[turbofan] move label generation to code generator

src/compiler/instruction.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/common-operator.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/instruction.h"
 
 namespace v8 {
@@ skipping 402 matching lines @@
     (*blocks)[rpo_number] = InstructionBlockFor(zone, *it);
   }
   return blocks;
 }
 
 
 InstructionSequence::InstructionSequence(Zone* instruction_zone,
                                          InstructionBlocks* instruction_blocks)
     : zone_(instruction_zone),
       instruction_blocks_(instruction_blocks),
+      block_starts_(static_cast<int>(instruction_blocks_->size()), -1, zone()),
       constants_(ConstantMap::key_compare(),
                  ConstantMap::allocator_type(zone())),
       immediates_(zone()),
       instructions_(zone()),
       next_virtual_register_(0),
       pointer_maps_(zone()),
       doubles_(std::less<int>(), VirtualRegisterSet::allocator_type(zone())),
       references_(std::less<int>(), VirtualRegisterSet::allocator_type(zone())),
       deoptimization_entries_(zone()) {}
 
 
-Label* InstructionSequence::GetLabel(BasicBlock::RpoNumber rpo) {
-  return GetBlockStart(rpo)->label();
-}
-
-
 BlockStartInstruction* InstructionSequence::GetBlockStart(
     BasicBlock::RpoNumber rpo) {
   InstructionBlock* block = InstructionBlockAt(rpo);
-  BlockStartInstruction* block_start =
-      BlockStartInstruction::cast(InstructionAt(block->code_start()));
-  DCHECK_EQ(rpo.ToInt(), block_start->rpo_number().ToInt());
-  return block_start;
+  return BlockStartInstruction::cast(InstructionAt(block->code_start()));
 }
 
 
 void InstructionSequence::StartBlock(BasicBlock::RpoNumber rpo) {
   InstructionBlock* block = InstructionBlockAt(rpo);
-  block->set_code_start(static_cast<int>(instructions_.size()));
-  BlockStartInstruction* block_start =
-      BlockStartInstruction::New(zone(), block->id(), rpo);
+  int code_start = static_cast<int>(instructions_.size());
+  block->set_code_start(code_start);
+  block_starts_[rpo.ToSize()] = code_start;
+  BlockStartInstruction* block_start = BlockStartInstruction::New(zone());
   AddInstruction(block_start);
 }
 
 
 void InstructionSequence::EndBlock(BasicBlock::RpoNumber rpo) {
   int end = static_cast<int>(instructions_.size());
   InstructionBlock* block = InstructionBlockAt(rpo);
   DCHECK(block->code_start() >= 0 && block->code_start() < end);
   block->set_code_end(end);
 }
@@ skipping 12 matching lines @@
     pointer_map->set_instruction_position(index);
     instr->set_pointer_map(pointer_map);
     pointer_maps_.push_back(pointer_map);
   }
   return index;
 }
 
 
 const InstructionBlock* InstructionSequence::GetInstructionBlock(
     int instruction_index) const {
-  // TODO(turbofan): Optimize this.
-  for (;;) {
-    DCHECK_LE(0, instruction_index);
-    Instruction* instruction = InstructionAt(instruction_index--);
-    if (instruction->IsBlockStart()) {
-      return instruction_blocks_->at(
-          BlockStartInstruction::cast(instruction)->rpo_number().ToSize());
-    }
-  }
+  auto begin = block_starts_.begin();
+  auto end = std::lower_bound(begin, block_starts_.end(), instruction_index,
+                              std::less_equal<int>());
+  auto block = instruction_blocks_->at(std::distance(begin, end) - 1);
+  DCHECK(block->code_start() <= instruction_index &&
+         instruction_index < block->code_end());
+  return block;
 }
 
 
 bool InstructionSequence::IsReference(int virtual_register) const {
   return references_.find(virtual_register) != references_.end();
 }
 
 
 bool InstructionSequence::IsDouble(int virtual_register) const {
   return doubles_.find(virtual_register) != doubles_.end();
@@ skipping 165 matching lines @@
       os << " B" << succ_block->id();
     }
     os << "\n";
   }
   return os;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8