m4/bswap.m4

dnl Copyright (C) 2012-2014 Xiph.org Foundation
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dnl @synopsis XIPH_C_BSWAP32
dnl
dnl @author Erik de Castro Lopo <erikd@mega-nerd.com>
dnl
dnl Dtermine whether the compiler has the __builtin_bswap32() intrinsic which
dnl is likely to be present for most versions of GCC as well as Clang.

AC_DEFUN([XIPH_C_BSWAP32],
[AC_CACHE_CHECK(for bswap32 intrinsic,
  ac_cv_c_bswap32,

  # Initialize to no
  ac_cv_c_bswap32=no
  HAVE_BSWAP32=0

  [AC_TRY_LINK([],
    return __builtin_bswap32 (0) ;,
    ac_cv_c_bswap32=yes
    HAVE_BSWAP32=1
  )]
  AC_DEFINE_UNQUOTED(HAVE_BSWAP32, ${HAVE_BSWAP32},
    [Compiler has the __builtin_bswap32 intrinsic])

  )]
)# XIPH_C_BSWAP32


dnl @synopsis XIPH_C_BSWAP16
dnl
dnl @author Erik de Castro Lopo <erikd@mega-nerd.com>
dnl
dnl Dtermine whether the compiler has the __builtin_bswap16() intrinsic which
dnl is likely to be present for most versions of GCC as well as Clang.

AC_DEFUN([XIPH_C_BSWAP16],
[AC_CACHE_CHECK(for bswap16 intrinsic,
  ac_cv_c_bswap16,

  # Initialize to no
  ac_cv_c_bswap16=no
  HAVE_BSWAP16=0

  [AC_TRY_LINK([],
    return __builtin_bswap16 (0) ;,
    ac_cv_c_bswap16=yes
    HAVE_BSWAP16=1
  )]
  AC_DEFINE_UNQUOTED(HAVE_BSWAP16, ${HAVE_BSWAP16},
    [Compiler has the __builtin_bswap16 intrinsic])

  )]
)# XIPH_C_BSWAP16