Re: Long lines and bidi

[Paul Eggert <eggert@cs.ucla.edu>]

[-- Attachment #1: Type: text/plain, Size: 1070 bytes --]

On 02/08/2013 08:52 AM, Eli Zaretskii wrote:
>> > So, ~90% of time spent in scan_buffer is:
>> > 
>> > 799                while (*cursor != target && --cursor >= ceiling_addr)
>> > 800                  ;

> Which cannot be optimized.

It can be sped up somewhat, by using memrchr.

This won't solve these performance issues, but it helps:
on my platform (x86-64 Ubuntu 12.10) I ran Dmitry's scroll-both benchmark
<http://lists.gnu.org/archive/html/emacs-devel/2013-02/msg00147.html>
on a real file (the trunk's src/xdisp.c), and it was 25% faster overall
(1.19 seconds versus 1.49 seconds) when I used memrchr there
and memchr for forward searches.

I'll attach the patch I used.  Eli, it'll need a bit of hacking to
port to MS-Windows, since the substitute memrchr implementation
(which is supplied) will need to be compiled.

Dmitry, is this something you can easily try with your benchmarks?

Most of the attached patch is boilerplate taken unmodified from gnulib,
to support memrchr on non-GNU platforms.  The key part of the change is
at the end, to src/search.c.


[-- Attachment #2: memchr.txt --]
[-- Type: text/plain, Size: 75410 bytes --]

=== modified file '.bzrignore'
--- .bzrignore	2013-02-01 06:30:51 +0000
+++ .bzrignore	2013-02-09 03:12:48 +0000
@@ -97,6 +97,7 @@
 lib/stdio.h
 lib/stdint.h
 lib/stdlib.h
+lib/string.h
 lib/sys/
 lib/SYS
 lib/time.h

=== modified file 'ChangeLog'
--- ChangeLog	2013-02-08 23:37:17 +0000
+++ ChangeLog	2013-02-09 03:12:48 +0000
@@ -1,3 +1,11 @@
+2013-02-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Tune redisplay by using memchr and memrchr.
+	* .bzrignore: Add string.h.
+	* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
+	* lib/memrchr.c, lib/string.in.h, m4/memrchr.m4, m4/string_h.m4:
+	New files, from gnulib.
+
 2013-02-08  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Merge from gnulib, incorporating:

=== modified file 'admin/ChangeLog'
--- admin/ChangeLog	2013-02-01 06:30:51 +0000
+++ admin/ChangeLog	2013-02-09 03:12:48 +0000
@@ -1,3 +1,8 @@
+2013-02-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Tune redisplay by using memchr and memrchr.
+	* merge-gnulib (GNULIB_MODULES): Add memrchr.
+
 2013-02-01  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Use fdopendir, fstatat and readlinkat, for efficiency (Bug#13539).

=== modified file 'admin/merge-gnulib'
--- admin/merge-gnulib	2013-02-01 06:30:51 +0000
+++ admin/merge-gnulib	2013-02-09 03:12:48 +0000
@@ -31,7 +31,8 @@
   dtoastr dtotimespec dup2 environ execinfo faccessat
   fcntl-h fdopendir filemode fstatat getloadavg getopt-gnu gettime gettimeofday
   ignore-value intprops largefile lstat
-  manywarnings mktime pselect pthread_sigmask putenv readlink readlinkat
+  manywarnings memrchr mktime
+  pselect pthread_sigmask putenv readlink readlinkat
   sig2str socklen stat-time stdalign stdarg stdbool stdio
   strftime strtoimax strtoumax symlink sys_stat
   sys_time time timer-time timespec-add timespec-sub unsetenv utimens

=== modified file 'lib/gnulib.mk'
--- lib/gnulib.mk	2013-02-08 23:37:17 +0000
+++ lib/gnulib.mk	2013-02-09 03:12:48 +0000
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=dup --avoid=errno --avoid=fchdir --avoid=fcntl --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl-h fdopendir filemode fstatat getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings mktime pselect pthread_sigmask putenv readlink readlinkat sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub unsetenv utimens warnings
+# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=dup --avoid=errno --avoid=fchdir --avoid=fcntl --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl-h fdopendir filemode fstatat getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings memrchr mktime pselect pthread_sigmask putenv readlink readlinkat sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub unsetenv utimens warnings
 
 
 MOSTLYCLEANFILES += core *.stackdump
@@ -480,6 +480,15 @@
 
 ## end   gnulib module lstat
 
+## begin gnulib module memrchr
+
+
+EXTRA_DIST += memrchr.c
+
+EXTRA_libgnu_a_SOURCES += memrchr.c
+
+## end   gnulib module memrchr
+
 ## begin gnulib module mktime
 
 
@@ -1105,6 +1114,106 @@
 
 ## end   gnulib module strftime
 
+## begin gnulib module string
+
+BUILT_SOURCES += string.h
+
+# We need the following in order to create <string.h> when the system
+# doesn't have one that works with the given compiler.
+string.h: string.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(WARN_ON_USE_H)
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
+	  sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+	      -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+	      -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+	      -e 's|@''NEXT_STRING_H''@|$(NEXT_STRING_H)|g' \
+	      -e 's/@''GNULIB_FFSL''@/$(GNULIB_FFSL)/g' \
+	      -e 's/@''GNULIB_FFSLL''@/$(GNULIB_FFSLL)/g' \
+	      -e 's/@''GNULIB_MBSLEN''@/$(GNULIB_MBSLEN)/g' \
+	      -e 's/@''GNULIB_MBSNLEN''@/$(GNULIB_MBSNLEN)/g' \
+	      -e 's/@''GNULIB_MBSCHR''@/$(GNULIB_MBSCHR)/g' \
+	      -e 's/@''GNULIB_MBSRCHR''@/$(GNULIB_MBSRCHR)/g' \
+	      -e 's/@''GNULIB_MBSSTR''@/$(GNULIB_MBSSTR)/g' \
+	      -e 's/@''GNULIB_MBSCASECMP''@/$(GNULIB_MBSCASECMP)/g' \
+	      -e 's/@''GNULIB_MBSNCASECMP''@/$(GNULIB_MBSNCASECMP)/g' \
+	      -e 's/@''GNULIB_MBSPCASECMP''@/$(GNULIB_MBSPCASECMP)/g' \
+	      -e 's/@''GNULIB_MBSCASESTR''@/$(GNULIB_MBSCASESTR)/g' \
+	      -e 's/@''GNULIB_MBSCSPN''@/$(GNULIB_MBSCSPN)/g' \
+	      -e 's/@''GNULIB_MBSPBRK''@/$(GNULIB_MBSPBRK)/g' \
+	      -e 's/@''GNULIB_MBSSPN''@/$(GNULIB_MBSSPN)/g' \
+	      -e 's/@''GNULIB_MBSSEP''@/$(GNULIB_MBSSEP)/g' \
+	      -e 's/@''GNULIB_MBSTOK_R''@/$(GNULIB_MBSTOK_R)/g' \
+	      -e 's/@''GNULIB_MEMCHR''@/$(GNULIB_MEMCHR)/g' \
+	      -e 's/@''GNULIB_MEMMEM''@/$(GNULIB_MEMMEM)/g' \
+	      -e 's/@''GNULIB_MEMPCPY''@/$(GNULIB_MEMPCPY)/g' \
+	      -e 's/@''GNULIB_MEMRCHR''@/$(GNULIB_MEMRCHR)/g' \
+	      -e 's/@''GNULIB_RAWMEMCHR''@/$(GNULIB_RAWMEMCHR)/g' \
+	      -e 's/@''GNULIB_STPCPY''@/$(GNULIB_STPCPY)/g' \
+	      -e 's/@''GNULIB_STPNCPY''@/$(GNULIB_STPNCPY)/g' \
+	      -e 's/@''GNULIB_STRCHRNUL''@/$(GNULIB_STRCHRNUL)/g' \
+	      -e 's/@''GNULIB_STRDUP''@/$(GNULIB_STRDUP)/g' \
+	      -e 's/@''GNULIB_STRNCAT''@/$(GNULIB_STRNCAT)/g' \
+	      -e 's/@''GNULIB_STRNDUP''@/$(GNULIB_STRNDUP)/g' \
+	      -e 's/@''GNULIB_STRNLEN''@/$(GNULIB_STRNLEN)/g' \
+	      -e 's/@''GNULIB_STRPBRK''@/$(GNULIB_STRPBRK)/g' \
+	      -e 's/@''GNULIB_STRSEP''@/$(GNULIB_STRSEP)/g' \
+	      -e 's/@''GNULIB_STRSTR''@/$(GNULIB_STRSTR)/g' \
+	      -e 's/@''GNULIB_STRCASESTR''@/$(GNULIB_STRCASESTR)/g' \
+	      -e 's/@''GNULIB_STRTOK_R''@/$(GNULIB_STRTOK_R)/g' \
+	      -e 's/@''GNULIB_STRERROR''@/$(GNULIB_STRERROR)/g' \
+	      -e 's/@''GNULIB_STRERROR_R''@/$(GNULIB_STRERROR_R)/g' \
+	      -e 's/@''GNULIB_STRSIGNAL''@/$(GNULIB_STRSIGNAL)/g' \
+	      -e 's/@''GNULIB_STRVERSCMP''@/$(GNULIB_STRVERSCMP)/g' \
+	      < $(srcdir)/string.in.h | \
+	  sed -e 's|@''HAVE_FFSL''@|$(HAVE_FFSL)|g' \
+	      -e 's|@''HAVE_FFSLL''@|$(HAVE_FFSLL)|g' \
+	      -e 's|@''HAVE_MBSLEN''@|$(HAVE_MBSLEN)|g' \
+	      -e 's|@''HAVE_MEMCHR''@|$(HAVE_MEMCHR)|g' \
+	      -e 's|@''HAVE_DECL_MEMMEM''@|$(HAVE_DECL_MEMMEM)|g' \
+	      -e 's|@''HAVE_MEMPCPY''@|$(HAVE_MEMPCPY)|g' \
+	      -e 's|@''HAVE_DECL_MEMRCHR''@|$(HAVE_DECL_MEMRCHR)|g' \
+	      -e 's|@''HAVE_RAWMEMCHR''@|$(HAVE_RAWMEMCHR)|g' \
+	      -e 's|@''HAVE_STPCPY''@|$(HAVE_STPCPY)|g' \
+	      -e 's|@''HAVE_STPNCPY''@|$(HAVE_STPNCPY)|g' \
+	      -e 's|@''HAVE_STRCHRNUL''@|$(HAVE_STRCHRNUL)|g' \
+	      -e 's|@''HAVE_DECL_STRDUP''@|$(HAVE_DECL_STRDUP)|g' \
+	      -e 's|@''HAVE_DECL_STRNDUP''@|$(HAVE_DECL_STRNDUP)|g' \
+	      -e 's|@''HAVE_DECL_STRNLEN''@|$(HAVE_DECL_STRNLEN)|g' \
+	      -e 's|@''HAVE_STRPBRK''@|$(HAVE_STRPBRK)|g' \
+	      -e 's|@''HAVE_STRSEP''@|$(HAVE_STRSEP)|g' \
+	      -e 's|@''HAVE_STRCASESTR''@|$(HAVE_STRCASESTR)|g' \
+	      -e 's|@''HAVE_DECL_STRTOK_R''@|$(HAVE_DECL_STRTOK_R)|g' \
+	      -e 's|@''HAVE_DECL_STRERROR_R''@|$(HAVE_DECL_STRERROR_R)|g' \
+	      -e 's|@''HAVE_DECL_STRSIGNAL''@|$(HAVE_DECL_STRSIGNAL)|g' \
+	      -e 's|@''HAVE_STRVERSCMP''@|$(HAVE_STRVERSCMP)|g' \
+	      -e 's|@''REPLACE_STPNCPY''@|$(REPLACE_STPNCPY)|g' \
+	      -e 's|@''REPLACE_MEMCHR''@|$(REPLACE_MEMCHR)|g' \
+	      -e 's|@''REPLACE_MEMMEM''@|$(REPLACE_MEMMEM)|g' \
+	      -e 's|@''REPLACE_STRCASESTR''@|$(REPLACE_STRCASESTR)|g' \
+	      -e 's|@''REPLACE_STRCHRNUL''@|$(REPLACE_STRCHRNUL)|g' \
+	      -e 's|@''REPLACE_STRDUP''@|$(REPLACE_STRDUP)|g' \
+	      -e 's|@''REPLACE_STRSTR''@|$(REPLACE_STRSTR)|g' \
+	      -e 's|@''REPLACE_STRERROR''@|$(REPLACE_STRERROR)|g' \
+	      -e 's|@''REPLACE_STRERROR_R''@|$(REPLACE_STRERROR_R)|g' \
+	      -e 's|@''REPLACE_STRNCAT''@|$(REPLACE_STRNCAT)|g' \
+	      -e 's|@''REPLACE_STRNDUP''@|$(REPLACE_STRNDUP)|g' \
+	      -e 's|@''REPLACE_STRNLEN''@|$(REPLACE_STRNLEN)|g' \
+	      -e 's|@''REPLACE_STRSIGNAL''@|$(REPLACE_STRSIGNAL)|g' \
+	      -e 's|@''REPLACE_STRTOK_R''@|$(REPLACE_STRTOK_R)|g' \
+	      -e 's|@''UNDEFINE_STRTOK_R''@|$(UNDEFINE_STRTOK_R)|g' \
+	      -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+	      -e '/definition of _GL_ARG_NONNULL/r $(ARG_NONNULL_H)' \
+	      -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)'; \
+	      < $(srcdir)/string.in.h; \
+	} > $@-t && \
+	mv $@-t $@
+MOSTLYCLEANFILES += string.h string.h-t
+
+EXTRA_DIST += string.in.h
+
+## end   gnulib module string
+
 ## begin gnulib module strtoimax
 
