Commit | Line | Data |
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005de2e8 | 1 | # trunc.m4 serial 9 |
af07e104 | 2 | dnl Copyright (C) 2007, 2010-2013 Free Software Foundation, Inc. |
49114fd4 LC |
3 | dnl This file is free software; the Free Software Foundation |
4 | dnl gives unlimited permission to copy and/or distribute it, | |
5 | dnl with or without modifications, as long as this notice is preserved. | |
6 | ||
7 | AC_DEFUN([gl_FUNC_TRUNC], | |
8 | [ | |
9 | m4_divert_text([DEFAULTS], [gl_trunc_required=plain]) | |
10 | AC_REQUIRE([gl_MATH_H_DEFAULTS]) | |
11 | dnl Persuade glibc <math.h> to declare trunc(). | |
12 | AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) | |
13 | dnl Test whether trunc() is declared. | |
35428fb6 | 14 | AC_CHECK_DECLS([trunc], , , [[#include <math.h>]]) |
49114fd4 LC |
15 | if test "$ac_cv_have_decl_trunc" = yes; then |
16 | dnl Test whether trunc() can be used without libm. | |
17 | TRUNC_LIBM=? | |
18 | AC_LINK_IFELSE( | |
19 | [AC_LANG_PROGRAM( | |
20 | [[#ifndef __NO_MATH_INLINES | |
21 | # define __NO_MATH_INLINES 1 /* for glibc */ | |
22 | #endif | |
23 | #include <math.h> | |
24 | double x;]], | |
25 | [[x = trunc(x);]])], | |
26 | [TRUNC_LIBM=]) | |
27 | if test "$TRUNC_LIBM" = "?"; then | |
28 | save_LIBS="$LIBS" | |
29 | LIBS="$LIBS -lm" | |
30 | AC_LINK_IFELSE( | |
31 | [AC_LANG_PROGRAM( | |
32 | [[#ifndef __NO_MATH_INLINES | |
33 | # define __NO_MATH_INLINES 1 /* for glibc */ | |
34 | #endif | |
35 | #include <math.h> | |
36 | double x;]], | |
37 | [[x = trunc(x);]])], | |
38 | [TRUNC_LIBM="-lm"]) | |
39 | LIBS="$save_LIBS" | |
40 | fi | |
41 | if test "$TRUNC_LIBM" = "?"; then | |
42 | TRUNC_LIBM= | |
43 | fi | |
44 | m4_ifdef([gl_FUNC_TRUNC_IEEE], [ | |
45 | if test $gl_trunc_required = ieee && test $REPLACE_TRUNC = 0; then | |
005de2e8 | 46 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
49114fd4 LC |
47 | AC_CACHE_CHECK([whether trunc works according to ISO C 99 with IEC 60559], |
48 | [gl_cv_func_trunc_ieee], | |
49 | [ | |
50 | save_LIBS="$LIBS" | |
51 | LIBS="$LIBS $TRUNC_LIBM" | |
52 | AC_RUN_IFELSE( | |
53 | [AC_LANG_SOURCE([[ | |
54 | #ifndef __NO_MATH_INLINES | |
55 | # define __NO_MATH_INLINES 1 /* for glibc */ | |
56 | #endif | |
57 | #include <math.h> | |
58 | ]gl_DOUBLE_MINUS_ZERO_CODE[ | |
59 | ]gl_DOUBLE_SIGNBIT_CODE[ | |
231c0e0e LC |
60 | static double dummy (double f) { return 0; } |
61 | int main (int argc, char *argv[]) | |
49114fd4 | 62 | { |
231c0e0e | 63 | double (*my_trunc) (double) = argc ? trunc : dummy; |
49114fd4 | 64 | /* Test whether trunc (-0.0) is -0.0. */ |
231c0e0e | 65 | if (signbitd (minus_zerod) && !signbitd (my_trunc (minus_zerod))) |
49114fd4 LC |
66 | return 1; |
67 | return 0; | |
68 | } | |
69 | ]])], | |
70 | [gl_cv_func_trunc_ieee=yes], | |
71 | [gl_cv_func_trunc_ieee=no], | |
005de2e8 LC |
72 | [case "$host_os" in |
73 | # Guess yes on glibc systems. | |
74 | *-gnu*) gl_cv_func_trunc_ieee="guessing yes" ;; | |
75 | # If we don't know, assume the worst. | |
76 | *) gl_cv_func_trunc_ieee="guessing no" ;; | |
77 | esac | |
78 | ]) | |
49114fd4 LC |
79 | LIBS="$save_LIBS" |
80 | ]) | |
81 | case "$gl_cv_func_trunc_ieee" in | |
82 | *yes) ;; | |
83 | *) REPLACE_TRUNC=1 ;; | |
84 | esac | |
85 | fi | |
86 | ]) | |
87 | else | |
88 | HAVE_DECL_TRUNC=0 | |
89 | fi | |
90 | if test $HAVE_DECL_TRUNC = 0 || test $REPLACE_TRUNC = 1; then | |
3d458a81 | 91 | dnl No libraries are needed to link lib/trunc.c. |
49114fd4 LC |
92 | TRUNC_LIBM= |
93 | fi | |
94 | AC_SUBST([TRUNC_LIBM]) | |
95 | ]) |