Record the lazy deoptimization environmnent only at LLazyBailout-instructions...

src/ia32/lithium-ia32.cc

 // Copyright 2011 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 638 matching lines @@
 }
 
 
 LInstruction* LChunkBuilder::AssignEnvironment(LInstruction* instr) {
   HEnvironment* hydrogen_env = current_block_->last_environment();
   instr->set_environment(CreateEnvironment(hydrogen_env));
   return 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) {
   allocator_->MarkAsCall();
   instr = AssignPointerMap(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
   // after the call will try to deoptimize to the point before the call.
   // Thus we still need to attach environment to this call even if
   // call sequence can not deoptimize eagerly.
   bool needs_environment =
       (can_deoptimize == CAN_DEOPTIMIZE_EAGERLY) || !hinstr->HasSideEffects();
   if (needs_environment && !instr->HasEnvironment()) {
     instr = AssignEnvironment(instr);
@@ skipping 1171 matching lines @@
     if (instr->HasAssignedIndexAt(i)) {
       env->Bind(instr->GetAssignedIndexAt(i), value);
     } else {
       env->Push(value);
     }
   }
   ASSERT(env->length() == instr->environment_length());
 
   // If there is an instruction pending deoptimization environment create a
   // lazy bailout instruction to capture the environment.
   if (pending_deoptimization_ast_id_ == instr->ast_id()) {

[Kevin Millikin (Chromium), 2011/01/24 13:31:38]

This should really be:

if (pending_deoptimization_ast_id_ != AstNode::kNoNumber) {
  ASSERT(pending_deoptimization_ast_id_ == instr->ast_id());
  ...

     LLazyBailout* lazy_bailout = new LLazyBailout;
     LInstruction* result = AssignEnvironment(lazy_bailout);

[Kevin Millikin (Chromium), 2011/01/24 13:31:38]

I'm worried that the uses in this environment appear to come after the gap the
precedes it, but the environment before the gap is the one that is recorded.

Is that a problem?

-    instructions_pending_deoptimization_environment_->
-        set_deoptimization_environment(result->environment());
-    ClearInstructionPendingDeoptimizationEnvironment();
+    pending_deoptimization_ast_id_ = AstNode::kNoNumber;
     return result;
   }
 
   return NULL;
 }
 
 
 LInstruction* LChunkBuilder::DoStackCheck(HStackCheck* instr) {
   return MarkAsCall(new LStackCheck, instr);
 }
@@ skipping 15 matching lines @@
 LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
   HEnvironment* outer = current_block_->last_environment()->outer();
   current_block_->UpdateEnvironment(outer);
   return NULL;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32