Revert of VectorICs: megamorphic keyed loads in crankshaft don't need…

… a vector. (patchset v8#3 id:40001 of https://codereview.chromium.org/1067573003/)

Reason for revert:
[Sheriff] Speculative revert for windows failure... will reland if it doesn't help:
http://build.chromium.org/p/client.v8/builders/V8%20Win32%20-%20debug%20-%202/builds/2891

Original issue's description:
> VectorICs: megamorphic keyed loads in crankshaft don't need a vector.
>
> They are content with a dummy vector, as MISSES won't result in
> changing the real vector/slot at all.
>
> BUG=
>
> Committed: https://crrev.com/c8e4d57d3b3036a05902f5b916cb5d853a57393c
> Cr-Commit-Position: refs/heads/master@{#27788}

TBR=dcarney@chromium.org,mvstanton@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/1060263003

Cr-Commit-Position: refs/heads/master@{#27790}

src/arm/lithium-codegen-arm.cc

@@ -3399,7 +3399,7 @@ void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
   DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
   DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
 
-  if (instr->hydrogen()->HasVectorAndSlot()) {
+  if (FLAG_vector_ics) {
     EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
   }
 

src/arm64/lithium-codegen-arm64.cc

@@ -3635,8 +3635,7 @@ void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
   DCHECK(ToRegister(instr->context()).is(cp));
   DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
   DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
-
-  if (instr->hydrogen()->HasVectorAndSlot()) {
+  if (FLAG_vector_ics) {
     EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
   }
 

src/code-factory.cc

@@ -53,7 +53,7 @@ Callable CodeFactory::KeyedLoadICInOptimizedCode(
     Isolate* isolate, InlineCacheState initialization_state) {
   auto code = KeyedLoadIC::initialize_stub_in_optimized_code(
       isolate, initialization_state);
-  if (FLAG_vector_ics && initialization_state != MEGAMORPHIC) {
+  if (FLAG_vector_ics) {
     return Callable(code, VectorLoadICDescriptor(isolate));
   }
   return Callable(code, LoadDescriptor(isolate));

src/hydrogen-instructions.h

@@ -6716,11 +6716,7 @@ class HLoadKeyedGeneric FINAL : public HTemplateInstruction<3> {
   Handle<TypeFeedbackVector> feedback_vector() const {
     return feedback_vector_;
   }
-  bool HasVectorAndSlot() const {
-    DCHECK(!FLAG_vector_ics || initialization_state_ == MEGAMORPHIC ||
-           feedback_vector_.is_null());
-    return !feedback_vector_.is_null();
-  }
+  bool HasVectorAndSlot() const { return FLAG_vector_ics; }
   void SetVectorAndSlot(Handle<TypeFeedbackVector> vector,
                         FeedbackVectorICSlot slot) {
     DCHECK(FLAG_vector_ics);

