Refactor to support multiple outputs in location summary

runtime/vm/intermediate_language_mips.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_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 11 matching lines @@
 namespace dart {
 
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(bool, propagate_ic_data);
 DECLARE_FLAG(bool, use_osr);
 
 // Generic summary for call instructions that have all arguments pushed
 // on the stack and return the result in a fixed register V0.
 LocationSummary* Instruction::MakeCallSummary() {
   LocationSummary* result = new LocationSummary(0, 0, LocationSummary::kCall);
-  result->set_out(Location::RegisterLocation(V0));
+  result->set_out(0, Location::RegisterLocation(V0));
   return result;
 }
 
 
 LocationSummary* PushArgumentInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps= 0;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   locs->set_in(0, Location::AnyOrConstant(value()));
@@ skipping 79 matching lines @@
 }
 
 
 LocationSummary* IfThenElseInstr::MakeLocationSummary(bool opt) const {
   comparison()->InitializeLocationSummary(opt);
   return comparison()->locs();
 }
 
 
 void IfThenElseInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  const Register result = locs()->out().reg();
+  const Register result = locs()->out(0).reg();
 
   Location left = locs()->in(0);
   Location right = locs()->in(1);
   ASSERT(!left.IsConstant() || !right.IsConstant());
 
   // Clear out register.
   __ mov(result, ZR);
 
   // Emit comparison code. This must not overwrite the result register.
   BranchLabels labels = { NULL, NULL, NULL };
@@ skipping 59 matching lines @@
     }
   }
 }
 
 
 LocationSummary* ClosureCallInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 0;
   const intptr_t kNumTemps = 1;
   LocationSummary* result =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
-  result->set_out(Location::RegisterLocation(V0));
+  result->set_out(0, Location::RegisterLocation(V0));
   result->set_temp(0, Location::RegisterLocation(S4));  // Arg. descriptor.
   return result;
 }
 
 
 void ClosureCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   // The arguments to the stub include the closure, as does the arguments
   // descriptor.
   Register temp_reg = locs()->temp(0).reg();
   int argument_count = ArgumentCount();
@@ skipping 13 matching lines @@
 
 LocationSummary* LoadLocalInstr::MakeLocationSummary(bool opt) const {
   return LocationSummary::Make(0,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void LoadLocalInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("LoadLocalInstr");
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   __ lw(result, Address(FP, local().index() * kWordSize));
 }
 
 
 LocationSummary* StoreLocalInstr::MakeLocationSummary(bool opt) const {
   return LocationSummary::Make(1,
                                Location::SameAsFirstInput(),
                                LocationSummary::kNoCall);
 }
 
 
 void StoreLocalInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("StoreLocalInstr");
   Register value = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   ASSERT(result == value);  // Assert that register assignment is correct.
   __ sw(value, Address(FP, local().index() * kWordSize));
 }
 
 
 LocationSummary* ConstantInstr::MakeLocationSummary(bool opt) const {
   return LocationSummary::Make(0,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void ConstantInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   // The register allocator drops constant definitions that have no uses.
-  if (!locs()->out().IsInvalid()) {
+  if (!locs()->out(0).IsInvalid()) {
     __ TraceSimMsg("ConstantInstr");
-    Register result = locs()->out().reg();
+    Register result = locs()->out(0).reg();
     __ LoadObject(result, value());
   }
 }
 
 
 LocationSummary* AssertAssignableInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 3;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   summary->set_in(0, Location::RegisterLocation(A0));  // Value.
   summary->set_in(1, Location::RegisterLocation(A2));  // Instantiator.
   summary->set_in(2, Location::RegisterLocation(A1));  // Type arguments.
-  summary->set_out(Location::RegisterLocation(A0));
+  summary->set_out(0, Location::RegisterLocation(A0));
   return summary;
 }
 
 
 LocationSummary* AssertBooleanInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   locs->set_in(0, Location::RegisterLocation(A0));
-  locs->set_out(Location::RegisterLocation(A0));
+  locs->set_out(0, Location::RegisterLocation(A0));
   return locs;
 }
 
 
 static void EmitAssertBoolean(Register reg,
                               intptr_t token_pos,
                               intptr_t deopt_id,
                               LocationSummary* locs,
                               FlowGraphCompiler* compiler) {
   // Check that the type of the value is allowed in conditional context.
@@ skipping 10 matching lines @@
                                 1,
                                 locs);
   // We should never return here.
   __ break_(0);
   __ Bind(&done);
 }
 
 
 void AssertBooleanInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register obj = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
 
   __ TraceSimMsg("AssertBooleanInstr");
   EmitAssertBoolean(obj, token_pos(), deopt_id(), locs(), compiler);
   ASSERT(obj == result);
 }
 
 
 LocationSummary* EqualityCompareInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 2;
   if (operation_cid() == kMintCid) {
     const intptr_t kNumTemps = 1;
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     locs->set_in(0, Location::RequiresFpuRegister());
     locs->set_in(1, Location::RequiresFpuRegister());
     locs->set_temp(0, Location::RequiresRegister());
-    locs->set_out(Location::RequiresRegister());
+    locs->set_out(0, Location::RequiresRegister());
     return locs;
   }
   if (operation_cid() == kDoubleCid) {
     const intptr_t kNumTemps = 0;
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     locs->set_in(0, Location::RequiresFpuRegister());
     locs->set_in(1, Location::RequiresFpuRegister());
-    locs->set_out(Location::RequiresRegister());
+    locs->set_out(0, Location::RequiresRegister());
     return locs;
   }
   if (operation_cid() == kSmiCid) {
     const intptr_t kNumTemps = 0;
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     locs->set_in(0, Location::RegisterOrConstant(left()));
     // Only one input can be a constant operand. The case of two constant
     // operands should be handled by constant propagation.
     locs->set_in(1, locs->in(0).IsConstant()
                         ? Location::RequiresRegister()
                         : Location::RegisterOrConstant(right()));
-    locs->set_out(Location::RequiresRegister());
+    locs->set_out(0, Location::RequiresRegister());
     return locs;
   }
   UNREACHABLE();
   return NULL;
 }
 
 
 static void LoadValueCid(FlowGraphCompiler* compiler,
                          Register value_cid_reg,
                          Register value_reg,
@@ skipping 177 matching lines @@
 
 void EqualityCompareInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT((kind() == Token::kNE) || (kind() == Token::kEQ));
   __ Comment("EqualityCompareInstr");
 
