diff options
Diffstat (limited to 'm4/bswap.m4')
| -rw-r--r-- | m4/bswap.m4 | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/m4/bswap.m4 b/m4/bswap.m4 index 926f820e..72af3333 100644 --- a/m4/bswap.m4 +++ b/m4/bswap.m4 @@ -1,4 +1,4 @@ -dnl Copyright (C) 2012 Xiph.org Foundation +dnl Copyright (C) 2012-2014 Xiph.org Foundation dnl dnl Redistribution and use in source and binary forms, with or without dnl modification, are permitted provided that the following conditions @@ -53,3 +53,30 @@ AC_DEFUN([XIPH_C_BSWAP32], )] )# 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 instrinsic, + 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 |