[turbofan] Avoid useless bit masking in typed lowering.

test/unittests/compiler/js-typed-lowering-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/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node-properties-inl.h"
@@ skipping 91 matching lines @@
       context, effect, control));
   ASSERT_TRUE(r.Changed());
   EXPECT_THAT(
       r.replacement(),
       IsPhi(kMachAnyTagged,
             IsBooleanNot(IsNumberEqual(p0, IsNumberConstant(0))), p1, control));
 }
 
 
 // -----------------------------------------------------------------------------
+// JSShiftLeft
+
+
+TEST_F(JSTypedLoweringTest, JSShiftLeftWithSigned32AndConstant) {
+  Node* const lhs = Parameter(Type::Signed32());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  TRACED_FORRANGE(int32_t, rhs, 0, 31) {
+    Reduction r =
+        Reduce(graph()->NewNode(javascript()->ShiftLeft(), lhs,
+                                NumberConstant(rhs), context, effect, control));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsWord32Shl(lhs, IsNumberConstant(rhs)));
+  }
+}
+
+
+TEST_F(JSTypedLoweringTest, JSShiftLeftWithSigned32AndUnsigned32) {
+  Node* const lhs = Parameter(Type::Signed32());
+  Node* const rhs = Parameter(Type::Unsigned32());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  Reduction r = Reduce(graph()->NewNode(javascript()->ShiftLeft(), lhs, rhs,
+                                        context, effect, control));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(),
+              IsWord32Shl(lhs, IsWord32And(rhs, IsInt32Constant(0x1f))));
+}
+
+
+// -----------------------------------------------------------------------------
+// JSShiftRight
+
+
+TEST_F(JSTypedLoweringTest, JSShiftRightWithSigned32AndConstant) {
+  Node* const lhs = Parameter(Type::Signed32());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  TRACED_FORRANGE(int32_t, rhs, 0, 31) {
+    Reduction r =
+        Reduce(graph()->NewNode(javascript()->ShiftRight(), lhs,
+                                NumberConstant(rhs), context, effect, control));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsWord32Sar(lhs, IsNumberConstant(rhs)));
+  }
+}
+
+
+TEST_F(JSTypedLoweringTest, JSShiftRightWithSigned32AndUnsigned32) {
+  Node* const lhs = Parameter(Type::Signed32());
+  Node* const rhs = Parameter(Type::Unsigned32());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  Reduction r = Reduce(graph()->NewNode(javascript()->ShiftRight(), lhs, rhs,
+                                        context, effect, control));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(),
+              IsWord32Sar(lhs, IsWord32And(rhs, IsInt32Constant(0x1f))));
+}
+
+
+// -----------------------------------------------------------------------------
+// JSShiftRightLogical
+
+
+TEST_F(JSTypedLoweringTest, JSShiftRightLogicalWithUnsigned32AndConstant) {
+  Node* const lhs = Parameter(Type::Unsigned32());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  TRACED_FORRANGE(int32_t, rhs, 0, 31) {
+    Reduction r =
+        Reduce(graph()->NewNode(javascript()->ShiftRightLogical(), lhs,
+                                NumberConstant(rhs), context, effect, control));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsWord32Shr(lhs, IsNumberConstant(rhs)));
+  }
+}
+
+
+TEST_F(JSTypedLoweringTest, JSShiftRightLogicalWithUnsigned32AndUnsigned32) {
+  Node* const lhs = Parameter(Type::Unsigned32());
+  Node* const rhs = Parameter(Type::Unsigned32());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  Reduction r = Reduce(graph()->NewNode(javascript()->ShiftRightLogical(), lhs,
+                                        rhs, context, effect, control));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(),
+              IsWord32Shr(lhs, IsWord32And(rhs, IsInt32Constant(0x1f))));
+}
+
+
+// -----------------------------------------------------------------------------
 // JSLoadProperty
 
 
 TEST_F(JSTypedLoweringTest, JSLoadPropertyFromExternalTypedArray) {
   const size_t kLength = 17;
   double backing_store[kLength];
   Handle<JSArrayBuffer> buffer =
       NewArrayBuffer(backing_store, sizeof(backing_store));
   VectorSlotPair feedback(Handle<TypeFeedbackVector>::null(),
                           FeedbackVectorICSlot::Invalid());
@@ skipping 61 matching lines @@
                       IsIntPtrConstant(bit_cast<intptr_t>(&backing_store[0])),
                       key, IsNumberConstant(array->length()->Number()), value,
                       effect, control));
     }
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8