Use hardware support for byteswapping on glibc x86 etc.

On Fedora 19 x86-64, the new bswap_64 needs 1 instruction,
whereas the old swap64 needed 30.
* admin/merge-gnulib (GNULIB_MODULES): Add byteswap.
* lib/byteswap.in.h, m4/byteswap.m4: New files, copied from Gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* src/fringe.c (init_fringe_bitmap) [WORDS_BIGENDIAN]:
* src/sound.c (le2hl, le2hs, be2hl) [!WINDOWSNT]:
Use byteswap.h's macros to swap bytes.
* src/lisp.h (swap16, swap32, swap64): Remove.
All uses replaced by bswap_16, bswap_32, bswap_64.

13 files changed, 130 insertions, 57 deletions

diff --git a/ChangeLog b/ChangeLog
index 44e83d25737..4769f5d575d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-10-04  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Use hardware insns for byteswapping on glibc hosts that support it.
+	* lib/byteswap.in.h, m4/byteswap.m4: New files, copied from Gnulib.
+	* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
+
 2013-10-03  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Merge from gnulib, incorporating:
diff --git a/admin/ChangeLog b/admin/ChangeLog
index 29118deba7f..837a0a2e6d2 100644
--- a/admin/ChangeLog
+++ b/admin/ChangeLog
@@ -1,3 +1,8 @@
+2013-10-04  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Use hardware support for byteswapping on glibc x86 etc.
+	* merge-gnulib (GNULIB_MODULES): Add byteswap.
+
 2013-08-28  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* unidata/Makefile.in (SHELL): Now @SHELL@, not /bin/sh,
diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index 97126704d10..aba0fa67a1a 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -26,7 +26,7 @@
 GNULIB_URL=git://git.savannah.gnu.org/gnulib.git
 
 GNULIB_MODULES='
-  alloca-opt c-ctype c-strcase
+  alloca-opt byteswap c-ctype c-strcase
   careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512
   dtoastr dtotimespec dup2 environ execinfo faccessat
   fcntl fcntl-h fdatasync fdopendir filemode fstatat fsync
diff --git a/lib/byteswap.in.h b/lib/byteswap.in.h
new file mode 100644
index 00000000000..a323ca3570a
--- /dev/null
+++ b/lib/byteswap.in.h
@@ -0,0 +1,44 @@
+/* byteswap.h - Byte swapping
+   Copyright (C) 2005, 2007, 2009-2013 Free Software Foundation, Inc.
+   Written by Oskar Liljeblad <oskar@osk.mine.nu>, 2005.
+
+   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/>.  */
+
+#ifndef _GL_BYTESWAP_H
+#define _GL_BYTESWAP_H
+
+/* Given an unsigned 16-bit argument X, return the value corresponding to
+   X with reversed byte order.  */
+#define bswap_16(x) ((((x) & 0x00FF) << 8) | \
+                     (((x) & 0xFF00) >> 8))
+
+/* Given an unsigned 32-bit argument X, return the value corresponding to
+   X with reversed byte order.  */
+#define bswap_32(x) ((((x) & 0x000000FF) << 24) | \
+                     (((x) & 0x0000FF00) << 8) | \
+                     (((x) & 0x00FF0000) >> 8) | \
+                     (((x) & 0xFF000000) >> 24))
+
+/* Given an unsigned 64-bit argument X, return the value corresponding to
+   X with reversed byte order.  */
+#define bswap_64(x) ((((x) & 0x00000000000000FFULL) << 56) | \
+                     (((x) & 0x000000000000FF00ULL) << 40) | \
+                     (((x) & 0x0000000000FF0000ULL) << 24) | \
+                     (((x) & 0x00000000FF000000ULL) << 8) | \
+                     (((x) & 0x000000FF00000000ULL) >> 8) | \
+                     (((x) & 0x0000FF0000000000ULL) >> 24) | \
+                     (((x) & 0x00FF000000000000ULL) >> 40) | \
+                     (((x) & 0xFF00000000000000ULL) >> 56))
+
+#endif /* _GL_BYTESWAP_H */
diff --git a/lib/gnulib.mk b/lib/gnulib.mk
index 14d45e798e5..73381f2bdce 100644
--- a/lib/gnulib.mk
+++ b/lib/gnulib.mk
@@ -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=close --avoid=dup --avoid=fchdir --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 fcntl-h fdatasync fdopendir filemode fstatat fsync getloadavg getopt-gnu gettime gettimeofday intprops largefile lstat manywarnings memrchr mkostemp mktime pipe2 pselect pthread_sigmask putenv qacl 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=close --avoid=dup --avoid=fchdir --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 byteswap c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode fstatat fsync getloadavg getopt-gnu gettime gettimeofday intprops largefile lstat manywarnings memrchr mkostemp mktime pipe2 pselect pthread_sigmask putenv qacl 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
@@ -81,6 +81,29 @@ libgnu_a_SOURCES += binary-io.h binary-io.c
 
