Enable stub generation using Hydrogen/Lithium (again)

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 e102803c094d04d6c27af7f70df3aac591e9d9e1..defdafa6748a27d149550dfe7fe338777876a2e6 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -44,10 +44,10 @@ LITHIUM_CONCRETE_INSTRUCTION_LIST(DEFINE_COMPILE)
 #undef DEFINE_COMPILE
 
 LOsrEntry::LOsrEntry() {
-  for (int i = 0; i < Register::kNumAllocatableRegisters; ++i) {
+  for (int i = 0; i < Register::NumAllocatableRegisters(); ++i) {
     register_spills_[i] = NULL;
   }
-  for (int i = 0; i < DoubleRegister::kNumAllocatableRegisters; ++i) {
+  for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); ++i) {
     double_register_spills_[i] = NULL;
   }
 }
@@ -619,6 +619,8 @@ LInstruction* LChunkBuilder::AssignEnvironment(LInstruction* instr) {
 LInstruction* LChunkBuilder::MarkAsCall(LInstruction* instr,
                                         HInstruction* hinstr,
                                         CanDeoptimize can_deoptimize) {
+  info()->MarkAsNonDeferredCalling();
+
 #ifdef DEBUG
   instr->VerifyCall();
 #endif
@@ -1617,8 +1619,12 @@ LInstruction* LChunkBuilder::DoForceRepresentation(HForceRepresentation* bad) {
 LInstruction* LChunkBuilder::DoChange(HChange* instr) {
   Representation from = instr->from();
   Representation to = instr->to();
+  // Only mark conversions that might need to allocate as calling rather than
+  // all changes. This makes simple, non-allocating conversion not have to force
+  // building a stack frame.
   if (from.IsTagged()) {
     if (to.IsDouble()) {
+      info()->MarkAsDeferredCalling();
       LOperand* value = UseRegister(instr->value());
       LNumberUntagD* res = new(zone()) LNumberUntagD(value);
       return AssignEnvironment(DefineAsRegister(res));
@@ -1636,6 +1642,7 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
     }
   } else if (from.IsDouble()) {
     if (to.IsTagged()) {
+      info()->MarkAsDeferredCalling();
       LOperand* value = UseRegister(instr->value());
       LOperand* temp = TempRegister();
 
@@ -1649,6 +1656,7 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
       return AssignEnvironment(DefineAsRegister(new(zone()) LDoubleToI(value)));
     }
   } else if (from.IsInteger32()) {
+    info()->MarkAsDeferredCalling();
     if (to.IsTagged()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
@@ -2115,8 +2123,17 @@ LInstruction* LChunkBuilder::DoOsrEntry(HOsrEntry* instr) {
 
 
 LInstruction* LChunkBuilder::DoParameter(HParameter* instr) {
-  int spill_index = chunk()->GetParameterStackSlot(instr->index());
-  return DefineAsSpilled(new(zone()) LParameter, spill_index);
+  LParameter* result = new(zone()) LParameter;
+  if (info()->IsOptimizing()) {
+    int spill_index = chunk()->GetParameterStackSlot(instr->index());
+    return DefineAsSpilled(result, spill_index);
+  } else {
+    ASSERT(info()->IsStub());
+    CodeStubInterfaceDescriptor* descriptor =
+        info()->code_stub()->GetInterfaceDescriptor(info()->isolate());
+    Register reg = descriptor->register_params[instr->index()];
+    return DefineFixed(result, reg);
+  }
 }
 
 
@@ -2212,6 +2229,7 @@ LInstruction* LChunkBuilder::DoSimulate(HSimulate* instr) {
 
 
 LInstruction* LChunkBuilder::DoStackCheck(HStackCheck* instr) {
+  info()->MarkAsDeferredCalling();
   if (instr->is_function_entry()) {
     return MarkAsCall(new(zone()) LStackCheck, instr);
   } else {