V2 [PATCH] x86: Also require MMX for __builtin_ia32_maskmovq

[Uros Bizjak]

On Mon, Nov 2, 2020 at 8:24 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> MMX emulation with SEE is implemented at MMX intrinsic level, not at MMX
> instruction level.  _mm_maskmove_si64 intrinsic for "MASKMOVQ mm1, mm2"
> is emulated with __builtin_ia32_maskmovdqu.  Since SSE "MASKMOVQ mm1, mm2"
> builtin function, __builtin_ia32_maskmovq, can't be emulated with XMM
> registers, make __builtin_ia32_maskmovq also require MMX instead of SSE
> only.
>
> gcc/
>
>         PR target/97140
>         * config/i386/i386-expand.c (ix86_expand_builtin): Require MMX
>         for __builtin_ia32_maskmovq.
>
> gcc/testsuite/
>
>         PR target/97140
>         * gcc.target/i386/pr97140.c: New test.

OK with a small nit below.

Thanks,
Uros.

> ---
>  gcc/config/i386/i386-expand.c           |  6 +++++-
>  gcc/testsuite/gcc.target/i386/pr97140.c | 10 ++++++++++
>  2 files changed, 15 insertions(+), 1 deletion(-)
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr97140.c
>
> diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
> index 9d2eb7f0308..06d349535fd 100644
> --- a/gcc/config/i386/i386-expand.c
> +++ b/gcc/config/i386/i386-expand.c
> @@ -11074,7 +11074,11 @@ ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
>         == (OPTION_MASK_ISA_FMA | OPTION_MASK_ISA_FMA4))
>        && (isa & (OPTION_MASK_ISA_FMA | OPTION_MASK_ISA_FMA4)) != 0)
>      isa |= (OPTION_MASK_ISA_FMA | OPTION_MASK_ISA_FMA4);
> -  if ((bisa & OPTION_MASK_ISA_MMX) && !TARGET_MMX && TARGET_MMX_WITH_SSE)

Please put some vertical space here and at the end of the following if clause.

> +  /* NB: __builtin_ia32_maskmovq requires MMX.  */
> +  if (fcode != IX86_BUILTIN_MASKMOVQ
> +      && (bisa & OPTION_MASK_ISA_MMX)
> +      && !TARGET_MMX
> +      && TARGET_MMX_WITH_SSE)
>      {
>        bisa &= ~OPTION_MASK_ISA_MMX;
>        bisa |= OPTION_MASK_ISA_SSE2;
> diff --git a/gcc/testsuite/gcc.target/i386/pr97140.c b/gcc/testsuite/gcc.target/i386/pr97140.c
> new file mode 100644
> index 00000000000..edb39d916ea
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr97140.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -msse2 -mno-mmx -Wno-psabi" } */
> +
> +typedef int __m64 __attribute__ ((__vector_size__ (8), __may_alias__));
> +typedef char __v8qi __attribute__ ((__vector_size__ (8)));
> +void
> +_mm_maskmove_si64 (__m64 __A, __m64 __N, char *__P)
> +{
> +    __builtin_ia32_maskmovq ((__v8qi)__A, (__v8qi)__N, __P); /* { dg-error "needs isa option -msse -m3dnowa -mmmx" } */
> +}
> --
> 2.28.0
>