From: Hongtao Liu <crazylht@gmail.com>
To: Uros Bizjak <ubizjak@gmail.com>
Cc: "H.J. Lu" <hjl.tools@gmail.com>,
Hongtao Liu <hongtao.liu@intel.com>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] x86: Compile CPUID functions with -mgeneral-regs-only
Date: Fri, 25 Jun 2021 10:56:43 +0800 [thread overview]
Message-ID: <CAMZc-bxxNx7sSXh=t=yFKEiacsFdNQDLnYokkiBoeoZQcwwnow@mail.gmail.com> (raw)
In-Reply-To: <CAFULd4b9Dk9M9OS7Ykb-C9dcn242f0J9noRqhdmEcXbZ9U1c9g@mail.gmail.com>
On Fri, Jun 25, 2021 at 12:13 AM Uros Bizjak via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Thu, Jun 24, 2021 at 2:12 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > CPUID functions are used to detect CPU features. If vector ISAs
> > are enabled, compiler is free to use them in these functions. Add
> > __attribute__ ((target("general-regs-only"))) to CPUID functions
> > to avoid vector instructions.
>
> These functions are intended to be inlined, so how does target
> attribute affect inlining?
I guess w/ -O0. they may not be inlined, that's why H.J adds those
attributes to those functions.
pr96814.dump:
0804aa40 <main>:
804aa40: 8d 4c 24 04 lea 0x4(%esp),%ecx
...
804aa63: 6a 07 push $0x7
804aa65: e8 e0 e7 ff ff call 804924a <__get_cpuid_count>
Also we need to add a target attribute to avx512f_os_support (), and
that would be enough to fix the AVX512 part.
Moreover, all check functions in below files may also need to deal with:
adx-check.h
aes-avx-check.h
aes-check.h
amx-check.h
attr-nocf-check-1a.c
attr-nocf-check-3a.c
avx2-check.h
avx2-vpop-check.h
avx512bw-check.h
avx512-check.h
avx512dq-check.h
avx512er-check.h
avx512f-check.h
avx512vl-check.h
avx-check.h
bmi2-check.h
bmi-check.h
cf_check-1.c
cf_check-2.c
cf_check-3.c
cf_check-4.c
cf_check-5.c
f16c-check.h
fma4-check.h
fma-check.h
isa-check.h
lzcnt-check.h
m128-check.h
m256-check.h
m512-check.h
mmx-3dnow-check.h
mmx-check.h
pclmul-avx-check.h
pclmul-check.h
pr39315-check.c
rtm-check.h
sha-check.h
spellcheck-options-1.c
spellcheck-options-2.c
spellcheck-options-3.c
spellcheck-options-4.c
spellcheck-options-5.c
sse2-check.h
sse3-check.h
sse4_1-check.h
sse4_2-check.h
sse4a-check.h
sse-check.h
ssse3-check.h
stack-check-11.c
stack-check-12.c
stack-check-17.c
stack-check-18.c
stack-check-19.c
xop-check.h
>
> Uros.
>
> >
> > gcc/
> >
> > PR target/101185
> > * config/i386/cpuid.h (__get_cpuid_max): Add
> > __attribute__ ((target("general-regs-only"))).
> > (__get_cpuid): Likewise.
> > (__get_cpuid_count): Likewise.
> > (__cpuidex): Likewise.
> >
> > gcc/testsuite/
> >
> > PR target/101185
> > * gcc.target/i386/avx512-check.h (check_osxsave): Add
> > __attribute__ ((target("general-regs-only"))).
> > (main): Likewise.
> > ---
> > gcc/config/i386/cpuid.h | 4 ++++
> > gcc/testsuite/gcc.target/i386/avx512-check.h | 2 ++
> > 2 files changed, 6 insertions(+)
> >
> > diff --git a/gcc/config/i386/cpuid.h b/gcc/config/i386/cpuid.h
> > index aebc17c6827..74881ee91e5 100644
> > --- a/gcc/config/i386/cpuid.h
> > +++ b/gcc/config/i386/cpuid.h
> > @@ -243,6 +243,7 @@
> > pointer is non-null, then first four bytes of the signature
> > (as found in ebx register) are returned in location pointed by sig. */
> >
> > +__attribute__ ((target("general-regs-only")))
> > static __inline unsigned int
> > __get_cpuid_max (unsigned int __ext, unsigned int *__sig)
> > {
> > @@ -298,6 +299,7 @@ __get_cpuid_max (unsigned int __ext, unsigned int *__sig)
> > supported and returns 1 for valid cpuid information or 0 for
> > unsupported cpuid leaf. All pointers are required to be non-null. */
> >
> > +__attribute__ ((target("general-regs-only")))
> > static __inline int
> > __get_cpuid (unsigned int __leaf,
> > unsigned int *__eax, unsigned int *__ebx,
> > @@ -315,6 +317,7 @@ __get_cpuid (unsigned int __leaf,
> >
> > /* Same as above, but sub-leaf can be specified. */
> >
> > +__attribute__ ((target("general-regs-only")))
> > static __inline int
> > __get_cpuid_count (unsigned int __leaf, unsigned int __subleaf,
> > unsigned int *__eax, unsigned int *__ebx,
> > @@ -330,6 +333,7 @@ __get_cpuid_count (unsigned int __leaf, unsigned int __subleaf,
> > return 1;
> > }
> >
> > +__attribute__ ((target("general-regs-only")))
> > static __inline void
> > __cpuidex (int __cpuid_info[4], int __leaf, int __subleaf)
> > {
> > diff --git a/gcc/testsuite/gcc.target/i386/avx512-check.h b/gcc/testsuite/gcc.target/i386/avx512-check.h
> > index 0a377dba1d5..406faf8fe03 100644
> > --- a/gcc/testsuite/gcc.target/i386/avx512-check.h
> > +++ b/gcc/testsuite/gcc.target/i386/avx512-check.h
> > @@ -25,6 +25,7 @@ do_test (void)
> > }
> > #endif
> >
> > +__attribute__ ((target("general-regs-only")))
> > static int
> > check_osxsave (void)
> > {
> > @@ -34,6 +35,7 @@ check_osxsave (void)
> > return (ecx & bit_OSXSAVE) != 0;
> > }
> >
> > +__attribute__ ((target("general-regs-only")))
> > int
> > main ()
> > {
> > --
> > 2.31.1
> >
--
BR,
Hongtao
next prev parent reply other threads:[~2021-06-25 2:51 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-24 12:12 H.J. Lu
2021-06-24 12:35 ` Richard Biener
2021-06-24 12:41 ` H.J. Lu
2021-06-24 12:47 ` Richard Biener
2021-06-24 13:00 ` H.J. Lu
2021-06-24 16:12 ` Uros Bizjak
2021-06-24 18:00 ` H.J. Lu
2021-06-25 2:56 ` Hongtao Liu [this message]
2021-06-25 7:49 ` Uros Bizjak
2021-06-25 12:39 ` [PATCH v2] x86: Check AVX512 without mask instructions H.J. Lu
2021-07-14 12:27 ` PING^1 " H.J. Lu
2021-07-26 3:33 ` Hongtao Liu
2021-07-30 10:02 ` Uros Bizjak
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAMZc-bxxNx7sSXh=t=yFKEiacsFdNQDLnYokkiBoeoZQcwwnow@mail.gmail.com' \
--to=crazylht@gmail.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=hjl.tools@gmail.com \
--cc=hongtao.liu@intel.com \
--cc=ubizjak@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).