On Thu, Feb 14, 2019 at 10:02 PM H.J. Lu <hjl.tools@gmail.com> wrote:

> > > > > gcc/
> > > > >
> > > > >         PR target/89021
> > > > >         * config/i386/i386-builtin.def: Enable MMX intrinsics with
> > > > >         SSE/SSE2/SSSE3.
> > > > >         * config/i386/i386.c (ix86_option_override_internal): Don't
> > > > >         enable MMX ISA with TARGET_MMX_WITH_SSE by default.
> > > > >         (ix86_init_mmx_sse_builtins): Enable MMX intrinsics with
> > > > >         SSE/SSE2/SSSE3.
> > > > >         (ix86_expand_builtin): Allow SSE/SSE2/SSSE3 to emulate MMX
> > > > >         intrinsics with TARGET_MMX_WITH_SSE.
> > > > >         * config/i386/mmintrin.h: Don't require MMX in 64-bit mode.
> > > > >
> > >
> > > >
> > > > > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> > > > > index a9abbe8706b..1d417e08734 100644
> > > > > --- a/gcc/config/i386/i386.c
> > > > > +++ b/gcc/config/i386/i386.c
> > > > > @@ -4165,12 +4165,15 @@ ix86_option_override_internal (bool main_args_p,
> > > > >        opts->x_target_flags
> > > > >         |= TARGET_SUBTARGET64_DEFAULT & ~opts_set->x_target_flags;
> > > > >
> > > > > -      /* Enable by default the SSE and MMX builtins.  Do allow the user to
> > > > > -        explicitly disable any of these.  In particular, disabling SSE and
> > > > > -        MMX for kernel code is extremely useful.  */
> > > > > +      /* Enable the SSE and MMX builtins by default.  Don't enable MMX
> > > > > +         ISA with TARGET_MMX_WITH_SSE by default.  Do allow the user to
> > > > > +        explicitly disable any of these.  In particular, disabling SSE
> > > > > +        and MMX for kernel code is extremely useful.  */
> > > > >        if (!ix86_arch_specified)
> > > > >        opts->x_ix86_isa_flags
> > > > > -       |= ((OPTION_MASK_ISA_SSE2 | OPTION_MASK_ISA_SSE | OPTION_MASK_ISA_MMX
> > > > > +       |= ((OPTION_MASK_ISA_SSE2 | OPTION_MASK_ISA_SSE
> > > > > +            | (TARGET_MMX_WITH_SSE_P (opts->x_ix86_isa_flags)
> > > > > +               ? 0 : OPTION_MASK_ISA_MMX)
> > > > >              | TARGET_SUBTARGET64_ISA_DEFAULT)
> > > > >              & ~opts->x_ix86_isa_flags_explicit);
> > > >
> > > > Please split the above into two clauses, the first that sets SSE and
> > > > MMX by default, and the second to or with
> > > >
> > > > opts->x_ix86_isa_flags
> > > >      |= TARGET_SUBTARGET64_ISA_DEFAULT & ~opts->x_ix86_isa_flags_explicit
> > > >
> > >
> > > Like this?
> >
> > Yes, but also split the comment.
>
> I will go with
>
>      /* Enable by default the SSE and MMX builtins.  Do allow the user to
>          explicitly disable any of these.  In particular, disabling SSE and
>          MMX for kernel code is extremely useful.  */
>       if (!ix86_arch_specified)
>         {
>           /* Don't enable MMX ISA with TARGET_MMX_WITH_SSE.  */
>           opts->x_ix86_isa_flags
>             |= ((OPTION_MASK_ISA_SSE2 | OPTION_MASK_ISA_SSE
>                  | (TARGET_MMX_WITH_SSE_P (opts->x_ix86_isa_flags)
>                     ? 0 : OPTION_MASK_ISA_MMX))
>                 & ~opts->x_ix86_isa_flags_explicit);
>           opts->x_ix86_isa_flags
>             |= (TARGET_SUBTARGET64_ISA_DEFAULT
>                 & ~opts->x_ix86_isa_flags_explicit);
>         }

I'll commit the following patch that finally defines
TARGET_SUBTARGET64_ISA_DEFAULT. You could then simply clear the MMX
bit from x_i86_isa_flags, like:

      if (!ix86_arch_specified)
    opts->x_ix86_isa_flags
      |= TARGET_SUBTARGET64_ISA_DEFAULT & ~opts->x_ix86_isa_flags_explicit;

      /* Don't enable MMX ISA with TARGET_MMX_WITH_SSE.  */
      if (TARGET_MMX_WITH_SSE_P (opts->x_ix86_isa_flags))
    opts->x_ix86_isa_flags &= ~OPTION_MASK_ISA_MMX;

Uros.