log2-ieee: Work around test failure on NetBSD 5.1 and Solaris 10.

[gnulib.git] / m4 / floorf.m4

diff --git a/m4/floorf.m4 b/m4/floorf.m4
index d426569..6e792a1 100644 (file)
--- a/m4/floorf.m4
+++ b/m4/floorf.m4
@@ -1,5 +1,5 @@
-# floorf.m4 serial 9
-dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+# floorf.m4 serial 12
+dnl Copyright (C) 2007, 2009-2012 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.
@@ -11,7 +11,7 @@ AC_DEFUN([gl_FUNC_FLOORF],
   dnl Persuade glibc <math.h> to declare floorf().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   dnl Test whether floorf() is declared.
-  AC_CHECK_DECLS([floorf], , , [#include <math.h>])
+  AC_CHECK_DECLS([floorf], , , [[#include <math.h>]])
   if test "$ac_cv_have_decl_floorf" = yes; then
     dnl Test whether floorf() can be used without libm.
     gl_FUNC_FLOORF_LIBS
@@ -35,10 +35,12 @@ AC_DEFUN([gl_FUNC_FLOORF],
 #include <math.h>
 ]gl_FLOAT_MINUS_ZERO_CODE[
 ]gl_FLOAT_SIGNBIT_CODE[
-int main()
+static float dummy (float f) { return 0; }
+int main (int argc, char *argv[])
 {
+  float (*my_floorf) (float) = argc ? floorf : dummy;
   /* Test whether floorf (-0.0f) is -0.0f.  */
-  if (signbitf (minus_zerof) && !signbitf (floorf (minus_zerof)))
+  if (signbitf (minus_zerof) && !signbitf (my_floorf (minus_zerof)))
     return 1;
   return 0;
 }
@@ -76,8 +78,9 @@ AC_DEFUN([gl_FUNC_FLOORF_LIBS],
            # define __NO_MATH_INLINES 1 /* for glibc */
            #endif
            #include <math.h>
+           float (*funcptr) (float) = floorf;
            float x;]],
-         [[x = floorf(x);]])],
+         [[x = funcptr(x) + floorf(x);]])],
       [gl_cv_func_floorf_libm=])
     if test "$gl_cv_func_floorf_libm" = "?"; then
       save_LIBS="$LIBS"
@@ -88,8 +91,9 @@ AC_DEFUN([gl_FUNC_FLOORF_LIBS],
              # define __NO_MATH_INLINES 1 /* for glibc */
              #endif
              #include <math.h>
+             float (*funcptr) (float) = floorf;
              float x;]],
-           [[x = floorf(x);]])],
+           [[x = funcptr(x) + floorf(x);]])],
         [gl_cv_func_floorf_libm="-lm"])
       LIBS="$save_LIBS"
     fi