Improve representation inference for HUnknownOSRValue.

src/hydrogen.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 2502 matching lines @@
     return NULL;
   }
   graph()->EliminateRedundantPhis();
   if (!graph()->CheckArgumentsPhiUses()) {
     Bailout("Unsupported phi use of arguments");
     return NULL;
   }
   if (FLAG_eliminate_dead_phis) graph()->EliminateUnreachablePhis();
   graph()->CollectPhis();
 
+  if (graph()->has_osr_loop_entry()) {
+    const ZoneList<HPhi*>* phis = graph()->osr_loop_entry()->phis();
+    for (int j = 0; j < phis->length(); j++) {
+      HPhi* phi = phis->at(j);
+      graph()->osr_values()->at(phi->merged_index())->set_incoming_value(phi);
+    }
+  }
+
   HInferRepresentation rep(graph());
   rep.Analyze();
 
   graph()->MarkDeoptimizeOnUndefined();
   graph()->InsertRepresentationChanges();
 
   graph()->InitializeInferredTypes();
   graph()->Canonicalize();
 
   // Perform common subexpression elimination and loop-invariant code motion.
@@ skipping 552 matching lines @@
     set_current_block(break_block);
   }
 }
 
 
 bool HGraphBuilder::HasOsrEntryAt(IterationStatement* statement) {
   return statement->OsrEntryId() == info()->osr_ast_id();
 }
 
 
-void HGraphBuilder::PreProcessOsrEntry(IterationStatement* statement) {
-  if (!HasOsrEntryAt(statement)) return;
+bool HGraphBuilder::PreProcessOsrEntry(IterationStatement* statement) {
+  if (!HasOsrEntryAt(statement)) return false;
 
   HBasicBlock* non_osr_entry = graph()->CreateBasicBlock();
   HBasicBlock* osr_entry = graph()->CreateBasicBlock();
   HValue* true_value = graph()->GetConstantTrue();
   HBranch* test = new(zone()) HBranch(true_value, non_osr_entry, osr_entry);
   current_block()->Finish(test);
 
   HBasicBlock* loop_predecessor = graph()->CreateBasicBlock();
   non_osr_entry->Goto(loop_predecessor);
 
   set_current_block(osr_entry);
   int osr_entry_id = statement->OsrEntryId();
   int first_expression_index = environment()->first_expression_index();
   int length = environment()->length();
+  ZoneList<HUnknownOSRValue*>* osr_values =
+      new(zone()) ZoneList<HUnknownOSRValue*>(length);
+
   for (int i = 0; i < first_expression_index; ++i) {
     HUnknownOSRValue* osr_value = new(zone()) HUnknownOSRValue;
     AddInstruction(osr_value);
     environment()->Bind(i, osr_value);
+    osr_values->Add(osr_value);
   }
 
   if (first_expression_index != length) {
     environment()->Drop(length - first_expression_index);
     for (int i = first_expression_index; i < length; ++i) {
       HUnknownOSRValue* osr_value = new(zone()) HUnknownOSRValue;
       AddInstruction(osr_value);
       environment()->Push(osr_value);
+      osr_values->Add(osr_value);
     }
   }
 
+  graph()->set_osr_values(osr_values);
+
   AddSimulate(osr_entry_id);
   AddInstruction(new(zone()) HOsrEntry(osr_entry_id));
   HContext* context = new(zone()) HContext;
   AddInstruction(context);
   environment()->BindContext(context);
   current_block()->Goto(loop_predecessor);
   loop_predecessor->SetJoinId(statement->EntryId());
   set_current_block(loop_predecessor);
+  return true;
 }
 
 
 void HGraphBuilder::VisitLoopBody(IterationStatement* stmt,
                                   HBasicBlock* loop_entry,
                                   BreakAndContinueInfo* break_info) {
   BreakAndContinueScope push(break_info, this);
   AddSimulate(stmt->StackCheckId());
   HValue* context = environment()->LookupContext();
   HStackCheck* stack_check =
     new(zone()) HStackCheck(context, HStackCheck::kBackwardsBranch);
   AddInstruction(stack_check);
   ASSERT(loop_entry->IsLoopHeader());
   loop_entry->loop_information()->set_stack_check(stack_check);
   CHECK_BAILOUT(Visit(stmt->body()));
 }
 
 
 void HGraphBuilder::VisitDoWhileStatement(DoWhileStatement* stmt) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   ASSERT(current_block() != NULL);
-  PreProcessOsrEntry(stmt);
+  bool osr_entry = PreProcessOsrEntry(stmt);
   HBasicBlock* loop_entry = CreateLoopHeaderBlock();
   current_block()->Goto(loop_entry);
   set_current_block(loop_entry);
+  if (osr_entry) graph()->set_osr_loop_entry(loop_entry);
 
