[turbofan] Reduce Word32And masking with shifted inputs.

test/unittests/compiler/machine-operator-reducer-unittest.cc

Index: test/unittests/compiler/machine-operator-reducer-unittest.cc
diff --git a/test/unittests/compiler/machine-operator-reducer-unittest.cc b/test/unittests/compiler/machine-operator-reducer-unittest.cc
index 41e69f0a833532647e0b024e5e9467fb5ce180a7..3037ff7307871341a73c60d43c1223ca374d1a39 100644
--- a/test/unittests/compiler/machine-operator-reducer-unittest.cc
+++ b/test/unittests/compiler/machine-operator-reducer-unittest.cc
@@ -501,6 +501,30 @@ TEST_F(MachineOperatorReducerTest, TruncateInt64ToInt32WithConstant) {
 // Word32And
 
 
+TEST_F(MachineOperatorReducerTest, Word32AndWithWord32ShlWithConstant) {
+  Node* const p0 = Parameter(0);
+
+  TRACED_FORRANGE(int32_t, l, 1, 31) {
+    TRACED_FORRANGE(int32_t, k, 1, l) {
+      // (x << L) & (-1 << K) => x << L
+      Reduction const r1 = Reduce(graph()->NewNode(
+          machine()->Word32And(),
+          graph()->NewNode(machine()->Word32Shl(), p0, Int32Constant(l)),
+          Int32Constant(-1 << k)));
+      ASSERT_TRUE(r1.Changed());
+      EXPECT_THAT(r1.replacement(), IsWord32Shl(p0, IsInt32Constant(l)));
+
+      // (-1 << K) & (x << L) => x << L
+      Reduction const r2 = Reduce(graph()->NewNode(
+          machine()->Word32And(), Int32Constant(-1 << k),
+          graph()->NewNode(machine()->Word32Shl(), p0, Int32Constant(l))));
+      ASSERT_TRUE(r2.Changed());
+      EXPECT_THAT(r2.replacement(), IsWord32Shl(p0, IsInt32Constant(l)));
+    }
+  }
+}
+
+
 TEST_F(MachineOperatorReducerTest, Word32AndWithWord32AndWithConstant) {
   Node* const p0 = Parameter(0);