[crankshaft] Get rid of the StoreFrameContext instruction.

src/crankshaft/hydrogen.cc

Index: src/crankshaft/hydrogen.cc
diff --git a/src/crankshaft/hydrogen.cc b/src/crankshaft/hydrogen.cc
index ae037f351f1d5a4158d6667ad0dfff5fd698a3d1..c59c8e5337afe750648fd5c50154e505f3fc672c 100644
--- a/src/crankshaft/hydrogen.cc
+++ b/src/crankshaft/hydrogen.cc
@@ -4699,12 +4699,8 @@ void HOptimizedGraphBuilder::VisitBlock(Block* stmt) {
         HInstruction* inner_context = Add<HCallRuntime>(
             Runtime::FunctionForId(Runtime::kPushBlockContext), 2);
         inner_context->SetFlag(HValue::kHasNoObservableSideEffects);
-        HInstruction* instr = Add<HStoreFrameContext>(inner_context);
         set_scope(scope);
         environment()->BindContext(inner_context);
-        if (instr->HasObservableSideEffects()) {
-          AddSimulate(stmt->EntryId(), REMOVABLE_SIMULATE);

[Benedikt Meurer, 2016/03/30 07:07:56]

Please also remove this BailoutId from the Statement if it's never used.

-        }
       }
       VisitDeclarations(scope->declarations());
       AddSimulate(stmt->DeclsId(), REMOVABLE_SIMULATE);
@@ -4719,11 +4715,7 @@ void HOptimizedGraphBuilder::VisitBlock(Block* stmt) {
         inner_context, nullptr,
         HObjectAccess::ForContextSlot(Context::PREVIOUS_INDEX));
 
-    HInstruction* instr = Add<HStoreFrameContext>(outer_context);
     environment()->BindContext(outer_context);
-    if (instr->HasObservableSideEffects()) {
-      AddSimulate(stmt->ExitId(), REMOVABLE_SIMULATE);

[Benedikt Meurer, 2016/03/30 07:07:56]

Please also remove this BailoutId from the Statement if it's never used.

-    }
   }
   HBasicBlock* break_block = break_info.break_block();
   if (break_block != NULL) {
@@ -4863,10 +4855,6 @@ void HOptimizedGraphBuilder::VisitContinueStatement(
           HObjectAccess::ForContextSlot(Context::PREVIOUS_INDEX));
       context = context_instruction;
     }
-    HInstruction* instr = Add<HStoreFrameContext>(context);
-    if (instr->HasObservableSideEffects()) {
-      AddSimulate(stmt->target()->EntryId(), REMOVABLE_SIMULATE);
-    }
     environment()->BindContext(context);
   }
 
@@ -4900,10 +4888,6 @@ void HOptimizedGraphBuilder::VisitBreakStatement(BreakStatement* stmt) {
           HObjectAccess::ForContextSlot(Context::PREVIOUS_INDEX));
       context = context_instruction;
     }
-    HInstruction* instr = Add<HStoreFrameContext>(context);
-    if (instr->HasObservableSideEffects()) {
-      AddSimulate(stmt->target()->ExitId(), REMOVABLE_SIMULATE);
-    }
     environment()->BindContext(context);
   }
   Goto(break_block);