[PATCH] x86-64: Implement strcspn/strpbrk/strspn IFUNC selectors in C

[Adhemerval Zanella]

On 12/06/2017 13:12, H.J. Lu wrote:
> Implement strcspn/strpbrk/strspn 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 strcspn/strpbrk/strspn functions within libc.
> 
> Any comments?
> 
> H.J.
> ---
> 	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
> 	strcspn-sse2, strpbrk-sse2 and strspn-sse2.
> 	* sysdeps/x86_64/strcspn.S (STRPBRK_P): Removed.
> 	Check USE_AS_STRPBRK instead of STRPBRK_P.
> 	* sysdeps/x86_64/strpbrk.S (USE_AS_STRPBRK): New.
> 	* sysdeps/x86_64/multiarch/ifunc-sse4_2.h: New file.
> 	* sysdeps/x86_64/multiarch/strcspn-sse2.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strcspn.c: Likewise.
> 	* sysdeps/x86_64/multiarch/strpbrk-sse2.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strpbrk.c: Likewise.
> 	* sysdeps/x86_64/multiarch/strspn-sse2.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strspn.c: Likewise.
> 	* sysdeps/x86_64/multiarch/strcspn.S: Removed.
> 	* sysdeps/x86_64/multiarch/strpbrk.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strspn.S: Likewise.
> 	* sysdeps/x86_64/multiarch/strpbrk-c.c: Remove "#ifdef SHARED"
> 	and "#endif".

LGTM.