ceil-ieee: Work around bug on AIX 7.1.

* m4/ceil.m4 (gl_FUNC_CEIL): Test also the sign of ceil (-0.3).
* doc/posix-functions/ceil.texi: Mention the AIX 7.1 problem.

diff --git a/ChangeLog b/ChangeLog
index 41bd84a43dea1d6f96dbc4ef8576dcf9bd6e3d08..1c0136a24bfd02b5f92709cbd5f5ed91a2e55db3 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-06-19  Bruno Haible  <bruno@clisp.org>
+
+       ceil-ieee: Work around bug on AIX 7.1.
+       * m4/ceil.m4 (gl_FUNC_CEIL): Test also the sign of ceil (-0.3).
+       * doc/posix-functions/ceil.texi: Mention the AIX 7.1 problem.
+
 2011-06-18  Bruno Haible  <bruno@clisp.org>
 
        fsync test: Avoid test failure on MacOS X and AIX.

diff --git a/doc/posix-functions/ceil.texi b/doc/posix-functions/ceil.texi
index 3c5c659a4f13892c20750ab7cf992840dcd55982..d11c790b7e76a3a14fcbb56a5fb9924ebad72362 100644 (file)
--- a/doc/posix-functions/ceil.texi
+++ b/doc/posix-functions/ceil.texi
@@ -13,6 +13,10 @@ Portability problems fixed by either Gnulib module @code{ceil} or @code{ceil-iee
 Portability problems fixed by Gnulib module @code{ceil-ieee}:
 @itemize
 @item
+This function returns a positive zero for an argument between -1 and 0
+on some platforms:
+AIX 7.1.
+@item
 This function returns a positive zero for a minus zero argument
 on some platforms:
 OSF/1 5.1.

diff --git a/m4/ceil.m4 b/m4/ceil.m4
index 157407745b12524b16e594a24b409450591a52f5..fd335d2ceeac3916031731436aa247186a71118e 100644 (file)
--- a/m4/ceil.m4
+++ b/m4/ceil.m4
@@ -1,4 +1,4 @@
-# ceil.m4 serial 6
+# ceil.m4 serial 7
 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,
@@ -30,10 +30,14 @@ AC_DEFUN([gl_FUNC_CEIL],
 ]gl_DOUBLE_SIGNBIT_CODE[
 int main()
 {
+  int result = 0;
   /* Test whether ceil (-0.0) is -0.0.  */
   if (signbitd (minus_zerod) && !signbitd (ceil (minus_zerod)))
-    return 1;
-  return 0;
+    result |= 1;
+  /* Test whether ceil (-0.3) is -0.0.  */
+  if (signbitd (-0.3) && !signbitd (ceil (-0.3)))
+    result |= 2;
+  return result;
 }
             ]])],
             [gl_cv_func_ceil_ieee=yes],