so it depends on what type has the argument passed to it.
> If an argument of incorrect type is passed, the sqrt comparison
> simplification can create invalid GIMPLE.
>
> The patch fixes it by punting if there is a mismatch of types.
> As I didn't want to reindent 133 lines, the first hunk contains an
> ugly hack with if (false). If you prefer reindentation, I can do that
> too.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
So why does this get pas gimple_call_combined_fn ()? Are those
internal functions at the point we match them? Otherwise we
invoke gimple_builtin_call_types_compatible_p on them. If
they are internal functions why did we rewrite the calls to them
when the types do not match? If gimple_builtin_call_types_compatible_p
is fine then why did the frontend assign BUILT_IN_SQRT to the
function decls?
Richard.
> 2022-04-05 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/105150
> * match.pd (sqrt (x) cmp real_cst, sqrt (x) cmp sqrt (y)): Punt
> if sqrt operand has incompatible types.
>
> * gcc.dg/pr105150.c: New test.
>
> --- gcc/match.pd.jj 2022-03-18 18:32:36.000000000 +0100
> +++ gcc/match.pd 2022-04-04 19:49:28.621934784 +0200
> @@ -4927,6 +4927,10 @@ (define_operator_list SYNC_FETCH_AND_AND
> (simplify
> (cmp (sq @0) REAL_CST@1)
> (switch
> + (if (!types_match (TREE_TYPE (@0), TREE_TYPE (@1)))
> + /* Punt if there is a type mismatch. */
> + (if (false)
> + @1))
> (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (@1)))
> (switch
> /* sqrt(x) < y is always false, if y is negative. */
> @@ -5062,7 +5066,7 @@ (define_operator_list SYNC_FETCH_AND_AND
> /* Transform sqrt(x) cmp sqrt(y) -> x cmp y. */
> (simplify
> (cmp (sq @0) (sq @1))
> - (if (! HONOR_NANS (@0))
> + (if (! HONOR_NANS (@0) && types_match (TREE_TYPE (@0), TREE_TYPE (@1)))
> (cmp @0 @1))))))
>
> /* Optimize various special cases of (FTYPE) N CMP (FTYPE) M. */
> --- gcc/testsuite/gcc.dg/pr105150.c.jj 2022-04-04 19:53:03.597935060
> +0200
> +++ gcc/testsuite/gcc.dg/pr105150.c 2022-04-04 19:54:55.734370333 +0200
> @@ -0,0 +1,8 @@
> +/* PR tree-optimization/105150 */
> +/* { dg-options "-w -Ofast" } */
> +
> +#define A(name) __typeof (__builtin_##name (0)) name (); \
> + float name##1 () { return !name (1); } \
> + double name##2 () { return name (1.0L); }
> +#define B(name) A(name) A(name##l)
> +B (sqrt)
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Ivo Totev; HRB 36809 (AG Nuernberg)