   Label is_true, is_false;
   BranchLabels labels = { &is_true, &is_false, &is_false };
   Condition true_condition = EmitComparisonCode(compiler, labels);
   EmitBranchOnCondition(compiler, true_condition, labels);
 
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   Label done;
   __ Bind(&is_false);
   __ LoadObject(result, Bool::False());
   __ b(&done);
   __ Bind(&is_true);
   __ LoadObject(result, Bool::True());
   __ Bind(&done);
 }
 
 
@@ skipping 58 matching lines @@
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
   if (operation_cid() == kMintCid) {
     const intptr_t kNumTemps = 2;
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     locs->set_in(0, Location::RequiresFpuRegister());
     locs->set_in(1, Location::RequiresFpuRegister());
     locs->set_temp(0, Location::RequiresRegister());
     locs->set_temp(1, Location::RequiresRegister());
-    locs->set_out(Location::RequiresRegister());
+    locs->set_out(0, Location::RequiresRegister());
     return locs;
   }
   if (operation_cid() == 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());
+    summary->set_out(0, Location::RequiresRegister());
     return summary;
   }
   ASSERT(operation_cid() == kSmiCid);
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RegisterOrConstant(left()));
   // Only one input can be a constant operand. The case of two constant
   // operands should be handled by constant propagation.
   summary->set_in(1, summary->in(0).IsConstant()
                          ? Location::RequiresRegister()
                          : Location::RegisterOrConstant(right()));
-  summary->set_out(Location::RequiresRegister());
+  summary->set_out(0, Location::RequiresRegister());
   return summary;
 }
 
 
 Condition RelationalOpInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                                 BranchLabels labels) {
   if (operation_cid() == kSmiCid) {
     return EmitSmiComparisonOp(compiler, *locs(), kind(), labels);
   } else {
     ASSERT(operation_cid() == kDoubleCid);
     return EmitDoubleComparisonOp(compiler, *locs(), kind(), labels);
   }
 }
 
 
 void RelationalOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("RelationalOpInstr");
 
   Label is_true, is_false;
   BranchLabels labels = { &is_true, &is_false, &is_false };
   Condition true_condition = EmitComparisonCode(compiler, labels);
   EmitBranchOnCondition(compiler, true_condition, labels);
 
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   Label done;
   __ Bind(&is_false);
   __ LoadObject(result, Bool::False());
   __ b(&done);
   __ Bind(&is_true);
   __ LoadObject(result, Bool::True());
   __ Bind(&done);
 }
 
 
 void RelationalOpInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                        BranchInstr* branch) {
   __ TraceSimMsg("RelationalOpInstr");
 
   BranchLabels labels = compiler->CreateBranchLabels(branch);
   Condition true_condition = EmitComparisonCode(compiler, labels);
   EmitBranchOnCondition(compiler, true_condition, labels);
 }
 
 
 LocationSummary* NativeCallInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 0;
   const intptr_t kNumTemps = 3;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   locs->set_temp(0, Location::RegisterLocation(A1));
   locs->set_temp(1, Location::RegisterLocation(A2));
   locs->set_temp(2, Location::RegisterLocation(T5));
-  locs->set_out(Location::RegisterLocation(V0));
+  locs->set_out(0, Location::RegisterLocation(V0));
   return locs;
 }
 
 
 void NativeCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("NativeCallInstr");
   ASSERT(locs()->temp(0).reg() == A1);
   ASSERT(locs()->temp(1).reg() == A2);
   ASSERT(locs()->temp(2).reg() == T5);
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
 
   // Push the result place holder initialized to NULL.
   __ PushObject(Object::ZoneHandle());
   // Pass a pointer to the first argument in A2.
   if (!function().HasOptionalParameters()) {
     __ AddImmediate(A2, FP, (kParamEndSlotFromFp +
                              function().NumParameters()) * kWordSize);
   } else {
     __ AddImmediate(A2, FP, kFirstLocalSlotFromFp * kWordSize);
   }
@@ skipping 34 matching lines @@
   const intptr_t kNumInputs = 1;
   // TODO(fschneider): Allow immediate operands for the char code.
   return LocationSummary::Make(kNumInputs,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void StringFromCharCodeInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register char_code = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
 
   __ TraceSimMsg("StringFromCharCodeInstr");
 
   __ LoadImmediate(result,
                    reinterpret_cast<uword>(Symbols::PredefinedAddress()));
   __ AddImmediate(result, Symbols::kNullCharCodeSymbolOffset * kWordSize);
   __ sll(TMP, char_code, 1);  // Char code is a smi.
   __ addu(TMP, TMP, result);
   __ lw(result, Address(TMP));
 }
 
 
 LocationSummary* StringToCharCodeInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   return LocationSummary::Make(kNumInputs,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void StringToCharCodeInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("StringToCharCodeInstr");
 
   ASSERT(cid_ == kOneByteStringCid);
   Register str = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   Label done, is_one;
   __ lw(result, FieldAddress(str, String::length_offset()));
   __ BranchEqual(result, Smi::RawValue(1), &is_one);
   __ LoadImmediate(result, Smi::RawValue(-1));
   __ b(&done);
   __ Bind(&is_one);
   __ lbu(result, FieldAddress(str, OneByteString::data_offset()));
   __ SmiTag(result);
   __ Bind(&done);
 }
 
 
 LocationSummary* StringInterpolateInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   summary->set_in(0, Location::RegisterLocation(A0));
-  summary->set_out(Location::RegisterLocation(V0));
+  summary->set_out(0, Location::RegisterLocation(V0));
   return summary;
 }
 
 
 void StringInterpolateInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register array = locs()->in(0).reg();
   __ Push(array);
   const int kNumberOfArguments = 1;
   const Array& kNoArgumentNames = Object::null_array();
   compiler->GenerateStaticCall(deopt_id(),
                                token_pos(),
                                CallFunction(),
                                kNumberOfArguments,
                                kNoArgumentNames,
                                locs());
-  ASSERT(locs()->out().reg() == V0);
+  ASSERT(locs()->out(0).reg() == V0);
 }
 
