X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fceil.m4;h=b9052976f2912e49042c7b978e6a6bfd2d085021;hb=a4ed524753cd61bd2c52b9af041eabe83ea1d503;hp=9a8eb058306778c62328e14beb7588d4fba372e7;hpb=1fd8064a06ed3ca83f73c495e998e66c225e395b;p=gnulib.git

diff --git a/m4/ceil.m4 b/m4/ceil.m4
index 9a8eb0583..b9052976f 100644
--- a/m4/ceil.m4
+++ b/m4/ceil.m4
@@ -1,16 +1,62 @@
-# ceil.m4 serial 2
-dnl Copyright (C) 2007 Free Software Foundation, Inc.
+# ceil.m4 serial 8
+dnl Copyright (C) 2007, 2009-2011 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.
 
 AC_DEFUN([gl_FUNC_CEIL],
 [
+  m4_divert_text([DEFAULTS], [gl_ceil_required=plain])
+  AC_REQUIRE([gl_MATH_H_DEFAULTS])
   dnl Test whether ceil() can be used without libm.
   gl_FUNC_CEIL_LIBS
   if test "$CEIL_LIBM" = "?"; then
     CEIL_LIBM=
   fi
+  m4_ifdef([gl_FUNC_CEIL_IEEE], [
+    if test $gl_ceil_required = ieee && test $REPLACE_CEIL = 0; then
+      AC_CACHE_CHECK([whether ceil works according to ISO C 99 with IEC 60559],
+        [gl_cv_func_ceil_ieee],
+        [
+          save_LIBS="$LIBS"
+          LIBS="$LIBS $CEIL_LIBM"
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+]gl_DOUBLE_MINUS_ZERO_CODE[
+]gl_DOUBLE_SIGNBIT_CODE[
+static double dummy (double f) { return 0; }
+int main (int argc, char *argv[])
+{
+  double (*my_ceil) (double) = argc ? ceil : dummy;
+  int result = 0;
+  /* Test whether ceil (-0.0) is -0.0.  */
+  if (signbitd (minus_zerod) && !signbitd (my_ceil (minus_zerod)))
+    result |= 1;
+  /* Test whether ceil (-0.3) is -0.0.  */
+  if (signbitd (-0.3) && !signbitd (my_ceil (-0.3)))
+    result |= 2;
+  return result;
+}
+            ]])],
+            [gl_cv_func_ceil_ieee=yes],
+            [gl_cv_func_ceil_ieee=no],
+            [gl_cv_func_ceil_ieee="guessing no"])
+          LIBS="$save_LIBS"
+        ])
+      case "$gl_cv_func_ceil_ieee" in
+        *yes) ;;
+        *) REPLACE_CEIL=1 ;;
+      esac
+    fi
+  ])
+  if test $REPLACE_CEIL = 1; then
+    dnl No libraries are needed to link lib/ceil.c.
+    CEIL_LIBM=
+  fi
   AC_SUBST([CEIL_LIBM])
 ])
 
@@ -18,29 +64,31 @@ AC_DEFUN([gl_FUNC_CEIL],
 # Sets CEIL_LIBM.
 AC_DEFUN([gl_FUNC_CEIL_LIBS],
 [
-  AC_CACHE_VAL([gl_func_ceil_libm], [
-    gl_func_ceil_libm=?
-    AC_TRY_LINK([
-       #ifndef __NO_MATH_INLINES
-       # define __NO_MATH_INLINES 1 /* for glibc */
-       #endif
-       #include <math.h>
-       double x;],
-      [x = ceil(x);],
-      [gl_func_ceil_libm=])
-    if test "$gl_func_ceil_libm" = "?"; then
+  gl_CACHE_VAL_SILENT([gl_cv_func_ceil_libm], [
+    gl_cv_func_ceil_libm=?
+    AC_LINK_IFELSE(
+      [AC_LANG_PROGRAM(
+         [[#ifndef __NO_MATH_INLINES
+           # define __NO_MATH_INLINES 1 /* for glibc */
+           #endif
+           #include <math.h>
+           double x;]],
+         [[x = ceil(x);]])],
+      [gl_cv_func_ceil_libm=])
+    if test "$gl_cv_func_ceil_libm" = "?"; then
       save_LIBS="$LIBS"
       LIBS="$LIBS -lm"
-      AC_TRY_LINK([
-         #ifndef __NO_MATH_INLINES
-         # define __NO_MATH_INLINES 1 /* for glibc */
-         #endif
-         #include <math.h>
-         double x;],
-        [x = ceil(x);],
-        [gl_func_ceil_libm="-lm"])
+      AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM(
+           [[#ifndef __NO_MATH_INLINES
+             # define __NO_MATH_INLINES 1 /* for glibc */
+             #endif
+             #include <math.h>
+             double x;]],
+           [[x = ceil(x);]])],
+        [gl_cv_func_ceil_libm="-lm"])
       LIBS="$save_LIBS"
     fi
   ])
-  CEIL_LIBM="$gl_func_ceil_libm"
+  CEIL_LIBM="$gl_cv_func_ceil_libm"
 ])