Merge (x & y) == 0 pattern to emit a single test instruction.

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 147 matching lines @@
 bool IfThenElseInstr::IsSupported() {
   return true;
 }
 
 
 bool IfThenElseInstr::Supports(ComparisonInstr* comparison,
                                Value* v1,
                                Value* v2) {
   if (!(comparison->IsStrictCompare() &&
         !comparison->AsStrictCompare()->needs_number_check()) &&
-      !(comparison->IsEqualityCompare() &&
-        (comparison->AsEqualityCompare()->receiver_class_id() == kSmiCid))) {
+      !comparison->IsSmiEquality()) {
     return false;
   }
 
   intptr_t v1_value, v2_value;
 
   if (!BindsToSmiConstant(v1, &v1_value) ||
       !BindsToSmiConstant(v2, &v2_value)) {
     return false;
   }
 
@@ skipping 731 matching lines @@
                              *ic_data());
   if (branch->is_checked()) {
     EmitAssertBoolean(RAX, token_pos(), deopt_id(), locs(), compiler);
   }
   Condition branch_condition = (kind() == Token::kNE) ? NOT_EQUAL : EQUAL;
   __ CompareObject(RAX, Bool::True());
   branch->EmitBranchOnCondition(compiler, branch_condition);
 }
 
 
+LocationSummary* TestSmiInstr::MakeLocationSummary() const {
+  const intptr_t kNumInputs = 2;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* locs =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  locs->set_in(0, Location::RequiresRegister());
+  // Only one input can be a constant operand. The case of two constant
+  // operands should be handled by constant propagation.
+  locs->set_in(1, Location::RegisterOrConstant(right()));
+  return locs;
+}
+
+
+void TestSmiInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  // Never emitted outside of the BranchInstr.
+  UNREACHABLE();
+}
+
+
+void TestSmiInstr::EmitBranchCode(FlowGraphCompiler* compiler,
+                                  BranchInstr* branch) {
+  Condition branch_condition = (kind() == Token::kNE) ? NOT_ZERO : ZERO;
+  Location right = locs()->in(1);
+  if (right.IsConstant()) {
+    ASSERT(right.constant().IsSmi());
+    const int64_t imm =
+        reinterpret_cast<int64_t>(right.constant().raw());
+    __ testq(locs()->in(0).reg(), Immediate(imm));
+  } else {
+    __ testq(locs()->in(0).reg(), right.reg());
+  }
+  branch->EmitBranchOnCondition(compiler, branch_condition);
+}
+
+
 LocationSummary* RelationalOpInstr::MakeLocationSummary() const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
   if (operands_class_id() == kDoubleCid) {
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     summary->set_in(0, Location::RequiresFpuRegister());
     summary->set_in(1, Location::RequiresFpuRegister());
     summary->set_out(Location::RequiresRegister());
     return summary;
@@ skipping 2649 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64