 
 LocationSummary* LoadUntaggedInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   return LocationSummary::Make(kNumInputs,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void LoadUntaggedInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register object = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   __ LoadFromOffset(result, object, offset() - kHeapObjectTag);
 }
 
 
 LocationSummary* LoadClassIdInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   return LocationSummary::Make(kNumInputs,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void LoadClassIdInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register object = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   Label load, done;
   __ andi(CMPRES1, object, Immediate(kSmiTagMask));
   __ bne(CMPRES1, ZR, &load);
   __ LoadImmediate(result, Smi::RawValue(kSmiCid));
   __ b(&done);
   __ Bind(&load);
   __ LoadClassId(result, object);
   __ SmiTag(result);
   __ Bind(&done);
 }
@@ skipping 78 matching lines @@
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   locs->set_in(0, Location::RequiresRegister());
   // The smi index is either untagged (element size == 1), or it is left smi
   // tagged (for all element sizes > 1).
   // TODO(regis): Revisit and see if the index can be immediate.
   locs->set_in(1, Location::WritableRegister());
   if ((representation() == kUnboxedDouble) ||
       (representation() == kUnboxedFloat32x4) ||
       (representation() == kUnboxedInt32x4)) {
-    locs->set_out(Location::RequiresFpuRegister());
+    locs->set_out(0, Location::RequiresFpuRegister());
   } else {
-    locs->set_out(Location::RequiresRegister());
+    locs->set_out(0, Location::RequiresRegister());
   }
   return locs;
 }
 
 
 void LoadIndexedInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("LoadIndexedInstr");
   Register array = locs()->in(0).reg();
   Location index = locs()->in(1);
 
@@ skipping 37 matching lines @@
     // mode, then we must load the offset into a register and add it to the
     // index.
     element_address = Address(index.reg(),
         FlowGraphCompiler::DataOffsetFor(class_id()) - kHeapObjectTag);
   }
 
   if ((representation() == kUnboxedDouble) ||
       (representation() == kUnboxedMint) ||
       (representation() == kUnboxedFloat32x4) ||
       (representation() == kUnboxedInt32x4)) {
-    DRegister result = locs()->out().fpu_reg();
+    DRegister result = locs()->out(0).fpu_reg();
     switch (class_id()) {
       case kTypedDataInt32ArrayCid:
         UNIMPLEMENTED();
         break;
       case kTypedDataUint32ArrayCid:
         UNIMPLEMENTED();
         break;
       case kTypedDataFloat32ArrayCid:
         // Load single precision float.
         __ lwc1(EvenFRegisterOf(result), element_address);
         break;
       case kTypedDataFloat64ArrayCid:
         __ LoadDFromOffset(result, index.reg(),
             FlowGraphCompiler::DataOffsetFor(class_id()) - kHeapObjectTag);
         break;
       case kTypedDataInt32x4ArrayCid:
       case kTypedDataFloat32x4ArrayCid:
         UNIMPLEMENTED();
         break;
     }
     return;
   }
 
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   switch (class_id()) {
     case kTypedDataInt8ArrayCid:
       ASSERT(index_scale() == 1);
       __ lb(result, element_address);
       __ SmiTag(result);
       break;
     case kTypedDataUint8ArrayCid:
     case kTypedDataUint8ClampedArrayCid:
     case kExternalTypedDataUint8ArrayCid:
     case kExternalTypedDataUint8ClampedArrayCid:
@@ skipping 589 matching lines @@
       : instruction_(instruction), cls_(cls) { }
 
   virtual void EmitNativeCode(FlowGraphCompiler* compiler) {
     __ Comment("StoreInstanceFieldSlowPath");
     __ Bind(entry_label());
     const Code& stub =
         Code::Handle(StubCode::GetAllocationStubForClass(cls_));
     const ExternalLabel label(cls_.ToCString(), stub.EntryPoint());
 
     LocationSummary* locs = instruction_->locs();
-    locs->live_registers()->Remove(locs->out());
+    locs->live_registers()->Remove(locs->out(0));
 
     compiler->SaveLiveRegisters(locs);
     compiler->GenerateCall(Scanner::kNoSourcePos,  // No token position.
                            &label,
                            PcDescriptors::kOther,
                            locs);
     __ mov(locs->temp(0).reg(), V0);
     compiler->RestoreLiveRegisters(locs);
 
     __ b(exit_label());
@@ skipping 168 matching lines @@
   __ Bind(&skip_store);
 }
 
 
 LocationSummary* LoadStaticFieldInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
-  summary->set_out(Location::RequiresRegister());
+  summary->set_out(0, Location::RequiresRegister());
   return summary;
 }
 
 
 // When the parser is building an implicit static getter for optimization,
 // it can generate a function body where deoptimization ids do not line up
 // with the unoptimized code.
 //
 // This is safe only so long as LoadStaticFieldInstr cannot deoptimize.
 void LoadStaticFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("LoadStaticFieldInstr");
   Register field = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   __ lw(result, FieldAddress(field, Field::value_offset()));
 }
 
 
 LocationSummary* StoreStaticFieldInstr::MakeLocationSummary(bool opt) const {
   LocationSummary* locs = new LocationSummary(1, 1, LocationSummary::kNoCall);
   locs->set_in(0, value()->NeedsStoreBuffer() ? Location::WritableRegister()
                                               : Location::RequiresRegister());
   locs->set_temp(0, Location::RequiresRegister());
   return locs;
@@ skipping 17 matching lines @@
 
 
 LocationSummary* InstanceOfInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 3;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   summary->set_in(0, Location::RegisterLocation(A0));
   summary->set_in(1, Location::RegisterLocation(A2));
   summary->set_in(2, Location::RegisterLocation(A1));
-  summary->set_out(Location::RegisterLocation(V0));
+  summary->set_out(0, Location::RegisterLocation(V0));
   return summary;
 }
 
 
 void InstanceOfInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(locs()->in(0).reg() == A0);  // Value.
   ASSERT(locs()->in(1).reg() == A2);  // Instantiator.
   ASSERT(locs()->in(2).reg() == A1);  // Instantiator type arguments.
 
