[turbofan] decouple register allocation from schedule and graph

R=bmeurer@chromium.org, jarin@chromium.org

BUG=

Review URL: https://codereview.chromium.org/664683002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24717 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/instruction-selector.cc

@@ -853,8 +853,17 @@ void InstructionSelector::VisitParameter(Node* node) {
 
 void InstructionSelector::VisitPhi(Node* node) {
   // TODO(bmeurer): Emit a PhiInstruction here.
-  for (InputIter i = node->inputs().begin(); i != node->inputs().end(); ++i) {
+  PhiInstruction* phi = new (instruction_zone())
-    MarkAsUsed(*i);
+      PhiInstruction(instruction_zone(), sequence()->GetVirtualRegister(node));
+  sequence()->InstructionBlockAt(current_block_->GetRpoNumber())->AddPhi(phi);
+  Node::Inputs inputs = node->inputs();
+  size_t j = 0;
+  for (Node::Inputs::iterator iter(inputs.begin()); iter != inputs.end();
+       ++iter, ++j) {
+    MarkAsUsed(*iter);
+    // TODO(mstarzinger): Use a ValueInputIterator instead.
+    if (j >= current_block_->PredecessorCount()) continue;
+    phi->operands().push_back(sequence()->GetVirtualRegister(*iter));
   }
 }
 

src/compiler/instruction.cc

@@ -317,12 +317,75 @@ std::ostream& operator<<(std::ostream& os, const Constant& constant) {
 }
 
 
+static BasicBlock::RpoNumber GetRpo(BasicBlock* block) {
+  if (block == NULL) return BasicBlock::RpoNumber::Invalid();
+  return block->GetRpoNumber();
+}
+
+
+static BasicBlock::RpoNumber GetLoopEndRpo(const BasicBlock* block) {
+  if (!block->IsLoopHeader()) return BasicBlock::RpoNumber::Invalid();
+  return BasicBlock::RpoNumber::FromInt(block->loop_end());
+}
+
+
+InstructionBlock::InstructionBlock(Zone* zone, const BasicBlock* block)
+    : successors_(block->SuccessorCount(), BasicBlock::RpoNumber::Invalid(),
+                  zone),
+      predecessors_(block->PredecessorCount(), BasicBlock::RpoNumber::Invalid(),
+                    zone),
+      phis_(zone),
+      rpo_number_(block->GetRpoNumber()),
+      loop_header_(GetRpo(block->loop_header())),
+      loop_end_(GetLoopEndRpo(block)),
+      code_start_(-1),
+      code_end_(-1) {
+  // Map successors and precessors
+  size_t index = 0;
+  for (BasicBlock::Successors::const_iterator it = block->successors_begin();
+       it != block->successors_end(); ++it, ++index) {
+    successors_[index] = (*it)->GetRpoNumber();
+  }
+  index = 0;
+  for (BasicBlock::Predecessors::const_iterator
+           it = block->predecessors_begin();
+       it != block->predecessors_end(); ++it, ++index) {
+    predecessors_[index] = (*it)->GetRpoNumber();
+  }
+}
+
+
+size_t InstructionBlock::PredecessorIndexOf(
+    BasicBlock::RpoNumber rpo_number) const {
+  size_t j = 0;
+  for (InstructionBlock::Predecessors::const_iterator i = predecessors_.begin();
+       i != predecessors_.end(); ++i, ++j) {
+    if (*i == rpo_number) break;
+  }
+  return j;
+}
+
+
+static void InitializeInstructionBlocks(Zone* zone, const Schedule* schedule,
+                                        InstructionBlocks* blocks) {
+  DCHECK(blocks->size() == schedule->rpo_order()->size());
+  size_t rpo_number = 0;
+  for (BasicBlockVector::const_iterator it = schedule->rpo_order()->begin();
+       it != schedule->rpo_order()->end(); ++it, ++rpo_number) {
+    DCHECK_EQ(NULL, (*blocks)[rpo_number]);
+    DCHECK((*it)->GetRpoNumber().ToSize() == rpo_number);
+    (*blocks)[rpo_number] = new (zone) InstructionBlock(zone, *it);
+  }
+}
+
+
 InstructionSequence::InstructionSequence(Linkage* linkage, Graph* graph,
                                          Schedule* schedule)
-    : zone_(schedule->zone()),
+    : zone_(schedule->zone()),  // TODO(dcarney): new zone.
       node_count_(graph->NodeCount()),
       node_map_(zone()->NewArray<int>(node_count_)),
-      block_data_(static_cast<int>(schedule->BasicBlockCount()), zone()),
+      instruction_blocks_(static_cast<int>(schedule->rpo_order()->size()), NULL,
+                          zone()),
       linkage_(linkage),
       schedule_(schedule),
       constants_(ConstantMap::key_compare(),
@@ -337,6 +400,7 @@ InstructionSequence::InstructionSequence(Linkage* linkage, Graph* graph,
   for (int i = 0; i < node_count_; ++i) {
     node_map_[i] = -1;
   }
+  InitializeInstructionBlocks(zone(), schedule, &instruction_blocks_);
 }
 
 
@@ -408,6 +472,20 @@ BasicBlock* InstructionSequence::GetBasicBlock(int instruction_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_
+          [BlockStartInstruction::cast(instruction)->rpo_number().ToSize()];
+    }
+  }
+}
+
+
 bool InstructionSequence::IsReference(int virtual_register) const {
   return references_.find(virtual_register) != references_.end();
 }

src/compiler/instruction.h

@@ -753,6 +753,81 @@ class FrameStateDescriptor : public ZoneObject {
 
 std::ostream& operator<<(std::ostream& os, const Constant& constant);
 