 ## end   gnulib module binary-io
 
+## begin gnulib module byteswap
+
+BUILT_SOURCES += $(BYTESWAP_H)
+
+# We need the following in order to create <byteswap.h> when the system
+# doesn't have one.
+if GL_GENERATE_BYTESWAP_H
+byteswap.h: byteswap.in.h $(top_builddir)/config.status
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  cat $(srcdir)/byteswap.in.h; \
+	} > $@-t && \
+	mv -f $@-t $@
+else
+byteswap.h: $(top_builddir)/config.status
+	rm -f $@
+endif
+MOSTLYCLEANFILES += byteswap.h byteswap.h-t
+
+EXTRA_DIST += byteswap.in.h
+
+## end   gnulib module byteswap
+
 ## begin gnulib module c-ctype
 
 libgnu_a_SOURCES += c-ctype.h c-ctype.c
diff --git a/m4/byteswap.m4 b/m4/byteswap.m4
new file mode 100644
index 00000000000..7566903dc49
--- /dev/null
+++ b/m4/byteswap.m4
@@ -0,0 +1,19 @@
+# byteswap.m4 serial 4
+dnl Copyright (C) 2005, 2007, 2009-2013 Free Software Foundation, 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.
+
+dnl Written by Oskar Liljeblad.
+
+AC_DEFUN([gl_BYTESWAP],
+[
+  dnl Prerequisites of lib/byteswap.in.h.
+  AC_CHECK_HEADERS([byteswap.h], [
+    BYTESWAP_H=''
+  ], [
+    BYTESWAP_H='byteswap.h'
+  ])
+  AC_SUBST([BYTESWAP_H])
+  AM_CONDITIONAL([GL_GENERATE_BYTESWAP_H], [test -n "$BYTESWAP_H"])
+])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 2e5a9cf97d1..ff36981c8d0 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -42,6 +42,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module allocator:
   # Code from module at-internal:
   # Code from module binary-io:
+  # Code from module byteswap:
   # Code from module c-ctype:
   # Code from module c-strcase:
   # Code from module careadlinkat:
@@ -169,6 +170,7 @@ AC_DEFUN([gl_INIT],
   gl_COMMON
   gl_source_base='lib'
   gl_FUNC_ALLOCA
+  gl_BYTESWAP
   AC_CHECK_FUNCS_ONCE([readlinkat])
   gl_CLOCK_TIME
   gl_CLOSE_STREAM
@@ -794,6 +796,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/at-func.c
   lib/binary-io.c
   lib/binary-io.h
+  lib/byteswap.in.h
   lib/c-ctype.c
   lib/c-ctype.h
   lib/c-strcase.h
@@ -912,6 +915,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/00gnulib.m4
   m4/acl.m4
   m4/alloca.m4
+  m4/byteswap.m4
   m4/c-strtod.m4
   m4/clock_time.m4
   m4/close-stream.m4
diff --git a/src/ChangeLog b/src/ChangeLog
index 4fae03d6965..38fb35ddf54 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,14 @@
 2013-10-04  Paul Eggert  <eggert@cs.ucla.edu>
 
+	Use hardware support for byteswapping on glibc x86 etc.
+	On Fedora 19 x86-64, the new bswap_64 needs 1 instruction,
+	whereas the old swap64 needed 30.
+	* fringe.c (init_fringe_bitmap) [WORDS_BIGENDIAN]:
+	* sound.c (le2hl, le2hs, be2hl) [!WINDOWSNT]:
+	Use byteswap.h's macros to swap bytes.
+	* lisp.h (swap16, swap32, swap64): Remove.
+	All uses replaced by bswap_16, bswap_32, bswap_64.
+
 	* bytecode.c (exec_byte_code): Use some more volatile variables
 	to work around local variables getting clobbered by longjmp.
 	Port to pre-C99, which doesn't allow decls after stmts.
diff --git a/src/data.c b/src/data.c
index b268616fd26..a6bfe50a3bb 100644
--- a/src/data.c
+++ b/src/data.c
@@ -21,6 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
 
+#include <byteswap.h>
 #include <intprops.h>
 
 #include "lisp.h"
@@ -3185,9 +3186,9 @@ size_t_to_host_endian (size_t val)
 {
 #ifdef WORDS_BIGENDIAN
 # if BITS_PER_SIZE_T == 64
-  return swap64 (val);
+  return bswap_64 (val);
 # else
-  return swap32 (val);
+  return bswap_32 (val);
 # endif
 #else
   return val;
diff --git a/src/fringe.c b/src/fringe.c
index 85103f7f08d..3537027f1dd 100644
--- a/src/fringe.c
+++ b/src/fringe.c
@@ -20,6 +20,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
 
+#include <byteswap.h>
+
 #include "lisp.h"
 #include "frame.h"
 #include "window.h"
@@ -1519,7 +1521,7 @@ init_fringe_bitmap (int which, struct fringe_bitmap *fb, int once_p)
 				   | (swap_nibble[(b>>12) & 0xf]));
 	      b >>= (16 - fb->width);
 #ifdef WORDS_BIGENDIAN
-	      b = ((b >> 8) | (b << 8));
+	      b = bswap_16 (b);
 #endif
 	      *bits++ = b;
 	    }
diff --git a/src/lisp.h b/src/lisp.h
index f949978ceed..2f0279ef542 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -4366,30 +4366,6 @@ functionp (Lisp_Object object)
     return 0;
 }
 
-INLINE uint16_t
-swap16 (uint16_t val)
-{
-    return (val << 8) | (val & 0xFF);
-}
-
-INLINE uint32_t
-swap32 (uint32_t val)
-{
-  uint32_t low = swap16 (val & 0xFFFF);
-  uint32_t high = swap16 (val >> 16);
-  return (low << 16) | high;
-}
-
-#ifdef UINT64_MAX
-INLINE uint64_t
-swap64 (uint64_t val)
-{
-  uint64_t low = swap32 (val & 0xFFFFFFFF);
-  uint64_t high = swap32 (val >> 32);
-  return (low << 32) | high;
-}
-#endif
-
 #if ((SIZE_MAX >> 31) >> 1) & 1
 # define BITS_PER_SIZE_T 64
 #else
diff --git a/src/sound.c b/src/sound.c
index 27e06b8abab..f8c6b483056 100644
--- a/src/sound.c
+++ b/src/sound.c
@@ -55,6 +55,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* BEGIN: Non Windows Includes */
 #ifndef WINDOWSNT
 
