[turbofan] Combine additional Word32And with Int32Add and negative power of two.

- (y << L + x) & (-1 << L) => (x & (-1 << L)) + y << L
- (x + y << L) & (-1 << L) => (x & (-1 << L)) + y << L

TEST=unittests
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/758603003

Cr-Commit-Position: refs/heads/master@{#25627}

src/compiler/machine-operator-reducer.cc

@@ -779,13 +779,37 @@ Reduction MachineOperatorReducer::ReduceWord32And(Node* node) {
     Int32BinopMatcher mleft(m.left().node());
     if (mleft.right().HasValue() &&
         (mleft.right().Value() & m.right().Value()) == mleft.right().Value()) {
-      // (x + K) & K => (x & K) + K
+      // (x + (K << L)) & (-1 << L) => (x & (-1 << L)) + (K << L)
       return Replace(graph()->NewNode(
           machine()->Int32Add(),
           graph()->NewNode(machine()->Word32And(), mleft.left().node(),
                            m.right().node()),
           mleft.right().node()));
     }
+    if (mleft.left().IsWord32Shl()) {
+      Int32BinopMatcher mleftleft(mleft.left().node());
+      if (mleftleft.right().Is(
+              base::bits::CountTrailingZeros32(m.right().Value()))) {
+        // (y << L + x) & (-1 << L) => (x & (-1 << L)) + y << L
+        return Replace(graph()->NewNode(
+            machine()->Int32Add(),
+            graph()->NewNode(machine()->Word32And(), mleft.right().node(),
+                             m.right().node()),
+            mleftleft.node()));
+      }
+    }
+    if (mleft.right().IsWord32Shl()) {
+      Int32BinopMatcher mleftright(mleft.right().node());
+      if (mleftright.right().Is(
+              base::bits::CountTrailingZeros32(m.right().Value()))) {
+        // (x + y << L) & (-1 << L) => (x & (-1 << L)) + y << L
+        return Replace(graph()->NewNode(
+            machine()->Int32Add(),
+            graph()->NewNode(machine()->Word32And(), mleft.left().node(),
+                             m.right().node()),
+            mleftright.node()));
+      }
+    }
   }
   return NoChange();
 }

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

@@ -532,9 +532,10 @@ TEST_F(MachineOperatorReducerTest, Word32AndWithWord32AndWithConstant) {
 
 TEST_F(MachineOperatorReducerTest, Word32AndWithInt32AddAndConstant) {
   Node* const p0 = Parameter(0);
+  Node* const p1 = Parameter(1);
 
-  TRACED_FOREACH(int32_t, k, kInt32Values) {
-    TRACED_FORRANGE(int32_t, l, 1, 31) {
+  TRACED_FORRANGE(int32_t, l, 1, 31) {
+    TRACED_FOREACH(int32_t, k, kInt32Values) {
       // (x + (K << L)) & (-1 << L) => (x & (-1 << L)) + (K << L)
       Reduction const r = Reduce(graph()->NewNode(
           machine()->Word32And(),
@@ -545,6 +546,24 @@ TEST_F(MachineOperatorReducerTest, Word32AndWithInt32AddAndConstant) {
                   IsInt32Add(IsWord32And(p0, IsInt32Constant(-1 << l)),
                              IsInt32Constant(k << l)));
     }
+
+    Node* s1 = graph()->NewNode(machine()->Word32Shl(), p1, Int32Constant(l));
+
+    // (y << L + x) & (-1 << L) => (x & (-1 << L)) + y << L
+    Reduction const r1 = Reduce(graph()->NewNode(
+        machine()->Word32And(), graph()->NewNode(machine()->Int32Add(), s1, p0),
+        Int32Constant(-1 << l)));
+    ASSERT_TRUE(r1.Changed());
+    EXPECT_THAT(r1.replacement(),
+                IsInt32Add(IsWord32And(p0, IsInt32Constant(-1 << l)), s1));
+
+    // (x + y << L) & (-1 << L) => (x & (-1 << L)) + y << L
+    Reduction const r2 = Reduce(graph()->NewNode(
+        machine()->Word32And(), graph()->NewNode(machine()->Int32Add(), p0, s1),
+        Int32Constant(-1 << l)));
+    ASSERT_TRUE(r2.Changed());
+    EXPECT_THAT(r2.replacement(),
+                IsInt32Add(IsWord32And(p0, IsInt32Constant(-1 << l)), s1));
   }
 }