 

=== added file 'lib/memrchr.c'
--- lib/memrchr.c	1970-01-01 00:00:00 +0000
+++ lib/memrchr.c	2013-02-09 03:12:48 +0000
@@ -0,0 +1,161 @@
+/* memrchr -- find the last occurrence of a byte in a memory block
+
+   Copyright (C) 1991, 1993, 1996-1997, 1999-2000, 2003-2013 Free Software
+   Foundation, Inc.
+
+   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).
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#if defined _LIBC
+# include <memcopy.h>
+#else
+# include <config.h>
+# define reg_char char
+#endif
+
+#include <string.h>
+#include <limits.h>
+
+#undef __memrchr
+#ifdef _LIBC
+# undef memrchr
+#endif
+
+#ifndef weak_alias
+# define __memrchr memrchr
+#endif
+
+/* Search no more than N bytes of S for C.  */
+void *
+__memrchr (void const *s, int c_in, size_t n)
+{
+  /* On 32-bit hardware, choosing longword to be a 32-bit unsigned
+     long instead of a 64-bit uintmax_t tends to give better
+     performance.  On 64-bit hardware, unsigned long is generally 64
+     bits already.  Change this typedef to experiment with
+     performance.  */
+  typedef unsigned long int longword;
+
+  const unsigned char *char_ptr;
+  const longword *longword_ptr;
+  longword repeated_one;
+  longword repeated_c;
+  unsigned reg_char c;
+
+  c = (unsigned char) c_in;
+
+  /* Handle the last few bytes by reading one byte at a time.
+     Do this until CHAR_PTR is aligned on a longword boundary.  */
+  for (char_ptr = (const unsigned char *) s + n;
+       n > 0 && (size_t) char_ptr % sizeof (longword) != 0;
+       --n)
+    if (*--char_ptr == c)
+      return (void *) char_ptr;
+
+  longword_ptr = (const longword *) char_ptr;
+
+  /* All these elucidatory comments refer to 4-byte longwords,
+     but the theory applies equally well to any size longwords.  */
+
+  /* Compute auxiliary longword values:
+     repeated_one is a value which has a 1 in every byte.
+     repeated_c has c in every byte.  */
+  repeated_one = 0x01010101;
+  repeated_c = c | (c << 8);
+  repeated_c |= repeated_c << 16;
+  if (0xffffffffU < (longword) -1)
+    {
+      repeated_one |= repeated_one << 31 << 1;
+      repeated_c |= repeated_c << 31 << 1;
+      if (8 < sizeof (longword))
+        {
+          size_t i;
+
+          for (i = 64; i < sizeof (longword) * 8; i *= 2)
+            {
+              repeated_one |= repeated_one << i;
+              repeated_c |= repeated_c << i;
+            }
+        }
+    }
+
+  /* Instead of the traditional loop which tests each byte, 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 equal to c.  We first use an xor
+     with repeated_c.  This reduces the task to testing whether *any of the
+     four* bytes in longword1 is zero.
+
+     We compute tmp =
+       ((longword1 - repeated_one) & ~longword1) & (repeated_one << 7).
+     That is, we perform the following operations:
+       1. Subtract repeated_one.
+       2. & ~longword1.
+       3. & a mask consisting of 0x80 in every byte.
+     Consider what happens in each byte:
+       - If a byte of longword1 is zero, step 1 and 2 transform it into 0xff,
+         and step 3 transforms it into 0x80.  A carry can also be propagated
+         to more significant bytes.
+       - If a byte of longword1 is nonzero, let its lowest 1 bit be at
+         position k (0 <= k <= 7); so the lowest k bits are 0.  After step 1,
+         the byte ends in a single bit of value 0 and k bits of value 1.
+         After step 2, the result is just k bits of value 1: 2^k - 1.  After
+         step 3, the result is 0.  And no carry is produced.
+     So, if longword1 has only non-zero bytes, tmp is zero.
+     Whereas if longword1 has a zero byte, call j the position of the least
+     significant zero byte.  Then the result has a zero at positions 0, ...,
+     j-1 and a 0x80 at position j.  We cannot predict the result at the more
+     significant bytes (positions j+1..3), but it does not matter since we
+     already have a non-zero bit at position 8*j+7.
+
+     So, the test whether any byte in longword1 is zero is equivalent to
+     testing whether tmp is nonzero.  */
+
+  while (n >= sizeof (longword))
+    {
+      longword longword1 = *--longword_ptr ^ repeated_c;
+
+      if ((((longword1 - repeated_one) & ~longword1)
+           & (repeated_one << 7)) != 0)
+        {
+          longword_ptr++;
+          break;
+        }
+      n -= sizeof (longword);
+    }
+
+  char_ptr = (const unsigned char *) longword_ptr;
+
+  /* At this point, we know that either n < sizeof (longword), or one of the
+     sizeof (longword) bytes starting at char_ptr is == c.  On little-endian
+     machines, we could determine the first such byte without any further
+     memory accesses, just by looking at the tmp result from the last loop
+     iteration.  But this does not work on big-endian machines.  Choose code
+     that works in both cases.  */
+
+  while (n-- > 0)
+    {
+      if (*--char_ptr == c)
+        return (void *) char_ptr;
+    }
+
+  return NULL;
+}
+#ifdef weak_alias
+weak_alias (__memrchr, memrchr)
+#endif

