1# =========================================================================== 2# http://www.gnu.org/software/autoconf-archive/ax_gcc_builtin.html 3# =========================================================================== 4# 5# SYNOPSIS 6# 7# AX_GCC_BUILTIN(BUILTIN) 8# 9# DESCRIPTION 10# 11# This macro checks if the compiler supports one of GCC's built-in 12# functions; many other compilers also provide those same built-ins. 13# 14# The BUILTIN parameter is the name of the built-in function. 15# 16# If BUILTIN is supported define HAVE_<BUILTIN>. Keep in mind that since 17# builtins usually start with two underscores they will be copied over 18# into the HAVE_<BUILTIN> definition (e.g. HAVE___BUILTIN_EXPECT for 19# __builtin_expect()). 20# 21# The macro caches its result in the ax_cv_have_<BUILTIN> variable (e.g. 22# ax_cv_have___builtin_expect). 23# 24# The macro currently supports the following built-in functions: 25# 26# __builtin_assume_aligned 27# __builtin_bswap32 28# __builtin_bswap64 29# __builtin_choose_expr 30# __builtin___clear_cache 31# __builtin_clrsb 32# __builtin_clrsbl 33# __builtin_clrsbll 34# __builtin_clz 35# __builtin_clzl 36# __builtin_clzll 37# __builtin_complex 38# __builtin_constant_p 39# __builtin_ctz 40# __builtin_ctzl 41# __builtin_ctzll 42# __builtin_expect 43# __builtin_ffs 44# __builtin_ffsl 45# __builtin_ffsll 46# __builtin_fpclassify 47# __builtin_huge_val 48# __builtin_huge_valf 49# __builtin_huge_vall 50# __builtin_inf 51# __builtin_infd128 52# __builtin_infd32 53# __builtin_infd64 54# __builtin_inff 55# __builtin_infl 56# __builtin_isinf_sign 57# __builtin_nan 58# __builtin_nand128 59# __builtin_nand32 60# __builtin_nand64 61# __builtin_nanf 62# __builtin_nanl 63# __builtin_nans 64# __builtin_nansf 65# __builtin_nansl 66# __builtin_object_size 67# __builtin_parity 68# __builtin_parityl 69# __builtin_parityll 70# __builtin_popcount 71# __builtin_popcountl 72# __builtin_popcountll 73# __builtin_powi 74# __builtin_powif 75# __builtin_powil 76# __builtin_prefetch 77# __builtin_trap 78# __builtin_types_compatible_p 79# __builtin_unreachable 80# 81# Unsuppored built-ins will be tested with an empty parameter set and the 82# result of the check might be wrong or meaningless so use with care. 83# 84# LICENSE 85# 86# Copyright (c) 2013 Gabriele Svelto <gabriele.svelto@gmail.com> 87# 88# Copying and distribution of this file, with or without modification, are 89# permitted in any medium without royalty provided the copyright notice 90# and this notice are preserved. This file is offered as-is, without any 91# warranty. 92 93#serial 2 94 95AC_DEFUN([AX_GCC_BUILTIN], [ 96 AS_VAR_PUSHDEF([ac_var], [ax_cv_have_$1]) 97 98 AC_CACHE_CHECK([for $1], [ac_var], [ 99 AC_LINK_IFELSE([AC_LANG_PROGRAM([], [ 100 m4_case([$1], 101 [__builtin_assume_aligned], [$1("", 0)], 102 [__builtin_bswap32], [$1(0)], 103 [__builtin_bswap64], [$1(0)], 104 [__builtin_choose_expr], [$1(0, 0, 0)], 105 [__builtin___clear_cache], [$1("", "")], 106 [__builtin_clrsb], [$1(0)], 107 [__builtin_clrsbl], [$1(0)], 108 [__builtin_clrsbll], [$1(0)], 109 [__builtin_clz], [$1(0)], 110 [__builtin_clzl], [$1(0)], 111 [__builtin_clzll], [$1(0)], 112 [__builtin_complex], [$1(0.0, 0.0)], 113 [__builtin_constant_p], [$1(0)], 114 [__builtin_ctz], [$1(0)], 115 [__builtin_ctzl], [$1(0)], 116 [__builtin_ctzll], [$1(0)], 117 [__builtin_expect], [$1(0, 0)], 118 [__builtin_ffs], [$1(0)], 119 [__builtin_ffsl], [$1(0)], 120 [__builtin_ffsll], [$1(0)], 121 [__builtin_fpclassify], [$1(0, 1, 2, 3, 4, 0.0)], 122 [__builtin_huge_val], [$1()], 123 [__builtin_huge_valf], [$1()], 124 [__builtin_huge_vall], [$1()], 125 [__builtin_inf], [$1()], 126 [__builtin_infd128], [$1()], 127 [__builtin_infd32], [$1()], 128 [__builtin_infd64], [$1()], 129 [__builtin_inff], [$1()], 130 [__builtin_infl], [$1()], 131 [__builtin_isinf_sign], [$1(0.0)], 132 [__builtin_nan], [$1("")], 133 [__builtin_nand128], [$1("")], 134 [__builtin_nand32], [$1("")], 135 [__builtin_nand64], [$1("")], 136 [__builtin_nanf], [$1("")], 137 [__builtin_nanl], [$1("")], 138 [__builtin_nans], [$1("")], 139 [__builtin_nansf], [$1("")], 140 [__builtin_nansl], [$1("")], 141 [__builtin_object_size], [$1("", 0)], 142 [__builtin_parity], [$1(0)], 143 [__builtin_parityl], [$1(0)], 144 [__builtin_parityll], [$1(0)], 145 [__builtin_popcount], [$1(0)], 146 [__builtin_popcountl], [$1(0)], 147 [__builtin_popcountll], [$1(0)], 148 [__builtin_powi], [$1(0, 0)], 149 [__builtin_powif], [$1(0, 0)], 150 [__builtin_powil], [$1(0, 0)], 151 [__builtin_prefetch], [$1("")], 152 [__builtin_trap], [$1()], 153 [__builtin_types_compatible_p], [$1(int, int)], 154 [__builtin_unreachable], [$1()], 155 [m4_warn([syntax], [Unsupported built-in $1, the test may fail]) 156 $1()] 157 ) 158 ])], 159 [AS_VAR_SET([ac_var], [yes])], 160 [AS_VAR_SET([ac_var], [no])]) 161 ]) 162 163 AS_IF([test yes = AS_VAR_GET([ac_var])], 164 [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_$1), 1, 165 [Define to 1 if the system has the `$1' built-in function])], []) 166 167 AS_VAR_POPDEF([ac_var]) 168]) 169