X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffmodl.m4;h=e223ae648cb6f5165ebbd464ee5a88a468da0c5c;hb=cd56634a4a8179fd5a4419fbb3e27211b042ab1c;hp=ff72c8c1255c12a4bda5ca411d0a873aa4048d62;hpb=0874a5828bbb4784e9c9d54243b3c978e8e54ece;p=gnulib.git

diff --git a/m4/fmodl.m4 b/m4/fmodl.m4
index ff72c8c12..e223ae648 100644
--- a/m4/fmodl.m4
+++ b/m4/fmodl.m4
@@ -1,5 +1,5 @@
-# fmodl.m4 serial 3
-dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
+# fmodl.m4 serial 5
+dnl Copyright (C) 2011-2014 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.
@@ -11,6 +11,9 @@ AC_DEFUN([gl_FUNC_FMODL],
   AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
   AC_REQUIRE([gl_FUNC_FMOD])
 
+  dnl Persuade glibc <math.h> to declare fmodl().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether fmodl() is declared.
   dnl AIX 5.1 has fmodl() in libc but doesn't declare it in <math.h>, and the
   dnl function produces NaN results for finite values.
@@ -31,6 +34,7 @@ AC_DEFUN([gl_FUNC_FMODL],
     fi
     m4_ifdef([gl_FUNC_FMODL_IEEE], [
       if test $gl_fmodl_required = ieee && test $REPLACE_FMODL = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
         AC_CACHE_CHECK([whether fmodl works according to ISO C 99 with IEC 60559],
           [gl_cv_func_fmodl_ieee],
           [
@@ -65,7 +69,13 @@ int main (int argc, char *argv[])
               ]])],
               [gl_cv_func_fmodl_ieee=yes],
               [gl_cv_func_fmodl_ieee=no],
-              [gl_cv_func_fmodl_ieee="guessing no"])
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_fmodl_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_fmodl_ieee="guessing no" ;;
+               esac
+              ])
             LIBS="$save_LIBS"
           ])
         case "$gl_cv_func_fmodl_ieee" in