[v8-dev] ARM: safepoints frame optimization

src/lithium-allocator.cc

 // Copyright 2012 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 616 matching lines @@
 
 LOperand* LAllocator::AllocateFixed(LUnallocated* operand,
                                     int pos,
                                     bool is_tagged) {
   TraceAlloc("Allocating fixed reg for op %d\n", operand->virtual_register());
   ASSERT(operand->HasFixedPolicy());
   if (operand->HasFixedSlotPolicy()) {
     operand->ConvertTo(LOperand::STACK_SLOT, operand->fixed_slot_index());
   } else if (operand->HasFixedRegisterPolicy()) {
     int reg_index = operand->fixed_register_index();
+    modified_registers_ |= 1 << reg_index;
     operand->ConvertTo(LOperand::REGISTER, reg_index);
   } else if (operand->HasFixedDoubleRegisterPolicy()) {
     int reg_index = operand->fixed_register_index();
+    modified_double_registers_ |= 1 << reg_index;
     operand->ConvertTo(LOperand::DOUBLE_REGISTER, reg_index);
   } else {
     UNREACHABLE();
   }
   if (is_tagged) {
     TraceAlloc("Fixed reg is tagged at %d\n", pos);
     LInstruction* instr = InstructionAt(pos);
     if (instr->HasPointerMap()) {
       instr->pointer_map()->RecordPointer(operand, chunk()->zone());
     }
@@ skipping 444 matching lines @@
 
 bool LAllocator::Allocate(LChunk* chunk) {
   ASSERT(chunk_ == NULL);
   chunk_ = static_cast<LPlatformChunk*>(chunk);
   assigned_registers_ =
       new(chunk->zone()) BitVector(Register::NumAllocatableRegisters(),
                                    chunk->zone());
   assigned_double_registers_ =
       new(chunk->zone()) BitVector(DoubleRegister::NumAllocatableRegisters(),
                                    chunk->zone());
+  modified_registers_ = kRegListEmpty;
+  modified_double_registers_ = kRegListEmpty;
   MeetRegisterConstraints();
   if (!AllocationOk()) return false;
   ResolvePhis();
   BuildLiveRanges();
   AllocateGeneralRegisters();
   if (!AllocationOk()) return false;
   AllocateDoubleRegisters();
   if (!AllocationOk()) return false;
   PopulatePointerMaps();
   ConnectRanges();
@@ skipping 1098 matching lines @@
     isolate()->GetHTracer()->TraceLiveRanges(name(), allocator_);
   }
 
 #ifdef DEBUG
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 
 } }  // namespace v8::internal