On Fri, Nov 25, 2022 at 01:39:04PM +0800, liuhongt wrote:
> Update in V3:
> Remove !flag_signaling_nans since there's already HONOR_NANS (BFmode).
>
> Here's the patch:
>
> After supporting real __bf16, the implementation of _mm_cvtsbh_ss went
> wrong.
>
> The patch add a builtin to generate pslld for the intrinsic, also
> extendbfsf2 is supported with pslld when !HONOR_NANS (BFmode).
>
> truncsfbf2 is supported with vcvtneps2bf16 when
> !HONOR_NANS (BFmode) && flag_unsafe_math_optimizations.
>
> gcc/ChangeLog:
>
> PR target/107748
> * config/i386/avx512bf16intrin.h (_mm_cvtsbh_ss): Refined.
> * config/i386/i386-builtin-types.def (FLOAT_FTYPE_BFLOAT16):
> New function type.
> * config/i386/i386-builtin.def (BDESC): New builtin.
> * config/i386/i386-expand.cc (ix86_expand_args_builtin):
> Handle the builtin.
> * config/i386/i386.md (extendbfsf2): New expander.
> (extendbfsf2_1): New define_insn.
> (truncsfbf2): Ditto.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/avx512bf16-cvtsbh2ss-1.c: Scan pslld.
> * gcc.target/i386/extendbfsf.c: New test.
LGTM.
Jakub
