A64: Synchronize with r17104.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index a5b8417e957ebfd0a80d98416b9c604eb14e685a..9b9ac04222923d8947e4e6cc6e11bd8b4c636ef6 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -353,19 +353,20 @@ void LAccessArgumentsAt::PrintDataTo(StringStream* stream) {
 }
 
 
-int LPlatformChunk::GetNextSpillIndex(bool is_double) {
+int LPlatformChunk::GetNextSpillIndex(RegisterKind kind) {
   return spill_slot_count_++;
 }
 
 
-LOperand* LPlatformChunk::GetNextSpillSlot(bool is_double) {
+LOperand* LPlatformChunk::GetNextSpillSlot(RegisterKind kind) {
   // All stack slots are Double stack slots on x64.
   // Alternatively, at some point, start using half-size
   // stack slots for int32 values.
-  int index = GetNextSpillIndex(is_double);
-  if (is_double) {
+  int index = GetNextSpillIndex(kind);
+  if (kind == DOUBLE_REGISTERS) {
     return LDoubleStackSlot::Create(index, zone());
   } else {
+    ASSERT(kind == GENERAL_REGISTERS);
     return LStackSlot::Create(index, zone());
   }
 }
@@ -445,7 +446,7 @@ LPlatformChunk* LChunkBuilder::Build() {
   // which will be subsumed into this frame.
   if (graph()->has_osr()) {
     for (int i = graph()->osr()->UnoptimizedFrameSlots(); i > 0; i--) {
-      chunk_->GetNextSpillIndex(false);
+      chunk_->GetNextSpillIndex(GENERAL_REGISTERS);
     }
   }
 
@@ -859,9 +860,31 @@ void LChunkBuilder::VisitInstruction(HInstruction* current) {
   HInstruction* old_current = current_instruction_;
   current_instruction_ = current;
   if (current->has_position()) position_ = current->position();
-  LInstruction* instr = current->CompileToLithium(this);
+
+  LInstruction* instr = NULL;
+  if (current->CanReplaceWithDummyUses()) {
+    HValue* first_operand = current->OperandCount() == 0
+        ? graph()->GetConstant1()
+        : current->OperandAt(0);
+    instr = DefineAsRegister(new(zone()) LDummyUse(UseAny(first_operand)));
+    for (int i = 1; i < current->OperandCount(); ++i) {
+      LInstruction* dummy =
+          new(zone()) LDummyUse(UseAny(current->OperandAt(i)));
+      dummy->set_hydrogen_value(current);
+      chunk_->AddInstruction(dummy, current_block_);
+    }
+  } else {
+    instr = current->CompileToLithium(this);
+  }
+
+  argument_count_ += current->argument_delta();
+  ASSERT(argument_count_ >= 0);
 
   if (instr != NULL) {
+    // Associate the hydrogen instruction first, since we may need it for
+    // the ClobbersRegisters() or ClobbersDoubleRegisters() calls below.
+    instr->set_hydrogen_value(current);
+
 #if DEBUG
     // Make sure that the lithium instruction has either no fixed register
     // constraints in temps or the result OR no uses that are only used at
@@ -898,7 +921,6 @@ void LChunkBuilder::VisitInstruction(HInstruction* current) {
     if (FLAG_stress_environments && !instr->HasEnvironment()) {
       instr = AssignEnvironment(instr);
     }
-    instr->set_hydrogen_value(current);
     chunk_->AddInstruction(instr, current_block_);
   }
   current_instruction_ = old_current;
@@ -990,7 +1012,7 @@ LEnvironment* LChunkBuilder::CreateEnvironment(
 
 
 LInstruction* LChunkBuilder::DoGoto(HGoto* instr) {
-  return new(zone()) LGoto(instr->FirstSuccessor()->block_id());
+  return new(zone()) LGoto(instr->FirstSuccessor());
 }
 
 
@@ -1000,16 +1022,10 @@ LInstruction* LChunkBuilder::DoDebugBreak(HDebugBreak* instr) {
 
 
 LInstruction* LChunkBuilder::DoBranch(HBranch* instr) {
-  HValue* value = instr->value();
-  if (value->EmitAtUses()) {
-    ASSERT(value->IsConstant());
-    ASSERT(!value->representation().IsDouble());
-    HBasicBlock* successor = HConstant::cast(value)->BooleanValue()
-        ? instr->FirstSuccessor()
-        : instr->SecondSuccessor();
-    return new(zone()) LGoto(successor->block_id());
-  }
+  LInstruction* goto_instr = CheckElideControlInstruction(instr);
+  if (goto_instr != NULL) return goto_instr;
 
+  HValue* value = instr->value();
   LBranch* result = new(zone()) LBranch(UseRegister(value));
   // Tagged values that are not known smis or booleans require a
   // deoptimization environment. If the instruction is generic no
@@ -1089,7 +1105,6 @@ LInstruction* LChunkBuilder::DoApplyArguments(HApplyArguments* instr) {
 
 
 LInstruction* LChunkBuilder::DoPushArgument(HPushArgument* instr) {
-  ++argument_count_;
   LOperand* argument = UseOrConstant(instr->argument());
   return new(zone()) LPushArgument(argument);
 }
@@ -1155,14 +1170,12 @@ LInstruction* LChunkBuilder::DoGlobalReceiver(HGlobalReceiver* instr) {
 
