On Fri, 24 Nov 2023, Jakub Jelinek wrote:
> Hi!
>
> The following testcase is lowered by the bitint lowering pass, then
> vectorizer vectorizes one of the loops in it, so we have
> vect__18.6_34 = VIEW_CONVERT_EXPR<vector(4) unsigned long>(x_35(D));
> _8 = BIT_FIELD_REF <vect__18.6_34, 64, 0>;
> ...
> _18 = BIT_FIELD_REF <vect__18.6_34, 64, 64>;
> etc. where x_35(D) is _BitInt(256) argument. That is valid BIT_FIELD_REF,
> the first argument is a vector and it extracts the vector elements from it.
> Then comes forwprop4 and simplifies that using match.pd into
> _8 = (unsigned long) x_35(D);
> ...
> _18 = BIT_FIELD_REF <x_35(D), 64, 64>;
> and tree-cfg verification ICEs on the latter (though, even the first cast
> is kind of undesirable after bitint lowering, we want large/huge bitints
> lowered). The ICE is because if BIT_FIELD_REFs first argument has
> INTEGRAL_TYPE_P, we require type_has_mode_precision_p, but that is not the
> case of _BitInt(256), it has BLKmode.
>
> The following patch fixes it by doing the BIT_FIELD_REF with VCE to
> BIT_FIELD_REF simplification only if the result is valid.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
> 2023-11-23 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/112673
> * match.pd (bit_field_ref (vce @0) -> bit_field_ref @0): Only simplify
> if either @0 doesn't have scalar integral type or if it has mode
> precision.
>
> * gcc.dg/pr112673.c: New test.
>
> --- gcc/match.pd.jj 2023-11-17 15:10:43.306043972 +0100
> +++ gcc/match.pd 2023-11-23 18:09:22.538414897 +0100
> @@ -8285,7 +8285,9 @@ (define_operator_list SYNC_FETCH_AND_AND
>
> (simplify
> (BIT_FIELD_REF (view_convert @0) @1 @2)
> - (BIT_FIELD_REF @0 @1 @2))
> + (if (! INTEGRAL_TYPE_P (TREE_TYPE (@0))
> + || type_has_mode_precision_p (TREE_TYPE (@0)))
> + (BIT_FIELD_REF @0 @1 @2)))
>
> (simplify
> (BIT_FIELD_REF @0 @1 integer_zerop)
> --- gcc/testsuite/gcc.dg/pr112673.c.jj 2023-11-23 18:29:44.540260525
> +0100
> +++ gcc/testsuite/gcc.dg/pr112673.c 2023-11-23 18:31:31.863765381 +0100
> @@ -0,0 +1,10 @@
> +/* PR tree-optimization/112673 */
> +/* { dg-do compile { target bitint575 } } */
> +/* { dg-options "-O3" } */
> +/* { dg-additional-options "-mavx2" { target i?86-*-* x86_64-*-* } } */
> +
> +int
> +foo (_BitInt(256) x)
> +{
> + return __builtin_ctzg ((unsigned _BitInt(512)) x);
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)
