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authorH.J. Lu <hjl.tools@gmail.com>2017-06-09 05:44:30 -0700
committerH.J. Lu <hjl.tools@gmail.com>2017-06-09 05:44:41 -0700
commit5ac7aa1d7cce8580f8225c33c819991abca102b9 (patch)
treea03a58010d692384042b6430b288e8197d77f1b4 /ChangeLog
parent8fe57365bfb5a417d911ab715a5671b3b1d7b155 (diff)
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x86-64: Optimize memrchr with AVX2
Optimize memrchr with AVX2 to search 32 bytes with a single vector
compare instruction.  It is as fast as SSE2 memrchr for small data
sizes and up to 1X faster for large data sizes on Haswell.  Select
AVX2 memrchr on AVX2 machines where vzeroupper is preferred and AVX
unaligned load is fast.

	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
	memrchr-sse2 and memrchr-avx2.
	* sysdeps/x86_64/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add tests for __memrchr_avx2 and
	__memrchr_sse2.
	* sysdeps/x86_64/multiarch/memrchr-avx2.S: New file.
	* sysdeps/x86_64/multiarch/memrchr-sse2.S: Likewise.
	* sysdeps/x86_64/multiarch/memrchr.c: Likewise.
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+++ b/ChangeLog
@@ -1,6 +1,17 @@
 2017-06-09  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
+	memrchr-sse2 and memrchr-avx2.
+	* sysdeps/x86_64/multiarch/ifunc-impl-list.c
+	(__libc_ifunc_impl_list): Add tests for __memrchr_avx2 and
+	__memrchr_sse2.
+	* sysdeps/x86_64/multiarch/memrchr-avx2.S: New file.
+	* sysdeps/x86_64/multiarch/memrchr-sse2.S: Likewise.
+	* sysdeps/x86_64/multiarch/memrchr.c: Likewise.
+
+2017-06-09  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
 	strchr-sse2, strchrnul-sse2, strchr-avx2, strchrnul-avx2,
 	wcschr-sse2 and wcschr-avx2.
 	* sysdeps/x86_64/multiarch/ifunc-impl-list.c