=== added file 'lib/string.in.h'
--- lib/string.in.h	1970-01-01 00:00:00 +0000
+++ lib/string.in.h	2013-02-09 03:12:48 +0000
@@ -0,0 +1,1029 @@
+/* A GNU-like <string.h>.
+
+   Copyright (C) 1995-1996, 2001-2013 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef _@GUARD_PREFIX@_STRING_H
+
+#if __GNUC__ >= 3
+@PRAGMA_SYSTEM_HEADER@
+#endif
+@PRAGMA_COLUMNS@
+
+/* The include_next requires a split double-inclusion guard.  */
+#@INCLUDE_NEXT@ @NEXT_STRING_H@
+
+#ifndef _@GUARD_PREFIX@_STRING_H
+#define _@GUARD_PREFIX@_STRING_H
+
+/* NetBSD 5.0 mis-defines NULL.  */
+#include <stddef.h>
+
+/* MirBSD defines mbslen as a macro.  */
+#if @GNULIB_MBSLEN@ && defined __MirBSD__
+# include <wchar.h>
+#endif
+
+/* The __attribute__ feature is available in gcc versions 2.5 and later.
+   The attribute __pure__ was added in gcc 2.96.  */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE /* empty */
+#endif
+
+/* NetBSD 5.0 declares strsignal in <unistd.h>, not in <string.h>.  */
+/* But in any case avoid namespace pollution on glibc systems.  */
+#if (@GNULIB_STRSIGNAL@ || defined GNULIB_POSIXCHECK) && defined __NetBSD__ \
+    && ! defined __GLIBC__
+# include <unistd.h>
+#endif
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_ARG_NONNULL is copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+
+/* Find the index of the least-significant set bit.  */
+#if @GNULIB_FFSL@
+# if !@HAVE_FFSL@
+_GL_FUNCDECL_SYS (ffsl, int, (long int i));
+# endif
+_GL_CXXALIAS_SYS (ffsl, int, (long int i));
+_GL_CXXALIASWARN (ffsl);
+#elif defined GNULIB_POSIXCHECK
+# undef ffsl
+# if HAVE_RAW_DECL_FFSL
+_GL_WARN_ON_USE (ffsl, "ffsl is not portable - use the ffsl module");
+# endif
+#endif
+
+
+/* Find the index of the least-significant set bit.  */
+#if @GNULIB_FFSLL@
+# if !@HAVE_FFSLL@
+_GL_FUNCDECL_SYS (ffsll, int, (long long int i));
+# endif
+_GL_CXXALIAS_SYS (ffsll, int, (long long int i));
+_GL_CXXALIASWARN (ffsll);
+#elif defined GNULIB_POSIXCHECK
+# undef ffsll
+# if HAVE_RAW_DECL_FFSLL
+_GL_WARN_ON_USE (ffsll, "ffsll is not portable - use the ffsll module");
+# endif
+#endif
+
+
+/* Return the first instance of C within N bytes of S, or NULL.  */
+#if @GNULIB_MEMCHR@
+# if @REPLACE_MEMCHR@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define memchr rpl_memchr
+#  endif
+_GL_FUNCDECL_RPL (memchr, void *, (void const *__s, int __c, size_t __n)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (memchr, void *, (void const *__s, int __c, size_t __n));
+# else
+#  if ! @HAVE_MEMCHR@
+_GL_FUNCDECL_SYS (memchr, void *, (void const *__s, int __c, size_t __n)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1)));
+#  endif
+  /* On some systems, this function is defined as an overloaded function:
+       extern "C" { const void * std::memchr (const void *, int, size_t); }
+       extern "C++" { void * std::memchr (void *, int, size_t); }  */
+_GL_CXXALIAS_SYS_CAST2 (memchr,
+                        void *, (void const *__s, int __c, size_t __n),
+                        void const *, (void const *__s, int __c, size_t __n));
+# endif
+# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 10) && !defined __UCLIBC__) \
+     && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+_GL_CXXALIASWARN1 (memchr, void *, (void *__s, int __c, size_t __n));
+_GL_CXXALIASWARN1 (memchr, void const *,
+                   (void const *__s, int __c, size_t __n));
+# else
+_GL_CXXALIASWARN (memchr);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef memchr
+/* Assume memchr is always declared.  */
+_GL_WARN_ON_USE (memchr, "memchr has platform-specific bugs - "
+                 "use gnulib module memchr for portability" );
+#endif
+
+/* Return the first occurrence of NEEDLE in HAYSTACK.  */
+#if @GNULIB_MEMMEM@
+# if @REPLACE_MEMMEM@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define memmem rpl_memmem
+#  endif
+_GL_FUNCDECL_RPL (memmem, void *,
+                  (void const *__haystack, size_t __haystack_len,
+                   void const *__needle, size_t __needle_len)
+                  _GL_ATTRIBUTE_PURE
+                  _GL_ARG_NONNULL ((1, 3)));
+_GL_CXXALIAS_RPL (memmem, void *,
+                  (void const *__haystack, size_t __haystack_len,
+                   void const *__needle, size_t __needle_len));
+# else
+#  if ! @HAVE_DECL_MEMMEM@
+_GL_FUNCDECL_SYS (memmem, void *,
+                  (void const *__haystack, size_t __haystack_len,
+                   void const *__needle, size_t __needle_len)
+                  _GL_ATTRIBUTE_PURE
+                  _GL_ARG_NONNULL ((1, 3)));
+#  endif
+_GL_CXXALIAS_SYS (memmem, void *,
+                  (void const *__haystack, size_t __haystack_len,
+                   void const *__needle, size_t __needle_len));
+# endif
+_GL_CXXALIASWARN (memmem);
+#elif defined GNULIB_POSIXCHECK
+# undef memmem
+# if HAVE_RAW_DECL_MEMMEM
+_GL_WARN_ON_USE (memmem, "memmem is unportable and often quadratic - "
+                 "use gnulib module memmem-simple for portability, "
+                 "and module memmem for speed" );
+# endif
+#endif
+
+/* Copy N bytes of SRC to DEST, return pointer to bytes after the
+   last written byte.  */
+#if @GNULIB_MEMPCPY@
+# if ! @HAVE_MEMPCPY@
+_GL_FUNCDECL_SYS (mempcpy, void *,
+                  (void *restrict __dest, void const *restrict __src,
+                   size_t __n)
+                  _GL_ARG_NONNULL ((1, 2)));
+# endif
+_GL_CXXALIAS_SYS (mempcpy, void *,
+                  (void *restrict __dest, void const *restrict __src,
+                   size_t __n));
+_GL_CXXALIASWARN (mempcpy);
+#elif defined GNULIB_POSIXCHECK
+# undef mempcpy
+# if HAVE_RAW_DECL_MEMPCPY
+_GL_WARN_ON_USE (mempcpy, "mempcpy is unportable - "
+                 "use gnulib module mempcpy for portability");
+# endif
+#endif
+
+/* Search backwards through a block for a byte (specified as an int).  */
+#if @GNULIB_MEMRCHR@
+# if ! @HAVE_DECL_MEMRCHR@
+_GL_FUNCDECL_SYS (memrchr, void *, (void const *, int, size_t)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1)));
+# endif
+  /* On some systems, this function is defined as an overloaded function:
+       extern "C++" { const void * std::memrchr (const void *, int, size_t); }
+       extern "C++" { void * std::memrchr (void *, int, size_t); }  */
+_GL_CXXALIAS_SYS_CAST2 (memrchr,
+                        void *, (void const *, int, size_t),
+                        void const *, (void const *, int, size_t));
+# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 10) && !defined __UCLIBC__) \
+     && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+_GL_CXXALIASWARN1 (memrchr, void *, (void *, int, size_t));
+_GL_CXXALIASWARN1 (memrchr, void const *, (void const *, int, size_t));
+# else
+_GL_CXXALIASWARN (memrchr);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef memrchr
+# if HAVE_RAW_DECL_MEMRCHR
+_GL_WARN_ON_USE (memrchr, "memrchr is unportable - "
+                 "use gnulib module memrchr for portability");
+# endif
+#endif
+
+/* Find the first occurrence of C in S.  More efficient than
+   memchr(S,C,N), at the expense of undefined behavior if C does not
+   occur within N bytes.  */
+#if @GNULIB_RAWMEMCHR@
+# if ! @HAVE_RAWMEMCHR@
+_GL_FUNCDECL_SYS (rawmemchr, void *, (void const *__s, int __c_in)
+                                     _GL_ATTRIBUTE_PURE
+                                     _GL_ARG_NONNULL ((1)));
+# endif
+  /* On some systems, this function is defined as an overloaded function:
+       extern "C++" { const void * std::rawmemchr (const void *, int); }
+       extern "C++" { void * std::rawmemchr (void *, int); }  */
+_GL_CXXALIAS_SYS_CAST2 (rawmemchr,
+                        void *, (void const *__s, int __c_in),
+                        void const *, (void const *__s, int __c_in));
+# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 10) && !defined __UCLIBC__) \
+     && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+_GL_CXXALIASWARN1 (rawmemchr, void *, (void *__s, int __c_in));
+_GL_CXXALIASWARN1 (rawmemchr, void const *, (void const *__s, int __c_in));
+# else
+_GL_CXXALIASWARN (rawmemchr);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef rawmemchr
+# if HAVE_RAW_DECL_RAWMEMCHR
+_GL_WARN_ON_USE (rawmemchr, "rawmemchr is unportable - "
+                 "use gnulib module rawmemchr for portability");
+# endif
+#endif
+
+/* Copy SRC to DST, returning the address of the terminating '\0' in DST.  */
+#if @GNULIB_STPCPY@
+# if ! @HAVE_STPCPY@
+_GL_FUNCDECL_SYS (stpcpy, char *,
+                  (char *restrict __dst, char const *restrict __src)
+                  _GL_ARG_NONNULL ((1, 2)));
+# endif
+_GL_CXXALIAS_SYS (stpcpy, char *,
+                  (char *restrict __dst, char const *restrict __src));
+_GL_CXXALIASWARN (stpcpy);
+#elif defined GNULIB_POSIXCHECK
+# undef stpcpy
+# if HAVE_RAW_DECL_STPCPY
+_GL_WARN_ON_USE (stpcpy, "stpcpy is unportable - "
+                 "use gnulib module stpcpy for portability");
+# endif
+#endif
+
+/* Copy no more than N bytes of SRC to DST, returning a pointer past the
+   last non-NUL byte written into DST.  */
+#if @GNULIB_STPNCPY@
+# if @REPLACE_STPNCPY@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef stpncpy
+#   define stpncpy rpl_stpncpy
+#  endif
+_GL_FUNCDECL_RPL (stpncpy, char *,
+                  (char *restrict __dst, char const *restrict __src,
+                   size_t __n)
+                  _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (stpncpy, char *,
+                  (char *restrict __dst, char const *restrict __src,
+                   size_t __n));
+# else
+#  if ! @HAVE_STPNCPY@
+_GL_FUNCDECL_SYS (stpncpy, char *,
+                  (char *restrict __dst, char const *restrict __src,
+                   size_t __n)
+                  _GL_ARG_NONNULL ((1, 2)));
+#  endif
+_GL_CXXALIAS_SYS (stpncpy, char *,
+                  (char *restrict __dst, char const *restrict __src,
+                   size_t __n));
+# endif
+_GL_CXXALIASWARN (stpncpy);
+#elif defined GNULIB_POSIXCHECK
+# undef stpncpy
+# if HAVE_RAW_DECL_STPNCPY
+_GL_WARN_ON_USE (stpncpy, "stpncpy is unportable - "
+                 "use gnulib module stpncpy for portability");
+# endif
+#endif
+
+#if defined GNULIB_POSIXCHECK
+/* strchr() does not work with multibyte strings if the locale encoding is
+   GB18030 and the character to be searched is a digit.  */
+# undef strchr
+/* Assume strchr is always declared.  */
+_GL_WARN_ON_USE (strchr, "strchr cannot work correctly on character strings "
+                 "in some multibyte locales - "
+                 "use mbschr if you care about internationalization");
+#endif
+
+/* Find the first occurrence of C in S or the final NUL byte.  */
+#if @GNULIB_STRCHRNUL@
+# if @REPLACE_STRCHRNUL@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define strchrnul rpl_strchrnul
+#  endif
+_GL_FUNCDECL_RPL (strchrnul, char *, (const char *__s, int __c_in)
+                                     _GL_ATTRIBUTE_PURE
+                                     _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (strchrnul, char *,
+                  (const char *str, int ch));
+# else
+#  if ! @HAVE_STRCHRNUL@
+_GL_FUNCDECL_SYS (strchrnul, char *, (char const *__s, int __c_in)
+                                     _GL_ATTRIBUTE_PURE
+                                     _GL_ARG_NONNULL ((1)));
+#  endif
+  /* On some systems, this function is defined as an overloaded function:
+       extern "C++" { const char * std::strchrnul (const char *, int); }
+       extern "C++" { char * std::strchrnul (char *, int); }  */
+_GL_CXXALIAS_SYS_CAST2 (strchrnul,
+                        char *, (char const *__s, int __c_in),
+                        char const *, (char const *__s, int __c_in));
+# endif
+# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 10) && !defined __UCLIBC__) \
+     && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+_GL_CXXALIASWARN1 (strchrnul, char *, (char *__s, int __c_in));
+_GL_CXXALIASWARN1 (strchrnul, char const *, (char const *__s, int __c_in));
+# else
+_GL_CXXALIASWARN (strchrnul);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strchrnul
+# if HAVE_RAW_DECL_STRCHRNUL
+_GL_WARN_ON_USE (strchrnul, "strchrnul is unportable - "
+                 "use gnulib module strchrnul for portability");
+# endif
+#endif
+
+/* Duplicate S, returning an identical malloc'd string.  */
+#if @GNULIB_STRDUP@
+# if @REPLACE_STRDUP@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strdup
+#   define strdup rpl_strdup
+#  endif
+_GL_FUNCDECL_RPL (strdup, char *, (char const *__s) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (strdup, char *, (char const *__s));
+# else
+#  if defined __cplusplus && defined GNULIB_NAMESPACE && defined strdup
+    /* strdup exists as a function and as a macro.  Get rid of the macro.  */
+#   undef strdup
+#  endif
+#  if !(@HAVE_DECL_STRDUP@ || defined strdup)
+_GL_FUNCDECL_SYS (strdup, char *, (char const *__s) _GL_ARG_NONNULL ((1)));
+#  endif
+_GL_CXXALIAS_SYS (strdup, char *, (char const *__s));
+# endif
+_GL_CXXALIASWARN (strdup);
