On Mon, Jun 17, 2013 at 6:11 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> This instruction has the predicates/constraints wrong, the r/m argument is
> the middle-one, the value from which it should be extracted, rather than
> the packed start/length argument. This got broken with PR50766, where the
> patch hasn't touched just BMI2, but for unknown reasons also this BMI
> instruction which was handled right in GCC 4.6.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/4.8/4.7?
>
> BTW, the AVX2 docs document _bextr_u{32,64} 3 argument intrinsics, rather
> than the __bextr_u{32,64} 2 argument intrinsics we have in GCC right now.
> Something to fix up (as the names are different, perhaps we can both the old
> ones and the new ones implemented say as return __bextr_u32 (x, (y & 255) |
> (z << 8)); or similar)?
It looks to me that GCC's double-underscored version is wrong. We are
looking for compatibility with official bmiintrin.h header. Kirill,
can you please comment on this issue?
> 2013-06-17 Jakub Jelinek <ja...@redhat.com>
>
> PR target/57623
> * config/i386/i386.md (bmi_bextr_<mode>): Swap predicates and
> constraints of operand 1 and 2.
>
> * gcc.target/i386/bmi-bextr-3.c: New test.
The fix itself looks good to me as far as insn is concerned, but
please wait until the issue with builtins is resolved.
Thanks,
Uros.