+
+// TODO(dcarney): this is a temporary hack.  turn into an actual instruction.
+class PhiInstruction : public ZoneObject {
+ public:
+  PhiInstruction(Zone* zone, int virtual_register)
+      : virtual_register_(virtual_register), operands_(zone) {}
+
+  int virtual_register() const { return virtual_register_; }
+  const IntVector& operands() const { return operands_; }
+  IntVector& operands() { return operands_; }
+
+ private:
+  const int virtual_register_;
+  IntVector operands_;
+};
+
+
+// Analogue of BasicBlock for Instructions instead of Nodes.
+class InstructionBlock : public ZoneObject {
+ public:
+  explicit InstructionBlock(Zone* zone, const BasicBlock* block);
+
+  // Instruction indexes (used by the register allocator).
+  int first_instruction_index() const {
+    DCHECK(code_start_ >= 0);
+    DCHECK(code_end_ > 0);
+    DCHECK(code_end_ >= code_start_);
+    return code_start_;
+  }
+  int last_instruction_index() const {
+    DCHECK(code_start_ >= 0);
+    DCHECK(code_end_ > 0);
+    DCHECK(code_end_ >= code_start_);
+    return code_end_ - 1;
+  }
+
+  int32_t code_start() const { return code_start_; }
+  void set_code_start(int32_t start) { code_start_ = start; }
+
+  int32_t code_end() const { return code_end_; }
+  void set_code_end(int32_t end) { code_end_ = end; }
+
+  BasicBlock::RpoNumber rpo_number() const { return rpo_number_; }
+  BasicBlock::RpoNumber loop_header() const { return loop_header_; }
+  BasicBlock::RpoNumber loop_end() const {
+    DCHECK(IsLoopHeader());
+    return loop_end_;
+  }
+  inline bool IsLoopHeader() const { return loop_end_.IsValid(); }
+
+  typedef ZoneVector<BasicBlock::RpoNumber> Predecessors;
+  const Predecessors& predecessors() const { return predecessors_; }
+  size_t PredecessorCount() const { return predecessors_.size(); }
+  size_t PredecessorIndexOf(BasicBlock::RpoNumber rpo_number) const;
+
+  typedef ZoneVector<BasicBlock::RpoNumber> Successors;
+  const Successors& successors() const { return successors_; }
+  size_t SuccessorCount() const { return successors_.size(); }
+
+  typedef ZoneVector<PhiInstruction*> PhiInstructions;
+  const PhiInstructions& phis() const { return phis_; }
+  void AddPhi(PhiInstruction* phi) { phis_.push_back(phi); }
+
+ private:
+  Successors successors_;
+  Predecessors predecessors_;
+  PhiInstructions phis_;
+  // TODO(dcarney): probably dont't need this.
+  BasicBlock::RpoNumber rpo_number_;
+  BasicBlock::RpoNumber loop_header_;
+  BasicBlock::RpoNumber loop_end_;
+  int32_t code_start_;  // start index of arch-specific code.
+  int32_t code_end_;    // end index of arch-specific code.
+};
+
 typedef ZoneDeque<Constant> ConstantDeque;
 typedef std::map<int, Constant, std::less<int>,
                  zone_allocator<std::pair<int, Constant> > > ConstantMap;
@@ -760,6 +835,7 @@ typedef std::map<int, Constant, std::less<int>,
 typedef ZoneDeque<Instruction*> InstructionDeque;
 typedef ZoneDeque<PointerMap*> PointerMapDeque;
 typedef ZoneVector<FrameStateDescriptor*> DeoptimizationVector;
+typedef ZoneVector<InstructionBlock*> InstructionBlocks;
 
 // Represents architecture-specific generated code before, during, and after
 // register allocation.
@@ -774,18 +850,32 @@ class InstructionSequence FINAL {
   int node_count() const { return node_count_; }
 
   int BasicBlockCount() const {
-    return static_cast<int>(schedule_->rpo_order()->size());
+    return static_cast<int>(instruction_blocks_.size());
   }
 
   BasicBlock* BlockAt(int rpo_number) const {
     return (*schedule_->rpo_order())[rpo_number];
   }
 
-  BasicBlock* GetContainingLoop(BasicBlock* block) {
+  InstructionBlock* InstructionBlockAt(BasicBlock::RpoNumber rpo_number) {
-    return block->loop_header();
+    return GetBlock(rpo_number);
+  }
+
+  const InstructionBlock* InstructionBlockAt(
+      BasicBlock::RpoNumber rpo_number) const {
+    return GetBlock(rpo_number);
+  }
+
+  // TODO(dcarney): move to register allocator.
+  const InstructionBlock* GetContainingLoop(
+      const InstructionBlock* block) const {
+    BasicBlock::RpoNumber index = block->loop_header();
+    if (!index.IsValid()) return NULL;
+    return instruction_blocks_[index.ToInt()];
   }
 
