From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Subject: Re: [PATCH] x86-64: Implement memmove family IFUNC selectors in C
Date: Wed, 14 Jun 2017 18:38:00 -0000 [thread overview]
Message-ID: <2866dd6e-9cfd-6991-0fb2-a57e97e6a9ba@linaro.org> (raw)
In-Reply-To: <20170612160930.GA25262@gmail.com>
On 12/06/2017 13:09, H.J. Lu wrote:
> Implement memmove family IFUNC selectors in C.
>
> All internal calls within libc.so can use IFUNC on x86-64 since unlike
> x86, x86-64 supports PC-relative addressing to access the GOT entry so
> that it can call via PLT without using an extra register. For libc.a,
> we can't use IFUNC for functions which are called before IFUNC has been
> initialized. Use IFUNC internally reduces the icache footprint since
> libc.so and other codes in the process use the same implementations.
> This patch uses IFUNC for memmove family functions within libc.
>
> Any comments?>
> H.J.
> ---
> 2017-06-07 H.J. Lu <hongjiu.lu@intel.com>
> Erich Elsen <eriche@google.com>
> Adhemerval Zanella <adhemerval.zanella@linaro.org>
>
> * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
> memmove-sse2-unaligned-erms, memcpy_chk-nonshared,
> mempcpy_chk-nonshared and memmove_chk-nonshared.
> * sysdeps/x86_64/multiarch/ifunc-impl-list.c
> (__libc_ifunc_impl_list): Add tests for __memmove_chk_erms,
> __memcpy_chk_erms and __mempcpy_chk_erms. Update comments.
> * sysdeps/x86_64/multiarch/ifunc-memmove.h: New file.
> * sysdeps/x86_64/multiarch/memcpy.c: Likewise.
> * sysdeps/x86_64/multiarch/memcpy_chk-nonshared.S: Likewise.
> * sysdeps/x86_64/multiarch/memcpy_chk.c: Likewise.
> * sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S: Likewise.
> * sysdeps/x86_64/multiarch/memmove.c: Likewise.
> * sysdeps/x86_64/multiarch/memmove_chk-nonshared.S: Likewise.
> * sysdeps/x86_64/multiarch/memmove_chk.c: Likewise.
> * sysdeps/x86_64/multiarch/mempcpy.c: Likewise.
> * sysdeps/x86_64/multiarch/mempcpy_chk-nonshared.S: Likewise.
> * sysdeps/x86_64/multiarch/mempcpy_chk.c: Likewise.
> * sysdeps/x86_64/multiarch/memcpy.S: Removed.
> * sysdeps/x86_64/multiarch/memcpy_chk.S: Likewise.
> * sysdeps/x86_64/multiarch/memmove.S: Likewise.
> * sysdeps/x86_64/multiarch/memmove_chk.S: Likewise.
> * sysdeps/x86_64/multiarch/mempcpy.S: Likewise.
> * sysdeps/x86_64/multiarch/mempcpy_chk.S: Likewise.
> * sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
> (__mempcpy_chk_erms): New function.
> (__memmove_chk_erms): Likewise.
> (__memcpy_chk_erms): New alias.
LGTM, thanks.
prev parent reply other threads:[~2017-06-14 18:38 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-12 16:09 H.J. Lu
2017-06-14 18:38 ` Adhemerval Zanella [this message]
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