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authorUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
committerUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
commita334319f6530564d22e775935d9c91663623a1b4 (patch)
treeb5877475619e4c938e98757d518bb1e9cbead751 /string/memrchr.c
parent0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (diff)
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(CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4.
Diffstat (limited to 'string/memrchr.c')
-rw-r--r--string/memrchr.c210
1 files changed, 0 insertions, 210 deletions
diff --git a/string/memrchr.c b/string/memrchr.c
deleted file mode 100644
index 21662b1bd7..0000000000
--- a/string/memrchr.c
+++ /dev/null
@@ -1,210 +0,0 @@
-/* memrchr -- find the last occurrence of a byte in a memory block
-   Copyright (C) 1991, 93, 96, 97, 99, 2000 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Based on strlen implementation by Torbjorn Granlund (tege@sics.se),
-   with help from Dan Sahlin (dan@sics.se) and
-   commentary by Jim Blandy (jimb@ai.mit.edu);
-   adaptation to memchr suggested by Dick Karpinski (dick@cca.ucsf.edu),
-   and implemented by Roland McGrath (roland@ai.mit.edu).
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 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
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
-
-#include <stdlib.h>
-
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#undef __ptr_t
-#if defined __cplusplus || (defined __STDC__ && __STDC__)
-# define __ptr_t void *
-#else /* Not C++ or ANSI C.  */
-# define __ptr_t char *
-#endif /* C++ or ANSI C.  */
-
-#if defined _LIBC
-# include <string.h>
-# include <memcopy.h>
-#else
-# define reg_char char
-#endif
-
-#if defined HAVE_LIMITS_H || defined _LIBC
-# include <limits.h>
-#endif
-
-#define LONG_MAX_32_BITS 2147483647
-
-#ifndef LONG_MAX
-# define LONG_MAX LONG_MAX_32_BITS
-#endif
-
-#include <sys/types.h>
-
-#undef __memrchr
-#undef memrchr
-
-#ifndef weak_alias
-# define __memrchr memrchr
-#endif
-
-/* Search no more than N bytes of S for C.  */
-__ptr_t
-__memrchr (s, c_in, n)
-     const __ptr_t s;
-     int c_in;
-     size_t n;
-{
-  const unsigned char *char_ptr;
-  const unsigned long int *longword_ptr;
-  unsigned long int longword, magic_bits, charmask;
-  unsigned reg_char c;
-
-  c = (unsigned char) c_in;
-
-  /* Handle the last few characters by reading one character at a time.
-     Do this until CHAR_PTR is aligned on a longword boundary.  */
-  for (char_ptr = (const unsigned char *) s + n;
-       n > 0 && ((unsigned long int) char_ptr
-		 & (sizeof (longword) - 1)) != 0;
-       --n)
-    if (*--char_ptr == c)
-      return (__ptr_t) char_ptr;
-
-  /* All these elucidatory comments refer to 4-byte longwords,
-     but the theory applies equally well to 8-byte longwords.  */
-
-  longword_ptr = (const unsigned long int *) char_ptr;
-
-  /* Bits 31, 24, 16, and 8 of this number are zero.  Call these bits
-     the "holes."  Note that there is a hole just to the left of
-     each byte, with an extra at the end:
-
-     bits:  01111110 11111110 11111110 11111111
-     bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD
-
-     The 1-bits make sure that carries propagate to the next 0-bit.
-     The 0-bits provide holes for carries to fall into.  */
-
-  if (sizeof (longword) != 4 && sizeof (longword) != 8)
-    abort ();
-
-#if LONG_MAX <= LONG_MAX_32_BITS
-  magic_bits = 0x7efefeff;
-#else
-  magic_bits = ((unsigned long int) 0x7efefefe << 32) | 0xfefefeff;
-#endif
-
-  /* Set up a longword, each of whose bytes is C.  */
-  charmask = c | (c << 8);
-  charmask |= charmask << 16;
-#if LONG_MAX > LONG_MAX_32_BITS
-  charmask |= charmask << 32;
-#endif
-
-  /* Instead of the traditional loop which tests each character,
-     we will test a longword at a time.  The tricky part is testing
-     if *any of the four* bytes in the longword in question are zero.  */
-  while (n >= sizeof (longword))
-    {
-      /* We tentatively exit the loop if adding MAGIC_BITS to
-	 LONGWORD fails to change any of the hole bits of LONGWORD.
-
-	 1) Is this safe?  Will it catch all the zero bytes?
-	 Suppose there is a byte with all zeros.  Any carry bits
-	 propagating from its left will fall into the hole at its
-	 least significant bit and stop.  Since there will be no
-	 carry from its most significant bit, the LSB of the
-	 byte to the left will be unchanged, and the zero will be
-	 detected.
-
-	 2) Is this worthwhile?  Will it ignore everything except
-	 zero bytes?  Suppose every byte of LONGWORD has a bit set
-	 somewhere.  There will be a carry into bit 8.  If bit 8
-	 is set, this will carry into bit 16.  If bit 8 is clear,
-	 one of bits 9-15 must be set, so there will be a carry
-	 into bit 16.  Similarly, there will be a carry into bit
-	 24.  If one of bits 24-30 is set, there will be a carry
-	 into bit 31, so all of the hole bits will be changed.
-
-	 The one misfire occurs when bits 24-30 are clear and bit
-	 31 is set; in this case, the hole at bit 31 is not
-	 changed.  If we had access to the processor carry flag,
-	 we could close this loophole by putting the fourth hole
-	 at bit 32!
-
-	 So it ignores everything except 128's, when they're aligned
-	 properly.
-
-	 3) But wait!  Aren't we looking for C, not zero?
-	 Good point.  So what we do is XOR LONGWORD with a longword,
-	 each of whose bytes is C.  This turns each byte that is C
-	 into a zero.  */
-
-      longword = *--longword_ptr ^ charmask;
-
-      /* Add MAGIC_BITS to LONGWORD.  */
-      if ((((longword + magic_bits)
-
-	    /* Set those bits that were unchanged by the addition.  */
-	    ^ ~longword)
-
-	   /* Look at only the hole bits.  If any of the hole bits
-	      are unchanged, most likely one of the bytes was a
-	      zero.  */
-	   & ~magic_bits) != 0)
-	{
-	  /* Which of the bytes was C?  If none of them were, it was
-	     a misfire; continue the search.  */
-
-	  const unsigned char *cp = (const unsigned char *) longword_ptr;
-
-#if LONG_MAX > 2147483647
-	  if (cp[7] == c)
-	    return (__ptr_t) &cp[7];
-	  if (cp[6] == c)
-	    return (__ptr_t) &cp[6];
-	  if (cp[5] == c)
-	    return (__ptr_t) &cp[5];
-	  if (cp[4] == c)
-	    return (__ptr_t) &cp[4];
-#endif
-	  if (cp[3] == c)
-	    return (__ptr_t) &cp[3];
-	  if (cp[2] == c)
-	    return (__ptr_t) &cp[2];
-	  if (cp[1] == c)
-	    return (__ptr_t) &cp[1];
-	  if (cp[0] == c)
-	    return (__ptr_t) cp;
-	}
-
-      n -= sizeof (longword);
-    }
-
-  char_ptr = (const unsigned char *) longword_ptr;
-
-  while (n-- > 0)
-    {
-      if (*--char_ptr == c)
-	return (__ptr_t) char_ptr;
-    }
-
-  return 0;
-}
-#ifdef weak_alias
-weak_alias (__memrchr, memrchr)
-#endif