Initial revision

diff --git a/sysdeps/alpha/strchr.c b/sysdeps/alpha/strchr.c
new file mode 100644 (file)
index 0000000..8cf2024
--- /dev/null
+++ b/sysdeps/alpha/strchr.c
@@ -0,0 +1,85 @@
+/* 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.  */
+
+char *
+strchr (const char *str, int c)
+{
+  const char *char_ptr;
+  const unsigned long int *longword_ptr;
+  unsigned long int charmask;
+
+  c = (unsigned char) c;
+
+  /* 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 NULL;
+    else if (*char_ptr == c)
+      return char_ptr;
+
+  longword_ptr = (unsigned long int *) char_ptr;
+
+  /* Set up a longword, each of whose bytes is C.  */
+  charmask = c | (c << 8);
+  charmask |= charmask << 16;
+  charmask |= charmask << 32;
+
+  for (;;)
+    {
+      const unsigned long int longword = *longword_ptr++;
+      int ge, le, zero;
+
+      /* Set bits in ZERO if bytes in LONGWORD are zero.  */
+      asm ("cmpbge $31, %1, %0" : "=r" (zero) : "r" (longword));
+
+      /* Set bits in GE if bytes in CHARMASK are >= bytes in LONGWORD.  */
+      asm ("cmpbge %1, %2, %0" : "=r" (ge) : "r" (charmask), "r" (longword));
+
+      /* Set bits in LE if bytes in CHARMASK are <= bytes in LONGWORD.  */
+      asm ("cmpbge %2, %1, %0" : "=r" (le) : "r" (charmask), "r" (longword));
+
+      /* Bytes that are both <= and >= are == to C.  */
+      if (zero || (ge & le))
+       {
+         /* Which of the bytes was the C?  */
+
+         const char *cp = (const char *) (longword_ptr - 1);
+
+         if (cp[0] == c)
+           return cp;
+         if (cp[0] == 0)
+           return NULL;
+         if (cp[1] == c)
+           return &cp[1];
+         if (cp[1] == 0)
+           return NULL;
+         if (cp[2] == c)
+           return &cp[2];
+         if (cp[2] == 0)
+           return NULL;
+         if (cp[3] == c)
+           return &cp[3];
+         return NULL;
+       }
+    }
+}