   __ Comment("InstanceOfInstr");
   compiler->GenerateInstanceOf(token_pos(),
                                deopt_id(),
                                type(),
                                negate_result(),
                                locs());
-  ASSERT(locs()->out().reg() == V0);
+  ASSERT(locs()->out(0).reg() == V0);
 }
 
 
 LocationSummary* CreateArrayInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   locs->set_in(0, Location::RegisterLocation(A0));
   locs->set_in(1, Location::RegisterLocation(A1));
-  locs->set_out(Location::RegisterLocation(V0));
+  locs->set_out(0, Location::RegisterLocation(V0));
   return locs;
 }
 
 
 void CreateArrayInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("CreateArrayInstr");
   // Allocate the array.  A1 = length, A0 = element type.
   ASSERT(locs()->in(0).reg() == A0);
   ASSERT(locs()->in(1).reg() == A1);
   compiler->GenerateCall(token_pos(),
                          &StubCode::AllocateArrayLabel(),
                          PcDescriptors::kOther,
                          locs());
-  ASSERT(locs()->out().reg() == V0);
+  ASSERT(locs()->out(0).reg() == V0);
 }
 
 
 class BoxDoubleSlowPath : public SlowPathCode {
  public:
   explicit BoxDoubleSlowPath(Instruction* instruction)
       : instruction_(instruction) { }
 
   virtual void EmitNativeCode(FlowGraphCompiler* compiler) {
     __ Comment("BoxDoubleSlowPath");
     __ Bind(entry_label());
     const Class& double_class = compiler->double_class();
     const Code& stub =
         Code::Handle(StubCode::GetAllocationStubForClass(double_class));
     const ExternalLabel label(double_class.ToCString(), stub.EntryPoint());
 
     LocationSummary* locs = instruction_->locs();
-    locs->live_registers()->Remove(locs->out());
+    locs->live_registers()->Remove(locs->out(0));
 
     compiler->SaveLiveRegisters(locs);
     compiler->GenerateCall(Scanner::kNoSourcePos,  // No token position.
                            &label,
                            PcDescriptors::kOther,
                            locs);
-    if (locs->out().reg() != V0) {
-      __ mov(locs->out().reg(), V0);
+    if (locs->out(0).reg() != V0) {
+      __ mov(locs->out(0).reg(), V0);
     }
     compiler->RestoreLiveRegisters(locs);
 
     __ b(exit_label());
   }
 
  private:
   Instruction* instruction_;
 };
 
@@ skipping 10 matching lines @@
 
   locs->set_in(0, Location::RequiresRegister());
 
   if (IsUnboxedLoad() && opt) {
     locs->AddTemp(Location::RequiresRegister());
   } else if (IsPotentialUnboxedLoad()) {
     locs->AddTemp(opt ? Location::RequiresFpuRegister()
                       : Location::FpuRegisterLocation(D1));
     locs->AddTemp(Location::RequiresRegister());
   }
-  locs->set_out(Location::RequiresRegister());
+  locs->set_out(0, Location::RequiresRegister());
   return locs;
 }
 
 
 void LoadFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register instance_reg = locs()->in(0).reg();
   if (IsUnboxedLoad() && compiler->is_optimizing()) {
-    DRegister result = locs()->out().fpu_reg();
+    DRegister result = locs()->out(0).fpu_reg();
     Register temp = locs()->temp(0).reg();
     __ lw(temp, FieldAddress(instance_reg, offset_in_bytes()));
     intptr_t cid = field()->UnboxedFieldCid();
     switch (cid) {
       case kDoubleCid:
         __ LoadDFromOffset(result, temp,
                            Double::value_offset() - kHeapObjectTag);
         break;
       default:
         UNREACHABLE();
     }
     return;
   }
 
   Label done;
-  Register result_reg = locs()->out().reg();
+  Register result_reg = locs()->out(0).reg();
   if (IsPotentialUnboxedLoad()) {
     Register temp = locs()->temp(1).reg();
     DRegister value = locs()->temp(0).fpu_reg();
 
     Label load_pointer;
     Label load_double;
 
     __ LoadObject(result_reg, Field::ZoneHandle(field()->raw()));
 
     FieldAddress field_cid_operand(result_reg, Field::guarded_cid_offset());
@@ skipping 37 matching lines @@
   __ Bind(&done);
 }
 
 
 LocationSummary* InstantiateTypeInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   locs->set_in(0, Location::RegisterLocation(T0));
-  locs->set_out(Location::RegisterLocation(T0));
+  locs->set_out(0, Location::RegisterLocation(T0));
   return locs;
 }
 
 
 void InstantiateTypeInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("InstantiateTypeInstr");
   Register instantiator_reg = locs()->in(0).reg();
-  Register result_reg = locs()->out().reg();
+  Register result_reg = locs()->out(0).reg();
 
   // 'instantiator_reg' is the instantiator TypeArguments object (or null).
   // A runtime call to instantiate the type is required.
   __ addiu(SP, SP, Immediate(-3 * kWordSize));
   __ LoadObject(TMP, Object::ZoneHandle());
   __ sw(TMP, Address(SP, 2 * kWordSize));  // Make room for the result.
   __ LoadObject(TMP, type());
   __ sw(TMP, Address(SP, 1 * kWordSize));
   // Push instantiator type arguments.
   __ sw(instantiator_reg, Address(SP, 0 * kWordSize));
@@ skipping 11 matching lines @@
 }
 
 
 LocationSummary* InstantiateTypeArgumentsInstr::MakeLocationSummary(
     bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   locs->set_in(0, Location::RegisterLocation(T0));
-  locs->set_out(Location::RegisterLocation(T0));
+  locs->set_out(0, Location::RegisterLocation(T0));
   return locs;
 }
 
 
 void InstantiateTypeArgumentsInstr::EmitNativeCode(
     FlowGraphCompiler* compiler) {
   __ TraceSimMsg("InstantiateTypeArgumentsInstr");
   Register instantiator_reg = locs()->in(0).reg();
-  Register result_reg = locs()->out().reg();
+  Register result_reg = locs()->out(0).reg();
   ASSERT(instantiator_reg == T0);
   ASSERT(instantiator_reg == result_reg);
 
