From 4eed3157327f8406921658442a11af7e9d84d603 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 4 Oct 2013 00:36:22 -0700
Subject: 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.
---
 m4/byteswap.m4    | 19 +++++++++++++++++++
 m4/gnulib-comp.m4 |  4 ++++
 2 files changed, 23 insertions(+)
 create mode 100644 m4/byteswap.m4

(limited to 'm4')

diff --git a/m4/byteswap.m4 b/m4/byteswap.m4
new file mode 100644
index 0000000000..7566903dc4
--- /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 2e5a9cf97d..ff36981c8d 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
-- 
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