m4/ceil.m4

   1 # ceil.m4 serial 5
   2 dnl Copyright (C) 2007, 2009-2011 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_CEIL],
   8 [
   9   m4_divert_text([DEFAULTS], [gl_ceil_required=plain])
  10   AC_REQUIRE([gl_MATH_H_DEFAULTS])
  11   dnl Test whether ceil() can be used without libm.
  12   gl_FUNC_CEIL_LIBS
  13   if test "$CEIL_LIBM" = "?"; then
  14     CEIL_LIBM=
  15   fi
  16   m4_ifdef([gl_FUNC_CEIL_IEEE], [
  17     if test $gl_ceil_required = ieee && test $REPLACE_CEIL = 0; then
  18       AC_CACHE_CHECK([whether ceil works according to ISO C 99 with IEC 60559],
  19         [gl_cv_func_ceil_ieee],
  20         [
  21           save_LIBS="$LIBS"
  22           LIBS="$LIBS $CEIL_LIBM"
  23           AC_RUN_IFELSE(
  24             [AC_LANG_SOURCE([[
  25 #ifndef __NO_MATH_INLINES
  26 # define __NO_MATH_INLINES 1 /* for glibc */
  27 #endif
  28 #include <math.h>
  29 ]gl_DOUBLE_MINUS_ZERO_CODE[
  30 ]gl_DOUBLE_SIGNBIT_CODE[
  31 int main()
  32 {
  33   /* Test whether ceil (-0.0) is -0.0.  */
  34   if (signbitd (minus_zerod) && !signbitd (ceil (minus_zerod)))
  35     return 1;
  36   return 0;
  37 }
  38             ]])],
  39             [gl_cv_func_ceil_ieee=yes],
  40             [gl_cv_func_ceil_ieee=no],
  41             [gl_cv_func_ceil_ieee="guessing no"])
  42           LIBS="$save_LIBS"
  43         ])
  44       case "$gl_cv_func_ceil_ieee" in
  45         *yes) ;;
  46         *) REPLACE_CEIL=1 ;;
  47       esac
  48     fi
  49   ])
  50   if test $REPLACE_CEIL = 1; then
  51     AC_LIBOBJ([ceil])
  52     CEIL_LIBM=
  53   fi
  54   AC_SUBST([CEIL_LIBM])
  55 ])
  56
  57 # Determines the libraries needed to get the ceil() function.
  58 # Sets CEIL_LIBM.
  59 AC_DEFUN([gl_FUNC_CEIL_LIBS],
  60 [
  61   gl_CACHE_VAL_SILENT([gl_cv_func_ceil_libm], [
  62     gl_cv_func_ceil_libm=?
  63     AC_LINK_IFELSE(
  64       [AC_LANG_PROGRAM(
  65          [[#ifndef __NO_MATH_INLINES
  66            # define __NO_MATH_INLINES 1 /* for glibc */
  67            #endif
  68            #include <math.h>
  69            double x;]],
  70          [[x = ceil(x);]])],
  71       [gl_cv_func_ceil_libm=])
  72     if test "$gl_cv_func_ceil_libm" = "?"; then
  73       save_LIBS="$LIBS"
  74       LIBS="$LIBS -lm"
  75       AC_LINK_IFELSE(
  76         [AC_LANG_PROGRAM(
  77            [[#ifndef __NO_MATH_INLINES
  78              # define __NO_MATH_INLINES 1 /* for glibc */
  79              #endif
  80              #include <math.h>
  81              double x;]],
  82            [[x = ceil(x);]])],
  83         [gl_cv_func_ceil_libm="-lm"])
  84       LIBS="$save_LIBS"
  85     fi
  86   ])
  87   CEIL_LIBM="$gl_cv_func_ceil_libm"
  88 ])