   BasicBlock* GetBasicBlock(int instruction_index);
+  const InstructionBlock* GetInstructionBlock(int instruction_index) const;
 
   int GetVirtualRegister(const Node* node);
   // TODO(dcarney): find a way to remove this.
@@ -828,26 +918,32 @@ class InstructionSequence FINAL {
   void StartBlock(BasicBlock* block);
   void EndBlock(BasicBlock* block);
   void set_code_start(BasicBlock* block, int start) {
-    return GetBlockData(block->GetRpoNumber()).set_code_start(start);
+    return GetBlock(block->GetRpoNumber())->set_code_start(start);
   }
   void set_code_end(BasicBlock* block, int end) {
-    return GetBlockData(block->GetRpoNumber()).set_code_end(end);
+    return GetBlock(block->GetRpoNumber())->set_code_end(end);
   }
   // TODO(dcarney): use RpoNumber for all of the below.
   int code_start(BasicBlock::RpoNumber rpo_number) const {
-    return GetBlockData(rpo_number).code_start();
+    return GetBlock(rpo_number)->code_start();
   }
   int code_start(BasicBlock* block) const {
-    return GetBlockData(block->GetRpoNumber()).code_start();
+    return GetBlock(block->GetRpoNumber())->code_start();
   }
   int code_end(BasicBlock* block) const {
-    return GetBlockData(block->GetRpoNumber()).code_end();
+    return GetBlock(block->GetRpoNumber())->code_end();
   }
   int first_instruction_index(BasicBlock* block) const {
-    return GetBlockData(block->GetRpoNumber()).first_instruction_index();
+    return GetBlock(block->GetRpoNumber())->first_instruction_index();
   }
   int last_instruction_index(BasicBlock* block) const {
-    return GetBlockData(block->GetRpoNumber()).last_instruction_index();
+    return GetBlock(block->GetRpoNumber())->last_instruction_index();
+  }
+  int first_instruction_index(InstructionBlock* block) const {
+    return GetBlock(block->rpo_number())->first_instruction_index();
+  }
+  int last_instruction_index(InstructionBlock* block) const {
+    return GetBlock(block->rpo_number())->last_instruction_index();
   }
 
   int AddConstant(Node* node, Constant constant) {
@@ -892,51 +988,19 @@ class InstructionSequence FINAL {
   int GetFrameStateDescriptorCount();
 
  private:
-  class BlockData {
+  InstructionBlock* GetBlock(BasicBlock::RpoNumber rpo_number) const {
-   public:
+    return instruction_blocks_[rpo_number.ToSize()];
-    BlockData() : code_start_(-1), code_end_(-1) {}
-    // Instruction indexes (used by the register allocator).
-    int first_instruction_index() const {
-      DCHECK(code_start_ >= 0);
-      DCHECK(code_end_ > 0);
-      DCHECK(code_end_ >= code_start_);
-      return code_start_;
-    }
-    int last_instruction_index() const {
-      DCHECK(code_start_ >= 0);
-      DCHECK(code_end_ > 0);
-      DCHECK(code_end_ >= code_start_);
-      return code_end_ - 1;
-    }
-
-    int32_t code_start() const { return code_start_; }
-    void set_code_start(int32_t start) { code_start_ = start; }
-
-    int32_t code_end() const { return code_end_; }
-    void set_code_end(int32_t end) { code_end_ = end; }
-
-   private:
-    int32_t code_start_;  // start index of arch-specific code.
-    int32_t code_end_;    // end index of arch-specific code.
-  };
-
-  const BlockData& GetBlockData(BasicBlock::RpoNumber rpo_number) const {
-    return block_data_[rpo_number.ToSize()];
-  }
-  BlockData& GetBlockData(BasicBlock::RpoNumber rpo_number) {
-    return block_data_[rpo_number.ToSize()];
   }
 
   friend std::ostream& operator<<(std::ostream& os,
                                   const InstructionSequence& code);
 
   typedef std::set<int, std::less<int>, ZoneIntAllocator> VirtualRegisterSet;
-  typedef ZoneVector<BlockData> BlockDataVector;
 
   Zone* zone_;
   int node_count_;
   int* node_map_;
-  BlockDataVector block_data_;
+  InstructionBlocks instruction_blocks_;
   Linkage* linkage_;
   Schedule* schedule_;
   ConstantMap constants_;

src/compiler/register-allocator.cc

@@ -4,7 +4,6 @@
 
 #include "src/compiler/register-allocator.h"
 
-#include "src/compiler/generic-node-inl.h"
 #include "src/compiler/linkage.h"
 #include "src/hydrogen.h"
 #include "src/string-stream.h"
@@ -524,46 +523,40 @@ void RegisterAllocator::InitializeLivenessAnalysis() {
 }
 
 
-BitVector* RegisterAllocator::ComputeLiveOut(BasicBlock* block) {
+BitVector* RegisterAllocator::ComputeLiveOut(const InstructionBlock* block) {
   // Compute live out for the given block, except not including backward
   // successor edges.
   BitVector* live_out =
       new (zone()) BitVector(code()->VirtualRegisterCount(), zone());
 
   // Process all successor blocks.
-  for (BasicBlock::Successors::iterator i = block->successors_begin();
+  for (auto succ : block->successors()) {
-       i != block->successors_end(); ++i) {
     // Add values live on entry to the successor. Note the successor's
     // live_in will not be computed yet for backwards edges.
-    BasicBlock* successor = *i;
+    BitVector* live_in = live_in_sets_[succ.ToSize()];
-    BitVector* live_in = live_in_sets_[successor->rpo_number()];
     if (live_in != NULL) live_out->Union(*live_in);
 
