Config double register number as 1 for X87 Turbofan.

src/compiler/register-configuration.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/register-configuration.h"
 #include "src/globals.h"
 #include "src/macro-assembler.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 namespace {
 
 STATIC_ASSERT(RegisterConfiguration::kMaxGeneralRegisters >=
               Register::kNumRegisters);
 STATIC_ASSERT(RegisterConfiguration::kMaxDoubleRegisters >=
               DoubleRegister::kMaxNumRegisters);
 
 class ArchDefaultRegisterConfiguration : public RegisterConfiguration {
  public:
   ArchDefaultRegisterConfiguration()
-      : RegisterConfiguration(Register::kMaxNumAllocatableRegisters,
-                              DoubleRegister::kMaxNumAllocatableRegisters,
-                              DoubleRegister::NumAllocatableAliasedRegisters(),
-                              general_register_name_table_,
-                              double_register_name_table_) {
+      : RegisterConfiguration(
+           Register::kMaxNumAllocatableRegisters,
+           DoubleRegister::NumAllocatableRegistersForTurbo(),

[titzer, 2015/06/09 14:47:00]

This is the class meant to configure turbofan. Why don't we add the logic here
instead of everywhere else?

+           DoubleRegister::NumAllocatableAliasedRegistersForTurbo(),
+           general_register_name_table_,
+           double_register_name_table_) {
     DCHECK_EQ(Register::kMaxNumAllocatableRegisters,
               Register::NumAllocatableRegisters());
     for (int i = 0; i < Register::kMaxNumAllocatableRegisters; ++i) {
       general_register_name_table_[i] = Register::AllocationIndexToString(i);
     }
     for (int i = 0; i < DoubleRegister::kMaxNumAllocatableRegisters; ++i) {
       double_register_name_table_[i] =
           DoubleRegister::AllocationIndexToString(i);
     }
   }
@@ skipping 22 matching lines @@
     : num_general_registers_(num_general_registers),
       num_double_registers_(num_double_registers),
       num_aliased_double_registers_(num_aliased_double_registers),
       general_register_names_(general_register_names),
       double_register_names_(double_register_names) {}
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8