[turbofan] Add RegisterAllocator::NewLiveRange() utility method.

src/compiler/register-allocator.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/linkage.h"
 #include "src/compiler/register-allocator.h"
 #include "src/string-stream.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 718 matching lines @@
     TraceAlloc("Fixed reg is tagged at %d\n", pos);
     auto instr = InstructionAt(pos);
     if (instr->HasPointerMap()) {
       instr->pointer_map()->RecordPointer(operand, code_zone());
     }
   }
   return operand;
 }
 
 
+LiveRange* RegisterAllocator::NewLiveRange(int index) {
+  // The LiveRange object itself can go in the local zone, but the
+  // InstructionOperand needs to go in the code zone, since it may survive
+  // register allocation.
+  return new (local_zone()) LiveRange(index, code_zone());
+}
+
+
 LiveRange* RegisterAllocator::FixedLiveRangeFor(int index) {
   DCHECK(index < config()->num_general_registers());
   auto result = fixed_live_ranges()[index];
   if (result == nullptr) {
-    // TODO(titzer): add a utility method to allocate a new LiveRange:
-    // The LiveRange object itself can go in this zone, but the
-    // InstructionOperand needs
-    // to go in the code zone, since it may survive register allocation.
-    result = new (local_zone()) LiveRange(FixedLiveRangeID(index), code_zone());
+    result = NewLiveRange(FixedLiveRangeID(index));
     DCHECK(result->IsFixed());
     result->kind_ = GENERAL_REGISTERS;
     SetLiveRangeAssignedRegister(result, index);
     fixed_live_ranges()[index] = result;
   }
   return result;
 }
 
 
 LiveRange* RegisterAllocator::FixedDoubleLiveRangeFor(int index) {
   DCHECK(index < config()->num_aliased_double_registers());
   auto result = fixed_double_live_ranges()[index];
   if (result == nullptr) {
-    result = new (local_zone())
-        LiveRange(FixedDoubleLiveRangeID(index), code_zone());
+    result = NewLiveRange(FixedDoubleLiveRangeID(index));
     DCHECK(result->IsFixed());
     result->kind_ = DOUBLE_REGISTERS;
     SetLiveRangeAssignedRegister(result, index);
     fixed_double_live_ranges()[index] = result;
   }
   return result;
 }
 
 
 LiveRange* RegisterAllocator::LiveRangeFor(int index) {
   if (index >= static_cast<int>(live_ranges().size())) {
     live_ranges().resize(index + 1, nullptr);
   }
   auto result = live_ranges()[index];
   if (result == nullptr) {
-    result = new (local_zone()) LiveRange(index, code_zone());
+    result = NewLiveRange(index);
     live_ranges()[index] = result;
   }
   return result;
 }
 
 
 GapInstruction* RegisterAllocator::GetLastGap(const InstructionBlock* block) {
   int last_instruction = block->last_instruction_index();
   return code()->GapAt(last_instruction - 1);
 }
@@ skipping 1793 matching lines @@
   } else {
     DCHECK(range->Kind() == GENERAL_REGISTERS);
     assigned_registers_->Add(reg);
   }
   range->set_assigned_register(reg, operand_cache());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8