re PR middle-end/17660 (manual's description of __attribute__((mode)) is poor,…

re PR middle-end/17660 (manual's description of __attribute__((mode)) is poor, arrangement is confusing)

2017-01-08  Sandra Loosemore  <sandra@codesourcery.com>

	PR middle-end/17660

	gcc/
	* extend.texi (Common Variable Attributes): Add xref to GCC
	Internals manual to explain mode attribute keywords.

From-SVN: r244215

gcc/ChangeLog

 2017-01-08  Sandra Loosemore  <sandra@codesourcery.com>
 
+	PR middle-end/17660
+
+	* extend.texi (Common Variable Attributes): Add xref to GCC
+	Internals manual to explain mode attribute keywords.
+
+2017-01-08  Sandra Loosemore  <sandra@codesourcery.com>
+
 	PR other/16519
 
 	* doc/invoke.texi (Option Summary): Move -pthread to Linker Options

gcc/doc/extend.texi

@@ -5725,6 +5725,8 @@ This attribute specifies the data type for the declaration---whichever
 type corresponds to the mode @var{mode}.  This in effect lets you
 request an integer or floating-point type according to its width.
 
+@xref{Machine Modes,,, gccint, GNU Compiler Collection (GCC) Internals},
+for a list of the possible keywords for @var{mode}.
 You may also specify a mode of @code{byte} or @code{__byte__} to
 indicate the mode corresponding to a one-byte integer, @code{word} or
 @code{__word__} for the mode of a one-word integer, and @code{pointer}