   // 'instantiator_reg' is the instantiator TypeArguments object (or null).
   ASSERT(!type_arguments().IsUninstantiatedIdentity() &&
          !type_arguments().CanShareInstantiatorTypeArguments(
              instantiator_class()));
   // If the instantiator is null and if the type argument vector
   // instantiated from null becomes a vector of dynamic, then use null as
   // the type arguments.
@@ skipping 43 matching lines @@
   __ Bind(&type_arguments_instantiated);
 }
 
 
 LocationSummary* AllocateContextInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 0;
   const intptr_t kNumTemps = 1;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   locs->set_temp(0, Location::RegisterLocation(T1));
-  locs->set_out(Location::RegisterLocation(V0));
+  locs->set_out(0, Location::RegisterLocation(V0));
   return locs;
 }
 
 
 void AllocateContextInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register temp = T1;
   ASSERT(locs()->temp(0).reg() == temp);
-  ASSERT(locs()->out().reg() == V0);
+  ASSERT(locs()->out(0).reg() == V0);
 
   __ TraceSimMsg("AllocateContextInstr");
   __ LoadImmediate(temp, num_context_variables());
   const ExternalLabel label("alloc_context",
                             StubCode::AllocateContextEntryPoint());
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
 }
 
 
 LocationSummary* CloneContextInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   locs->set_in(0, Location::RegisterLocation(T0));
-  locs->set_out(Location::RegisterLocation(T0));
+  locs->set_out(0, Location::RegisterLocation(T0));
   return locs;
 }
 
 
 void CloneContextInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register context_value = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
 
   __ TraceSimMsg("CloneContextInstr");
 
   __ addiu(SP, SP, Immediate(-2 * kWordSize));
   __ LoadObject(TMP, Object::ZoneHandle());  // Make room for the result.
   __ sw(TMP, Address(SP, 1 * kWordSize));
   __ sw(context_value, Address(SP, 0 * kWordSize));
 
   compiler->GenerateRuntimeCall(token_pos(),
                                 deopt_id(),
@@ skipping 116 matching lines @@
   }
   __ Bind(slow_path->exit_label());
 }
 
 
 static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
                              BinarySmiOpInstr* shift_left) {
   const bool is_truncating = shift_left->is_truncating();
   const LocationSummary& locs = *shift_left->locs();
   Register left = locs.in(0).reg();
-  Register result = locs.out().reg();
+  Register result = locs.out(0).reg();
   Label* deopt = shift_left->CanDeoptimize() ?
       compiler->AddDeoptStub(shift_left->deopt_id(), kDeoptBinarySmiOp) : NULL;
 
   __ TraceSimMsg("EmitSmiShiftLeft");
 
   if (locs.in(1).IsConstant()) {
     const Object& constant = locs.in(1).constant();
     ASSERT(constant.IsSmi());
     // Immediate shift operation takes 5 bits for the count.
     const intptr_t kCountLimit = 0x1F;
@@ skipping 103 matching lines @@
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   if (op_kind() == Token::kTRUNCDIV) {
     summary->set_in(0, Location::RequiresRegister());
     if (RightIsPowerOfTwoConstant()) {
       ConstantInstr* right_constant = right()->definition()->AsConstant();
       summary->set_in(1, Location::Constant(right_constant->value()));
     } else {
       summary->set_in(1, Location::RequiresRegister());
     }
     summary->AddTemp(Location::RequiresRegister());
-    summary->set_out(Location::RequiresRegister());
+    summary->set_out(0, Location::RequiresRegister());
     return summary;
   }
   if (op_kind() == Token::kMOD) {
     summary->set_in(0, Location::RequiresRegister());
     summary->set_in(1, Location::RequiresRegister());
     summary->AddTemp(Location::RequiresRegister());
-    summary->set_out(Location::RequiresRegister());
+    summary->set_out(0, Location::RequiresRegister());
     return summary;
   }
   summary->set_in(0, Location::RequiresRegister());
   summary->set_in(1, Location::RegisterOrSmiConstant(right()));
   if (((op_kind() == Token::kSHL) && !is_truncating()) ||
       (op_kind() == Token::kSHR)) {
     summary->AddTemp(Location::RequiresRegister());
   } else if (op_kind() == Token::kADD) {
     // Need an extra temp for the overflow detection code.
     summary->set_temp(0, Location::RequiresRegister());
   }
   // We make use of 3-operand instructions by not requiring result register
   // to be identical to first input register as on Intel.
-  summary->set_out(Location::RequiresRegister());
+  summary->set_out(0, Location::RequiresRegister());
   return summary;
 }
 
 
 void BinarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("BinarySmiOpInstr");
   if (op_kind() == Token::kSHL) {
     EmitSmiShiftLeft(compiler, this);
     return;
   }
 
   ASSERT(!is_truncating());
   Register left = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   Label* deopt = NULL;
   if (CanDeoptimize()) {
     deopt = compiler->AddDeoptStub(deopt_id(), kDeoptBinarySmiOp);
   }
 
   if (locs()->in(1).IsConstant()) {
     const Object& constant = locs()->in(1).constant();
     ASSERT(constant.IsSmi());
     int32_t imm = reinterpret_cast<int32_t>(constant.raw());
     switch (op_kind()) {
@@ skipping 317 matching lines @@
 
 LocationSummary* BoxDoubleInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 1;
   LocationSummary* summary =
       new LocationSummary(kNumInputs,
                           kNumTemps,
                           LocationSummary::kCallOnSlowPath);
   summary->set_in(0, Location::RequiresFpuRegister());
   summary->set_temp(0, Location::RequiresRegister());
-  summary->set_out(Location::RequiresRegister());
+  summary->set_out(0, Location::RequiresRegister());
   return summary;
 }
 
 
 void BoxDoubleInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   BoxDoubleSlowPath* slow_path = new BoxDoubleSlowPath(this);
   compiler->AddSlowPathCode(slow_path);
 
-  Register out_reg = locs()->out().reg();
+  Register out_reg = locs()->out(0).reg();
   DRegister value = locs()->in(0).fpu_reg();
 
