1 files changed, 56 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/writebarrier_test.go b/src/cmd/compile/internal/ssa/writebarrier_test.go
new file mode 100644
index 0000000..0b11afc
--- /dev/null
+++ b/src/cmd/compile/internal/ssa/writebarrier_test.go
@@ -0,0 +1,56 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssa
+
+import (
+	"cmd/compile/internal/types"
+	"testing"
+)
+
+func TestWriteBarrierStoreOrder(t *testing.T) {
+	// Make sure writebarrier phase works even StoreWB ops are not in dependency order
+	c := testConfig(t)
+	ptrType := c.config.Types.BytePtr
+	fun := c.Fun("entry",
+		Bloc("entry",
+			Valu("start", OpInitMem, types.TypeMem, 0, nil),
+			Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
+			Valu("sp", OpSP, c.config.Types.Uintptr, 0, nil),
+			Valu("v", OpConstNil, ptrType, 0, nil),
+			Valu("addr1", OpAddr, ptrType, 0, nil, "sb"),
+			Valu("wb2", OpStore, types.TypeMem, 0, ptrType, "addr1", "v", "wb1"),
+			Valu("wb1", OpStore, types.TypeMem, 0, ptrType, "addr1", "v", "start"), // wb1 and wb2 are out of order
+			Goto("exit")),
+		Bloc("exit",
+			Exit("wb2")))
+
+	CheckFunc(fun.f)
+	writebarrier(fun.f)
+	CheckFunc(fun.f)
+}
+
+func TestWriteBarrierPhi(t *testing.T) {
+	// Make sure writebarrier phase works for single-block loop, where
+	// a Phi op takes the store in the same block as argument.
+	// See issue #19067.
+	c := testConfig(t)
+	ptrType := c.config.Types.BytePtr
+	fun := c.Fun("entry",
+		Bloc("entry",
+			Valu("start", OpInitMem, types.TypeMem, 0, nil),
+			Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
+			Valu("sp", OpSP, c.config.Types.Uintptr, 0, nil),
+			Goto("loop")),
+		Bloc("loop",
+			Valu("phi", OpPhi, types.TypeMem, 0, nil, "start", "wb"),
+			Valu("v", OpConstNil, ptrType, 0, nil),
+			Valu("addr", OpAddr, ptrType, 0, nil, "sb"),
+			Valu("wb", OpStore, types.TypeMem, 0, ptrType, "addr", "v", "phi"), // has write barrier
+			Goto("loop")))
+
+	CheckFunc(fun.f)
+	writebarrier(fun.f)
+	CheckFunc(fun.f)
+}