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authorH.J. Lu <hjl.tools@gmail.com>2016-06-30 07:57:07 -0700
committerH.J. Lu <hjl.tools@gmail.com>2016-06-30 07:58:11 -0700
commit13efa86ece61bf84daca50cab30db1b0902fe2db (patch)
treee6ed4e21bb720ba21d069d61064a057be6f999db /sysdeps/x86
parent73fb56a4d51fd4437e4cde6dd3c8077a610f88a8 (diff)
downloadglibc-13efa86ece61bf84daca50cab30db1b0902fe2db.tar.gz
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Check Prefer_ERMS in memmove/memcpy/mempcpy/memset
Although the Enhanced REP MOVSB/STOSB (ERMS) implementations of memmove,
memcpy, mempcpy and memset aren't used by the current processors, this
patch adds Prefer_ERMS check in memmove, memcpy, mempcpy and memset so
that they can be used in the future.

	* sysdeps/x86/cpu-features.h (bit_arch_Prefer_ERMS): New.
	(index_arch_Prefer_ERMS): Likewise.
	* sysdeps/x86_64/multiarch/memcpy.S (__new_memcpy): Return
	__memcpy_erms for Prefer_ERMS.
	* sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
	(__memmove_erms): Enabled for libc.a.
	* ysdeps/x86_64/multiarch/memmove.S (__libc_memmove): Return
	__memmove_erms or Prefer_ERMS.
	* sysdeps/x86_64/multiarch/mempcpy.S (__mempcpy): Return
	__mempcpy_erms for Prefer_ERMS.
	* sysdeps/x86_64/multiarch/memset.S (memset): Return
	__memset_erms for Prefer_ERMS.
Diffstat (limited to 'sysdeps/x86')
-rw-r--r--sysdeps/x86/cpu-features.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index 2bd93713a1..97ffe765f4 100644
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -36,6 +36,7 @@
 #define bit_arch_Prefer_MAP_32BIT_EXEC		(1 << 16)
 #define bit_arch_Prefer_No_VZEROUPPER		(1 << 17)
 #define bit_arch_Fast_Unaligned_Copy		(1 << 18)
+#define bit_arch_Prefer_ERMS			(1 << 19)
 
 /* CPUID Feature flags.  */
 
@@ -105,6 +106,7 @@
 # define index_arch_Prefer_MAP_32BIT_EXEC FEATURE_INDEX_1*FEATURE_SIZE
 # define index_arch_Prefer_No_VZEROUPPER FEATURE_INDEX_1*FEATURE_SIZE
 # define index_arch_Fast_Unaligned_Copy	FEATURE_INDEX_1*FEATURE_SIZE
+# define index_arch_Prefer_ERMS		FEATURE_INDEX_1*FEATURE_SIZE
 
 
 # if defined (_LIBC) && !IS_IN (nonlib)
@@ -274,6 +276,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 # define index_arch_Prefer_MAP_32BIT_EXEC FEATURE_INDEX_1
 # define index_arch_Prefer_No_VZEROUPPER FEATURE_INDEX_1
 # define index_arch_Fast_Unaligned_Copy	FEATURE_INDEX_1
+# define index_arch_Prefer_ERMS		FEATURE_INDEX_1
 
 #endif	/* !__ASSEMBLER__ */