re PR c/46946 (contradiction in docs for -Ofast and -ffast-math)

2011-01-12  Richard Guenther  <rguenther@suse.de>

	PR other/46946
	* doc/invoke.texi (ffast-math): Document it is turned on
	with -Ofast.

From-SVN: r168709

gcc/ChangeLog

+2011-01-12  Richard Guenther  <rguenther@suse.de>
+
+	PR other/46946
+	* doc/invoke.texi (ffast-math): Document it is turned on
+	with -Ofast.
+
 2011-01-12  Jan Hubicka  <jh@suse.cz>
 
 	PR tree-optimization/47233

gcc/doc/invoke.texi

@@ -7792,10 +7792,10 @@ Sets @option{-fno-math-errno}, @option{-funsafe-math-optimizations},
 
 This option causes the preprocessor macro @code{__FAST_MATH__} to be defined.
 
-This option is not turned on by any @option{-O} option since
-it can result in incorrect output for programs which depend on
-an exact implementation of IEEE or ISO rules/specifications for
-math functions. It may, however, yield faster code for programs
+This option is not turned on by any @option{-O} option besides
+@option{-Ofast} since it can result in incorrect output for programs
+which depend on an exact implementation of IEEE or ISO rules/specifications
+for math functions. It may, however, yield faster code for programs
 that do not require the guarantees of these specifications.
 
 @item -fno-math-errno