+#elif defined GNULIB_POSIXCHECK
+# undef strdup
+# if HAVE_RAW_DECL_STRDUP
+_GL_WARN_ON_USE (strdup, "strdup is unportable - "
+                 "use gnulib module strdup for portability");
+# endif
+#endif
+
+/* Append no more than N characters from SRC onto DEST.  */
+#if @GNULIB_STRNCAT@
+# if @REPLACE_STRNCAT@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strncat
+#   define strncat rpl_strncat
+#  endif
+_GL_FUNCDECL_RPL (strncat, char *, (char *dest, const char *src, size_t n)
+                                   _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (strncat, char *, (char *dest, const char *src, size_t n));
+# else
+_GL_CXXALIAS_SYS (strncat, char *, (char *dest, const char *src, size_t n));
+# endif
+_GL_CXXALIASWARN (strncat);
+#elif defined GNULIB_POSIXCHECK
+# undef strncat
+# if HAVE_RAW_DECL_STRNCAT
+_GL_WARN_ON_USE (strncat, "strncat is unportable - "
+                 "use gnulib module strncat for portability");
+# endif
+#endif
+
+/* Return a newly allocated copy of at most N bytes of STRING.  */
+#if @GNULIB_STRNDUP@
+# if @REPLACE_STRNDUP@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strndup
+#   define strndup rpl_strndup
+#  endif
+_GL_FUNCDECL_RPL (strndup, char *, (char const *__string, size_t __n)
+                                   _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (strndup, char *, (char const *__string, size_t __n));
+# else
+#  if ! @HAVE_DECL_STRNDUP@
+_GL_FUNCDECL_SYS (strndup, char *, (char const *__string, size_t __n)
+                                   _GL_ARG_NONNULL ((1)));
+#  endif
+_GL_CXXALIAS_SYS (strndup, char *, (char const *__string, size_t __n));
+# endif
+_GL_CXXALIASWARN (strndup);
+#elif defined GNULIB_POSIXCHECK
+# undef strndup
+# if HAVE_RAW_DECL_STRNDUP
+_GL_WARN_ON_USE (strndup, "strndup is unportable - "
+                 "use gnulib module strndup for portability");
+# endif
+#endif
+
+/* Find the length (number of bytes) of STRING, but scan at most
+   MAXLEN bytes.  If no '\0' terminator is found in that many bytes,
+   return MAXLEN.  */
+#if @GNULIB_STRNLEN@
+# if @REPLACE_STRNLEN@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strnlen
+#   define strnlen rpl_strnlen
+#  endif
+_GL_FUNCDECL_RPL (strnlen, size_t, (char const *__string, size_t __maxlen)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (strnlen, size_t, (char const *__string, size_t __maxlen));
+# else
+#  if ! @HAVE_DECL_STRNLEN@
+_GL_FUNCDECL_SYS (strnlen, size_t, (char const *__string, size_t __maxlen)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1)));
+#  endif
+_GL_CXXALIAS_SYS (strnlen, size_t, (char const *__string, size_t __maxlen));
+# endif
+_GL_CXXALIASWARN (strnlen);
+#elif defined GNULIB_POSIXCHECK
+# undef strnlen
+# if HAVE_RAW_DECL_STRNLEN
+_GL_WARN_ON_USE (strnlen, "strnlen is unportable - "
+                 "use gnulib module strnlen for portability");
+# endif
+#endif
+
+#if defined GNULIB_POSIXCHECK
+/* strcspn() assumes the second argument is a list of single-byte characters.
+   Even in this simple case, it does not work with multibyte strings if the
+   locale encoding is GB18030 and one of the characters to be searched is a
+   digit.  */
+# undef strcspn
+/* Assume strcspn is always declared.  */
+_GL_WARN_ON_USE (strcspn, "strcspn cannot work correctly on character strings "
+                 "in multibyte locales - "
+                 "use mbscspn if you care about internationalization");
+#endif
+
+/* Find the first occurrence in S of any character in ACCEPT.  */
+#if @GNULIB_STRPBRK@
+# if ! @HAVE_STRPBRK@
+_GL_FUNCDECL_SYS (strpbrk, char *, (char const *__s, char const *__accept)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1, 2)));
+# endif
+  /* On some systems, this function is defined as an overloaded function:
+       extern "C" { const char * strpbrk (const char *, const char *); }
+       extern "C++" { char * strpbrk (char *, const char *); }  */
+_GL_CXXALIAS_SYS_CAST2 (strpbrk,
+                        char *, (char const *__s, char const *__accept),
+                        const char *, (char const *__s, char const *__accept));
+# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 10) && !defined __UCLIBC__) \
+     && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+_GL_CXXALIASWARN1 (strpbrk, char *, (char *__s, char const *__accept));
+_GL_CXXALIASWARN1 (strpbrk, char const *,
+                   (char const *__s, char const *__accept));
+# else
+_GL_CXXALIASWARN (strpbrk);
+# endif
+# if defined GNULIB_POSIXCHECK
+/* strpbrk() assumes the second argument is a list of single-byte characters.
+   Even in this simple case, it does not work with multibyte strings if the
+   locale encoding is GB18030 and one of the characters to be searched is a
+   digit.  */
+#  undef strpbrk
+_GL_WARN_ON_USE (strpbrk, "strpbrk cannot work correctly on character strings "
+                 "in multibyte locales - "
+                 "use mbspbrk if you care about internationalization");
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strpbrk
+# if HAVE_RAW_DECL_STRPBRK
+_GL_WARN_ON_USE (strpbrk, "strpbrk is unportable - "
+                 "use gnulib module strpbrk for portability");
+# endif
+#endif
+
+#if defined GNULIB_POSIXCHECK
+/* strspn() assumes the second argument is a list of single-byte characters.
+   Even in this simple case, it cannot work with multibyte strings.  */
+# undef strspn
+/* Assume strspn is always declared.  */
+_GL_WARN_ON_USE (strspn, "strspn cannot work correctly on character strings "
+                 "in multibyte locales - "
+                 "use mbsspn if you care about internationalization");
+#endif
+
+#if defined GNULIB_POSIXCHECK
+/* strrchr() does not work with multibyte strings if the locale encoding is
+   GB18030 and the character to be searched is a digit.  */
+# undef strrchr
+/* Assume strrchr is always declared.  */
+_GL_WARN_ON_USE (strrchr, "strrchr cannot work correctly on character strings "
+                 "in some multibyte locales - "
+                 "use mbsrchr if you care about internationalization");
+#endif
+
+/* Search the next delimiter (char listed in DELIM) starting at *STRINGP.
+   If one is found, overwrite it with a NUL, and advance *STRINGP
+   to point to the next char after it.  Otherwise, set *STRINGP to NULL.
+   If *STRINGP was already NULL, nothing happens.
+   Return the old value of *STRINGP.
+
+   This is a variant of strtok() that is multithread-safe and supports
+   empty fields.
+
+   Caveat: It modifies the original string.
+   Caveat: These functions cannot be used on constant strings.
+   Caveat: The identity of the delimiting character is lost.
+   Caveat: It doesn't work with multibyte strings unless all of the delimiter
+           characters are ASCII characters < 0x30.
+
+   See also strtok_r().  */
+#if @GNULIB_STRSEP@
+# if ! @HAVE_STRSEP@
+_GL_FUNCDECL_SYS (strsep, char *,
+                  (char **restrict __stringp, char const *restrict __delim)
+                  _GL_ARG_NONNULL ((1, 2)));
+# endif
+_GL_CXXALIAS_SYS (strsep, char *,
+                  (char **restrict __stringp, char const *restrict __delim));
+_GL_CXXALIASWARN (strsep);
+# if defined GNULIB_POSIXCHECK
+#  undef strsep
+_GL_WARN_ON_USE (strsep, "strsep cannot work correctly on character strings "
+                 "in multibyte locales - "
+                 "use mbssep if you care about internationalization");
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strsep
+# if HAVE_RAW_DECL_STRSEP
+_GL_WARN_ON_USE (strsep, "strsep is unportable - "
+                 "use gnulib module strsep for portability");
+# endif
+#endif
+
+#if @GNULIB_STRSTR@
+# if @REPLACE_STRSTR@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define strstr rpl_strstr
+#  endif
+_GL_FUNCDECL_RPL (strstr, char *, (const char *haystack, const char *needle)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (strstr, char *, (const char *haystack, const char *needle));
+# else
+  /* On some systems, this function is defined as an overloaded function:
+       extern "C++" { const char * strstr (const char *, const char *); }
+       extern "C++" { char * strstr (char *, const char *); }  */
+_GL_CXXALIAS_SYS_CAST2 (strstr,
+                        char *, (const char *haystack, const char *needle),
+                        const char *, (const char *haystack, const char *needle));
+# endif
+# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 10) && !defined __UCLIBC__) \
+     && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+_GL_CXXALIASWARN1 (strstr, char *, (char *haystack, const char *needle));
+_GL_CXXALIASWARN1 (strstr, const char *,
+                   (const char *haystack, const char *needle));
+# else
+_GL_CXXALIASWARN (strstr);
+# endif
+#elif defined GNULIB_POSIXCHECK
+/* strstr() does not work with multibyte strings if the locale encoding is
+   different from UTF-8:
+   POSIX says that it operates on "strings", and "string" in POSIX is defined
+   as a sequence of bytes, not of characters.  */
+# undef strstr
+/* Assume strstr is always declared.  */
+_GL_WARN_ON_USE (strstr, "strstr is quadratic on many systems, and cannot "
+                 "work correctly on character strings in most "
+                 "multibyte locales - "
+                 "use mbsstr if you care about internationalization, "
+                 "or use strstr if you care about speed");
+#endif
+
+/* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
+   comparison.  */
+#if @GNULIB_STRCASESTR@
+# if @REPLACE_STRCASESTR@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define strcasestr rpl_strcasestr
+#  endif
+_GL_FUNCDECL_RPL (strcasestr, char *,
+                  (const char *haystack, const char *needle)
+                  _GL_ATTRIBUTE_PURE
+                  _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (strcasestr, char *,
+                  (const char *haystack, const char *needle));
+# else
+#  if ! @HAVE_STRCASESTR@
+_GL_FUNCDECL_SYS (strcasestr, char *,
+                  (const char *haystack, const char *needle)
+                  _GL_ATTRIBUTE_PURE
+                  _GL_ARG_NONNULL ((1, 2)));
+#  endif
+  /* On some systems, this function is defined as an overloaded function:
+       extern "C++" { const char * strcasestr (const char *, const char *); }
+       extern "C++" { char * strcasestr (char *, const char *); }  */
+_GL_CXXALIAS_SYS_CAST2 (strcasestr,
+                        char *, (const char *haystack, const char *needle),
+                        const char *, (const char *haystack, const char *needle));
+# endif
+# if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 10) && !defined __UCLIBC__) \
+     && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+_GL_CXXALIASWARN1 (strcasestr, char *, (char *haystack, const char *needle));
+_GL_CXXALIASWARN1 (strcasestr, const char *,
+                   (const char *haystack, const char *needle));
+# else
+_GL_CXXALIASWARN (strcasestr);
+# endif
+#elif defined GNULIB_POSIXCHECK
+/* strcasestr() does not work with multibyte strings:
+   It is a glibc extension, and glibc implements it only for unibyte
+   locales.  */
+# undef strcasestr
+# if HAVE_RAW_DECL_STRCASESTR
+_GL_WARN_ON_USE (strcasestr, "strcasestr does work correctly on character "
+                 "strings in multibyte locales - "
+                 "use mbscasestr if you care about "
+                 "internationalization, or use c-strcasestr if you want "
+                 "a locale independent function");
+# endif
+#endif
+
+/* Parse S into tokens separated by characters in DELIM.
+   If S is NULL, the saved pointer in SAVE_PTR is used as
+   the next starting point.  For example:
+        char s[] = "-abc-=-def";
+        char *sp;
+        x = strtok_r(s, "-", &sp);      // x = "abc", sp = "=-def"
+        x = strtok_r(NULL, "-=", &sp);  // x = "def", sp = NULL
+        x = strtok_r(NULL, "=", &sp);   // x = NULL
+                // s = "abc\0-def\0"
+
+   This is a variant of strtok() that is multithread-safe.
+
+   For the POSIX documentation for this function, see:
+   http://www.opengroup.org/susv3xsh/strtok.html
+
+   Caveat: It modifies the original string.
+   Caveat: These functions cannot be used on constant strings.
+   Caveat: The identity of the delimiting character is lost.
+   Caveat: It doesn't work with multibyte strings unless all of the delimiter
+           characters are ASCII characters < 0x30.
+
+   See also strsep().  */
+#if @GNULIB_STRTOK_R@
+# if @REPLACE_STRTOK_R@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strtok_r
+#   define strtok_r rpl_strtok_r
+#  endif
+_GL_FUNCDECL_RPL (strtok_r, char *,
+                  (char *restrict s, char const *restrict delim,
+                   char **restrict save_ptr)
+                  _GL_ARG_NONNULL ((2, 3)));
+_GL_CXXALIAS_RPL (strtok_r, char *,
+                  (char *restrict s, char const *restrict delim,
+                   char **restrict save_ptr));
+# else
+#  if @UNDEFINE_STRTOK_R@ || defined GNULIB_POSIXCHECK
+#   undef strtok_r
