summaryrefslogtreecommitdiff
path: root/m4/ceill.m4
blob: 1add8417628877f4dfc6694279a912fb5fc1cae5 (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
# ceill.m4 serial 20
dnl Copyright (C) 2007, 2009-2020 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_CEILL],
[
  m4_divert_text([DEFAULTS], [gl_ceill_required=plain])
  AC_REQUIRE([gl_MATH_H_DEFAULTS])
  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

  dnl Persuade glibc <math.h> to declare ceill().
  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])

  dnl Test whether ceill() is declared.
  AC_CHECK_DECLS([ceill], , , [[#include <math.h>]])
  if test "$ac_cv_have_decl_ceill" = yes; then
    dnl Test whether ceill() can be used without libm.
    gl_FUNC_CEILL_LIBS
    if test "$CEILL_LIBM" = "?"; then
      dnl Sun C 5.0 on Solaris declares ceill() and has it in the system-wide
      dnl libm.so, but not in the libm.so that the compiler uses.
      REPLACE_CEILL=1
    fi
    m4_ifdef([gl_FUNC_CEILL_IEEE], [
      if test $gl_ceill_required = ieee && test $REPLACE_CEILL = 0; then
        AC_CACHE_CHECK([whether ceill works according to ISO C 99 with IEC 60559],
          [gl_cv_func_ceill_ieee],
          [
            save_LIBS="$LIBS"
            LIBS="$LIBS $CEILL_LIBM"
            AC_RUN_IFELSE(
              [AC_LANG_SOURCE([[
#ifndef __NO_MATH_INLINES
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
]gl_LONG_DOUBLE_SIGNBIT_CODE[
static long double dummy (long double f) { return 0; }
int main (int argc, char *argv[])
{
  long double (* volatile my_ceill) (long double) = argc ? ceill : dummy;
  /* Test whether ceill (-0.3L) is -0.0L.  */
  if (signbitl (minus_zerol) && !signbitl (my_ceill (-0.3L)))
    return 1;
  return 0;
}
              ]])],
              [gl_cv_func_ceill_ieee=yes],
              [gl_cv_func_ceill_ieee=no],
              [case "$host_os" in
                                # Guess yes on glibc systems.
                 *-gnu* | gnu*) gl_cv_func_ceill_ieee="guessing yes" ;;
                                # Guess yes on musl systems.
                 *-musl*)       gl_cv_func_ceill_ieee="guessing yes" ;;
                                # Guess yes on native Windows.
                 mingw*)        gl_cv_func_ceill_ieee="guessing yes" ;;
                                # If we don't know, obey --enable-cross-guesses.
                 *)             gl_cv_func_ceill_ieee="$gl_cross_guess_normal" ;;
               esac
              ])
            LIBS="$save_LIBS"
          ])
        case "$gl_cv_func_ceill_ieee" in
          *yes) ;;
          *) REPLACE_CEILL=1 ;;
        esac
      fi
    ])
  else
    HAVE_DECL_CEILL=0
  fi
  dnl On OpenBSD5.6 the system's native ceill() is buggy:
  dnl it returns '0' for small values. Test for this anomaly.
  if test $REPLACE_CEILL = 0 ; then
    AC_CACHE_CHECK([whether ceill() breaks with small values],
        [gl_cv_func_ceill_buggy],
        [
          save_LIBS="$LIBS"
          LIBS="$CEILL_LIBM"
          AC_RUN_IFELSE(
           [AC_LANG_PROGRAM(
             [[#include <math.h>
long double d = 0.3L;]],
             [[return (!(ceill (d) == 1)); ]])],
             [gl_cv_func_ceill_buggy=no], [gl_cv_func_ceill_buggy=yes],
             [case "$host_os" in
                openbsd*) gl_cv_func_ceill_buggy="guessing yes" ;;
                          # Guess no on native Windows.
                mingw*)   gl_cv_func_ceill_buggy="guessing no" ;;
                *)        gl_cv_func_ceill_buggy="guessing no" ;;
              esac
             ])
          LIBS="$save_LIBS"
        ])
    case "$gl_cv_func_ceill_buggy" in
      *yes)
        REPLACE_CEILL=1 ;;
    esac
  fi
  if test $HAVE_DECL_CEILL = 0 || test $REPLACE_CEILL = 1; then
    dnl Find libraries needed to link lib/ceill.c.
    if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
      AC_REQUIRE([gl_FUNC_CEIL])
      CEILL_LIBM="$CEIL_LIBM"
    else
      CEILL_LIBM=
    fi
  fi
  AC_SUBST([CEILL_LIBM])
])

# Determines the libraries needed to get the ceill() function.
# Sets CEILL_LIBM.
AC_DEFUN([gl_FUNC_CEILL_LIBS],
[
  gl_CACHE_VAL_SILENT([gl_cv_func_ceill_libm], [
    gl_cv_func_ceill_libm=?
    AC_LINK_IFELSE(
      [AC_LANG_PROGRAM(
         [[#ifndef __NO_MATH_INLINES
           # define __NO_MATH_INLINES 1 /* for glibc */
           #endif
           #include <math.h>
           long double (*funcptr) (long double) = ceill;
           long double x;]],
         [[x = funcptr(x) + ceill(x);]])],
      [gl_cv_func_ceill_libm=])
    if test "$gl_cv_func_ceill_libm" = "?"; then
      save_LIBS="$LIBS"
      LIBS="$LIBS -lm"
      AC_LINK_IFELSE(
        [AC_LANG_PROGRAM(
           [[#ifndef __NO_MATH_INLINES
             # define __NO_MATH_INLINES 1 /* for glibc */
             #endif
             #include <math.h>
             long double (*funcptr) (long double) = ceill;
             long double x;]],
           [[x = funcptr(x) + ceill(x);]])],
        [gl_cv_func_ceill_libm="-lm"])
      LIBS="$save_LIBS"
    fi
  ])
  CEILL_LIBM="$gl_cv_func_ceill_libm"
])