isnan: port to VAX

[gnulib.git] / m4 / fmodf.m4

diff --git a/m4/fmodf.m4 b/m4/fmodf.m4
index 812140d..f3779dd 100644 (file)
--- a/m4/fmodf.m4
+++ b/m4/fmodf.m4
@@ -1,5 +1,5 @@
-# fmodf.m4 serial 2
-dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
+# fmodf.m4 serial 5
+dnl Copyright (C) 2011-2013 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.
@@ -10,6 +10,9 @@ AC_DEFUN([gl_FUNC_FMODF],
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_FMOD])
 
+  dnl Persuade glibc <math.h> to declare fmodf().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether fmodf() exists. Assume that fmodf(), if it exists, is
   dnl defined in the same library as fmod().
   save_LIBS="$LIBS"
@@ -20,6 +23,7 @@ AC_DEFUN([gl_FUNC_FMODF],
     FMODF_LIBM="$FMOD_LIBM"
     m4_ifdef([gl_FUNC_FMODF_IEEE], [
       if test $gl_fmodf_required = ieee && test $REPLACE_FMODF = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
         AC_CACHE_CHECK([whether fmodf works according to ISO C 99 with IEC 60559],
           [gl_cv_func_fmodf_ieee],
           [
@@ -43,7 +47,6 @@ static float dummy (float x, float y) { return 0; }
 int main (int argc, char *argv[])
 {
   float (*my_fmodf) (float, float) = argc ? fmodf : dummy;
-  float i;
   float f;
   /* Test fmodf(...,0.0f).
      This test fails on OSF/1 5.1.  */
@@ -55,7 +58,13 @@ int main (int argc, char *argv[])
               ]])],
               [gl_cv_func_fmodf_ieee=yes],
               [gl_cv_func_fmodf_ieee=no],
-              [gl_cv_func_fmodf_ieee="guessing no"])
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_fmodf_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_fmodf_ieee="guessing no" ;;
+               esac
+              ])
             LIBS="$save_LIBS"
           ])
         case "$gl_cv_func_fmodf_ieee" in