+#  endif
+#  if ! @HAVE_DECL_STRTOK_R@
+_GL_FUNCDECL_SYS (strtok_r, char *,
+                  (char *restrict s, char const *restrict delim,
+                   char **restrict save_ptr)
+                  _GL_ARG_NONNULL ((2, 3)));
+#  endif
+_GL_CXXALIAS_SYS (strtok_r, char *,
+                  (char *restrict s, char const *restrict delim,
+                   char **restrict save_ptr));
+# endif
+_GL_CXXALIASWARN (strtok_r);
+# if defined GNULIB_POSIXCHECK
+_GL_WARN_ON_USE (strtok_r, "strtok_r cannot work correctly on character "
+                 "strings in multibyte locales - "
+                 "use mbstok_r if you care about internationalization");
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strtok_r
+# if HAVE_RAW_DECL_STRTOK_R
+_GL_WARN_ON_USE (strtok_r, "strtok_r is unportable - "
+                 "use gnulib module strtok_r for portability");
+# endif
+#endif
+
+
+/* The following functions are not specified by POSIX.  They are gnulib
+   extensions.  */
+
+#if @GNULIB_MBSLEN@
+/* Return the number of multibyte characters in the character string STRING.
+   This considers multibyte characters, unlike strlen, which counts bytes.  */
+# ifdef __MirBSD__  /* MirBSD defines mbslen as a macro.  Override it.  */
+#  undef mbslen
+# endif
+# if @HAVE_MBSLEN@  /* AIX, OSF/1, MirBSD define mbslen already in libc.  */
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define mbslen rpl_mbslen
+#  endif
+_GL_FUNCDECL_RPL (mbslen, size_t, (const char *string)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (mbslen, size_t, (const char *string));
+# else
+_GL_FUNCDECL_SYS (mbslen, size_t, (const char *string)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_SYS (mbslen, size_t, (const char *string));
+# endif
+_GL_CXXALIASWARN (mbslen);
+#endif
+
+#if @GNULIB_MBSNLEN@
+/* Return the number of multibyte characters in the character string starting
+   at STRING and ending at STRING + LEN.  */
+_GL_EXTERN_C size_t mbsnlen (const char *string, size_t len)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1));
+#endif
+
+#if @GNULIB_MBSCHR@
+/* Locate the first single-byte character C in the character string STRING,
+   and return a pointer to it.  Return NULL if C is not found in STRING.
+   Unlike strchr(), this function works correctly in multibyte locales with
+   encodings such as GB18030.  */
+# if defined __hpux
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define mbschr rpl_mbschr /* avoid collision with HP-UX function */
+#  endif
+_GL_FUNCDECL_RPL (mbschr, char *, (const char *string, int c)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (mbschr, char *, (const char *string, int c));
+# else
+_GL_FUNCDECL_SYS (mbschr, char *, (const char *string, int c)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_SYS (mbschr, char *, (const char *string, int c));
+# endif
+_GL_CXXALIASWARN (mbschr);
+#endif
+
+#if @GNULIB_MBSRCHR@
+/* Locate the last single-byte character C in the character string STRING,
+   and return a pointer to it.  Return NULL if C is not found in STRING.
+   Unlike strrchr(), this function works correctly in multibyte locales with
+   encodings such as GB18030.  */
+# if defined __hpux || defined __INTERIX
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define mbsrchr rpl_mbsrchr /* avoid collision with system function */
+#  endif
+_GL_FUNCDECL_RPL (mbsrchr, char *, (const char *string, int c)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (mbsrchr, char *, (const char *string, int c));
+# else
+_GL_FUNCDECL_SYS (mbsrchr, char *, (const char *string, int c)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_SYS (mbsrchr, char *, (const char *string, int c));
+# endif
+_GL_CXXALIASWARN (mbsrchr);
+#endif
+
+#if @GNULIB_MBSSTR@
+/* Find the first occurrence of the character string NEEDLE in the character
+   string HAYSTACK.  Return NULL if NEEDLE is not found in HAYSTACK.
+   Unlike strstr(), this function works correctly in multibyte locales with
+   encodings different from UTF-8.  */
+_GL_EXTERN_C char * mbsstr (const char *haystack, const char *needle)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_MBSCASECMP@
+/* Compare the character strings S1 and S2, ignoring case, returning less than,
+   equal to or greater than zero if S1 is lexicographically less than, equal to
+   or greater than S2.
+   Note: This function may, in multibyte locales, return 0 for strings of
+   different lengths!
+   Unlike strcasecmp(), this function works correctly in multibyte locales.  */
+_GL_EXTERN_C int mbscasecmp (const char *s1, const char *s2)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_MBSNCASECMP@
+/* Compare the initial segment of the character string S1 consisting of at most
+   N characters with the initial segment of the character string S2 consisting
+   of at most N characters, ignoring case, returning less than, equal to or
+   greater than zero if the initial segment of S1 is lexicographically less
+   than, equal to or greater than the initial segment of S2.
+   Note: This function may, in multibyte locales, return 0 for initial segments
+   of different lengths!
+   Unlike strncasecmp(), this function works correctly in multibyte locales.
+   But beware that N is not a byte count but a character count!  */
+_GL_EXTERN_C int mbsncasecmp (const char *s1, const char *s2, size_t n)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_MBSPCASECMP@
+/* Compare the initial segment of the character string STRING consisting of
+   at most mbslen (PREFIX) characters with the character string PREFIX,
+   ignoring case.  If the two match, return a pointer to the first byte
+   after this prefix in STRING.  Otherwise, return NULL.
+   Note: This function may, in multibyte locales, return non-NULL if STRING
+   is of smaller length than PREFIX!
+   Unlike strncasecmp(), this function works correctly in multibyte
+   locales.  */
+_GL_EXTERN_C char * mbspcasecmp (const char *string, const char *prefix)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_MBSCASESTR@
+/* Find the first occurrence of the character string NEEDLE in the character
+   string HAYSTACK, using case-insensitive comparison.
+   Note: This function may, in multibyte locales, return success even if
+   strlen (haystack) < strlen (needle) !
+   Unlike strcasestr(), this function works correctly in multibyte locales.  */
+_GL_EXTERN_C char * mbscasestr (const char *haystack, const char *needle)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_MBSCSPN@
+/* Find the first occurrence in the character string STRING of any character
+   in the character string ACCEPT.  Return the number of bytes from the
+   beginning of the string to this occurrence, or to the end of the string
+   if none exists.
+   Unlike strcspn(), this function works correctly in multibyte locales.  */
+_GL_EXTERN_C size_t mbscspn (const char *string, const char *accept)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_MBSPBRK@
+/* Find the first occurrence in the character string STRING of any character
+   in the character string ACCEPT.  Return the pointer to it, or NULL if none
+   exists.
+   Unlike strpbrk(), this function works correctly in multibyte locales.  */
+# if defined __hpux
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define mbspbrk rpl_mbspbrk /* avoid collision with HP-UX function */
+#  endif
+_GL_FUNCDECL_RPL (mbspbrk, char *, (const char *string, const char *accept)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_RPL (mbspbrk, char *, (const char *string, const char *accept));
+# else
+_GL_FUNCDECL_SYS (mbspbrk, char *, (const char *string, const char *accept)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1, 2)));
+_GL_CXXALIAS_SYS (mbspbrk, char *, (const char *string, const char *accept));
+# endif
+_GL_CXXALIASWARN (mbspbrk);
+#endif
+
+#if @GNULIB_MBSSPN@
+/* Find the first occurrence in the character string STRING of any character
+   not in the character string REJECT.  Return the number of bytes from the
+   beginning of the string to this occurrence, or to the end of the string
+   if none exists.
+   Unlike strspn(), this function works correctly in multibyte locales.  */
+_GL_EXTERN_C size_t mbsspn (const char *string, const char *reject)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_MBSSEP@
+/* Search the next delimiter (multibyte character listed in the character
+   string DELIM) starting at the character string *STRINGP.
+   If one is found, overwrite it with a NUL, and advance *STRINGP to point
+   to the next multibyte character after it.  Otherwise, set *STRINGP to NULL.
+   If *STRINGP was already NULL, nothing happens.
+   Return the old value of *STRINGP.
+
+   This is a variant of mbstok_r() that supports empty fields.
+
+   Caveat: It modifies the original string.
+   Caveat: These functions cannot be used on constant strings.
+   Caveat: The identity of the delimiting character is lost.
+
+   See also mbstok_r().  */
+_GL_EXTERN_C char * mbssep (char **stringp, const char *delim)
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_MBSTOK_R@
+/* Parse the character string STRING into tokens separated by characters in
+   the character string DELIM.
+   If STRING is NULL, the saved pointer in SAVE_PTR is used as
+   the next starting point.  For example:
+        char s[] = "-abc-=-def";
+        char *sp;
+        x = mbstok_r(s, "-", &sp);      // x = "abc", sp = "=-def"
+        x = mbstok_r(NULL, "-=", &sp);  // x = "def", sp = NULL
+        x = mbstok_r(NULL, "=", &sp);   // x = NULL
+                // s = "abc\0-def\0"
+
+   Caveat: It modifies the original string.
+   Caveat: These functions cannot be used on constant strings.
+   Caveat: The identity of the delimiting character is lost.
+
+   See also mbssep().  */
+_GL_EXTERN_C char * mbstok_r (char *string, const char *delim, char **save_ptr)
+     _GL_ARG_NONNULL ((2, 3));
+#endif
+
+/* Map any int, typically from errno, into an error message.  */
+#if @GNULIB_STRERROR@
+# if @REPLACE_STRERROR@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strerror
+#   define strerror rpl_strerror
+#  endif
+_GL_FUNCDECL_RPL (strerror, char *, (int));
+_GL_CXXALIAS_RPL (strerror, char *, (int));
+# else
+_GL_CXXALIAS_SYS (strerror, char *, (int));
+# endif
+_GL_CXXALIASWARN (strerror);
+#elif defined GNULIB_POSIXCHECK
+# undef strerror
+/* Assume strerror is always declared.  */
+_GL_WARN_ON_USE (strerror, "strerror is unportable - "
+                 "use gnulib module strerror to guarantee non-NULL result");
+#endif
+
+/* Map any int, typically from errno, into an error message.  Multithread-safe.
+   Uses the POSIX declaration, not the glibc declaration.  */
+#if @GNULIB_STRERROR_R@
+# if @REPLACE_STRERROR_R@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strerror_r
+#   define strerror_r rpl_strerror_r
+#  endif
+_GL_FUNCDECL_RPL (strerror_r, int, (int errnum, char *buf, size_t buflen)
+                                   _GL_ARG_NONNULL ((2)));
+_GL_CXXALIAS_RPL (strerror_r, int, (int errnum, char *buf, size_t buflen));
+# else
+#  if !@HAVE_DECL_STRERROR_R@
+_GL_FUNCDECL_SYS (strerror_r, int, (int errnum, char *buf, size_t buflen)
+                                   _GL_ARG_NONNULL ((2)));
+#  endif
+_GL_CXXALIAS_SYS (strerror_r, int, (int errnum, char *buf, size_t buflen));
+# endif
+# if @HAVE_DECL_STRERROR_R@
+_GL_CXXALIASWARN (strerror_r);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef strerror_r
+# if HAVE_RAW_DECL_STRERROR_R
+_GL_WARN_ON_USE (strerror_r, "strerror_r is unportable - "
+                 "use gnulib module strerror_r-posix for portability");
+# endif
+#endif
+
+#if @GNULIB_STRSIGNAL@
+# if @REPLACE_STRSIGNAL@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define strsignal rpl_strsignal
+#  endif
+_GL_FUNCDECL_RPL (strsignal, char *, (int __sig));
+_GL_CXXALIAS_RPL (strsignal, char *, (int __sig));
+# else
+#  if ! @HAVE_DECL_STRSIGNAL@
+_GL_FUNCDECL_SYS (strsignal, char *, (int __sig));
+#  endif
+/* Need to cast, because on Cygwin 1.5.x systems, the return type is
+   'const char *'.  */
+_GL_CXXALIAS_SYS_CAST (strsignal, char *, (int __sig));
+# endif
+_GL_CXXALIASWARN (strsignal);
+#elif defined GNULIB_POSIXCHECK
+# undef strsignal
+# if HAVE_RAW_DECL_STRSIGNAL
+_GL_WARN_ON_USE (strsignal, "strsignal is unportable - "
+                 "use gnulib module strsignal for portability");
+# endif
+#endif
+
+#if @GNULIB_STRVERSCMP@
+# if !@HAVE_STRVERSCMP@
+_GL_FUNCDECL_SYS (strverscmp, int, (const char *, const char *)
+                                   _GL_ATTRIBUTE_PURE
+                                   _GL_ARG_NONNULL ((1, 2)));
+# endif
+_GL_CXXALIAS_SYS (strverscmp, int, (const char *, const char *));
+_GL_CXXALIASWARN (strverscmp);
+#elif defined GNULIB_POSIXCHECK
+# undef strverscmp
+# if HAVE_RAW_DECL_STRVERSCMP
+_GL_WARN_ON_USE (strverscmp, "strverscmp is unportable - "
+                 "use gnulib module strverscmp for portability");
+# endif
+#endif
+
+
+#endif /* _@GUARD_PREFIX@_STRING_H */
+#endif /* _@GUARD_PREFIX@_STRING_H */