   __ TryAllocate(compiler->double_class(),
                  slow_path->entry_label(),
                  out_reg,
                  locs()->temp(0).reg());
   __ Bind(slow_path->exit_label());
   __ StoreDToOffset(value, out_reg, Double::value_offset() - kHeapObjectTag);
 }
 
 
 LocationSummary* UnboxDoubleInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t value_cid = value()->Type()->ToCid();
   const bool needs_writable_input = (value_cid == kSmiCid);
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, needs_writable_input
                      ? Location::WritableRegister()
                      : Location::RequiresRegister());
-  summary->set_out(Location::RequiresFpuRegister());
+  summary->set_out(0, Location::RequiresFpuRegister());
   return summary;
 }
 
 
 void UnboxDoubleInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   const intptr_t value_cid = value()->Type()->ToCid();
   const Register value = locs()->in(0).reg();
-  const DRegister result = locs()->out().fpu_reg();
+  const DRegister result = locs()->out(0).fpu_reg();
 
   if (value_cid == kDoubleCid) {
     __ LoadDFromOffset(result, value, Double::value_offset() - kHeapObjectTag);
   } else if (value_cid == kSmiCid) {
     __ SmiUntag(value);  // Untag input before conversion.
     __ mtc1(value, STMP1);
     __ cvtdw(result, STMP1);
   } else {
     Label* deopt = compiler->AddDeoptStub(deopt_id_, kDeoptBinaryDoubleOp);
     Label is_smi, done;
@@ skipping 80 matching lines @@
 }
 
 
 LocationSummary* BinaryDoubleOpInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresFpuRegister());
   summary->set_in(1, Location::RequiresFpuRegister());
-  summary->set_out(Location::RequiresFpuRegister());
+  summary->set_out(0, Location::RequiresFpuRegister());
   return summary;
 }
 
 
 void BinaryDoubleOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   DRegister left = locs()->in(0).fpu_reg();
   DRegister right = locs()->in(1).fpu_reg();
-  DRegister result = locs()->out().fpu_reg();
+  DRegister result = locs()->out(0).fpu_reg();
   switch (op_kind()) {
     case Token::kADD: __ addd(result, left, right); break;
     case Token::kSUB: __ subd(result, left, right); break;
     case Token::kMUL: __ muld(result, left, right); break;
     case Token::kDIV: __ divd(result, left, right); break;
     default: UNREACHABLE();
   }
 }
 
 
@@ skipping 334 matching lines @@
 
 
 LocationSummary* MathUnaryInstr::MakeLocationSummary(bool opt) const {
   if ((kind() == MethodRecognizer::kMathSin) ||
       (kind() == MethodRecognizer::kMathCos)) {
     const intptr_t kNumInputs = 1;
     const intptr_t kNumTemps = 0;
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
     summary->set_in(0, Location::FpuRegisterLocation(D6));
-    summary->set_out(Location::FpuRegisterLocation(D0));
+    summary->set_out(0, Location::FpuRegisterLocation(D0));
     return summary;
   }
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresFpuRegister());
-  summary->set_out(Location::RequiresFpuRegister());
+  summary->set_out(0, Location::RequiresFpuRegister());
   return summary;
 }
 
 
 void MathUnaryInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   if (kind() == MethodRecognizer::kMathSqrt) {
-    __ sqrtd(locs()->out().fpu_reg(), locs()->in(0).fpu_reg());
+    __ sqrtd(locs()->out(0).fpu_reg(), locs()->in(0).fpu_reg());
   } else {
     __ CallRuntime(TargetFunction(), InputCount());
   }
 }
 
 
 LocationSummary* MathMinMaxInstr::MakeLocationSummary(bool opt) const {
   if (result_cid() == kDoubleCid) {
     const intptr_t kNumInputs = 2;
     const intptr_t kNumTemps = 1;
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     summary->set_in(0, Location::RequiresFpuRegister());
     summary->set_in(1, Location::RequiresFpuRegister());
     // Reuse the left register so that code can be made shorter.
-    summary->set_out(Location::SameAsFirstInput());
+    summary->set_out(0, Location::SameAsFirstInput());
     summary->set_temp(0, Location::RequiresRegister());
     return summary;
   }
   ASSERT(result_cid() == kSmiCid);
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
   summary->set_in(1, Location::RequiresRegister());
   // Reuse the left register so that code can be made shorter.
-  summary->set_out(Location::SameAsFirstInput());
+  summary->set_out(0, Location::SameAsFirstInput());
   return summary;
 }
 
 
 void MathMinMaxInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT((op_kind() == MethodRecognizer::kMathMin) ||
          (op_kind() == MethodRecognizer::kMathMax));
   const intptr_t is_min = (op_kind() == MethodRecognizer::kMathMin);
   if (result_cid() == kDoubleCid) {
     Label done, returns_nan, are_equal;
     DRegister left = locs()->in(0).fpu_reg();
     DRegister right = locs()->in(1).fpu_reg();
-    DRegister result = locs()->out().fpu_reg();
+    DRegister result = locs()->out(0).fpu_reg();
     Register temp = locs()->temp(0).reg();
     __ cund(left, right);
     __ bc1t(&returns_nan);
     __ ceqd(left, right);
     __ bc1t(&are_equal);
     if (is_min) {
       __ coltd(left, right);
     } else {
       __ coltd(right, left);
     }
@@ skipping 24 matching lines @@
     }
     __ movd(result, right);
     __ Bind(&done);
     return;
   }
 
   Label done;
   ASSERT(result_cid() == kSmiCid);
   Register left = locs()->in(0).reg();
   Register right = locs()->in(1).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   ASSERT(result == left);
   if (is_min) {
     __ BranchSignedLessEqual(left, right, &done);
   } else {
     __ BranchSignedGreaterEqual(left, right, &done);
   }
   __ mov(result, right);
   __ Bind(&done);
 }
 
 
 LocationSummary* UnarySmiOpInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
   // We make use of 3-operand instructions by not requiring result register
   // to be identical to first input register as on Intel.
-  summary->set_out(Location::RequiresRegister());
+  summary->set_out(0, Location::RequiresRegister());
   return summary;
 }
 
 
 void UnarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register value = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   switch (op_kind()) {
     case Token::kNEGATE: {
       Label* deopt = compiler->AddDeoptStub(deopt_id(),
                                             kDeoptUnaryOp);
       __ SubuDetectOverflow(result, ZR, value, CMPRES1);
       __ bltz(CMPRES1, deopt);
       break;
     }
     case Token::kBIT_NOT:
       __ nor(result, value, ZR);
       __ addiu(result, result, Immediate(-1));  // Remove inverted smi-tag.
       break;
     default:
       UNREACHABLE();
   }
 }
 
