Uros Bizjak <ubiz...@gmail.com> 于2020年10月14日周三 下午7:19写道：
>
> > > Please also add -muintr to g++.dg/other/i386-{2,3}.C and
> > > >> > > gcc.target/i386-sse-{12,13,14,22,23}.c. This will test new
intrinsics
> > > >> > > header.
> > > >> > >
> > > >> >
> > > >> > Thanks for your review. We found that without adding -muintr,
the intrinsics header could also be tested. Make-check for these file all
get passed.
> > > >> >
> > > >> > And there is no intrinsic/builtin with const int parameter. So
we remove -muintr from these files.
> > > >>
> > > >> Can your double check that relevant instructions are indeed
generated?
> > > >> Without -muintr, relevant patterns in i386.md are effectively
blocked,
> > > >> and perhaps a call to __builtin_ia32_* is generated instead.
> > > >
> > > >
> > > > Yes, in sse-14.s we have
> > > >
> > > > _clui:
> > > > .LFB136:
> > > > .cfi_startproc
> > > > pushq %rbp
> > > > .cfi_def_cfa_offset 16
> > > > .cfi_offset 6, -16
> > > > movq %rsp, %rbp
> > > > .cfi_def_cfa_register 6
> > > > clui
> > > > nop
> > > > popq %rbp
> > > > .cfi_def_cfa 7, 8
> > > > ret
> > > > .cfi_endproc
> > >
> > > Strange, without -muintr, it should not be generated, and some error
> > > about failed inlining due to target specific option mismatch shoul be
> > > emitted.
> > >
> > > Can you please investigate this a bit more?
> > >
> >
> > Because of function target attribute?
>
> I don't think so. Please consider this similar testcase:
>
> --cut here--
> #ifndef __SSE2__
> #pragma GCC push_options
> #pragma GCC target("sse2")
> #define __DISABLE_SSE2__
> #endif /* __SSE2__ */
>
> typedef double __v2df __attribute__ ((__vector_size__ (16)));
> typedef double __m128d __attribute__ ((__vector_size__ (16),
__may_alias__));
>
> extern __inline __m128d __attribute__((__gnu_inline__,
> __always_inline__, __artificial__))
> _mm_add_sd (__m128d __A, __m128d __B)
> {
> return (__m128d)__builtin_ia32_addsd ((__v2df)__A, (__v2df)__B);
> }
>
> #ifdef __DISABLE_SSE2__
> #undef __DISABLE_SSE2__
> #pragma GCC pop_options
> #endif /* __DISABLE_SSE2__ */
>
>
> __v2df foo (__v2df a, __v2df b)
> {
> return _mm_add_sd (a, b);
> }
> --cut here--
>
> $ gcc -O2 -mno-sse2 -S -dp sse2.c
> sse2.c: In function ‘foo’:
> sse2.c:11:1: error: inlining failed in call to ‘always_inline’
> ‘_mm_add_sd’: target specific option mismatch
> 11 | _mm_add_sd (__m128d __A, __m128d __B)
> | ^~~~~~~~~~
> sse2.c:24:10: note: called from here
> 24 | return _mm_add_sd (a, b);
> | ^~~~~~~~~~~~~~~~~
>
> I'd expect some similar warning from missing -mumip.
>
For this case, I can confirm uintr could generate similar warning without
-muintr. But
sse-{12,13,14,22,23}.c will not test intrinsic call for uintr, since it
doesn't have const
int parameter intrinsics.
sse-{13,14,22,23}.c has
#define extern
#define __inline
So intrinsic will be treated as common call to builtin, then
#pragma GCC push_options
#pragma GCC target("uintr")
ensures the builtin could be expanded correctly.
I think the intrinsic call test should be in uintr-1.c, so it is redundant
to add -muintr in sse-{12,13,14,22,23}.c
or x86gprintrin-*.c.
>
> Uros.