 LInstruction* LChunkBuilder::DoCallConstantFunction(
     HCallConstantFunction* instr) {
-  argument_count_ -= instr->argument_count();
   return MarkAsCall(DefineFixed(new(zone()) LCallConstantFunction, rax), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoInvokeFunction(HInvokeFunction* instr) {
   LOperand* function = UseFixed(instr->function(), rdi);
-  argument_count_ -= instr->argument_count();
   LInvokeFunction* result = new(zone()) LInvokeFunction(function);
   return MarkAsCall(DefineFixed(result, rax), instr, CANNOT_DEOPTIMIZE_EAGERLY);
 }
@@ -1264,33 +1277,28 @@ LInstruction* LChunkBuilder::DoMathPowHalf(HUnaryMathOperation* instr) {
 LInstruction* LChunkBuilder::DoCallKeyed(HCallKeyed* instr) {
   ASSERT(instr->key()->representation().IsTagged());
   LOperand* key = UseFixed(instr->key(), rcx);
-  argument_count_ -= instr->argument_count();
   LCallKeyed* result = new(zone()) LCallKeyed(key);
   return MarkAsCall(DefineFixed(result, rax), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallNamed(HCallNamed* instr) {
-  argument_count_ -= instr->argument_count();
   return MarkAsCall(DefineFixed(new(zone()) LCallNamed, rax), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallGlobal(HCallGlobal* instr) {
-  argument_count_ -= instr->argument_count();
   return MarkAsCall(DefineFixed(new(zone()) LCallGlobal, rax), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallKnownGlobal(HCallKnownGlobal* instr) {
-  argument_count_ -= instr->argument_count();
   return MarkAsCall(DefineFixed(new(zone()) LCallKnownGlobal, rax), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallNew(HCallNew* instr) {
   LOperand* constructor = UseFixed(instr->constructor(), rdi);
-  argument_count_ -= instr->argument_count();
   LCallNew* result = new(zone()) LCallNew(constructor);
   return MarkAsCall(DefineFixed(result, rax), instr);
 }
@@ -1298,7 +1306,6 @@ LInstruction* LChunkBuilder::DoCallNew(HCallNew* instr) {
 
 LInstruction* LChunkBuilder::DoCallNewArray(HCallNewArray* instr) {
   LOperand* constructor = UseFixed(instr->constructor(), rdi);
-  argument_count_ -= instr->argument_count();
   LCallNewArray* result = new(zone()) LCallNewArray(constructor);
   return MarkAsCall(DefineFixed(result, rax), instr);
 }
@@ -1306,14 +1313,12 @@ LInstruction* LChunkBuilder::DoCallNewArray(HCallNewArray* instr) {
 
 LInstruction* LChunkBuilder::DoCallFunction(HCallFunction* instr) {
   LOperand* function = UseFixed(instr->function(), rdi);
-  argument_count_ -= instr->argument_count();
   LCallFunction* result = new(zone()) LCallFunction(function);
   return MarkAsCall(DefineFixed(result, rax), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoCallRuntime(HCallRuntime* instr) {
-  argument_count_ -= instr->argument_count();
   return MarkAsCall(DefineFixed(new(zone()) LCallRuntime, rax), instr);
 }
 
@@ -1639,6 +1644,8 @@ LInstruction* LChunkBuilder::DoCompareNumericAndBranch(
 
 LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
     HCompareObjectEqAndBranch* instr) {
+  LInstruction* goto_instr = CheckElideControlInstruction(instr);
+  if (goto_instr != NULL) return goto_instr;
   LOperand* left = UseRegisterAtStart(instr->left());
   LOperand* right = UseRegisterOrConstantAtStart(instr->right());
   return new(zone()) LCmpObjectEqAndBranch(left, right);
@@ -2053,7 +2060,14 @@ LInstruction* LChunkBuilder::DoStoreContextSlot(HStoreContextSlot* instr) {
 
 
 LInstruction* LChunkBuilder::DoLoadNamedField(HLoadNamedField* instr) {
-  if (instr->access().IsExternalMemory() && instr->access().offset() == 0) {
+  // Use the special mov rax, moffs64 encoding for external
+  // memory accesses with 64-bit word-sized values.
+  if (instr->access().IsExternalMemory() &&
+      instr->access().offset() == 0 &&
+      (instr->access().representation().IsSmi() ||
+       instr->access().representation().IsTagged() ||
+       instr->access().representation().IsHeapObject() ||
+       instr->access().representation().IsExternal())) {
     LOperand* obj = UseRegisterOrConstantAtStart(instr->object());
     return DefineFixed(new(zone()) LLoadNamedField(obj), rax);
   }
@@ -2374,7 +2388,6 @@ LInstruction* LChunkBuilder::DoUnknownOSRValue(HUnknownOSRValue* instr) {
 
 
 LInstruction* LChunkBuilder::DoCallStub(HCallStub* instr) {
-  argument_count_ -= instr->argument_count();
   return MarkAsCall(DefineFixed(new(zone()) LCallStub, rax), instr);
 }
 
@@ -2496,7 +2509,7 @@ LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
   if (env->entry()->arguments_pushed()) {
     int argument_count = env->arguments_environment()->parameter_count();
     pop = new(zone()) LDrop(argument_count);
-    argument_count_ -= argument_count;
+    ASSERT(instr->argument_delta() == -argument_count);
   }
 
   HEnvironment* outer = current_block_->last_environment()->