gnulib/import/m4/float_h.m4

   1 # float_h.m4 serial 9
   2 dnl Copyright (C) 2007, 2009-2016 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_FLOAT_H],
   8 [
   9   AC_REQUIRE([AC_PROG_CC])
  10   AC_REQUIRE([AC_CANONICAL_HOST])
  11   FLOAT_H=
  12   REPLACE_FLOAT_LDBL=0
  13   case "$host_os" in
  14     aix* | beos* | openbsd* | mirbsd* | irix*)
  15       FLOAT_H=float.h
  16       ;;
  17     freebsd*)
  18       case "$host_cpu" in
  19 changequote(,)dnl
  20         i[34567]86 )
  21 changequote([,])dnl
  22           FLOAT_H=float.h
  23           ;;
  24         x86_64 )
  25           # On x86_64 systems, the C compiler may still be generating
  26           # 32-bit code.
  27           AC_EGREP_CPP([yes],
  28             [#if defined __LP64__ || defined __x86_64__ || defined __amd64__
  29              yes
  30              #endif],
  31             [],
  32             [FLOAT_H=float.h])
  33           ;;
  34       esac
  35       ;;
  36     linux*)
  37       case "$host_cpu" in
  38         powerpc*)
  39           FLOAT_H=float.h
  40           ;;
  41       esac
  42       ;;
  43   esac
  44   case "$host_os" in
  45     aix* | freebsd* | linux*)
  46       if test -n "$FLOAT_H"; then
  47         REPLACE_FLOAT_LDBL=1
  48       fi
  49       ;;
  50   esac
  51
  52   dnl Test against glibc-2.7 Linux/SPARC64 bug.
  53   REPLACE_ITOLD=0
  54   AC_CACHE_CHECK([whether conversion from 'int' to 'long double' works],
  55     [gl_cv_func_itold_works],
  56     [
  57       AC_RUN_IFELSE(
  58         [AC_LANG_SOURCE([[
  59 int i = -1;
  60 volatile long double ld;
  61 int main ()
  62 {
  63   ld += i * 1.0L;
  64   if (ld > 0)
  65     return 1;
  66   return 0;
  67 }]])],
  68         [gl_cv_func_itold_works=yes],
  69         [gl_cv_func_itold_works=no],
  70         [case "$host" in
  71            sparc*-*-linux*)
  72              AC_EGREP_CPP([yes],
  73                [#if defined __LP64__ || defined __arch64__
  74                 yes
  75                 #endif],
  76                [gl_cv_func_itold_works="guessing no"],
  77                [gl_cv_func_itold_works="guessing yes"])
  78              ;;
  79            *) gl_cv_func_itold_works="guessing yes" ;;
  80          esac
  81         ])
  82     ])
  83   case "$gl_cv_func_itold_works" in
  84     *no)
  85       REPLACE_ITOLD=1
  86       dnl We add the workaround to <float.h> but also to <math.h>,
  87       dnl to increase the chances that the fix function gets pulled in.
  88       FLOAT_H=float.h
  89       ;;
  90   esac
  91
  92   if test -n "$FLOAT_H"; then
  93     gl_NEXT_HEADERS([float.h])
  94   fi
  95   AC_SUBST([FLOAT_H])
  96   AM_CONDITIONAL([GL_GENERATE_FLOAT_H], [test -n "$FLOAT_H"])
  97   AC_SUBST([REPLACE_ITOLD])
  98 ])