diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index 587bb7e2fb..f1447009da 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -3417,9 +3417,17 @@ func (s *state) rtcall(fn *obj.LSym, returns bool, results []*Type, args ...*ssa
 
 // do *left = right for type t.
 func (s *state) storeType(t *Type, left, right *ssa.Value, skip skipMask) {
+	if skip == 0 && (!haspointers(t) || ssa.IsStackAddr(left)) {
+		// Known to not have write barrier. Store the whole type.
+		s.vars[&memVar] = s.newValue3A(ssa.OpStore, ssa.TypeMem, t, left, right, s.mem())
+		return
+	}
+
 	// store scalar fields first, so write barrier stores for
 	// pointer fields can be grouped together, and scalar values
 	// don't need to be live across the write barrier call.
+	// TODO: if the writebarrier pass knows how to reorder stores,
+	// we can do a single store here as long as skip==0.
 	s.storeTypeScalars(t, left, right, skip)
 	if skip&skipPtr == 0 && haspointers(t) {
 		s.storeTypePtrs(t, left, right)
diff --git a/src/cmd/compile/internal/ssa/writebarrier.go b/src/cmd/compile/internal/ssa/writebarrier.go
index 3447540309..43349bfaf5 100644
--- a/src/cmd/compile/internal/ssa/writebarrier.go
+++ b/src/cmd/compile/internal/ssa/writebarrier.go
@@ -19,7 +19,7 @@ func needwb(v *Value) bool {
 	if !t.HasPointer() {
 		return false
 	}
-	if isStackAddr(v.Args[0]) {
+	if IsStackAddr(v.Args[0]) {
 		return false // write on stack doesn't need write barrier
 	}
 	return true
@@ -316,8 +316,8 @@ func round(o int64, r int64) int64 {
 	return (o + r - 1) &^ (r - 1)
 }
 
-// isStackAddr returns whether v is known to be an address of a stack slot
-func isStackAddr(v *Value) bool {
+// IsStackAddr returns whether v is known to be an address of a stack slot
+func IsStackAddr(v *Value) bool {
 	for v.Op == OpOffPtr || v.Op == OpAddPtr || v.Op == OpPtrIndex || v.Op == OpCopy {
 		v = v.Args[0]
 	}