Re: [PATCH] i386: Fix up types in __builtin_{inf,huge_val,nan{,s},fabs,copysign}q builtins [PR109884]

[Uros Bizjak <ubizjak@gmail.com>]

On Wed, May 17, 2023 at 8:08 PM Jakub Jelinek <jakub@redhat.com> wrote:
>
> Hi!
>
> When _Float128 support has been added to C++ for 13.1,  float128t_type_node
> tree has been added - in C float128_type_node and float128t_type_node is
> the same and represents both _Float128 and __float128, but in C++ they
> are distinct types which have different handling in the FEs.
> When doing that change, I mistakenly forgot to change FLOAT128 primitive
> type, which is used for the __builtin_{inf,huge_val,nan{,s},fabs,copysign}q
> builtins results and some of their arguments (and nothing else).
>
> The following patch fixes that.
> On ia64 we already use float128t_type_node for those builtins, pa while
> it has __float128 that type is the same as long double and so those builtins
> have long double types and on powerpc seems we  don't have these builtins
> but instead define macros which map them to __builtin_*f128.  That will
> not work properly in C++, perhaps we should change those macros to be
> function-like and cast to __float128.
>
> Anyway, bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk
> and 13.2?
>
> 2023-05-17  Jakub Jelinek  <jakub@redhat.com>
>
>         PR c++/109884
>         * config/i386/i386-builtin-types.def (FLOAT128): Use
>         float128t_type_node rather than float128_type_node.
>
>         * c-c++-common/pr109884.c: New test.

OK for master and branch.

Thanks,
Uros.

>
> --- gcc/config/i386/i386-builtin-types.def.jj   2022-11-28 22:25:15.838734978 +0100
> +++ gcc/config/i386/i386-builtin-types.def      2023-05-17 10:24:04.297929428 +0200
> @@ -73,7 +73,7 @@ DEF_PRIMITIVE_TYPE (BFLOAT16, ix86_bf16_
>  DEF_PRIMITIVE_TYPE (FLOAT, float_type_node)
>  DEF_PRIMITIVE_TYPE (DOUBLE, double_type_node)
>  DEF_PRIMITIVE_TYPE (FLOAT80, float80_type_node)
> -DEF_PRIMITIVE_TYPE (FLOAT128, float128_type_node)
> +DEF_PRIMITIVE_TYPE (FLOAT128, float128t_type_node)
>  DEF_PRIMITIVE_TYPE (CONST_STRING, const_string_type_node)
>
>  # MMX vectors
> --- gcc/testsuite/c-c++-common/pr109884.c.jj    2023-05-17 10:41:42.295838862 +0200
> +++ gcc/testsuite/c-c++-common/pr109884.c       2023-05-17 10:56:51.731872318 +0200
> @@ -0,0 +1,32 @@
> +/* PR c++/109884 */
> +/* PowerPC doesn't define these as builtins, but macros expanding to
> +   *f128 builtins.  */
> +/* { dg-do compile { target { __float128 && { { c || c++11 } && { ! powerpc*-*-* } } } } } */
> +/* { dg-add-options __float128 } */
> +
> +#ifdef __cplusplus
> +template <typename T, typename U>
> +struct is_same {
> +  static const bool value = false;
> +};
> +
> +template <typename T>
> +struct is_same <T, T> {
> +  static const bool value = true;
> +};
> +#define HAS_TYPE(E, U) static_assert (is_same <decltype (E), U>::value, "")
> +#else
> +#define HAS_TYPE(E, U) _Static_assert (_Generic (E, default : 0, U : 1), "")
> +#endif
> +
> +void
> +foo ()
> +{
> +  __float128 a = 0;
> +  HAS_TYPE (__builtin_infq (), __float128);
> +  HAS_TYPE (__builtin_huge_valq (), __float128);
> +  HAS_TYPE (__builtin_nanq (""), __float128);
> +  HAS_TYPE (__builtin_nansq (""), __float128);
> +  HAS_TYPE (__builtin_fabsq (a), __float128);
> +  HAS_TYPE (__builtin_copysignq (a, a), __float128);
> +}
>
>         Jakub
>