2009-12-17 Sandra Loosemore <sandra@codesourcery.com>

[pf3gnuchains/gcc-fork.git] / gcc / doc / rtl.texi

diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index 4888eb3..eda42c7 100644 (file)
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -2614,9 +2614,12 @@ a set bit indicates it is taken from @var{vec1}.
 @findex vec_select
 @item (vec_select:@var{m} @var{vec1} @var{selection})
 This describes an operation that selects parts of a vector.  @var{vec1} is
-the source vector, @var{selection} is a @code{parallel} that contains a
+the source vector, and @var{selection} is a @code{parallel} that contains a
 @code{const_int} for each of the subparts of the result vector, giving the
-number of the source subpart that should be stored into it.
+number of the source subpart that should be stored into it.  
+The result mode @var{m} is either the submode for a single element of
+@var{vec1} (if only one subpart is selected), or another vector mode 
+with that element submode (if multiple subparts are selected).
 
 @findex vec_concat
 @item (vec_concat:@var{m} @var{vec1} @var{vec2})