src/hydrogen.cc

@@ -5406,8 +5406,11 @@ void HOptimizedGraphBuilder::VisitVariableProxy(VariableProxy* expr) {
                                     variable->name(),
                                     ast_context()->is_for_typeof());
         if (FLAG_vector_ics) {
-          instr->SetVectorAndSlot(handle(current_feedback_vector(), isolate()),
-                                  expr->VariableFeedbackSlot());
+          Handle<SharedFunctionInfo> current_shared =
+              function_state()->compilation_info()->shared_info();
+          instr->SetVectorAndSlot(
+              handle(current_shared->feedback_vector(), isolate()),
+              expr->VariableFeedbackSlot());
         }
         return ast_context()->ReturnInstruction(instr, expr->id());
       }
@@ -6898,8 +6901,10 @@ HInstruction* HOptimizedGraphBuilder::BuildNamedGeneric(
     HLoadNamedGeneric* result =
         New<HLoadNamedGeneric>(object, name, PREMONOMORPHIC);
     if (FLAG_vector_ics) {
+      Handle<SharedFunctionInfo> current_shared =
+          function_state()->compilation_info()->shared_info();
       Handle<TypeFeedbackVector> vector =
-          handle(current_feedback_vector(), isolate());
+          handle(current_shared->feedback_vector(), isolate());
       FeedbackVectorICSlot slot = expr->AsProperty()->PropertyFeedbackSlot();
       result->SetVectorAndSlot(vector, slot);
     }
@@ -6919,10 +6924,16 @@ HInstruction* HOptimizedGraphBuilder::BuildKeyedGeneric(
     HValue* key,
     HValue* value) {
   if (access_type == LOAD) {
-    // HLoadKeyedGeneric with vector ics benefits from being encoded as
-    // MEGAMORPHIC because the vector/slot combo becomes unnecessary.
-    HLoadKeyedGeneric* result = New<HLoadKeyedGeneric>(
-        object, key, FLAG_vector_ics ? MEGAMORPHIC : PREMONOMORPHIC);
+    HLoadKeyedGeneric* result =
+        New<HLoadKeyedGeneric>(object, key, PREMONOMORPHIC);
+    if (FLAG_vector_ics) {
+      Handle<SharedFunctionInfo> current_shared =
+          function_state()->compilation_info()->shared_info();
+      Handle<TypeFeedbackVector> vector =
+          handle(current_shared->feedback_vector(), isolate());
+      FeedbackVectorICSlot slot = expr->AsProperty()->PropertyFeedbackSlot();
+      result->SetVectorAndSlot(vector, slot);
+    }
     return result;
   } else {
     return New<HStoreKeyedGeneric>(object, key, value, function_language_mode(),
@@ -9314,8 +9325,10 @@ void HOptimizedGraphBuilder::VisitCall(Call* expr) {
           expr->IsUsingCallFeedbackICSlot(isolate())) {
         // We've never seen this call before, so let's have Crankshaft learn
         // through the type vector.
+        Handle<SharedFunctionInfo> current_shared =
+            function_state()->compilation_info()->shared_info();
         Handle<TypeFeedbackVector> vector =
-            handle(current_feedback_vector(), isolate());
+            handle(current_shared->feedback_vector(), isolate());
         FeedbackVectorICSlot slot = expr->CallFeedbackICSlot();
         call_function->SetVectorAndSlot(vector, slot);
       }

src/hydrogen.h

@@ -2157,12 +2157,6 @@ class HOptimizedGraphBuilder : public HGraphBuilder, public AstVisitor {
   TestContext* inlined_test_context() const {
     return function_state()->test_context();
   }
-  Handle<SharedFunctionInfo> current_shared_info() const {
-    return current_info()->shared_info();
-  }
-  TypeFeedbackVector* current_feedback_vector() const {
-    return current_shared_info()->feedback_vector();
-  }
   void ClearInlinedTestContext() {
     function_state()->ClearInlinedTestContext();
   }

src/ia32/lithium-codegen-ia32.cc

@@ -3235,7 +3235,7 @@ void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
   DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
   DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
 
-  if (instr->hydrogen()->HasVectorAndSlot()) {
+  if (FLAG_vector_ics) {
     EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
   }
 

src/ic/ic.cc

@@ -1005,7 +1005,7 @@ Handle<Code> KeyedLoadIC::initialize_stub(Isolate* isolate) {
 
 Handle<Code> KeyedLoadIC::initialize_stub_in_optimized_code(
     Isolate* isolate, State initialization_state) {
-  if (FLAG_vector_ics && initialization_state != MEGAMORPHIC) {
+  if (FLAG_vector_ics) {
     return VectorRawKeyedLoadStub(isolate).GetCode();
   }
   switch (initialization_state) {

src/mips/lithium-codegen-mips.cc

@@ -3342,7 +3342,7 @@ void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
   DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
   DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
 
-  if (instr->hydrogen()->HasVectorAndSlot()) {
+  if (FLAG_vector_ics) {
     EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
   }
 

src/mips64/lithium-codegen-mips64.cc

@@ -3397,7 +3397,7 @@ void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
   DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
   DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
 
-  if (instr->hydrogen()->HasVectorAndSlot()) {
+  if (FLAG_vector_ics) {
     EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
   }
 

src/x64/lithium-codegen-x64.cc

@@ -3310,7 +3310,7 @@ void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
   DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
   DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
 
-  if (instr->hydrogen()->HasVectorAndSlot()) {
+  if (FLAG_vector_ics) {
     EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
   }