gnulib/import/m4/float_h.m4

   1 # float_h.m4 serial 13
   2 dnl Copyright (C) 2007, 2009-2022 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   GL_GENERATE_FLOAT_H=false
  12   REPLACE_FLOAT_LDBL=0
  13   case "$host_os" in
  14     aix* | beos* | openbsd* | mirbsd* | irix*)
  15       GL_GENERATE_FLOAT_H=true
  16       ;;
  17     freebsd* | dragonfly*)
  18       case "$host_cpu" in
  19 changequote(,)dnl
  20         i[34567]86 )
  21 changequote([,])dnl
  22           GL_GENERATE_FLOAT_H=true
  23           ;;
  24         x86_64 )
  25           # On x86_64 systems, the C compiler may still be generating
  26           # 32-bit code.
  27           AC_COMPILE_IFELSE(
  28             [AC_LANG_SOURCE(
  29                [[#if defined __LP64__ || defined __x86_64__ || defined __amd64__
  30                   int ok;
  31                  #else
  32                   error fail
  33                  #endif
  34                ]])],
  35             [],
  36             [GL_GENERATE_FLOAT_H=true])
  37           ;;
  38       esac
  39       ;;
  40     linux*)
  41       case "$host_cpu" in
  42         powerpc*)
  43           GL_GENERATE_FLOAT_H=true
  44           ;;
  45       esac
  46       ;;
  47   esac
  48   case "$host_os" in
  49     aix* | freebsd* | dragonfly* | linux*)
  50       if $GL_GENERATE_FLOAT_H; then
  51         REPLACE_FLOAT_LDBL=1
  52       fi
  53       ;;
  54   esac
  55
  56   dnl Test against glibc-2.7 Linux/SPARC64 bug.
  57   REPLACE_ITOLD=0
  58   AC_CACHE_CHECK([whether conversion from 'int' to 'long double' works],
  59     [gl_cv_func_itold_works],
  60     [
  61       AC_RUN_IFELSE(
  62         [AC_LANG_SOURCE([[
  63 int i = -1;
  64 volatile long double ld;
  65 int main ()
  66 {
  67   ld += i * 1.0L;
  68   if (ld > 0)
  69     return 1;
  70   return 0;
  71 }]])],
  72         [gl_cv_func_itold_works=yes],
  73         [gl_cv_func_itold_works=no],
  74         [case "$host" in
  75            sparc*-*-linux*)
  76              AC_COMPILE_IFELSE(
  77                [AC_LANG_SOURCE(
  78                  [[#if defined __LP64__ || defined __arch64__
  79                     int ok;
  80                    #else
  81                     error fail
  82                    #endif
  83                  ]])],
  84                [gl_cv_func_itold_works="guessing no"],
  85                [gl_cv_func_itold_works="guessing yes"])
  86              ;;
  87                    # Guess yes on native Windows.
  88            mingw*) gl_cv_func_itold_works="guessing yes" ;;
  89            *)      gl_cv_func_itold_works="guessing yes" ;;
  90          esac
  91         ])
  92     ])
  93   case "$gl_cv_func_itold_works" in
  94     *no)
  95       REPLACE_ITOLD=1
  96       dnl We add the workaround to <float.h> but also to <math.h>,
  97       dnl to increase the chances that the fix function gets pulled in.
  98       GL_GENERATE_FLOAT_H=true
  99       ;;
 100   esac
 101
 102   if $GL_GENERATE_FLOAT_H; then
 103     gl_NEXT_HEADERS([float.h])
 104   fi
 105   AC_SUBST([REPLACE_ITOLD])
 106 ])