=== modified file 'm4/gnulib-comp.m4'
--- m4/gnulib-comp.m4	2013-02-01 06:30:51 +0000
+++ m4/gnulib-comp.m4	2013-02-09 03:12:48 +0000
@@ -83,6 +83,7 @@
   AC_REQUIRE([AC_SYS_LARGEFILE])
   # Code from module lstat:
   # Code from module manywarnings:
+  # Code from module memrchr:
   # Code from module mktime:
   # Code from module multiarch:
   # Code from module nocrash:
@@ -117,6 +118,7 @@
   # Code from module stdio:
   # Code from module stdlib:
   # Code from module strftime:
+  # Code from module string:
   # Code from module strtoimax:
   # Code from module strtoll:
   # Code from module strtoull:
@@ -242,6 +244,12 @@
     gl_PREREQ_LSTAT
   fi
   gl_SYS_STAT_MODULE_INDICATOR([lstat])
+  gl_FUNC_MEMRCHR
+  if test $ac_cv_func_memrchr = no; then
+    AC_LIBOBJ([memrchr])
+    gl_PREREQ_MEMRCHR
+  fi
+  gl_STRING_MODULE_INDICATOR([memrchr])
   gl_FUNC_MKTIME
   if test $REPLACE_MKTIME = 1; then
     AC_LIBOBJ([mktime])
@@ -294,6 +302,7 @@
   gl_STDIO_H
   gl_STDLIB_H
   gl_FUNC_GNU_STRFTIME
+  gl_HEADER_STRING_H
   gl_FUNC_STRTOIMAX
   if test $HAVE_STRTOIMAX = 0 || test $REPLACE_STRTOIMAX = 1; then
     AC_LIBOBJ([strtoimax])
@@ -757,6 +766,7 @@
   lib/lstat.c
   lib/md5.c
   lib/md5.h
+  lib/memrchr.c
   lib/mktime-internal.h
   lib/mktime.c
   lib/openat-priv.h
@@ -790,6 +800,7 @@
   lib/stdlib.in.h
   lib/strftime.c
   lib/strftime.h
+  lib/string.in.h
   lib/strtoimax.c
   lib/strtol.c
   lib/strtoll.c
@@ -848,6 +859,7 @@
   m4/lstat.m4
   m4/manywarnings.m4
   m4/md5.m4
+  m4/memrchr.m4
   m4/mktime.m4
   m4/multiarch.m4
   m4/nocrash.m4
@@ -877,6 +889,7 @@
   m4/stdio_h.m4
   m4/stdlib_h.m4
   m4/strftime.m4
+  m4/string_h.m4
   m4/strtoimax.m4
   m4/strtoll.m4
   m4/strtoull.m4

