Infrastructure classes for evaluating numeric relations between values.

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 53 matching lines @@
       dominator_(NULL),
       dominated_blocks_(4, graph->zone()),
       last_environment_(NULL),
       argument_count_(-1),
       first_instruction_index_(-1),
       last_instruction_index_(-1),
       deleted_phis_(4, graph->zone()),
       parent_loop_header_(NULL),
       is_inline_return_target_(false),
       is_deoptimizing_(false),
-      dominates_loop_successors_(false) { }
+      dominates_loop_successors_(false),
+      is_osr_entry_(false) { }
 
 
 void HBasicBlock::AttachLoopInformation() {
   ASSERT(!IsLoopHeader());
   loop_information_ = new(zone()) HLoopInformation(this, zone());
 }
 
 
 void HBasicBlock::DetachLoopInformation() {
   ASSERT(IsLoopHeader());
@@ skipping 3701 matching lines @@
     }
   }
 }
 
 
 bool HGraph::Optimize(SmartArrayPointer<char>* bailout_reason) {
   *bailout_reason = SmartArrayPointer<char>();
   OrderBlocks();
   AssignDominators();
 
+  // We need to create a HConstant "zero" now so that GVN will fold every
+  // zero-valued constant in the graph together.
+  // The constant is needed to make idef-based bounds check work: the pass
+  // evaluates relations with "zero" and that zero cannot be created after GVN.
+  GetConstant0();
+
 #ifdef DEBUG
   // Do a full verify after building the graph and computing dominators.
   Verify(true);
 #endif
 
   PropagateDeoptimizingMark();
   if (!CheckConstPhiUses()) {
     *bailout_reason = SmartArrayPointer<char>(StrDup(
         "Unsupported phi use of const variable"));
     return false;
@@ skipping 57 matching lines @@
   RestoreActualValues();
 
   return true;
 }
 
 
 void HGraph::SetupInformativeDefinitionsInBlock(HBasicBlock* block) {
   for (int phi_index = 0; phi_index < block->phis()->length(); phi_index++) {
     HPhi* phi = block->phis()->at(phi_index);
     phi->AddInformativeDefinitions();
+    phi->SetFlag(HValue::kIDefsProcessingDone);
     // We do not support phis that "redefine just one operand".
     ASSERT(!phi->IsInformativeDefinition());
   }
 
   for (HInstruction* i = block->first(); i != NULL; i = i->next()) {
     i->AddInformativeDefinitions();
+    i->SetFlag(HValue::kIDefsProcessingDone);
     i->UpdateRedefinedUsesWhileSettingUpInformativeDefinitions();
   }
 }
 
 
 // This method is recursive, so if its stack frame is large it could
 // cause a stack overflow.
 // To keep the individual stack frames small we do the actual work inside
 // SetupInformativeDefinitionsInBlock();
 void HGraph::SetupInformativeDefinitionsRecursively(HBasicBlock* block) {
@@ skipping 1000 matching lines @@
   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);
+  osr_entry->set_osr_entry();
   BailoutId 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, zone());
 
   for (int i = 0; i < first_expression_index; ++i) {
     HUnknownOSRValue* osr_value = new(zone()) HUnknownOSRValue;
     AddInstruction(osr_value);
     environment()->Bind(i, osr_value);
@@ skipping 5721 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal