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.

1 files changed, 44 insertions, 0 deletions

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 */