Commit | Line | Data |
---|---|---|
231c0e0e | 1 | # trunc.m4 serial 7 |
49114fd4 LC |
2 | dnl Copyright (C) 2007, 2010-2011 Free Software Foundation, Inc. |
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. | |
14 | AC_CHECK_DECLS([trunc], , , [#include <math.h>]) | |
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 $REPLACE_TRUNC = 0; then | |
46 | AC_CACHE_CHECK([whether trunc works according to ISO C 99 with IEC 60559], | |
47 | [gl_cv_func_trunc_ieee], | |
48 | [ | |
49 | save_LIBS="$LIBS" | |
50 | LIBS="$LIBS $TRUNC_LIBM" | |
51 | AC_RUN_IFELSE( | |
52 | [AC_LANG_SOURCE([[ | |
53 | #ifndef __NO_MATH_INLINES | |
54 | # define __NO_MATH_INLINES 1 /* for glibc */ | |
55 | #endif | |
56 | #include <math.h> | |
57 | ]gl_DOUBLE_MINUS_ZERO_CODE[ | |
58 | ]gl_DOUBLE_SIGNBIT_CODE[ | |
231c0e0e LC |
59 | static double dummy (double f) { return 0; } |
60 | int main (int argc, char *argv[]) | |
49114fd4 | 61 | { |
231c0e0e | 62 | double (*my_trunc) (double) = argc ? trunc : dummy; |
49114fd4 | 63 | /* Test whether trunc (-0.0) is -0.0. */ |
231c0e0e | 64 | if (signbitd (minus_zerod) && !signbitd (my_trunc (minus_zerod))) |
49114fd4 LC |
65 | return 1; |
66 | return 0; | |
67 | } | |
68 | ]])], | |
69 | [gl_cv_func_trunc_ieee=yes], | |
70 | [gl_cv_func_trunc_ieee=no], | |
71 | [gl_cv_func_trunc_ieee="guessing no"]) | |
72 | LIBS="$save_LIBS" | |
73 | ]) | |
74 | case "$gl_cv_func_trunc_ieee" in | |
75 | *yes) ;; | |
76 | *) REPLACE_TRUNC=1 ;; | |
77 | esac | |
78 | fi | |
79 | ]) | |
80 | else | |
81 | HAVE_DECL_TRUNC=0 | |
82 | fi | |
83 | if test $HAVE_DECL_TRUNC = 0 || test $REPLACE_TRUNC = 1; then | |
3d458a81 | 84 | dnl No libraries are needed to link lib/trunc.c. |
49114fd4 LC |
85 | TRUNC_LIBM= |
86 | fi | |
87 | AC_SUBST([TRUNC_LIBM]) | |
88 | ]) |