cmd/compile/internal/ppc64: disable DUFFZERO
Update #12108
If DUFFZERO is used within a tail call method it will overwrite the
link register.
Change-Id: I6abd2fde0f0ad909ccd55eb119b992673a74f0e2
Reviewed-on: https://go-review.googlesource.com/13570
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/src/cmd/compile/internal/ppc64/ggen.go b/src/cmd/compile/internal/ppc64/ggen.go
index 1b936b8..5b282eb 100644
--- a/src/cmd/compile/internal/ppc64/ggen.go
+++ b/src/cmd/compile/internal/ppc64/ggen.go
@@ -71,7 +71,10 @@
for i := int64(0); i < cnt; i += int64(gc.Widthptr) {
p = appendpp(p, ppc64.AMOVD, obj.TYPE_REG, ppc64.REGZERO, 0, obj.TYPE_MEM, ppc64.REGSP, 8+frame+lo+i)
}
- } else if cnt <= int64(128*gc.Widthptr) {
+ // TODO(dfc): https://golang.org/issue/12108
+ // If DUFFZERO is used inside a tail call (see genwrapper) it will
+ // overwrite the link register.
+ } else if false && cnt <= int64(128*gc.Widthptr) {
p = appendpp(p, ppc64.AADD, obj.TYPE_CONST, 0, 8+frame+lo-8, obj.TYPE_REG, ppc64.REGRT1, 0)
p.Reg = ppc64.REGSP
p = appendpp(p, obj.ADUFFZERO, obj.TYPE_NONE, 0, 0, obj.TYPE_MEM, 0, 0)
@@ -442,7 +445,10 @@
// The loop leaves R3 on the last zeroed dword
boff = 8
- } else if q >= 4 {
+ // TODO(dfc): https://golang.org/issue/12108
+ // If DUFFZERO is used inside a tail call (see genwrapper) it will
+ // overwrite the link register.
+ } else if false && q >= 4 {
p := gins(ppc64.ASUB, nil, &dst)
p.From.Type = obj.TYPE_CONST
p.From.Offset = 8