     // All phi input operands corresponding to this successor edge are live
     // out from this block.
-    size_t index = successor->PredecessorIndexOf(block);
+    const InstructionBlock* successor = code()->InstructionBlockAt(succ);
+    size_t index = successor->PredecessorIndexOf(block->rpo_number());
     DCHECK(index < successor->PredecessorCount());
-    for (BasicBlock::const_iterator j = successor->begin();
+    for (auto phi : successor->phis()) {
-         j != successor->end(); ++j) {
+      live_out->Add(phi->operands()[index]);
-      Node* phi = *j;
-      if (phi->opcode() != IrOpcode::kPhi) continue;
-      Node* input = phi->InputAt(static_cast<int>(index));
-      live_out->Add(code()->GetVirtualRegister(input));
     }
   }
   return live_out;
 }
 
 
-void RegisterAllocator::AddInitialIntervals(BasicBlock* block,
+void RegisterAllocator::AddInitialIntervals(const InstructionBlock* block,
                                             BitVector* live_out) {
   // Add an interval that includes the entire block to the live range for
   // each live_out value.
-  LifetimePosition start = LifetimePosition::FromInstructionIndex(
+  LifetimePosition start =
-      code()->first_instruction_index(block));
+      LifetimePosition::FromInstructionIndex(block->first_instruction_index());
-  LifetimePosition end =
+  LifetimePosition end = LifetimePosition::FromInstructionIndex(
-      LifetimePosition::FromInstructionIndex(
+                             block->last_instruction_index()).NextInstruction();
-          code()->last_instruction_index(block)).NextInstruction();
   BitVector::Iterator iterator(live_out);
   while (!iterator.Done()) {
     int operand_index = iterator.Current();
@@ -651,8 +644,8 @@ LiveRange* RegisterAllocator::LiveRangeFor(int index) {
 }
 
 
-GapInstruction* RegisterAllocator::GetLastGap(BasicBlock* block) {
+GapInstruction* RegisterAllocator::GetLastGap(const InstructionBlock* block) {
-  int last_instruction = code()->last_instruction_index(block);
+  int last_instruction = block->last_instruction_index();
   return code()->GapAt(last_instruction - 1);
 }
 
@@ -729,9 +722,9 @@ void RegisterAllocator::AddConstraintsGapMove(int index,
 }
 
 
-void RegisterAllocator::MeetRegisterConstraints(BasicBlock* block) {
+void RegisterAllocator::MeetRegisterConstraints(const InstructionBlock* block) {
-  int start = code()->first_instruction_index(block);
+  int start = block->first_instruction_index();
-  int end = code()->last_instruction_index(block);
+  int end = block->last_instruction_index();
   DCHECK_NE(-1, start);
   for (int i = start; i <= end; ++i) {
     if (code()->IsGapAt(i)) {
@@ -752,8 +745,8 @@ void RegisterAllocator::MeetRegisterConstraints(BasicBlock* block) {
 
 
 void RegisterAllocator::MeetRegisterConstraintsForLastInstructionInBlock(
-    BasicBlock* block) {
+    const InstructionBlock* block) {
-  int end = code()->last_instruction_index(block);
+  int end = block->last_instruction_index();
   Instruction* last_instruction = InstructionAt(end);
   for (size_t i = 0; i < last_instruction->OutputCount(); i++) {
     InstructionOperand* output_operand = last_instruction->OutputAt(i);
@@ -771,10 +764,10 @@ void RegisterAllocator::MeetRegisterConstraintsForLastInstructionInBlock(
         assigned = true;
       }
 
-      for (BasicBlock::Successors::iterator succ = block->successors_begin();
+      for (auto succ : block->successors()) {
-           succ != block->successors_end(); ++succ) {
+        const InstructionBlock* successor = code()->InstructionBlockAt(succ);
-        DCHECK((*succ)->PredecessorCount() == 1);
+        DCHECK(successor->PredecessorCount() == 1);
-        int gap_index = code()->first_instruction_index(*succ) + 1;
+        int gap_index = successor->first_instruction_index() + 1;
         DCHECK(code()->IsGapAt(gap_index));
 
         // Create an unconstrained operand for the same virtual register
@@ -788,10 +781,10 @@ void RegisterAllocator::MeetRegisterConstraintsForLastInstructionInBlock(
     }
 
     if (!assigned) {
-      for (BasicBlock::Successors::iterator succ = block->successors_begin();
+      for (auto succ : block->successors()) {
-           succ != block->successors_end(); ++succ) {
+        const InstructionBlock* successor = code()->InstructionBlockAt(succ);
-        DCHECK((*succ)->PredecessorCount() == 1);
+        DCHECK(successor->PredecessorCount() == 1);
-        int gap_index = code()->first_instruction_index(*succ) + 1;
+        int gap_index = successor->first_instruction_index() + 1;
         range->SetSpillStartIndex(gap_index);
 
         // This move to spill operand is not a real use. Liveness analysis
@@ -936,14 +929,14 @@ bool RegisterAllocator::IsOutputDoubleRegisterOf(Instruction* instr,
 }
 
 
-void RegisterAllocator::ProcessInstructions(BasicBlock* block,
+void RegisterAllocator::ProcessInstructions(const InstructionBlock* block,
                                             BitVector* live) {
-  int block_start = code()->first_instruction_index(block);
+  int block_start = block->first_instruction_index();
 
   LifetimePosition block_start_position =
       LifetimePosition::FromInstructionIndex(block_start);
 
-  for (int index = code()->last_instruction_index(block); index >= block_start;
+  for (int index = block->last_instruction_index(); index >= block_start;
        index--) {
     LifetimePosition curr_position =
         LifetimePosition::FromInstructionIndex(index);
@@ -1059,44 +1052,35 @@ void RegisterAllocator::ProcessInstructions(BasicBlock* block,
 }
 
