Change the register allocator so that it no longer tracks references...

src/register-allocator.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 20 matching lines @@
 #include "register-allocator-inl.h"
 
 namespace v8 {
 namespace internal {
 
 // -------------------------------------------------------------------------
 // Result implementation.
 
 
 Result::Result(Register reg) {
-  ASSERT(reg.is_valid());
+  ASSERT(reg.is_valid() && !RegisterAllocator::IsReserved(reg));
   CodeGeneratorScope::Current()->allocator()->Use(reg);
   value_ = StaticTypeField::encode(StaticType::UNKNOWN_TYPE)
       | TypeField::encode(REGISTER)
       | DataField::encode(reg.code_);
 }
 
 
 Result::Result(Register reg, StaticType type) {
-  ASSERT(reg.is_valid());
+  ASSERT(reg.is_valid() && !RegisterAllocator::IsReserved(reg));
   CodeGeneratorScope::Current()->allocator()->Use(reg);
   value_ = StaticTypeField::encode(type.static_type_)
       | TypeField::encode(REGISTER)
       | DataField::encode(reg.code_);
 }
 
 
 // -------------------------------------------------------------------------
 // RegisterAllocator implementation.
 
 
 Result RegisterAllocator::AllocateWithoutSpilling() {
   // Return the first free register, if any.
-  int free_reg = registers_.ScanForFreeRegister();
-  if (free_reg < kNumRegisters) {
-    Register free_result = { free_reg };
-    return Result(free_result);
+  int num = registers_.ScanForFreeRegister();
+  if (num == RegisterAllocator::kInvalidRegister) {
+    return Result();
   }
-  return Result();
+  return Result(RegisterAllocator::ToRegister(num));
 }
 
 
 Result RegisterAllocator::Allocate() {
   Result result = AllocateWithoutSpilling();
   if (!result.is_valid()) {
     // Ask the current frame to spill a register.
     ASSERT(cgen_->has_valid_frame());
     Register free_reg = cgen_->frame()->SpillAnyRegister();
     if (free_reg.is_valid()) {
@@ skipping 17 matching lines @@
     cgen_->frame()->Spill(target);
     ASSERT(!is_used(target));
     return Result(target);
   }
   // Otherwise (if it's referenced outside the frame) we cannot allocate it.
   return Result();
 }
 
 
 } }  // namespace v8::internal