 
 LocationSummary* UnaryDoubleOpInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 1;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresFpuRegister());
-  summary->set_out(Location::RequiresFpuRegister());
+  summary->set_out(0, Location::RequiresFpuRegister());
   summary->set_temp(0, Location::RequiresFpuRegister());
   return summary;
 }
 
 
 void UnaryDoubleOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   // TODO(zra): Implement vneg.
   const Double& minus_one = Double::ZoneHandle(Double::NewCanonical(-1));
   __ LoadObject(TMP, minus_one);
-  FpuRegister result = locs()->out().fpu_reg();
+  FpuRegister result = locs()->out(0).fpu_reg();
   FpuRegister value = locs()->in(0).fpu_reg();
   FpuRegister temp_fp = locs()->temp(0).fpu_reg();
   __ LoadDFromOffset(temp_fp, TMP, Double::value_offset() - kHeapObjectTag);
   __ muld(result, value, temp_fp);
 }
 
 
 
 LocationSummary* SmiToDoubleInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* result =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   result->set_in(0, Location::WritableRegister());
-  result->set_out(Location::RequiresFpuRegister());
+  result->set_out(0, Location::RequiresFpuRegister());
   return result;
 }
 
 
 void SmiToDoubleInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register value = locs()->in(0).reg();
-  FpuRegister result = locs()->out().fpu_reg();
+  FpuRegister result = locs()->out(0).fpu_reg();
   __ SmiUntag(value);
   __ mtc1(value, STMP1);
   __ cvtdw(result, STMP1);
 }
 
 
 LocationSummary* DoubleToIntegerInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* result =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   result->set_in(0, Location::RegisterLocation(T1));
-  result->set_out(Location::RegisterLocation(V0));
+  result->set_out(0, Location::RegisterLocation(V0));
   return result;
 }
 
 
 void DoubleToIntegerInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   Register value_obj = locs()->in(0).reg();
   ASSERT(result == V0);
   ASSERT(result != value_obj);
   __ LoadDFromOffset(DTMP, value_obj, Double::value_offset() - kHeapObjectTag);
   __ cvtwd(STMP1, DTMP);
   __ mfc1(result, STMP1);
 
   // Overflow is signaled with minint.
   Label do_call, done;
   // Check for overflow and that it fits into Smi.
@@ skipping 19 matching lines @@
   __ Bind(&done);
 }
 
 
 LocationSummary* DoubleToSmiInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* result = new LocationSummary(
       kNumInputs, kNumTemps, LocationSummary::kNoCall);
   result->set_in(0, Location::RequiresFpuRegister());
-  result->set_out(Location::RequiresRegister());
+  result->set_out(0, Location::RequiresRegister());
   return result;
 }
 
 
 void DoubleToSmiInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Label* deopt = compiler->AddDeoptStub(deopt_id(), kDeoptDoubleToSmi);
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   DRegister value = locs()->in(0).fpu_reg();
   __ cvtwd(STMP1, value);
   __ mfc1(result, STMP1);
 
   // Check for overflow and that it fits into Smi.
   __ LoadImmediate(TMP, 0xC0000000);
   __ subu(CMPRES1, result, TMP);
   __ bltz(CMPRES1, deopt);
   __ SmiTag(result);
 }
 
 
 LocationSummary* DoubleToDoubleInstr::MakeLocationSummary(bool opt) const {
   UNIMPLEMENTED();
   return NULL;
 }
 
 
 void DoubleToDoubleInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   UNIMPLEMENTED();
 }
 
 
 LocationSummary* DoubleToFloatInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* result =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   result->set_in(0, Location::RequiresFpuRegister());
-  result->set_out(Location::SameAsFirstInput());
+  result->set_out(0, Location::SameAsFirstInput());
   return result;
 }
 
 
 void DoubleToFloatInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   DRegister value = locs()->in(0).fpu_reg();
-  FRegister result = EvenFRegisterOf(locs()->out().fpu_reg());
+  FRegister result = EvenFRegisterOf(locs()->out(0).fpu_reg());
   __ cvtsd(result, value);
 }
 
 
 LocationSummary* FloatToDoubleInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* result =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   result->set_in(0, Location::RequiresFpuRegister());
-  result->set_out(Location::SameAsFirstInput());
+  result->set_out(0, Location::SameAsFirstInput());
   return result;
 }
 
 
 void FloatToDoubleInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   FRegister value = EvenFRegisterOf(locs()->in(0).fpu_reg());
-  DRegister result = locs()->out().fpu_reg();
+  DRegister result = locs()->out(0).fpu_reg();
   __ cvtds(result, value);
 }
 
 
 LocationSummary* InvokeMathCFunctionInstr::MakeLocationSummary(bool opt) const {
   // Calling convention on MIPS uses D6 and D7 to pass the first two
   // double arguments.
   ASSERT((InputCount() == 1) || (InputCount() == 2));
   const intptr_t kNumTemps = 0;
   LocationSummary* result =
       new LocationSummary(InputCount(), kNumTemps, LocationSummary::kCall);
   result->set_in(0, Location::FpuRegisterLocation(D6));
   if (InputCount() == 2) {
     result->set_in(1, Location::FpuRegisterLocation(D7));
   }
-  result->set_out(Location::FpuRegisterLocation(D0));
+  result->set_out(0, Location::FpuRegisterLocation(D0));
   return result;
 }
 
 
 void InvokeMathCFunctionInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   // For pow-function return NaN if exponent is NaN.
   Label do_call, skip_call;
   if (recognized_kind() == MethodRecognizer::kMathDoublePow) {
     // Pseudo code:
     // if (exponent == 0.0) return 0.0;
     // if (base == 1.0) return 1.0;
     // if (base.isNaN || exponent.isNaN) {
     //    return double.NAN;
     // }
     DRegister base = locs()->in(0).fpu_reg();
     DRegister exp = locs()->in(1).fpu_reg();
-    DRegister result = locs()->out().fpu_reg();
+    DRegister result = locs()->out(0).fpu_reg();
 