 
-void RegisterAllocator::ResolvePhis(BasicBlock* block) {
+void RegisterAllocator::ResolvePhis(const InstructionBlock* block) {
-  for (BasicBlock::const_iterator i = block->begin(); i != block->end(); ++i) {
+  for (auto phi : block->phis()) {
-    Node* phi = *i;
-    if (phi->opcode() != IrOpcode::kPhi) continue;
-
     UnallocatedOperand* phi_operand =
         new (code_zone()) UnallocatedOperand(UnallocatedOperand::NONE);
-    int phi_vreg = code()->GetVirtualRegister(phi);
+    int phi_vreg = phi->virtual_register();
     phi_operand->set_virtual_register(phi_vreg);
 
-    size_t j = 0;
+    for (size_t i = 0; i < phi->operands().size(); ++i) {
-    Node::Inputs inputs = phi->inputs();
-    for (Node::Inputs::iterator iter(inputs.begin()); iter != inputs.end();
-         ++iter, ++j) {
-      Node* op = *iter;
-      // TODO(mstarzinger): Use a ValueInputIterator instead.
-      if (j >= block->PredecessorCount()) continue;
       UnallocatedOperand* operand =
           new (code_zone()) UnallocatedOperand(UnallocatedOperand::ANY);
-      operand->set_virtual_register(code()->GetVirtualRegister(op));
+      operand->set_virtual_register(phi->operands()[i]);
-      BasicBlock* cur_block = block->PredecessorAt(j);
+      InstructionBlock* cur_block =
+          code()->InstructionBlockAt(block->predecessors()[i]);
       // The gap move must be added without any special processing as in
       // the AddConstraintsGapMove.
-      code()->AddGapMove(code()->last_instruction_index(cur_block) - 1, operand,
+      code()->AddGapMove(cur_block->last_instruction_index() - 1, operand,
                          phi_operand);
 
-      Instruction* branch =
+      Instruction* branch = InstructionAt(cur_block->last_instruction_index());
-          InstructionAt(code()->last_instruction_index(cur_block));
       DCHECK(!branch->HasPointerMap());
       USE(branch);
     }
 
     LiveRange* live_range = LiveRangeFor(phi_vreg);
     BlockStartInstruction* block_start =
-        code()->GetBlockStart(block->GetRpoNumber());
+        code()->GetBlockStart(block->rpo_number());
     block_start->GetOrCreateParallelMove(GapInstruction::START, code_zone())
         ->AddMove(phi_operand, live_range->GetSpillOperand(), code_zone());
-    live_range->SetSpillStartIndex(code()->first_instruction_index(block));
+    live_range->SetSpillStartIndex(block->first_instruction_index());
 
     // We use the phi-ness of some nodes in some later heuristics.
     live_range->set_is_phi(true);
@@ -1132,7 +1116,8 @@ bool RegisterAllocator::Allocate() {
 void RegisterAllocator::MeetRegisterConstraints() {
   RegisterAllocatorPhase phase("L_Register constraints", this);
   for (int i = 0; i < code()->BasicBlockCount(); ++i) {
-    MeetRegisterConstraints(code()->BlockAt(i));
+    MeetRegisterConstraints(
+        code()->InstructionBlockAt(BasicBlock::RpoNumber::FromInt(i)));
     if (!AllocationOk()) return;
   }
 }
@@ -1143,17 +1128,18 @@ void RegisterAllocator::ResolvePhis() {
 
   // Process the blocks in reverse order.
   for (int i = code()->BasicBlockCount() - 1; i >= 0; --i) {
-    ResolvePhis(code()->BlockAt(i));
+    ResolvePhis(code()->InstructionBlockAt(BasicBlock::RpoNumber::FromInt(i)));
   }
 }
 
 
-void RegisterAllocator::ResolveControlFlow(LiveRange* range, BasicBlock* block,
+void RegisterAllocator::ResolveControlFlow(LiveRange* range,
-                                           BasicBlock* pred) {
+                                           const InstructionBlock* block,
-  LifetimePosition pred_end = LifetimePosition::FromInstructionIndex(
+                                           const InstructionBlock* pred) {
-      code()->last_instruction_index(pred));
+  LifetimePosition pred_end =
-  LifetimePosition cur_start = LifetimePosition::FromInstructionIndex(
+      LifetimePosition::FromInstructionIndex(pred->last_instruction_index());
-      code()->first_instruction_index(block));
+  LifetimePosition cur_start =
+      LifetimePosition::FromInstructionIndex(block->first_instruction_index());
   LiveRange* pred_cover = NULL;
   LiveRange* cur_cover = NULL;
   LiveRange* cur_range = range;
@@ -1178,13 +1164,12 @@ void RegisterAllocator::ResolveControlFlow(LiveRange* range, BasicBlock* block,
     if (!pred_op->Equals(cur_op)) {
       GapInstruction* gap = NULL;
       if (block->PredecessorCount() == 1) {
-        gap = code()->GapAt(code()->first_instruction_index(block));
+        gap = code()->GapAt(block->first_instruction_index());
       } else {
         DCHECK(pred->SuccessorCount() == 1);
         gap = GetLastGap(pred);
 
-        Instruction* branch =
+        Instruction* branch = InstructionAt(pred->last_instruction_index());
-            InstructionAt(code()->last_instruction_index(pred));
         DCHECK(!branch->HasPointerMap());
         USE(branch);
       }
@@ -1211,8 +1196,9 @@ ParallelMove* RegisterAllocator::GetConnectingParallelMove(
 }
 
