summaryrefslogtreecommitdiff
path: root/m4/ax_gcc_builtin.m4
blob: b28a91b14a5e250d8115371b38860a5c4d1f85fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
# ===========================================================================
#      http://www.gnu.org/software/autoconf-archive/ax_gcc_builtin.html
# ===========================================================================
#
# SYNOPSIS
#
#   AX_GCC_BUILTIN(BUILTIN)
#
# DESCRIPTION
#
#   This macro checks if the compiler supports one of GCC's built-in
#   functions; many other compilers also provide those same built-ins.
#
#   The BUILTIN parameter is the name of the built-in function.
#
#   If BUILTIN is supported define HAVE_<BUILTIN>. Keep in mind that since
#   builtins usually start with two underscores they will be copied over
#   into the HAVE_<BUILTIN> definition (e.g. HAVE___BUILTIN_EXPECT for
#   __builtin_expect()).
#
#   The macro caches its result in the ax_cv_have_<BUILTIN> variable (e.g.
#   ax_cv_have___builtin_expect).
#
#   The macro currently supports the following built-in functions:
#
#    __builtin_assume_aligned
#    __builtin_bswap32
#    __builtin_bswap64
#    __builtin_choose_expr
#    __builtin___clear_cache
#    __builtin_clrsb
#    __builtin_clrsbl
#    __builtin_clrsbll
#    __builtin_clz
#    __builtin_clzl
#    __builtin_clzll
#    __builtin_complex
#    __builtin_constant_p
#    __builtin_ctz
#    __builtin_ctzl
#    __builtin_ctzll
#    __builtin_expect
#    __builtin_ffs
#    __builtin_ffsl
#    __builtin_ffsll
#    __builtin_fpclassify
#    __builtin_huge_val
#    __builtin_huge_valf
#    __builtin_huge_vall
#    __builtin_inf
#    __builtin_infd128
#    __builtin_infd32
#    __builtin_infd64
#    __builtin_inff
#    __builtin_infl
#    __builtin_isinf_sign
#    __builtin_nan
#    __builtin_nand128
#    __builtin_nand32
#    __builtin_nand64
#    __builtin_nanf
#    __builtin_nanl
#    __builtin_nans
#    __builtin_nansf
#    __builtin_nansl
#    __builtin_object_size
#    __builtin_parity
#    __builtin_parityl
#    __builtin_parityll
#    __builtin_popcount
#    __builtin_popcountl
#    __builtin_popcountll
#    __builtin_powi
#    __builtin_powif
#    __builtin_powil
#    __builtin_prefetch
#    __builtin_trap
#    __builtin_types_compatible_p
#    __builtin_unreachable
#
#   Unsuppored built-ins will be tested with an empty parameter set and the
#   result of the check might be wrong or meaningless so use with care.
#
# LICENSE
#
#   Copyright (c) 2013 Gabriele Svelto <gabriele.svelto@gmail.com>
#
#   Copying and distribution of this file, with or without modification, are
#   permitted in any medium without royalty provided the copyright notice
#   and this notice are preserved.  This file is offered as-is, without any
#   warranty.

#serial 2

AC_DEFUN([AX_GCC_BUILTIN], [
    AS_VAR_PUSHDEF([ac_var], [ax_cv_have_$1])

    AC_CACHE_CHECK([for $1], [ac_var], [
        AC_LINK_IFELSE([AC_LANG_PROGRAM([], [
            m4_case([$1],
                [__builtin_assume_aligned], [$1("", 0)],
                [__builtin_bswap32], [$1(0)],
                [__builtin_bswap64], [$1(0)],
                [__builtin_choose_expr], [$1(0, 0, 0)],
                [__builtin___clear_cache], [$1("", "")],
                [__builtin_clrsb], [$1(0)],
                [__builtin_clrsbl], [$1(0)],
                [__builtin_clrsbll], [$1(0)],
                [__builtin_clz], [$1(0)],
                [__builtin_clzl], [$1(0)],
                [__builtin_clzll], [$1(0)],
                [__builtin_complex], [$1(0.0, 0.0)],
                [__builtin_constant_p], [$1(0)],
                [__builtin_ctz], [$1(0)],
                [__builtin_ctzl], [$1(0)],
                [__builtin_ctzll], [$1(0)],
                [__builtin_expect], [$1(0, 0)],
                [__builtin_ffs], [$1(0)],
                [__builtin_ffsl], [$1(0)],
                [__builtin_ffsll], [$1(0)],
                [__builtin_fpclassify], [$1(0, 1, 2, 3, 4, 0.0)],
                [__builtin_huge_val], [$1()],
                [__builtin_huge_valf], [$1()],
                [__builtin_huge_vall], [$1()],
                [__builtin_inf], [$1()],
                [__builtin_infd128], [$1()],
                [__builtin_infd32], [$1()],
                [__builtin_infd64], [$1()],
                [__builtin_inff], [$1()],
                [__builtin_infl], [$1()],
                [__builtin_isinf_sign], [$1(0.0)],
                [__builtin_nan], [$1("")],
                [__builtin_nand128], [$1("")],
                [__builtin_nand32], [$1("")],
                [__builtin_nand64], [$1("")],
                [__builtin_nanf], [$1("")],
                [__builtin_nanl], [$1("")],
                [__builtin_nans], [$1("")],
                [__builtin_nansf], [$1("")],
                [__builtin_nansl], [$1("")],
                [__builtin_object_size], [$1("", 0)],
                [__builtin_parity], [$1(0)],
                [__builtin_parityl], [$1(0)],
                [__builtin_parityll], [$1(0)],
                [__builtin_popcount], [$1(0)],
                [__builtin_popcountl], [$1(0)],
                [__builtin_popcountll], [$1(0)],
                [__builtin_powi], [$1(0, 0)],
                [__builtin_powif], [$1(0, 0)],
                [__builtin_powil], [$1(0, 0)],
                [__builtin_prefetch], [$1("")],
                [__builtin_trap], [$1()],
                [__builtin_types_compatible_p], [$1(int, int)],
                [__builtin_unreachable], [$1()],
                [m4_warn([syntax], [Unsupported built-in $1, the test may fail])
                 $1()]
            )
            ])],
            [AS_VAR_SET([ac_var], [yes])],
            [AS_VAR_SET([ac_var], [no])])
    ])

    AS_IF([test yes = AS_VAR_GET([ac_var])],
        [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_$1), 1,
            [Define to 1 if the system has the `$1' built-in function])], [])

    AS_VAR_POPDEF([ac_var])
])