cmd/gc: mark panicslice as unlikely

No measurable impact on performance on amd64

R=golang-dev, khr, bradfitz
CC=golang-dev
https://golang.org/cl/13096045

diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index bc0a15e1a00cfe6239a7b233d5138242ec8365d5..98a5a8968e3d4ae5c73a807ffaa8b1553972fae2 100644 (file)
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -2729,6 +2729,7 @@ sliceany(Node* n, NodeList **init)
        if(chk0 != N || chk1 != N || chk2 != N) {
                chk = nod(OIF, N, N);
                chk->nbody = list1(mkcall("panicslice", T, init));
+               chk->likely = -1;
                if(chk0 != N)
                        chk->ntest = chk0;
                if(chk1 != N) {