[turbofan] Reduce Word32And masking with shifted inputs.

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

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator-reducer.h"
 #include "src/compiler/typer.h"
 #include "test/unittests/compiler/graph-unittest.h"
@@ skipping 483 matching lines @@
                 IsInt32Constant(bit_cast<int32_t>(
                     static_cast<uint32_t>(bit_cast<uint64_t>(x)))));
   }
 }
 
 
 // -----------------------------------------------------------------------------
 // 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);
 
   TRACED_FOREACH(int32_t, k, kInt32Values) {
     TRACED_FOREACH(int32_t, l, kInt32Values) {
       if (k == 0 || k == -1 || l == 0 || l == -1) continue;
 
       // (x & K) & L => x & (K & L)
       Reduction const r1 = Reduce(graph()->NewNode(
           machine()->Word32And(),
@@ skipping 879 matching lines @@
     Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
     EXPECT_THAT(r.replacement(),
                 IsStore(rep, base, index, value, effect, control));
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8