 
-BasicBlock* RegisterAllocator::GetBlock(LifetimePosition pos) {
+const InstructionBlock* RegisterAllocator::GetInstructionBlock(
-  return code()->GetBasicBlock(pos.InstructionIndex());
+    LifetimePosition pos) {
+  return code()->GetInstructionBlock(pos.InstructionIndex());
 }
 
 
@@ -1232,7 +1218,8 @@ void RegisterAllocator::ConnectRanges() {
         if (first_range->End().Value() == pos.Value()) {
           bool should_insert = true;
           if (IsBlockBoundary(pos)) {
-            should_insert = CanEagerlyResolveControlFlow(GetBlock(pos));
+            should_insert =
+                CanEagerlyResolveControlFlow(GetInstructionBlock(pos));
           }
           if (should_insert) {
             ParallelMove* move = GetConnectingParallelMove(pos);
@@ -1252,24 +1239,25 @@ void RegisterAllocator::ConnectRanges() {
 }
 
 
-bool RegisterAllocator::CanEagerlyResolveControlFlow(BasicBlock* block) const {
+bool RegisterAllocator::CanEagerlyResolveControlFlow(
+    const InstructionBlock* block) const {
   if (block->PredecessorCount() != 1) return false;
-  return block->PredecessorAt(0)->rpo_number() == block->rpo_number() - 1;
+  return block->predecessors()[0].IsNext(block->rpo_number());
 }
 
 
 void RegisterAllocator::ResolveControlFlow() {
   RegisterAllocatorPhase phase("L_Resolve control flow", this);
   for (int block_id = 1; block_id < code()->BasicBlockCount(); ++block_id) {
-    BasicBlock* block = code()->BlockAt(block_id);
+    const InstructionBlock* block =
+        code()->InstructionBlockAt(BasicBlock::RpoNumber::FromInt(block_id));
     if (CanEagerlyResolveControlFlow(block)) continue;
-    BitVector* live = live_in_sets_[block->rpo_number()];
+    BitVector* live = live_in_sets_[block->rpo_number().ToInt()];
     BitVector::Iterator iterator(live);
     while (!iterator.Done()) {
       int operand_index = iterator.Current();
-      for (BasicBlock::Predecessors::iterator i = block->predecessors_begin();
+      for (auto pred : block->predecessors()) {
-           i != block->predecessors_end(); ++i) {
+        const InstructionBlock* cur = code()->InstructionBlockAt(pred);
-        BasicBlock* cur = *i;
         LiveRange* cur_range = LiveRangeFor(operand_index);
         ResolveControlFlow(cur_range, block, cur);
       }
@@ -1285,7 +1273,8 @@ void RegisterAllocator::BuildLiveRanges() {
   // Process the blocks in reverse order.
   for (int block_id = code()->BasicBlockCount() - 1; block_id >= 0;
        --block_id) {
-    BasicBlock* block = code()->BlockAt(block_id);
+    const InstructionBlock* block =
+        code()->InstructionBlockAt(BasicBlock::RpoNumber::FromInt(block_id));
     BitVector* live = ComputeLiveOut(block);
     // Initially consider all live_out values live for the entire block. We
     // will shorten these intervals if necessary.
@@ -1295,19 +1284,16 @@ void RegisterAllocator::BuildLiveRanges() {
     // live values.
     ProcessInstructions(block, live);
     // All phi output operands are killed by this block.
-    for (BasicBlock::const_iterator i = block->begin(); i != block->end();
+    for (auto phi : block->phis()) {
-         ++i) {
-      Node* phi = *i;
-      if (phi->opcode() != IrOpcode::kPhi) continue;
-
       // The live range interval already ends at the first instruction of the
       // block.
-      int phi_vreg = code()->GetVirtualRegister(phi);
+      int phi_vreg = phi->virtual_register();
       live->Remove(phi_vreg);
 
       InstructionOperand* hint = NULL;
       InstructionOperand* phi_operand = NULL;
-      GapInstruction* gap = GetLastGap(block->PredecessorAt(0));
+      GapInstruction* gap =
+          GetLastGap(code()->InstructionBlockAt(block->predecessors()[0]));
 
       // TODO(titzer): no need to create the parallel move if it doesn't exit.
       ParallelMove* move =
@@ -1324,7 +1310,7 @@ void RegisterAllocator::BuildLiveRanges() {
       DCHECK(hint != NULL);
 
       LifetimePosition block_start = LifetimePosition::FromInstructionIndex(
-          code()->first_instruction_index(block));
+          block->first_instruction_index());
       Define(block_start, phi_operand, hint);
     }
 
@@ -1337,9 +1323,10 @@ void RegisterAllocator::BuildLiveRanges() {
       // for each value live on entry to the header.
       BitVector::Iterator iterator(live);
       LifetimePosition start = LifetimePosition::FromInstructionIndex(
-          code()->first_instruction_index(block));
+          block->first_instruction_index());
-      int end_index =
+      int end_index = code()
-          code()->last_instruction_index(code()->BlockAt(block->loop_end()));
+                          ->InstructionBlockAt(block->loop_end())
+                          ->last_instruction_index();
       LifetimePosition end =
           LifetimePosition::FromInstructionIndex(end_index).NextInstruction();
       while (!iterator.Done()) {
@@ -1350,7 +1337,8 @@ void RegisterAllocator::BuildLiveRanges() {
       }
 
