Remember required register kind when creating artificial virtual register.

src/lithium-allocator.cc

Index: src/lithium-allocator.cc
diff --git a/src/lithium-allocator.cc b/src/lithium-allocator.cc
index ac61c17ba7685615fe49dd3f66928e291b9f69a8..bc5d6cc5f25af5892d5f0e43e555d8331ff994b5 100644
--- a/src/lithium-allocator.cc
+++ b/src/lithium-allocator.cc
@@ -27,7 +27,6 @@
 
 #include "lithium-allocator.h"
 
-#include "data-flow.h"
 #include "hydrogen.h"
 #include "string-stream.h"
 
@@ -763,6 +762,7 @@ void LAllocator::AddConstraintsGapMove(int index,
 
 
 void LAllocator::MeetRegisterConstraints(HBasicBlock* block) {
+  first_artificial_register_ = next_virtual_register_;
   int start = block->first_instruction_index();
   int end = block->last_instruction_index();
   for (int i = start; i <= end; ++i) {
@@ -834,6 +834,13 @@ void LAllocator::MeetConstraintsBetween(InstructionSummary* first,
       } else if (cur_input->policy() == LUnallocated::WRITABLE_REGISTER) {
         LUnallocated* input_copy = cur_input->CopyUnconstrained();
         cur_input->set_virtual_register(next_virtual_register_++);
+
+        if (RequiredRegisterKind(input_copy->virtual_register()) ==
+            DOUBLE_REGISTERS) {
+          double_artificial_registers_.Add(
+              cur_input->virtual_register() - first_artificial_register_);
+        }
+
         second->AddTemp(cur_input);
         AddConstraintsGapMove(gap_index, input_copy, cur_input);
       }
@@ -1564,10 +1571,16 @@ bool LAllocator::HasTaggedValue(int virtual_register) const {
 
 
 RegisterKind LAllocator::RequiredRegisterKind(int virtual_register) const {
-  HValue* value = graph()->LookupValue(virtual_register);
-  if (value != NULL && value->representation().IsDouble()) {
+  if (virtual_register < first_artificial_register_) {
+    HValue* value = graph()->LookupValue(virtual_register);
+    if (value != NULL && value->representation().IsDouble()) {
+      return DOUBLE_REGISTERS;
+    }
+  } else if (double_artificial_registers_.Contains(
+      virtual_register - first_artificial_register_)) {
     return DOUBLE_REGISTERS;
   }
+
   return GENERAL_REGISTERS;
 }