[PATCH 17/39] And defines to __attribute__ (__noclone__) iff compiler supports it.

[Sam James]

"H.J. Lu" <hjl.tools@gmail.com> writes:

> On Sun, Dec 22, 2024 at 1:23 PM Sam James <sam@gentoo.org> wrote:
>>
>> "H.J. Lu" <hjl.tools@gmail.com> writes:
>>
>> > On Sun, Dec 22, 2024 at 12:35 PM Sam James <sam@gentoo.org> wrote:
>> >>
>> >> "H.J. Lu" <hjl.tools@gmail.com> writes:
>> >>
>> >> > From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
>> >> >
>> >> > Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
>> >> > ---
>> >> >  benchtests/bench-hash-funcs-kernel.h          |  4 ++--
>> >> >  benchtests/bench-hash-funcs.c                 |  2 +-
>> >> >  benchtests/bench-strchr.c                     |  4 ++--
>> >> >  debug/tst-backtrace.h                         |  2 +-
>> >> >  debug/tst-ssp-1.c                             |  2 +-
>> >> >  elf/tst-p_alignmod-base.c                     |  2 +-
>> >> >  gmon/tst-gmon.c                               |  8 +++++---
>> >> >  gmon/tst-mcount-overflow.c                    | 10 ++++++----
>> >> >  malloc/tst-malloc-thread-exit.c               |  2 +-
>> >> >  malloc/tst-malloc-thread-fail.c               |  2 +-
>> >> >  malloc/tst-mallocstate.c                      |  2 +-
>> >> >  misc/sys/cdefs.h                              |  7 +++++++
>> >> >  misc/tst-syscalls.c                           | 14 ++++++-------
>> >> >  nptl/tst-minstack-throw.cc                    |  8 ++++----
>> >> >  nptl/tst-thread-exit-clobber.cc               | 12 +++++------
>> >> >  nptl/tst-thread_local1.cc                     | 12 +++++------
>> >> >  stdlib/tst-makecontext-align.c                | 20 +++++++++----------
>> >> >  stdlib/tst-quick_exit.cc                      |  2 +-
>> >> >  stdlib/tst-setcontext10.c                     |  6 +++---
>> >> >  stdlib/tst-setcontext11.c                     |  2 +-
>> >> >  stdlib/tst-setcontext5.c                      |  4 ++--
>> >> >  stdlib/tst-setcontext8.c                      |  2 +-
>> >> >  stdlib/tst-setcontext9.c                      |  2 +-
>> >> >  stdlib/tst-swapcontext1.c                     |  8 ++++----
>> >> >  stdlib/tst-swapcontext2.c                     |  8 ++++----
>> >> >  stdlib/tst-thread-quick_exit.cc               |  2 +-
>> >> >  string/tst-xbzero-opt.c                       |  3 ++-
>> >> >  sysdeps/generic/tst-stack-align.h             |  2 +-
>> >> >  .../sysv/linux/x86_64/tst-cet-property-2.c    |  2 +-
>> >> >  .../sysv/linux/x86_64/tst-cet-setcontext-1.c  |  2 +-
>> >> >  .../unix/sysv/linux/x86_64/tst-cet-vfork-1.c  |  2 +-
>> >> >  .../sysv/linux/x86_64/tst-gnu2-tls2-amx.c     |  2 +-
>> >> >  sysdeps/x86/tst-ldbl-nonnormal-printf.c       |  2 +-
>> >> >  sysdeps/x86/tst-memchr-rtm.c                  |  4 ++--
>> >> >  sysdeps/x86/tst-memcmp-rtm.c                  |  4 ++--
>> >> >  sysdeps/x86/tst-memmove-rtm.c                 |  4 ++--
>> >> >  sysdeps/x86/tst-memrchr-rtm.c                 |  4 ++--
>> >> >  sysdeps/x86/tst-memset-rtm.c                  |  4 ++--
>> >> >  sysdeps/x86/tst-strchr-rtm.c                  |  4 ++--
>> >> >  sysdeps/x86/tst-strcmp-rtm.c                  |  4 ++--
>> >> >  sysdeps/x86/tst-strcpy-rtm.c                  |  4 ++--
>> >> >  sysdeps/x86/tst-strlen-rtm.c                  |  4 ++--
>> >> >  sysdeps/x86/tst-strncmp-rtm.c                 |  8 ++++----
>> >> >  sysdeps/x86/tst-strrchr-rtm.c                 |  4 ++--
>> >> >  sysdeps/x86_64/tst-rsi-strlen.c               |  2 +-
>> >> >  45 files changed, 113 insertions(+), 101 deletions(-)
>> >>
>> >> I'm suspicious of how many of these noinline+noclone uses should
>> >> actually be noipa but I'd need to check which GCC version it was added
>> >> to (maybe 7?) and it's not a blocker.
>> >
>> > Should
>> >
>> > __attribute__ ((optnone))
>> >
>> > be used for Clang instead?
>>
>> Yes, let's do that instead. It's better than trying to estimate what the
>> equivalents are in Clang.
>>
>
> I will send out the v2 with
>
> /*  Prevents a function from being considered for inlining and cloning.  */
> #ifdef __clang__
> # define __attribute_noinline_noclone__ __attribute__ ((optnone))
> #else
> # define __attribute_noinline_noclone__ __attribute__ ((noinline, noclone))
> #endif
>
> and replace every
>
> __attribute__ ((noinline, noclone))
>
> with
>
> __attribute_noinline_noclone__

The name isn't great if we do noipa in future. Maybe
__attribute_optimization_barrier__. Or just use your suggestion and we
can just sed in future. Either is fine.

>
> H.J.