I missed including the documentation patch in the last set. :-( Here it is:
Index: extend.texi
===================================================================
--- extend.texi (revision 220084)
+++ extend.texi (working copy)
@@ -17881,6 +17881,17 @@ void ignore_vec_dep (int *a, int k, int
@}
@end smallexample
+@table @code
+@item #pragma GCC unroll @var{"n"}
+@cindex pragma GCC unroll @var{"n"}
+
+With this pragma, the programmer informs the optimizer how many times
+a loop should be unrolled. A 0 or 1 informs the compiler to not
+perform any loop unrolling. The pragma must be immediately before
+@samp{#pragma ivdep} or a @code{for}, @code{while} or @code{do} loop
+and applies only to the loop that follows.
+
+@end table
@node Unnamed Fields
@section Unnamed struct/union fields within structs/unions
