initial import

1 files changed, 54 insertions, 0 deletions

diff --git a/sysdeps/alpha/strlen.c b/sysdeps/alpha/strlen.c
new file mode 100644
index 0000000000..d7744476ad
--- /dev/null
+++ b/sysdeps/alpha/strlen.c
@@ -0,0 +1,54 @@
+/* Copyright (C) 1992 Free Software Foundation, Inc.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <string.h>
+
+/* Return the length of the null-terminated string STR.  Scan for
+   the null terminator quickly by testing eight bytes at a time.  */
+
+size_t
+strlen (const char *str)
+{
+  const char *char_ptr;
+  const unsigned long int *longword_ptr;
+
+  /* Handle the first few characters by reading one character at a time.
+     Do this until STR is aligned on a 8-byte border.  */
+  for (char_ptr = str; ((unsigned long int) char_ptr & 7) != 0; ++char_ptr)
+    if (*char_ptr == '\0')
+      return char_ptr - str;
+
+  longword_ptr = (unsigned long int *) char_ptr;
+
+  for (;;)
+    {
+      int mask;
+      asm ("cmpbge %1, %2, %0" : "=r" (mask) : "r" (0), "r" (*longword_ptr++));
+      if (mask)
+	{
+	  /* Which of the bytes was the zero?  */
+
+	  const char *cp = (const char *) (longword_ptr - 1);
+	  int i;
+
+	  for (i = 0; i < 6; i++)
+	    if (cp[i] == 0)
+	      return cp - str + i;
+	  return cp - str + 7;
+	}
+    }
+}