+#include <byteswap.h>
+
 #include <sys/ioctl.h>
 
 /* FreeBSD has machine/soundcard.h.  Voxware sound driver docs mention
@@ -461,8 +463,7 @@ static u_int32_t
 le2hl (u_int32_t value)
 {
 #ifdef WORDS_BIGENDIAN
-  unsigned char *p = (unsigned char *) &value;
-  value = p[0] + (p[1] << 8) + (p[2] << 16) + (p[3] << 24);
+  value = bswap_32 (value);
 #endif
   return value;
 }
@@ -475,8 +476,7 @@ static u_int16_t
 le2hs (u_int16_t value)
 {
 #ifdef WORDS_BIGENDIAN
-  unsigned char *p = (unsigned char *) &value;
-  value = p[0] + (p[1] << 8);
+  value = bswap_16 (value);
 #endif
   return value;
 }
@@ -489,30 +489,11 @@ static u_int32_t
 be2hl (u_int32_t value)
 {
 #ifndef WORDS_BIGENDIAN
-  unsigned char *p = (unsigned char *) &value;
-  value = p[3] + (p[2] << 8) + (p[1] << 16) + (p[0] << 24);
+  value = bswap_32 (value);
 #endif
   return value;
 }
 
-
-#if 0 /* Currently not used.  */
-
-/* Convert 16-bit value VALUE which is in big-endian byte-order
-   to host byte-order.  */
-
-static u_int16_t
-be2hs (u_int16_t value)
-{
-#ifndef WORDS_BIGENDIAN
-  unsigned char *p = (unsigned char *) &value;
-  value = p[1] + (p[0] << 8);
-#endif
-  return value;
-}
-
-#endif /* 0 */
-
 /***********************************************************************
 			  RIFF-WAVE (*.wav)
  ***********************************************************************/
diff --git a/src/xsettings.c b/src/xsettings.c
index 8fe82fec74b..e5a66c4cf0a 100644
--- a/src/xsettings.c
+++ b/src/xsettings.c
@@ -22,6 +22,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <float.h>
 #include <limits.h>
 #include <fcntl.h>
+
+#include <byteswap.h>
+
 #include "lisp.h"
 #include "xterm.h"
 #include "xsettings.h"
@@ -405,7 +408,7 @@ parse_settings (unsigned char *prop,
 
   if (bytes < 12) return BadLength;
   memcpy (&n_settings, prop+8, 4);
-  if (my_bo != that_bo) n_settings = swap32 (n_settings);
+  if (my_bo != that_bo) n_settings = bswap_32 (n_settings);
   bytes_parsed = 12;
 
   memset (settings, 0, sizeof (*settings));
@@ -427,7 +430,7 @@ parse_settings (unsigned char *prop,
 
       memcpy (&nlen, prop+bytes_parsed, 2);
       bytes_parsed += 2;
-      if (my_bo != that_bo) nlen = swap16 (nlen);
+      if (my_bo != that_bo) nlen = bswap_16 (nlen);
       if (bytes_parsed+nlen > bytes) return BadLength;
       to_cpy = nlen > 127 ? 127 : nlen;
       memcpy (name, prop+bytes_parsed, to_cpy);
@@ -454,7 +457,7 @@ parse_settings (unsigned char *prop,
           if (want_this)
             {
               memcpy (&ival, prop+bytes_parsed, 4);
-              if (my_bo != that_bo) ival = swap32 (ival);
+              if (my_bo != that_bo) ival = bswap_32 (ival);
             }
           bytes_parsed += 4;
           break;
@@ -463,7 +466,7 @@ parse_settings (unsigned char *prop,
           if (bytes_parsed+4 > bytes) return BadLength;
           memcpy (&vlen, prop+bytes_parsed, 4);
           bytes_parsed += 4;
-          if (my_bo != that_bo) vlen = swap32 (vlen);
+          if (my_bo != that_bo) vlen = bswap_32 (vlen);
           if (want_this)
             {
               to_cpy = vlen > 127 ? 127 : vlen;