     Label check_base_is_one;
 
     // Check if exponent is 0.0 -> return 1.0;
     __ LoadObject(TMP, Double::ZoneHandle(Double::NewCanonical(0)));
     __ LoadDFromOffset(DTMP, TMP, Double::value_offset() - kHeapObjectTag);
     __ LoadObject(TMP, Double::ZoneHandle(Double::NewCanonical(1)));
     __ LoadDFromOffset(result, TMP, Double::value_offset() - kHeapObjectTag);
     // 'result' contains 1.0.
     __ cund(exp, exp);
@@ skipping 24 matching lines @@
   if (kind() == MergedMathInstr::kTruncDivMod) {
     const intptr_t kNumInputs = 2;
     const intptr_t kNumTemps = 3;
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     summary->set_in(0, Location::RequiresRegister());
     summary->set_in(1, Location::RequiresRegister());
     summary->set_temp(0, Location::RequiresRegister());
     summary->set_temp(1, Location::RequiresRegister());  // result_div.
     summary->set_temp(2, Location::RequiresRegister());  // result_mod.
-    summary->set_out(Location::RequiresRegister());
+    summary->set_out(0, Location::RequiresRegister());
     return summary;
   }
   UNIMPLEMENTED();
   return NULL;
 }
 
 
 void MergedMathInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Label* deopt = NULL;
   if (CanDeoptimize()) {
     deopt = compiler->AddDeoptStub(deopt_id(), kDeoptBinarySmiOp);
   }
   if (kind() == MergedMathInstr::kTruncDivMod) {
     Register left = locs()->in(0).reg();
     Register right = locs()->in(1).reg();
-    Register result = locs()->out().reg();
+    Register result = locs()->out(0).reg();
     Register temp = locs()->temp(0).reg();
     Register result_div = locs()->temp(1).reg();
     Register result_mod = locs()->temp(2).reg();
     Range* right_range = InputAt(1)->definition()->range();
     if ((right_range == NULL) || right_range->Overlaps(0, 0)) {
       // Handle divide by zero in runtime.
       __ beq(right, ZR, deopt);
     }
     __ sra(temp, left, kSmiTagSize);  // SmiUntag left into temp.
     __ sra(TMP, right, kSmiTagSize);  // SmiUntag right into TMP.
@@ skipping 87 matching lines @@
                             deopt,
                             deopt_id(),
                             instance_call()->token_pos(),
                             locs());
 }
 
 
 LocationSummary* BranchInstr::MakeLocationSummary(bool opt) const {
   comparison()->InitializeLocationSummary(opt);
   // Branches don't produce a result.
-  comparison()->locs()->set_out(Location::NoLocation());
+  comparison()->locs()->set_out(0, Location::NoLocation());
   return comparison()->locs();
 }
 
 
 void BranchInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("BranchInstr");
   comparison()->EmitBranchCode(compiler, this);
 }
 
 
@@ skipping 265 matching lines @@
 
 
 LocationSummary* CurrentContextInstr::MakeLocationSummary(bool opt) const {
   return LocationSummary::Make(0,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void CurrentContextInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  __ mov(locs()->out().reg(), CTX);
+  __ mov(locs()->out(0).reg(), CTX);
 }
 
 
 LocationSummary* StrictCompareInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
   if (needs_number_check()) {
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
     locs->set_in(0, Location::RegisterLocation(A0));
     locs->set_in(1, Location::RegisterLocation(A1));
-    locs->set_out(Location::RegisterLocation(A0));
+    locs->set_out(0, Location::RegisterLocation(A0));
     return locs;
   }
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   locs->set_in(0, Location::RegisterOrConstant(left()));
   // Only one of the inputs can be a constant. Choose register if the first one
   // is a constant.
   locs->set_in(1, locs->in(0).IsConstant()
                       ? Location::RequiresRegister()
                       : Location::RegisterOrConstant(right()));
-  locs->set_out(Location::RequiresRegister());
+  locs->set_out(0, Location::RequiresRegister());
   return locs;
 }
 
 
 Condition StrictCompareInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                                  BranchLabels labels) {
   Location left = locs()->in(0);
   Location right = locs()->in(1);
   ASSERT(!left.IsConstant() || !right.IsConstant());
   if (left.IsConstant()) {
@@ skipping 20 matching lines @@
 void StrictCompareInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("StrictCompareInstr");
   __ Comment("StrictCompareInstr");
   ASSERT(kind() == Token::kEQ_STRICT || kind() == Token::kNE_STRICT);
 
   Label is_true, is_false;
   BranchLabels labels = { &is_true, &is_false, &is_false };
   Condition true_condition = EmitComparisonCode(compiler, labels);
   EmitBranchOnCondition(compiler, true_condition, labels);
 
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
   Label done;
   __ Bind(&is_false);
   __ LoadObject(result, Bool::False());
   __ b(&done);
   __ Bind(&is_true);
   __ LoadObject(result, Bool::True());
   __ Bind(&done);
 }
 
 
@@ skipping 10 matching lines @@
 
 LocationSummary* BooleanNegateInstr::MakeLocationSummary(bool opt) const {
   return LocationSummary::Make(1,
                                Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void BooleanNegateInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register value = locs()->in(0).reg();
-  Register result = locs()->out().reg();
+  Register result = locs()->out(0).reg();
 
   __ LoadObject(result, Bool::True());
   __ LoadObject(TMP, Bool::False());
   __ subu(CMPRES1, value, result);
   __ movz(result, TMP, CMPRES1);  // If value is True, move False into result.
 }
 
 
 LocationSummary* AllocateObjectInstr::MakeLocationSummary(bool opt) const {
   return MakeCallSummary();
 }
 
 
 void AllocateObjectInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("AllocateObjectInstr");
   __ Comment("AllocateObjectInstr");
   const Code& stub = Code::Handle(StubCode::GetAllocationStubForClass(cls()));
   const ExternalLabel label(cls().ToCString(), stub.EntryPoint());
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS