# HG changeset patch
# User Bruno Haible <bruno@clisp.org>
# Date 1320621751 -3600
# Node ID 3e022c4e03161be78b2c5daf7aeb74d08b71c6bd
# Parent  ad562dcd34c28035efd538651ca484d96952ccdf
Doc about floating-point and math API.

* doc/posix-headers/float.texi: Mention problem with FLT_ROUNDS.
* doc/posix-headers/math.texi: Mention problem with math_errhandling.

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-11-06  Bruno Haible  <bruno@clisp.org>
+
+	Doc about floating-point and math API.
+	* doc/posix-headers/float.texi: Mention problem with FLT_ROUNDS.
+	* doc/posix-headers/math.texi: Mention problem with math_errhandling.
+
 2011-11-06  Bruno Haible  <bruno@clisp.org>
 
 	stdalign tests: Skip the test when compiled by Sun C.
diff --git a/doc/posix-headers/float.texi b/doc/posix-headers/float.texi
--- a/doc/posix-headers/float.texi
+++ b/doc/posix-headers/float.texi
@@ -25,4 +25,8 @@
 
 Portability problems not fixed by Gnulib:
 @itemize
+@item
+The macro @code{FLT_ROUNDS} is a constant expression and does not represent
+the current rounding mode on some platforms:
+glibc 2.11, HP-UX 11, mingw.
 @end itemize
diff --git a/doc/posix-headers/math.texi b/doc/posix-headers/math.texi
--- a/doc/posix-headers/math.texi
+++ b/doc/posix-headers/math.texi
@@ -32,4 +32,7 @@
 @item
 @code{NAN} is not a compile time constant with some compilers:
 OSF/1 with Compaq (ex-DEC) C 6.4.
+@item
+The macro or variable @code{math_errhandling} is not defined on some platforms:
+glibc 2.11, OpenBSD 4.9, NetBSD 5.1, UP-UX 11, IRIX 6.5, OSF/1 5.1, Cygwin 1.7.9, mingw, MSVC 9.
 @end itemize