From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Subject: Re: [PATCH] x86-64: Implement memset family IFUNC selectors in C
Date: Thu, 15 Jun 2017 15:27:00 -0000 [thread overview]
Message-ID: <d1600f35-e783-34d8-b2eb-1bfcfd628d7b@linaro.org> (raw)
In-Reply-To: <20170612160956.GB25262@gmail.com>
On 12/06/2017 13:09, H.J. Lu wrote:
> Implement memset 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 memset functions within libc.
>
> Any comments?
>
> H.J.
> ---
> 2017-06-07 H.J. Lu <hongjiu.lu@intel.com>
> Erich Elsen <eriche@google.com>
>
> * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
> memset-sse2-unaligned-erms, and memset_chk-nonshared.
> * sysdeps/x86_64/multiarch/ifunc-impl-list.c
> (__libc_ifunc_impl_list): Add test for __memset_chk_erms.
> Update comments.
> * sysdeps/x86_64/multiarch/ifunc-memset.h: New file.
> * sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S: Likewise.
> * sysdeps/x86_64/multiarch/memset.c: Likewise.
> * sysdeps/x86_64/multiarch/memset_chk-nonshared.S: Likewise.
> * sysdeps/x86_64/multiarch/memset_chk.c: Likewise.
> * sysdeps/x86_64/multiarch/memset.S: Removed.
> * sysdeps/x86_64/multiarch/memset_chk.S: Likewise.
> * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> (__memset_chk_erms): New function.
LGTM.
prev parent reply other threads:[~2017-06-15 15:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-12 16:09 H.J. Lu
2017-06-15 15:27 ` Adhemerval Zanella [this message]
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