       // Insert all values into the live in sets of all blocks in the loop.
-      for (int i = block->rpo_number() + 1; i < block->loop_end(); ++i) {
+      for (int i = block->rpo_number().ToInt() + 1;
+           i < block->loop_end().ToInt(); ++i) {
         live_in_sets_[i]->Union(*live);
       }
     }
@@ -1958,8 +1946,8 @@ void RegisterAllocator::AllocateBlockedReg(LiveRange* current) {
 
 LifetimePosition RegisterAllocator::FindOptimalSpillingPos(
     LiveRange* range, LifetimePosition pos) {
-  BasicBlock* block = GetBlock(pos.InstructionStart());
+  const InstructionBlock* block = GetInstructionBlock(pos.InstructionStart());
-  BasicBlock* loop_header =
+  const InstructionBlock* loop_header =
       block->IsLoopHeader() ? block : code()->GetContainingLoop(block);
 
   if (loop_header == NULL) return pos;
@@ -1971,7 +1959,7 @@ LifetimePosition RegisterAllocator::FindOptimalSpillingPos(
     // If possible try to move spilling position backwards to loop header.
     // This will reduce number of memory moves on the back edge.
     LifetimePosition loop_start = LifetimePosition::FromInstructionIndex(
-        code()->first_instruction_index(loop_header));
+        loop_header->first_instruction_index());
 
     if (range->Covers(loop_start)) {
       if (prev_use == NULL || prev_use->pos().Value() < loop_start.Value()) {
@@ -2086,8 +2074,8 @@ LifetimePosition RegisterAllocator::FindOptimalSplitPos(LifetimePosition start,
   // We have no choice
   if (start_instr == end_instr) return end;
 
-  BasicBlock* start_block = GetBlock(start);
+  const InstructionBlock* start_block = GetInstructionBlock(start);
-  BasicBlock* end_block = GetBlock(end);
+  const InstructionBlock* end_block = GetInstructionBlock(end);
 
   if (end_block == start_block) {
     // The interval is split in the same basic block. Split at the latest
@@ -2095,12 +2083,12 @@ LifetimePosition RegisterAllocator::FindOptimalSplitPos(LifetimePosition start,
     return end;
   }
 
-  BasicBlock* block = end_block;
+  const InstructionBlock* block = end_block;
   // Find header of outermost loop.
   // TODO(titzer): fix redundancy below.
   while (code()->GetContainingLoop(block) != NULL &&
-         code()->GetContainingLoop(block)->rpo_number() >
+         code()->GetContainingLoop(block)->rpo_number().ToInt() >
-             start_block->rpo_number()) {
+             start_block->rpo_number().ToInt()) {
     block = code()->GetContainingLoop(block);
   }
 
@@ -2109,7 +2097,7 @@ LifetimePosition RegisterAllocator::FindOptimalSplitPos(LifetimePosition start,
   if (block == end_block && !end_block->IsLoopHeader()) return end;
 
   return LifetimePosition::FromInstructionIndex(
-      code()->first_instruction_index(block));
+      block->first_instruction_index());
 }
 
 

src/compiler/register-allocator.h

@@ -7,8 +7,6 @@
 
 #include "src/allocation.h"
 #include "src/compiler/instruction.h"
-#include "src/compiler/node.h"
-#include "src/compiler/schedule.h"
 #include "src/macro-assembler.h"
 #include "src/zone.h"
 
@@ -378,21 +376,22 @@ class RegisterAllocator BASE_EMBEDDED {
   void ResolveControlFlow();
   void PopulatePointerMaps();  // TODO(titzer): rename to PopulateReferenceMaps.
   void AllocateRegisters();
-  bool CanEagerlyResolveControlFlow(BasicBlock* block) const;
+  bool CanEagerlyResolveControlFlow(const InstructionBlock* block) const;
   inline bool SafePointsAreInOrder() const;
 
   // Liveness analysis support.
   void InitializeLivenessAnalysis();
-  BitVector* ComputeLiveOut(BasicBlock* block);
+  BitVector* ComputeLiveOut(const InstructionBlock* block);
-  void AddInitialIntervals(BasicBlock* block, BitVector* live_out);
+  void AddInitialIntervals(const InstructionBlock* block, BitVector* live_out);
   bool IsOutputRegisterOf(Instruction* instr, int index);
   bool IsOutputDoubleRegisterOf(Instruction* instr, int index);
-  void ProcessInstructions(BasicBlock* block, BitVector* live);
+  void ProcessInstructions(const InstructionBlock* block, BitVector* live);
-  void MeetRegisterConstraints(BasicBlock* block);
+  void MeetRegisterConstraints(const InstructionBlock* block);
   void MeetConstraintsBetween(Instruction* first, Instruction* second,
                               int gap_index);
-  void MeetRegisterConstraintsForLastInstructionInBlock(BasicBlock* block);
+  void MeetRegisterConstraintsForLastInstructionInBlock(
-  void ResolvePhis(BasicBlock* block);
+      const InstructionBlock* block);
+  void ResolvePhis(const InstructionBlock* block);
 
   // Helper methods for building intervals.
   InstructionOperand* AllocateFixed(UnallocatedOperand* operand, int pos,
@@ -466,8 +465,8 @@ class RegisterAllocator BASE_EMBEDDED {
   bool IsBlockBoundary(LifetimePosition pos);
 
