From: Bill Schmidt <wschmidt@linux.ibm.com>
Date: Wed, 19 Dec 2018 18:34:25 +0000 (+0000)
Subject: backport: extend.texi (PowerPC Altivec/VSX Built-in Functions): Describe when a typed... 
X-Git-Tag: releases/gcc-7.5.0~713
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=01ba73bce3975c24d8e9bc1e5378d110aacccda3;p=thirdparty%2Fgcc.git

backport: extend.texi (PowerPC Altivec/VSX Built-in Functions): Describe when a typedef name can be used as the type specifier for a vector type...

2018-12-19  Bill Schmidt  <wschmidt@linux.ibm.com>

	Backport from mainline
	2018-12-18  Bill Schmidt  <wschmidt@linux.ibm.com>

	* doc/extend.texi (PowerPC Altivec/VSX Built-in Functions):
	Describe when a typedef name can be used as the type specifier for
	a vector type, and when it cannot.

From-SVN: r267284
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 894ffea28b12..56b1d8f82944 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2018-12-19  Bill Schmidt  <wschmidt@linux.ibm.com>
+
+        Backport from mainline
+        2018-12-18  Bill Schmidt  <wschmidt@linux.ibm.com>
+
+        * doc/extend.texi (PowerPC Altivec/VSX Built-in Functions):
+        Describe when a typedef name can be used as the type specifier for
+        a vector type, and when it cannot.
+
 2018-12-19  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	Backport from trunk
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index b0a1b7ffac6b..d1ba85e709a4 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -15566,7 +15566,30 @@ disabled.  To use them, you must include @code{<altivec.h>} instead.
 
 @item
 GCC allows using a @code{typedef} name as the type specifier for a
-vector type.
+vector type, but only under the following circumstances:
+
+@itemize @bullet
+
+@item
+When using @code{__vector} instead of @code{vector}; for example,
+
+@smallexample
+typedef signed short int16;
+__vector int16 data;
+@end smallexample
+
+@item
+When using @code{vector} in keyword-and-predefine mode; for example,
+
+@smallexample
+typedef signed short int16;
+vector int16 data;
+@end smallexample
+
+Note that keyword-and-predefine mode is enabled by disabling GNU
+extensions (e.g., by using @code{-std=c11}) and including
+@code{<altivec.h>}.
+@end itemize
 
 @item
 For C, overloaded functions are implemented with macros so the following