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authorH.J. Lu <hjl.tools@gmail.com>2021-03-05 07:26:42 -0800
committerH.J. Lu <hjl.tools@gmail.com>2022-01-27 12:47:19 -0800
commit5f59aaddc9be84a6ce8c71cab90ee08dbbd72af5 (patch)
tree49bd6c60949e027f9f1b38436f7fb4ba0e569b73 /sysdeps/x86_64/multiarch/strncmp.c
parentd584356fe8417790d20f024c5233c2d35a615ea2 (diff)
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x86-64: Add AVX optimized string/memory functions for RTM
Since VZEROUPPER triggers RTM abort while VZEROALL won't, select AVX
optimized string/memory functions with

	xtest
	jz	1f
	vzeroall
	ret
1:
	vzeroupper
	ret

at function exit on processors with usable RTM, but without 256-bit EVEX
instructions to avoid VZEROUPPER inside a transactionally executing RTM
region.

(cherry picked from commit 7ebba91361badf7531d4e75050627a88d424872f)
Diffstat (limited to 'sysdeps/x86_64/multiarch/strncmp.c')
-rw-r--r--sysdeps/x86_64/multiarch/strncmp.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/sysdeps/x86_64/multiarch/strncmp.c b/sysdeps/x86_64/multiarch/strncmp.c
index 4069946f80..880e39659f 100644
--- a/sysdeps/x86_64/multiarch/strncmp.c
+++ b/sysdeps/x86_64/multiarch/strncmp.c
@@ -30,6 +30,7 @@ extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
 extern __typeof (REDIRECT_NAME) OPTIMIZE (ssse3) attribute_hidden;
 extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden;
 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;
 extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden;
 
 static inline void *
@@ -46,6 +47,9 @@ IFUNC_SELECTOR (void)
 	  && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_AVX2_STRCMP))
 	return OPTIMIZE (evex);
 
+      if (CPU_FEATURES_CPU_P (cpu_features, RTM))
+	return OPTIMIZE (avx2_rtm);
+
       if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
 	return OPTIMIZE (avx2);
     }