   // Helper methods for resolving control flow.
-  void ResolveControlFlow(LiveRange* range, BasicBlock* block,
+  void ResolveControlFlow(LiveRange* range, const InstructionBlock* block,
-                          BasicBlock* pred);
+                          const InstructionBlock* pred);
 
   inline void SetLiveRangeAssignedRegister(LiveRange* range, int reg);
 
@@ -476,7 +475,7 @@ class RegisterAllocator BASE_EMBEDDED {
   ParallelMove* GetConnectingParallelMove(LifetimePosition pos);
 
   // Return the block which contains give lifetime position.
-  BasicBlock* GetBlock(LifetimePosition pos);
+  const InstructionBlock* GetInstructionBlock(LifetimePosition pos);
 
   // Helper methods for the fixed registers.
   int RegisterCount() const;
@@ -485,7 +484,7 @@ class RegisterAllocator BASE_EMBEDDED {
   LiveRange* FixedLiveRangeFor(int index);
   LiveRange* FixedDoubleLiveRangeFor(int index);
   LiveRange* LiveRangeFor(int index);
-  GapInstruction* GetLastGap(BasicBlock* block);
+  GapInstruction* GetLastGap(const InstructionBlock* block);
 
   const char* RegisterName(int allocation_index);
 

src/compiler/schedule.cc

@@ -35,12 +35,6 @@ bool BasicBlock::LoopContains(BasicBlock* block) const {
 }
 
 
-BasicBlock* BasicBlock::ContainingLoop() {
-  if (IsLoopHeader()) return this;
-  return loop_header();
-}
-
-
 void BasicBlock::AddSuccessor(BasicBlock* successor) {
   successors_.push_back(successor);
 }
@@ -88,16 +82,6 @@ void BasicBlock::set_loop_header(BasicBlock* loop_header) {
 }
 
 
-size_t BasicBlock::PredecessorIndexOf(BasicBlock* predecessor) {
-  size_t j = 0;
-  for (BasicBlock::Predecessors::iterator i = predecessors_.begin();
-       i != predecessors_.end(); ++i, ++j) {
-    if (*i == predecessor) break;
-  }
-  return j;
-}
-
-
 std::ostream& operator<<(std::ostream& os, const BasicBlock::Control& c) {
   switch (c) {
     case BasicBlock::kNone:

src/compiler/schedule.h

@@ -50,22 +50,33 @@ class BasicBlock FINAL : public ZoneObject {
     size_t index_;
   };
 
+  static const int kInvalidRpoNumber = -1;
   class RpoNumber FINAL {
    public:
-    int ToInt() const { return static_cast<int>(index_); }
+    int ToInt() const {
-    size_t ToSize() const { return index_; }
+      DCHECK(IsValid());
-    static RpoNumber FromInt(int index) {
+      return index_;
-      return RpoNumber(static_cast<size_t>(index));
     }
-    static RpoNumber Invalid() { return RpoNumber(static_cast<size_t>(-1)); }
+    size_t ToSize() const {
+      DCHECK(IsValid());
+      return static_cast<size_t>(index_);
+    }
+    bool IsValid() const { return index_ != kInvalidRpoNumber; }
+    static RpoNumber FromInt(int index) { return RpoNumber(index); }
+    static RpoNumber Invalid() { return RpoNumber(kInvalidRpoNumber); }
 
     bool IsNext(const RpoNumber other) const {
+      DCHECK(IsValid());
       return other.index_ == this->index_ + 1;
     }
 
+    bool operator==(RpoNumber other) const {
+      return this->index_ == other.index_;
+    }
+
    private:
-    explicit RpoNumber(size_t index) : index_(index) {}
+    explicit RpoNumber(int32_t index) : index_(index) {}
-    size_t index_;
+    int32_t index_;
   };
 
   BasicBlock(Zone* zone, Id id);
@@ -76,14 +87,25 @@ class BasicBlock FINAL : public ZoneObject {
   typedef ZoneVector<BasicBlock*> Predecessors;
   Predecessors::iterator predecessors_begin() { return predecessors_.begin(); }
   Predecessors::iterator predecessors_end() { return predecessors_.end(); }
+  Predecessors::const_iterator predecessors_begin() const {
+    return predecessors_.begin();
+  }
+  Predecessors::const_iterator predecessors_end() const {
+    return predecessors_.end();
+  }
   size_t PredecessorCount() const { return predecessors_.size(); }
   BasicBlock* PredecessorAt(size_t index) { return predecessors_[index]; }
-  size_t PredecessorIndexOf(BasicBlock* predecessor);
   void AddPredecessor(BasicBlock* predecessor);
 
   typedef ZoneVector<BasicBlock*> Successors;
   Successors::iterator successors_begin() { return successors_.begin(); }
   Successors::iterator successors_end() { return successors_.end(); }
+  Successors::const_iterator successors_begin() const {
+    return successors_.begin();
+  }
+  Successors::const_iterator successors_end() const {
+    return successors_.end();
+  }
   size_t SuccessorCount() const { return successors_.size(); }
   BasicBlock* SuccessorAt(size_t index) { return successors_[index]; }
   void AddSuccessor(BasicBlock* successor);
@@ -137,7 +159,6 @@ class BasicBlock FINAL : public ZoneObject {
   // Loop membership helpers.
   inline bool IsLoopHeader() const { return loop_end_ >= 0; }
   bool LoopContains(BasicBlock* block) const;
-  BasicBlock* ContainingLoop();
 
  private:
   int32_t rpo_number_;       // special RPO number of the block.