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Re: [PATCH] x86-64: Implement memset family IFUNC selectors in C

On 12/06/2017 13:09, H.J. Lu wrote:
> Implement memset family IFUNC selectors in C.
> All internal calls within 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
> 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  <>
> 	    Erich Elsen  <>
> 	* 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.


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