Add SSE4.2 support for strcmp and strncmp on x86-64.

ChangeLog

@@ -1,3 +1,15 @@
+2009-06-22  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* string/strncmp.c (STRNCMP): New.  Defined to strncmp if not
+	defined.
+	(strncmp): Renamed to STRNCMP.
+	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
+	strncmp-c for string.
+	* sysdeps/x86_64/multiarch/init-arch.h (HAS_SSE4_2): Define.
+	* sysdeps/x86_64/multiarch/strcmp.S: New file.
+	* sysdeps/x86_64/multiarch/strncmp.S: New file.
+	* sysdeps/x86_64/multiarch/strncmp-c.c: New file.
+
 2009-06-19  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* elf/Makefile (distribute): Add ifuncmain1staticpie.c,

string/strncmp.c

@@ -21,15 +21,16 @@
 
 #undef strncmp
 
+#ifndef STRNCMP
+#define STRNCMP strncmp
+#endif
+
 /* Compare no more than N characters of S1 and S2,
    returning less than, equal to or greater than zero
    if S1 is lexicographically less than, equal to or
    greater than S2.  */
 int
-strncmp (s1, s2, n)
-     const char *s1;
-     const char *s2;
-     size_t n;
+STRNCMP (const char *s1, const char *s2, size_t n)
 {
   unsigned reg_char c1 = '\0';
   unsigned reg_char c2 = '\0';
@@ -70,4 +71,5 @@ strncmp (s1, s2, n)
 
   return c1 - c2;
 }
-libc_hidden_builtin_def (strncmp)
+
+libc_hidden_builtin_def (STRNCMP)

sysdeps/x86_64/multiarch/Makefile

@@ -2,3 +2,7 @@ ifeq ($(subdir),csu)
 aux += init-arch
 gen-as-const-headers += ifunc-defines.sym
 endif
+
+ifeq ($(subdir),string)
+sysdep_routines += strncmp-c
+endif

sysdeps/x86_64/multiarch/init-arch.h

@@ -56,3 +56,6 @@ extern void __init_cpu_features (void) attribute_hidden;
 
 #define HAS_POPCOUNT \
   ((__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx & (1 << 23)) != 0)
+
+#define HAS_SSE4_2 \
+  ((__cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx & (1 << 20)) != 0)