[arm] Recognize comparisons of shifts with zero.

test/compiler-unittests/arm/instruction-selector-arm-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 "test/compiler-unittests/instruction-selector-unittest.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
@@ skipping 1076 matching lines @@
     EXPECT_EQ(shift.i_mode, s[0]->addressing_mode());
     ASSERT_EQ(3U, s[0]->InputCount());
     EXPECT_EQ(imm, s.ToInt32(s[0]->InputAt(2)));
     EXPECT_EQ(1U, s[0]->OutputCount());
     EXPECT_EQ(kFlags_set, s[0]->flags_mode());
     EXPECT_EQ(kEqual, s[0]->flags_condition());
   }
 }
 
 
+TEST_P(ShiftTest, Word32EqualToZeroWithParameters) {
+  const Shift shift = GetParam();
+  StreamBuilder m(this, kMachInt32, kMachInt32, kMachInt32);
+  m.Return(
+      m.Word32Equal(m.Int32Constant(0),
+                    (m.*shift.constructor)(m.Parameter(0), m.Parameter(1))));
+  Stream s = m.Build();
+  ASSERT_EQ(1U, s.size());
+  EXPECT_EQ(kArmMov, s[0]->arch_opcode());
+  EXPECT_EQ(shift.r_mode, s[0]->addressing_mode());
+  EXPECT_EQ(2U, s[0]->InputCount());
+  EXPECT_EQ(2U, s[0]->OutputCount());
+  EXPECT_EQ(kFlags_set, s[0]->flags_mode());
+  EXPECT_EQ(kEqual, s[0]->flags_condition());
+}
+
+
+TEST_P(ShiftTest, Word32EqualToZeroWithImmediate) {
+  const Shift shift = GetParam();
+  TRACED_FORRANGE(int32_t, imm, shift.i_low, shift.i_high) {
+    StreamBuilder m(this, kMachInt32, kMachInt32, kMachInt32);
+    m.Return(m.Word32Equal(
+        m.Int32Constant(0),
+        (m.*shift.constructor)(m.Parameter(0), m.Int32Constant(imm))));
+    Stream s = m.Build();
+    ASSERT_EQ(1U, s.size());
+    EXPECT_EQ(kArmMov, s[0]->arch_opcode());
+    EXPECT_EQ(shift.i_mode, s[0]->addressing_mode());
+    ASSERT_EQ(2U, s[0]->InputCount());
+    EXPECT_EQ(imm, s.ToInt32(s[0]->InputAt(1)));
+    EXPECT_EQ(2U, s[0]->OutputCount());
+    EXPECT_EQ(kFlags_set, s[0]->flags_mode());
+    EXPECT_EQ(kEqual, s[0]->flags_condition());
+  }
+}
+
+
 TEST_P(ShiftTest, Word32NotWithParameters) {
   const Shift shift = GetParam();
   StreamBuilder m(this, kMachInt32, kMachInt32, kMachInt32);
   m.Return(m.Word32Not((m.*shift.constructor)(m.Parameter(0), m.Parameter(1))));
   Stream s = m.Build();
   ASSERT_EQ(1U, s.size());
   EXPECT_EQ(kArmMvn, s[0]->arch_opcode());
   EXPECT_EQ(shift.r_mode, s[0]->addressing_mode());
   EXPECT_EQ(2U, s[0]->InputCount());
   EXPECT_EQ(1U, s[0]->OutputCount());
@@ skipping 610 matching lines @@
       ASSERT_EQ(3U, s[0]->InputCount());
       EXPECT_EQ(lsb, s.ToInt32(s[0]->InputAt(1)));
       EXPECT_EQ(width, s.ToInt32(s[0]->InputAt(2)));
     }
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8