doc/go1.21: document GOPPC64=power10 changes

For #44549

Change-Id: I1af1d4bbd01a4571a32815bfea16bc395524551a
Reviewed-on: https://go-review.googlesource.com/c/go/+/501358
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Eli Bendersky <eliben@google.com>

diff --git a/doc/go1.21.html b/doc/go1.21.html
index b5c473113d31515ce618d1d78df60926ae0083db..1d490843252c019b914f966e5bc7ffb13661c8ec 100644 (file)
--- a/doc/go1.21.html
+++ b/doc/go1.21.html
@@ -1203,6 +1203,22 @@ Do not send CLs removing the interior tags from such phrases.
   need to rename them.
 </p>
 
+<h3 id="PPC64">ppc64/ppc64le</h3>
+
+<p><!-- go.dev/issue/44549 -->
+  On Linux, <code>GOPPC64=power10</code> now generates PC-relative instructions, prefixed
+  instructions, and other new Power10 instructions. On AIX, <code>GOPPC64=power10</code>
+  generates Power10 instructions, but does not generate PC-relative instructions.
+</p>
+
+<p>
+  When building position-independent binaries for <code>GOPPC64=power10</code>
+  <code>GOOS=linux</code> <code>GOARCH=ppc64le</code>, users can expect reduced binary
+  sizes in most cases, in some cases 3.5%. Position-independent binaries are built for
+  ppc64le with the following <code>-buildmode</code> values:
+  <code>c-archive</code>, <code>c-shared</code>, <code>shared</code>, <code>pie</code>, <code>plugin</code>.
+</p>
+
 
 <!-- proposals for x repos that don't need to be mentioned here but
      are picked up by the relnote tool. -->