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RFC: Make string/memory functions optimized for unaligned SSE2 as default
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: GNU C Library <libc-alpha at sourceware dot org>, Ondrej Bilka <neleai at seznam dot cz>
- Date: Thu, 27 Aug 2015 10:02:36 -0700
- Subject: RFC: Make string/memory functions optimized for unaligned SSE2 as default
- Authentication-results: sourceware.org; auth=none
The current default string/memory functions for x86-64 in libc and ld.so were
implemented before SSE is allowed in ld.so and unaligned SSE load/store
is faster on most processors. Today, we can use the same string/memory
functions in libc and ld.so, most of x86-64 processors have fast unaligned
SSE load/store. We should update the default string/memory functions for
x864-64 to unaligned SSE2 version. Those functions are
memcpy-sse2-unaligned.S strcat-sse2-unaligned.S strncat-sse2-unaligned.S
stpcpy-sse2-unaligned.S strcmp-sse2-unaligned.S strncpy-sse2-unaligned.S
stpncpy-sse2-unaligned.S strcpy-sse2-unaligned.S strstr-sse2-unaligned.S
We should make them the default in libc and ld.so.
Any comments?
--
H.J.