X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fceilf.m4;h=deb207460e20dc278006822bc95728f378706f46;hb=7422b7ede18016dea87d207cbb7535428afba3ec;hp=e7a6a461c29df973eb8202daac8259ce71308ffb;hpb=d60f3b0c6b0f93a601acd1cfd3923f94ca05abb0;p=gnulib.git

diff --git a/m4/ceilf.m4 b/m4/ceilf.m4
index e7a6a461c..deb207460 100644
--- a/m4/ceilf.m4
+++ b/m4/ceilf.m4
@@ -1,5 +1,5 @@
-# ceilf.m4 serial 8
-dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+# ceilf.m4 serial 14
+dnl Copyright (C) 2007, 2009-2014 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.
@@ -11,7 +11,7 @@ AC_DEFUN([gl_FUNC_CEILF],
   dnl Persuade glibc <math.h> to declare ceilf().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   dnl Test whether ceilf() is declared.
-  AC_CHECK_DECLS([ceilf], , , [#include <math.h>])
+  AC_CHECK_DECLS([ceilf], , , [[#include <math.h>]])
   if test "$ac_cv_have_decl_ceilf" = yes; then
     dnl Test whether ceilf() can be used without libm.
     gl_FUNC_CEILF_LIBS
@@ -22,6 +22,7 @@ AC_DEFUN([gl_FUNC_CEILF],
     fi
     m4_ifdef([gl_FUNC_CEILF_IEEE], [
       if test $gl_ceilf_required = ieee && test $REPLACE_CEILF = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
         AC_CACHE_CHECK([whether ceilf works according to ISO C 99 with IEC 60559],
           [gl_cv_func_ceilf_ieee],
           [
@@ -35,17 +36,29 @@ AC_DEFUN([gl_FUNC_CEILF],
 #include <math.h>
 ]gl_FLOAT_MINUS_ZERO_CODE[
 ]gl_FLOAT_SIGNBIT_CODE[
-int main()
+static float dummy (float f) { return 0; }
+int main (int argc, char *argv[])
 {
+  float (*my_ceilf) (float) = argc ? ceilf : dummy;
+  int result = 0;
   /* Test whether ceilf (-0.0f) is -0.0f.  */
-  if (signbitf (minus_zerof) && !signbitf (ceilf (minus_zerof)))
-    return 1;
-  return 0;
+  if (signbitf (minus_zerof) && !signbitf (my_ceilf (minus_zerof)))
+    result |= 1;
+  /* Test whether ceilf (-0.3f) is -0.0f.  */
+  if (signbitf (-0.3f) && !signbitf (my_ceilf (-0.3f)))
+    result |= 2;
+  return result;
 }
               ]])],
               [gl_cv_func_ceilf_ieee=yes],
               [gl_cv_func_ceilf_ieee=no],
-              [gl_cv_func_ceilf_ieee="guessing no"])
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_ceilf_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_ceilf_ieee="guessing no" ;;
+               esac
+              ])
             LIBS="$save_LIBS"
           ])
         case "$gl_cv_func_ceilf_ieee" in
@@ -58,7 +71,7 @@ int main()
     HAVE_DECL_CEILF=0
   fi
   if test $HAVE_DECL_CEILF = 0 || test $REPLACE_CEILF = 1; then
-    AC_LIBOBJ([ceilf])
+    dnl No libraries are needed to link lib/ceilf.c.
     CEILF_LIBM=
   fi
   AC_SUBST([CEILF_LIBM])
@@ -76,8 +89,9 @@ AC_DEFUN([gl_FUNC_CEILF_LIBS],
            # define __NO_MATH_INLINES 1 /* for glibc */
            #endif
            #include <math.h>
+           float (*funcptr) (float) = ceilf;
            float x;]],
-         [[x = ceilf(x);]])],
+         [[x = funcptr(x) + ceilf(x);]])],
       [gl_cv_func_ceilf_libm=])
     if test "$gl_cv_func_ceilf_libm" = "?"; then
       save_LIBS="$LIBS"
@@ -88,8 +102,9 @@ AC_DEFUN([gl_FUNC_CEILF_LIBS],
              # define __NO_MATH_INLINES 1 /* for glibc */
              #endif
              #include <math.h>
+             float (*funcptr) (float) = ceilf;
              float x;]],
-           [[x = ceilf(x);]])],
+           [[x = funcptr(x) + ceilf(x);]])],
         [gl_cv_func_ceilf_libm="-lm"])
       LIBS="$save_LIBS"
     fi