On Thu, Apr 15, 2021 at 9:53 AM Uros Bizjak <ubiz...@gmail.com> wrote:
>
> On Thu, Apr 15, 2021 at 6:51 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> >
> > On Thu, Apr 15, 2021 at 9:34 AM Uros Bizjak <ubiz...@gmail.com> wrote:
> > >
> > > On Thu, Apr 15, 2021 at 6:26 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> > > >
> > > > On Thu, Apr 15, 2021 at 9:14 AM Uros Bizjak <ubiz...@gmail.com> wrote:
> > > > >
> > > > > On Thu, Apr 15, 2021 at 5:11 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> > > > > >
> > > > > > Use crc32 target option for CRC32 intrinsics to support CRC32
> > > > > > intrinsics
> > > > > > without enabling SSE vector instructions.
> > > > >
> > > > > There is no CRC32 ISA. crc32 is part of SSE4.2 [1] and current
> > > > > situation reflects that correctly.
> > > >
> > > > CRC32 is similar to POPCNT which was originally in SSE4.2. Now POPCNT
> > >
> > > It is not similar, POPCNT has its own CPUID flag and can be enabled
> > > independently of SSE4.2.
> > >
> > > > is a separate feature which is also enabled by SSE4.2. Enable CRC32
> > > > only
> > > > with SSE4.2 makes it impossible to use CRC32 with -mgeneral-regs-only.
> > > > This
> > > > patch addresses this issue the same way as POPCNT.
> > >
> > > CRC32 doesn't have its own CPUID flag, so PTA_CRC32 is pointless.
> >
> > PTA_CRC32 shouldn't be added.
> >
> > > OTOH, the situation is similar with MONITOR and MWAIT. These are
> >
> > There are no intrinsics for MONITOR nor MWAIT.
>
> pmmintrin.h:
>
> extern __inline void __attribute__((__gnu_inline__, __always_inline__,
> __artificial__))
> _mm_monitor (void const * __P, unsigned int __E, unsigned int __H)
> {
> __builtin_ia32_monitor (__P, __E, __H);
> }
>
> extern __inline void __attribute__((__gnu_inline__, __always_inline__,
> __artificial__))
> _mm_mwait (unsigned int __E, unsigned int __H)
> {
> __builtin_ia32_mwait (__E, __H);
> }
They can be moved to mwaitintrin.h with -mmwait.
> >
> > > enabled with SSE3 and don't use XMM registers. Also somewhat similar
> > > is FISTTP, but there is no intrinsic for this insn.
> >
> > True.
> >
> > Here is the v2 patch without PTA_CRC32.
> >
> > --
> > H.J.
--
H.J.
