Record the lazy deoptimization environmnent only at LLazyBailout-instructions.

This saves one pointer per LIR instructions. The change relies on the fact
that there is a LazyBailout instruction at all the places where we need
to register a lazy deoptimization environment.

Review URL: http://codereview.chromium.org/6348016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6441 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 3bfb10f..ce7b73b 100644 (file)
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -414,16 +414,20 @@ void LCodeGen::RegisterLazyDeoptimization(LInstruction* instr) {
   // Create the environment to bailout to. If the call has side effects
   // execution has to continue after the call otherwise execution can continue
   // from a previous bailout point repeating the call.
-  LEnvironment* deoptimization_environment;
-  if (instr->HasDeoptimizationEnvironment()) {
-    deoptimization_environment = instr->deoptimization_environment();
+  LEnvironment* lazy_deoptimization_environment;
+  ASSERT(!instr->IsControl());
+  ASSERT(instructions_->at(current_instruction_ + 1)->IsGap());
+  LInstruction* next_instr = instructions_->at(current_instruction_ + 2);
+  if (next_instr->IsLazyBailout()) {
+    ASSERT(next_instr->HasEnvironment());
+    lazy_deoptimization_environment = next_instr->environment();
   } else {
-    deoptimization_environment = instr->environment();
+    lazy_deoptimization_environment = instr->environment();
   }
 
-  RegisterEnvironmentForDeoptimization(deoptimization_environment);
+  RegisterEnvironmentForDeoptimization(lazy_deoptimization_environment);
   RecordSafepoint(instr->pointer_map(),
-                  deoptimization_environment->deoptimization_index());
+                  lazy_deoptimization_environment->deoptimization_index());
 }
 
 

diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index f422514..bc60bec 100644 (file)
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -656,22 +656,6 @@ LInstruction* LChunkBuilder::AssignEnvironment(LInstruction* instr) {
 }
 
 
-LInstruction* LChunkBuilder::SetInstructionPendingDeoptimizationEnvironment(
-    LInstruction* instr, int ast_id) {
-  ASSERT(instructions_pending_deoptimization_environment_ == NULL);
-  ASSERT(pending_deoptimization_ast_id_ == AstNode::kNoNumber);
-  instructions_pending_deoptimization_environment_ = instr;
-  pending_deoptimization_ast_id_ = ast_id;
-  return instr;
-}
-
-
-void LChunkBuilder::ClearInstructionPendingDeoptimizationEnvironment() {
-  instructions_pending_deoptimization_environment_ = NULL;
-  pending_deoptimization_ast_id_ = AstNode::kNoNumber;
-}
-
-
 LInstruction* LChunkBuilder::MarkAsCall(LInstruction* instr,
                                         HInstruction* hinstr,
                                         CanDeoptimize can_deoptimize) {
@@ -681,8 +665,8 @@ LInstruction* LChunkBuilder::MarkAsCall(LInstruction* instr,
   if (hinstr->HasSideEffects()) {
     ASSERT(hinstr->next()->IsSimulate());
     HSimulate* sim = HSimulate::cast(hinstr->next());
-    instr = SetInstructionPendingDeoptimizationEnvironment(
-        instr, sim->ast_id());
+    ASSERT(pending_deoptimization_ast_id_ == AstNode::kNoNumber);
+    pending_deoptimization_ast_id_ = sim->ast_id();
   }
 
   // If instruction does not have side-effects lazy deoptimization
@@ -1877,9 +1861,7 @@ LInstruction* LChunkBuilder::DoSimulate(HSimulate* instr) {
   if (pending_deoptimization_ast_id_ == instr->ast_id()) {
     LLazyBailout* lazy_bailout = new LLazyBailout;
     LInstruction* result = AssignEnvironment(lazy_bailout);
-    instructions_pending_deoptimization_environment_->
-        set_deoptimization_environment(result->environment());
-    ClearInstructionPendingDeoptimizationEnvironment();
+    pending_deoptimization_ast_id_ = AstNode::kNoNumber;
     return result;
   }
 

diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index 1cdd31e..3c233c9 100644 (file)
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -321,21 +321,10 @@ class LInstruction: public ZoneObject {
   void set_hydrogen_value(HValue* value) { hydrogen_value_ = value; }
   HValue* hydrogen_value() const { return hydrogen_value_; }
 
-  void set_deoptimization_environment(LEnvironment* env) {
-    deoptimization_environment_.set(env);
-  }
-  LEnvironment* deoptimization_environment() const {
-    return deoptimization_environment_.get();
-  }
-  bool HasDeoptimizationEnvironment() const {
-    return deoptimization_environment_.is_set();
-  }
-
  private:
   SetOncePointer<LEnvironment> environment_;
   SetOncePointer<LPointerMap> pointer_map_;
   HValue* hydrogen_value_;
-  SetOncePointer<LEnvironment> deoptimization_environment_;
 };
 
 
@@ -1881,7 +1870,6 @@ class LChunkBuilder BASE_EMBEDDED {
         argument_count_(0),
         allocator_(allocator),
         position_(RelocInfo::kNoPosition),
-        instructions_pending_deoptimization_environment_(NULL),
         pending_deoptimization_ast_id_(AstNode::kNoNumber) { }
 
   // Build the sequence for the graph.
@@ -1990,10 +1978,6 @@ class LChunkBuilder BASE_EMBEDDED {
       CanDeoptimize can_deoptimize = CANNOT_DEOPTIMIZE_EAGERLY);
   LInstruction* MarkAsSaveDoubles(LInstruction* instr);
 
-  LInstruction* SetInstructionPendingDeoptimizationEnvironment(
-      LInstruction* instr, int ast_id);
-  void ClearInstructionPendingDeoptimizationEnvironment();
-
   LEnvironment* CreateEnvironment(HEnvironment* hydrogen_env);
 
   void VisitInstruction(HInstruction* current);
@@ -2015,7 +1999,6 @@ class LChunkBuilder BASE_EMBEDDED {
   int argument_count_;
   LAllocator* allocator_;
   int position_;
-  LInstruction* instructions_pending_deoptimization_environment_;
   int pending_deoptimization_ast_id_;
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);