=== added file 'm4/memrchr.m4'
--- m4/memrchr.m4	1970-01-01 00:00:00 +0000
+++ m4/memrchr.m4	2013-02-09 03:12:48 +0000
@@ -0,0 +1,23 @@
+# memrchr.m4 serial 10
+dnl Copyright (C) 2002-2003, 2005-2007, 2009-2013 Free Software Foundation,
+dnl Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_MEMRCHR],
+[
+  dnl Persuade glibc <string.h> to declare memrchr().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  AC_CHECK_DECLS_ONCE([memrchr])
+  if test $ac_cv_have_decl_memrchr = no; then
+    HAVE_DECL_MEMRCHR=0
+  fi
+
+  AC_CHECK_FUNCS([memrchr])
+])
+
+# Prerequisites of lib/memrchr.c.
+AC_DEFUN([gl_PREREQ_MEMRCHR], [:])

=== added file 'm4/string_h.m4'
--- m4/string_h.m4	1970-01-01 00:00:00 +0000
+++ m4/string_h.m4	2013-02-09 03:12:48 +0000
@@ -0,0 +1,120 @@
+# Configure a GNU-like replacement for <string.h>.
+
+# Copyright (C) 2007-2013 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# serial 21
+
+# Written by Paul Eggert.
+
+AC_DEFUN([gl_HEADER_STRING_H],
+[
+  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
+  dnl once only, before all statements that occur in other macros.
+  AC_REQUIRE([gl_HEADER_STRING_H_BODY])
+])
+
+AC_DEFUN([gl_HEADER_STRING_H_BODY],
+[
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  gl_NEXT_HEADERS([string.h])
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use, and which is not
+  dnl guaranteed by C89.
+  gl_WARN_ON_USE_PREPARE([[#include <string.h>
+    ]],
+    [ffsl ffsll memmem mempcpy memrchr rawmemchr stpcpy stpncpy strchrnul
+     strdup strncat strndup strnlen strpbrk strsep strcasestr strtok_r
+     strerror_r strsignal strverscmp])
+])
+
+AC_DEFUN([gl_STRING_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_HEADER_STRING_H_DEFAULTS],
+[
+  GNULIB_FFSL=0;        AC_SUBST([GNULIB_FFSL])
+  GNULIB_FFSLL=0;       AC_SUBST([GNULIB_FFSLL])
+  GNULIB_MEMCHR=0;      AC_SUBST([GNULIB_MEMCHR])
+  GNULIB_MEMMEM=0;      AC_SUBST([GNULIB_MEMMEM])
+  GNULIB_MEMPCPY=0;     AC_SUBST([GNULIB_MEMPCPY])
+  GNULIB_MEMRCHR=0;     AC_SUBST([GNULIB_MEMRCHR])
+  GNULIB_RAWMEMCHR=0;   AC_SUBST([GNULIB_RAWMEMCHR])
+  GNULIB_STPCPY=0;      AC_SUBST([GNULIB_STPCPY])
+  GNULIB_STPNCPY=0;     AC_SUBST([GNULIB_STPNCPY])
+  GNULIB_STRCHRNUL=0;   AC_SUBST([GNULIB_STRCHRNUL])
+  GNULIB_STRDUP=0;      AC_SUBST([GNULIB_STRDUP])
+  GNULIB_STRNCAT=0;     AC_SUBST([GNULIB_STRNCAT])
+  GNULIB_STRNDUP=0;     AC_SUBST([GNULIB_STRNDUP])
+  GNULIB_STRNLEN=0;     AC_SUBST([GNULIB_STRNLEN])
+  GNULIB_STRPBRK=0;     AC_SUBST([GNULIB_STRPBRK])
+  GNULIB_STRSEP=0;      AC_SUBST([GNULIB_STRSEP])
+  GNULIB_STRSTR=0;      AC_SUBST([GNULIB_STRSTR])
+  GNULIB_STRCASESTR=0;  AC_SUBST([GNULIB_STRCASESTR])
+  GNULIB_STRTOK_R=0;    AC_SUBST([GNULIB_STRTOK_R])
+  GNULIB_MBSLEN=0;      AC_SUBST([GNULIB_MBSLEN])
+  GNULIB_MBSNLEN=0;     AC_SUBST([GNULIB_MBSNLEN])
+  GNULIB_MBSCHR=0;      AC_SUBST([GNULIB_MBSCHR])
+  GNULIB_MBSRCHR=0;     AC_SUBST([GNULIB_MBSRCHR])
+  GNULIB_MBSSTR=0;      AC_SUBST([GNULIB_MBSSTR])
+  GNULIB_MBSCASECMP=0;  AC_SUBST([GNULIB_MBSCASECMP])
+  GNULIB_MBSNCASECMP=0; AC_SUBST([GNULIB_MBSNCASECMP])
+  GNULIB_MBSPCASECMP=0; AC_SUBST([GNULIB_MBSPCASECMP])
+  GNULIB_MBSCASESTR=0;  AC_SUBST([GNULIB_MBSCASESTR])
+  GNULIB_MBSCSPN=0;     AC_SUBST([GNULIB_MBSCSPN])
+  GNULIB_MBSPBRK=0;     AC_SUBST([GNULIB_MBSPBRK])
+  GNULIB_MBSSPN=0;      AC_SUBST([GNULIB_MBSSPN])
+  GNULIB_MBSSEP=0;      AC_SUBST([GNULIB_MBSSEP])
+  GNULIB_MBSTOK_R=0;    AC_SUBST([GNULIB_MBSTOK_R])
+  GNULIB_STRERROR=0;    AC_SUBST([GNULIB_STRERROR])
+  GNULIB_STRERROR_R=0;  AC_SUBST([GNULIB_STRERROR_R])
+  GNULIB_STRSIGNAL=0;   AC_SUBST([GNULIB_STRSIGNAL])
+  GNULIB_STRVERSCMP=0;  AC_SUBST([GNULIB_STRVERSCMP])
+  HAVE_MBSLEN=0;        AC_SUBST([HAVE_MBSLEN])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_FFSL=1;                  AC_SUBST([HAVE_FFSL])
+  HAVE_FFSLL=1;                 AC_SUBST([HAVE_FFSLL])
+  HAVE_MEMCHR=1;                AC_SUBST([HAVE_MEMCHR])
+  HAVE_DECL_MEMMEM=1;           AC_SUBST([HAVE_DECL_MEMMEM])
+  HAVE_MEMPCPY=1;               AC_SUBST([HAVE_MEMPCPY])
+  HAVE_DECL_MEMRCHR=1;          AC_SUBST([HAVE_DECL_MEMRCHR])
+  HAVE_RAWMEMCHR=1;             AC_SUBST([HAVE_RAWMEMCHR])
+  HAVE_STPCPY=1;                AC_SUBST([HAVE_STPCPY])
+  HAVE_STPNCPY=1;               AC_SUBST([HAVE_STPNCPY])
+  HAVE_STRCHRNUL=1;             AC_SUBST([HAVE_STRCHRNUL])
+  HAVE_DECL_STRDUP=1;           AC_SUBST([HAVE_DECL_STRDUP])
+  HAVE_DECL_STRNDUP=1;          AC_SUBST([HAVE_DECL_STRNDUP])
+  HAVE_DECL_STRNLEN=1;          AC_SUBST([HAVE_DECL_STRNLEN])
+  HAVE_STRPBRK=1;               AC_SUBST([HAVE_STRPBRK])
+  HAVE_STRSEP=1;                AC_SUBST([HAVE_STRSEP])
+  HAVE_STRCASESTR=1;            AC_SUBST([HAVE_STRCASESTR])
+  HAVE_DECL_STRTOK_R=1;         AC_SUBST([HAVE_DECL_STRTOK_R])
+  HAVE_DECL_STRERROR_R=1;       AC_SUBST([HAVE_DECL_STRERROR_R])
+  HAVE_DECL_STRSIGNAL=1;        AC_SUBST([HAVE_DECL_STRSIGNAL])
+  HAVE_STRVERSCMP=1;            AC_SUBST([HAVE_STRVERSCMP])
+  REPLACE_MEMCHR=0;             AC_SUBST([REPLACE_MEMCHR])
+  REPLACE_MEMMEM=0;             AC_SUBST([REPLACE_MEMMEM])
+  REPLACE_STPNCPY=0;            AC_SUBST([REPLACE_STPNCPY])
+  REPLACE_STRDUP=0;             AC_SUBST([REPLACE_STRDUP])
+  REPLACE_STRSTR=0;             AC_SUBST([REPLACE_STRSTR])
+  REPLACE_STRCASESTR=0;         AC_SUBST([REPLACE_STRCASESTR])
+  REPLACE_STRCHRNUL=0;          AC_SUBST([REPLACE_STRCHRNUL])
+  REPLACE_STRERROR=0;           AC_SUBST([REPLACE_STRERROR])
+  REPLACE_STRERROR_R=0;         AC_SUBST([REPLACE_STRERROR_R])
+  REPLACE_STRNCAT=0;            AC_SUBST([REPLACE_STRNCAT])
+  REPLACE_STRNDUP=0;            AC_SUBST([REPLACE_STRNDUP])
+  REPLACE_STRNLEN=0;            AC_SUBST([REPLACE_STRNLEN])
+  REPLACE_STRSIGNAL=0;          AC_SUBST([REPLACE_STRSIGNAL])
+  REPLACE_STRTOK_R=0;           AC_SUBST([REPLACE_STRTOK_R])
+  UNDEFINE_STRTOK_R=0;          AC_SUBST([UNDEFINE_STRTOK_R])
+])

=== modified file 'src/ChangeLog'
--- src/ChangeLog	2013-02-08 17:42:09 +0000
+++ src/ChangeLog	2013-02-09 03:12:48 +0000
@@ -1,3 +1,11 @@
+2013-02-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Tune redisplay by using memchr and memrchr.
+	* search.c (scan_buffer): Omit first arg TARGET, as it's always '\n'.
+	All callers changed.
+	(scan_buffer, scan_newline): Use memchr and memrchr rather than
+	scanning byte-by-byte.
+
 2013-02-08  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* lread.c (skip_dyn_bytes): New function (bug#12598).

=== modified file 'src/editfns.c'
--- src/editfns.c	2013-01-23 20:07:28 +0000
+++ src/editfns.c	2013-02-09 03:12:48 +0000
@@ -735,8 +735,7 @@
 	      /* This is the ONLY_IN_LINE case, check that NEW_POS and
 		 FIELD_BOUND are on the same line by seeing whether
 		 there's an intervening newline or not.  */
-	      || (scan_buffer ('\n',
-			       XFASTINT (new_pos), XFASTINT (field_bound),
+	      || (scan_buffer (XFASTINT (new_pos), XFASTINT (field_bound),
 			       fwd ? -1 : 1, &shortage, 1),
 		  shortage != 0)))
 	/* Constrain NEW_POS to FIELD_BOUND.  */

=== modified file 'src/lisp.h'
--- src/lisp.h	2013-02-08 05:28:52 +0000
+++ src/lisp.h	2013-02-09 03:12:48 +0000
@@ -3338,7 +3338,7 @@
 extern ptrdiff_t fast_string_match_ignore_case (Lisp_Object, Lisp_Object);
 extern ptrdiff_t fast_looking_at (Lisp_Object, ptrdiff_t, ptrdiff_t,
                                   ptrdiff_t, ptrdiff_t, Lisp_Object);
-extern ptrdiff_t scan_buffer (int, ptrdiff_t, ptrdiff_t, ptrdiff_t,
+extern ptrdiff_t scan_buffer (ptrdiff_t, ptrdiff_t, ptrdiff_t,
 			      ptrdiff_t *, bool);
 extern EMACS_INT scan_newline (ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t,
 			       EMACS_INT, bool);

=== modified file 'src/search.c'
--- src/search.c	2013-02-08 14:44:53 +0000
+++ src/search.c	2013-02-09 03:12:48 +0000
@@ -619,7 +619,7 @@
 }
 
 \f
-/* Search for COUNT instances of the character TARGET between START and END.
+/* Search for COUNT newlines between START and END.
 
    If COUNT is positive, search forwards; END must be >= START.
    If COUNT is negative, search backwards for the -COUNTth instance;
@@ -634,13 +634,13 @@
    this is not the same as the usual convention for Emacs motion commands.
 
    If we don't find COUNT instances before reaching END, set *SHORTAGE
-   to the number of TARGETs left unfound, and return END.
+   to the number of newlines left unfound, and return END.
 
    If ALLOW_QUIT, set immediate_quit.  That's good to do
    except when inside redisplay.  */
 
 ptrdiff_t
-scan_buffer (int target, ptrdiff_t start, ptrdiff_t end,
+scan_buffer (ptrdiff_t start, ptrdiff_t end,
 	     ptrdiff_t count, ptrdiff_t *shortage, bool allow_quit)
 {
   struct region_cache *newline_cache;
@@ -656,7 +656,7 @@
   else
     {
       direction = -1;
-      if (!end) 
+      if (!end)
 	end = BEGV, end_byte = BEGV_BYTE;
     }
   if (end_byte == -1)
@@ -684,7 +684,7 @@
 
         /* If we're looking for a newline, consult the newline cache
            to see where we can avoid some scanning.  */
-        if (target == '\n' && newline_cache)
+        if (newline_cache)
           {
             ptrdiff_t next_change;
             immediate_quit = 0;
@@ -726,29 +726,28 @@
               unsigned char *scan_start = cursor;
 
               /* The dumb loop.  */
-              while (*cursor != target && ++cursor < ceiling_addr)
-                ;
+	      unsigned char *nl = memchr (cursor, '\n', ceiling_addr - cursor);
 
               /* If we're looking for newlines, cache the fact that
                  the region from start to cursor is free of them. */
-              if (target == '\n' && newline_cache)
+              if (newline_cache)
                 know_region_cache (current_buffer, newline_cache,
                                    BYTE_TO_CHAR (start_byte + scan_start - base),
-                                   BYTE_TO_CHAR (start_byte + cursor - base));
-
-              /* Did we find the target character?  */
-              if (cursor < ceiling_addr)
-                {
-                  if (--count == 0)
-                    {
-                      immediate_quit = 0;
-                      return BYTE_TO_CHAR (start_byte + cursor - base + 1);
-                    }
-                  cursor++;
-                }
+                                   BYTE_TO_CHAR (start_byte + (nl ? nl : ceiling_addr) - base));
+
+              /* Did we find the newline?  */
+              if (! nl)
+		break;
+
+	      if (--count == 0)
+		{
+		  immediate_quit = 0;
+		  return BYTE_TO_CHAR (start_byte + nl - base + 1);
+		}
+	      cursor = nl + 1;
             }
 
-          start = BYTE_TO_CHAR (start_byte + cursor - base);
+          start = BYTE_TO_CHAR (start_byte + ceiling_addr - base);
         }
       }
   else
@@ -760,7 +759,7 @@
 	ptrdiff_t tem;
 
         /* Consult the newline cache, if appropriate.  */
-        if (target == '\n' && newline_cache)
+        if (newline_cache)
           {
             ptrdiff_t next_change;
             immediate_quit = 0;
@@ -795,30 +794,29 @@
           while (cursor >= ceiling_addr)
             {
               unsigned char *scan_start = cursor;
-
-              while (*cursor != target && --cursor >= ceiling_addr)
-                ;
+	      unsigned char *nl = memrchr (ceiling_addr, '\n',
+					   cursor + 1 - ceiling_addr);
 
               /* If we're looking for newlines, cache the fact that
                  the region from after the cursor to start is free of them.  */
-              if (target == '\n' && newline_cache)
+              if (newline_cache)
                 know_region_cache (current_buffer, newline_cache,
-                                   BYTE_TO_CHAR (start_byte + cursor - base),
+                                   BYTE_TO_CHAR (start_byte + (nl ? nl : ceiling_addr - 1) - base),
                                    BYTE_TO_CHAR (start_byte + scan_start - base));
 
-              /* Did we find the target character?  */
-              if (cursor >= ceiling_addr)
-                {
-                  if (++count >= 0)
-                    {
-                      immediate_quit = 0;
-                      return BYTE_TO_CHAR (start_byte + cursor - base);
-                    }
-                  cursor--;
-                }
+              /* Did we find the newline?  */
+              if (! nl)
+		break;
+
+	      if (++count >= 0)
+		{
+		  immediate_quit = 0;
+		  return BYTE_TO_CHAR (start_byte + nl - base);
+		}
+	      cursor = nl - 1;
             }
 
-	  start = BYTE_TO_CHAR (start_byte + cursor - base);
+	  start = BYTE_TO_CHAR (start_byte + (ceiling_addr - 1) - base);
         }
       }
 
@@ -874,29 +872,25 @@
 	  ceiling = min (limit_byte - 1, ceiling);
 	  ceiling_addr = BYTE_POS_ADDR (ceiling) + 1;
 	  base = (cursor = BYTE_POS_ADDR (start_byte));
-	  while (1)
+
+	  do
 	    {
-	      while (*cursor != '\n' && ++cursor != ceiling_addr)
-		;
-
-	      if (cursor != ceiling_addr)
+	      unsigned char *nl = memchr (cursor, '\n', ceiling_addr - cursor);
+	      if (! nl)
+		break;
+	      if (--count == 0)
 		{
-		  if (--count == 0)
-		    {
-		      immediate_quit = old_immediate_quit;
-		      start_byte = start_byte + cursor - base + 1;
-		      start = BYTE_TO_CHAR (start_byte);
-		      TEMP_SET_PT_BOTH (start, start_byte);
-		      return 0;
-		    }
-		  else
-		    if (++cursor == ceiling_addr)
-		      break;
+		  immediate_quit = old_immediate_quit;
+		  start_byte += nl - base + 1;
+		  start = BYTE_TO_CHAR (start_byte);
+		  TEMP_SET_PT_BOTH (start, start_byte);
+		  return 0;
 		}
-	      else
-		break;
+	      cursor = nl + 1;
 	    }
-	  start_byte += cursor - base;
+	  while (cursor < ceiling_addr);
+
+	  start_byte += ceiling_addr - base;
 	}
     }
   else
@@ -905,31 +899,28 @@
 	{
 	  ceiling = BUFFER_FLOOR_OF (start_byte - 1);
 	  ceiling = max (limit_byte, ceiling);
-	  ceiling_addr = BYTE_POS_ADDR (ceiling) - 1;
+	  ceiling_addr = BYTE_POS_ADDR (ceiling);
 	  base = (cursor = BYTE_POS_ADDR (start_byte - 1) + 1);
 	  while (1)
 	    {
-	      while (--cursor != ceiling_addr && *cursor != '\n')
-		;
+	      unsigned char *nl = memrchr (ceiling_addr, '\n',
+					   cursor - ceiling_addr);
+	      if (! nl)
+		break;
 
-	      if (cursor != ceiling_addr)
+	      if (++count == 0)
 		{
-		  if (++count == 0)
-		    {
-		      immediate_quit = old_immediate_quit;
-		      /* Return the position AFTER the match we found.  */
-		      start_byte = start_byte + cursor - base + 1;
-		      start = BYTE_TO_CHAR (start_byte);
-		      TEMP_SET_PT_BOTH (start, start_byte);
-		      return 0;
-		    }
+		  immediate_quit = old_immediate_quit;
+		  /* Return the position AFTER the match we found.  */
+		  start_byte += nl - base + 1;
+		  start = BYTE_TO_CHAR (start_byte);
+		  TEMP_SET_PT_BOTH (start, start_byte);
+		  return 0;
 		}
-	      else
-		break;
+
+	      cursor = nl;
 	    }
-	  /* Here we add 1 to compensate for the last decrement
-	     of CURSOR, which took it past the valid range.  */
-	  start_byte += cursor - base + 1;
+	  start_byte += ceiling_addr - base;
 	}
     }
 
@@ -942,7 +933,7 @@
 ptrdiff_t
 find_next_newline_no_quit (ptrdiff_t from, ptrdiff_t cnt)
 {
-  return scan_buffer ('\n', from, 0, cnt, (ptrdiff_t *) 0, 0);
+  return scan_buffer (from, 0, cnt, (ptrdiff_t *) 0, 0);
 }
 
 /* Like find_next_newline, but returns position before the newline,
@@ -953,7 +944,7 @@
 find_before_next_newline (ptrdiff_t from, ptrdiff_t to, ptrdiff_t cnt)
 {
   ptrdiff_t shortage;
-  ptrdiff_t pos = scan_buffer ('\n', from, to, cnt, &shortage, 1);
+  ptrdiff_t pos = scan_buffer (from, to, cnt, &shortage, 1);
 
   if (shortage == 0)
     pos--;