   BreakAndContinueInfo break_info(stmt);
   CHECK_BAILOUT(VisitLoopBody(stmt, loop_entry, &break_info));
   HBasicBlock* body_exit =
       JoinContinue(stmt, current_block(), break_info.continue_block());
   HBasicBlock* loop_successor = NULL;
   if (body_exit != NULL && !stmt->cond()->ToBooleanIsTrue()) {
     set_current_block(body_exit);
     // The block for a true condition, the actual predecessor block of the
     // back edge.
@@ skipping 18 matching lines @@
                                       break_info.break_block());
   set_current_block(loop_exit);
 }
 
 
 void HGraphBuilder::VisitWhileStatement(WhileStatement* stmt) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   ASSERT(current_block() != NULL);
-  PreProcessOsrEntry(stmt);
+  bool osr_entry = PreProcessOsrEntry(stmt);
   HBasicBlock* loop_entry = CreateLoopHeaderBlock();
   current_block()->Goto(loop_entry);
   set_current_block(loop_entry);
+  if (osr_entry) graph()->set_osr_loop_entry(loop_entry);
+
 
   // If the condition is constant true, do not generate a branch.
   HBasicBlock* loop_successor = NULL;
   if (!stmt->cond()->ToBooleanIsTrue()) {
     HBasicBlock* body_entry = graph()->CreateBasicBlock();
     loop_successor = graph()->CreateBasicBlock();
     CHECK_BAILOUT(VisitForControl(stmt->cond(), body_entry, loop_successor));
     if (body_entry->HasPredecessor()) {
       body_entry->SetJoinId(stmt->BodyId());
       set_current_block(body_entry);
@@ skipping 21 matching lines @@
 
 
 void HGraphBuilder::VisitForStatement(ForStatement* stmt) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   if (stmt->init() != NULL) {
     CHECK_ALIVE(Visit(stmt->init()));
   }
   ASSERT(current_block() != NULL);
-  PreProcessOsrEntry(stmt);
+  bool osr_entry = PreProcessOsrEntry(stmt);
   HBasicBlock* loop_entry = CreateLoopHeaderBlock();
   current_block()->Goto(loop_entry);
   set_current_block(loop_entry);
+  if (osr_entry) graph()->set_osr_loop_entry(loop_entry);
 
   HBasicBlock* loop_successor = NULL;
   if (stmt->cond() != NULL) {
     HBasicBlock* body_entry = graph()->CreateBasicBlock();
     loop_successor = graph()->CreateBasicBlock();
     CHECK_BAILOUT(VisitForControl(stmt->cond(), body_entry, loop_successor));
     if (body_entry->HasPredecessor()) {
       body_entry->SetJoinId(stmt->BodyId());
       set_current_block(body_entry);
     }
@@ skipping 71 matching lines @@
   Push(start_index);
 
   HInstruction* index_cache = AddInstruction(
       new(zone()) HForInCacheArray(
           enumerable,
           map,
           DescriptorArray::kEnumCacheBridgeIndicesCacheIndex));
   HForInCacheArray::cast(array)->set_index_cache(
       HForInCacheArray::cast(index_cache));
 
-  PreProcessOsrEntry(stmt);
+  bool osr_entry = PreProcessOsrEntry(stmt);
   HBasicBlock* loop_entry = CreateLoopHeaderBlock();
   current_block()->Goto(loop_entry);
   set_current_block(loop_entry);
+  if (osr_entry) graph()->set_osr_loop_entry(loop_entry);
 
   HValue* index = environment()->ExpressionStackAt(0);
   HValue* limit = environment()->ExpressionStackAt(1);
 
   // Check that we still have more keys.
   HCompareIDAndBranch* compare_index =
       new(zone()) HCompareIDAndBranch(index, limit, Token::LT);
   compare_index->SetInputRepresentation(Representation::Integer32());
 
   HBasicBlock* loop_body = graph()->CreateBasicBlock();
@@ skipping 4772 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal