On Tue, Dec 14, 2021 at 04:07:55PM +0100, Martin Liška wrote:
> On 12/14/21 11:28, Jakub Jelinek wrote:
> > Wouldn't this be better done only if field_val has the msb set
>
> Yes, updated in the attached patch.
>
> > and keep the CONVERT_EXPR otherwise (why isn't it NOP_EXPR?)?
>
> Dunno, but I can prepare a separate patch (likely stage1 material,
> right)? Note that are other places that also use CONVERT_EXPR.
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?
> Thanks,
> Martin
> From 227450e9f3a506fdfcff67aa45135fe31f3f91f6 Mon Sep 17 00:00:00 2001
> From: Martin Liska <mli...@suse.cz>
> Date: Mon, 13 Dec 2021 15:34:30 +0100
> Subject: [PATCH] i386: Fix emissing of __builtin_cpu_supports.
>
> PR target/103661
>
> gcc/ChangeLog:
>
> * config/i386/i386-builtins.c (fold_builtin_cpu): Compare to 0
> as API expects that non-zero values are returned (do that
> it mask == 31).
> For "avx512vbmi2" argument, we return now 1 << 31, which is a
> negative integer value.
> ---
> gcc/config/i386/i386-builtins.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/config/i386/i386-builtins.c b/gcc/config/i386/i386-builtins.c
> index 0fb14b55712..bca244fc011 100644
> --- a/gcc/config/i386/i386-builtins.c
> +++ b/gcc/config/i386/i386-builtins.c
> @@ -2353,7 +2353,11 @@ fold_builtin_cpu (tree fndecl, tree *args)
> /* Return __cpu_model.__cpu_features[0] & field_val */
> final = build2 (BIT_AND_EXPR, unsigned_type_node, array_elt,
> build_int_cstu (unsigned_type_node, field_val));
> - return build1 (CONVERT_EXPR, integer_type_node, final);
> + if (isa_names_table[i].feature == 31)
> + return build2 (NE_EXPR, integer_type_node, final,
> + build_int_cst (unsigned_type_node, 0));
> + else
> + return build1 (CONVERT_EXPR, integer_type_node, final);
> }
> gcc_unreachable ();
> }
I'd use INT_TYPE_SIZE - 1 instead of 31. Otherwise LGTM.
Jakub
