[for-in] Record slow path feedback only when we hit %ForInFilter.

The only place in fullcodegen, where we know for sure that a for-in loop
entered the slow-path is right before the potential call to %ForInFilter.
So there's no point in also updating the mode eagerly during ForInPrepare.

R=yangguo@chromium.org
BUG=v8:3650
LOG=n

Review URL: https://codereview.chromium.org/1749033002

Cr-Commit-Position: refs/heads/master@{#34377}

src/full-codegen/arm/full-codegen-arm.cc

@@ -1076,10 +1076,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register r0. Iterate through that.
   __ bind(&fixed_array);
 
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(r1);
-  __ mov(r2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ str(r2, FieldMemOperand(r1, FixedArray::OffsetOfElementAt(vector_index)));
   __ mov(r1, Operand(Smi::FromInt(1)));  // Smi(1) indicates slow check
   __ Push(r1, r0);  // Smi and array
   __ ldr(r1, FieldMemOperand(r0, FixedArray::kLengthOffset));
@@ -1114,12 +1110,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ cmp(r4, Operand(r2));
   __ b(eq, &update_each);
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(r0);
   __ mov(r2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ str(r2, FieldMemOperand(r0, FixedArray::OffsetOfElementAt(vector_index)));

src/full-codegen/arm64/full-codegen-arm64.cc

@@ -1072,10 +1072,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register x0. Iterate through that.
   __ Bind(&fixed_array);
 
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(x1);
-  __ Mov(x10, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ Str(x10, FieldMemOperand(x1, FixedArray::OffsetOfElementAt(vector_index)));
   __ Mov(x1, Smi::FromInt(1));  // Smi(1) indicates slow check.
   __ Ldr(x2, FieldMemOperand(x0, FixedArray::kLengthOffset));
   __ Push(x1, x0, x2);  // Smi and array, fixed array length (as smi).
@@ -1108,12 +1104,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ Cmp(x11, x2);
   __ B(eq, &update_each);
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(x0);
   __ Mov(x10, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ Str(x10, FieldMemOperand(x0, FixedArray::OffsetOfElementAt(vector_index)));

src/full-codegen/ia32/full-codegen-ia32.cc

@@ -1008,11 +1008,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register eax. Iterate through that.
   __ bind(&fixed_array);
 
-  // No need for a write barrier, we are storing a Smi in the feedback vector.
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(ebx);
-  __ mov(FieldOperand(ebx, FixedArray::OffsetOfElementAt(vector_index)),
-         Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ push(Immediate(Smi::FromInt(1)));  // Smi(1) indicates slow check
   __ push(eax);  // Array
   __ mov(eax, FieldOperand(eax, FixedArray::kLengthOffset));
@@ -1043,12 +1038,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ cmp(edx, FieldOperand(ecx, HeapObject::kMapOffset));
   __ j(equal, &update_each, Label::kNear);
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(edx);
   __ mov(FieldOperand(edx, FixedArray::OffsetOfElementAt(vector_index)),
          Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate())));

src/full-codegen/mips/full-codegen-mips.cc

@@ -1072,11 +1072,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register v0. Iterate through that.
   __ bind(&fixed_array);
 
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(a1);
-  __ li(a2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ sw(a2, FieldMemOperand(a1, FixedArray::OffsetOfElementAt(vector_index)));
-
   __ li(a1, Operand(Smi::FromInt(1)));  // Smi(1) indicates slow check
   __ Push(a1, v0);  // Smi and array
   __ lw(a1, FieldMemOperand(v0, FixedArray::kLengthOffset));
@@ -1111,12 +1106,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ lw(t0, FieldMemOperand(a1, HeapObject::kMapOffset));
   __ Branch(&update_each, eq, t0, Operand(a2));
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(a0);
   __ li(a2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ sw(a2, FieldMemOperand(a0, FixedArray::OffsetOfElementAt(vector_index)));

src/full-codegen/mips64/full-codegen-mips64.cc

@@ -1073,11 +1073,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register v0. Iterate through that.
   __ bind(&fixed_array);
 
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(a1);
-  __ li(a2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ sd(a2, FieldMemOperand(a1, FixedArray::OffsetOfElementAt(vector_index)));
-
   __ li(a1, Operand(Smi::FromInt(1)));  // Smi(1) indicates slow check
   __ Push(a1, v0);  // Smi and array
   __ ld(a1, FieldMemOperand(v0, FixedArray::kLengthOffset));
@@ -1113,12 +1108,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ ld(a4, FieldMemOperand(a1, HeapObject::kMapOffset));
   __ Branch(&update_each, eq, a4, Operand(a2));
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(a0);
   __ li(a2, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ sd(a2, FieldMemOperand(a0, FixedArray::OffsetOfElementAt(vector_index)));

src/full-codegen/ppc/full-codegen-ppc.cc

@@ -1038,11 +1038,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register r3. Iterate through that.
   __ bind(&fixed_array);
 
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(r4);
-  __ mov(r5, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ StoreP(
-      r5, FieldMemOperand(r4, FixedArray::OffsetOfElementAt(vector_index)), r0);
   __ LoadSmiLiteral(r4, Smi::FromInt(1));  // Smi(1) indicates slow check
   __ Push(r4, r3);  // Smi and array
   __ LoadP(r4, FieldMemOperand(r3, FixedArray::kLengthOffset));
@@ -1079,12 +1074,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ cmp(r7, r5);
   __ beq(&update_each);
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(r3);
   __ mov(r5, Operand(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ StoreP(

src/full-codegen/x64/full-codegen-x64.cc

@@ -1029,11 +1029,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register rax. Iterate through that.
   __ bind(&fixed_array);
 
-  // No need for a write barrier, we are storing a Smi in the feedback vector.
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(rbx);
-  __ Move(FieldOperand(rbx, FixedArray::OffsetOfElementAt(vector_index)),
-          TypeFeedbackVector::MegamorphicSentinel(isolate()));
   __ movp(rcx, Operand(rsp, 0 * kPointerSize));  // Get enumerated object
   __ Push(Smi::FromInt(1));                      // Smi(1) indicates slow check
   __ Push(rax);  // Array
@@ -1069,12 +1064,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ cmpp(rdx, FieldOperand(rcx, HeapObject::kMapOffset));
   __ j(equal, &update_each, Label::kNear);
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(rdx);
   __ Move(FieldOperand(rdx, FixedArray::OffsetOfElementAt(vector_index)),
           TypeFeedbackVector::MegamorphicSentinel(isolate()));

src/full-codegen/x87/full-codegen-x87.cc

@@ -1000,11 +1000,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // We got a fixed array in register eax. Iterate through that.
   __ bind(&fixed_array);
 
-  // No need for a write barrier, we are storing a Smi in the feedback vector.
-  int const vector_index = SmiFromSlot(slot)->value();
-  __ EmitLoadTypeFeedbackVector(ebx);
-  __ mov(FieldOperand(ebx, FixedArray::OffsetOfElementAt(vector_index)),
-         Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate())));
   __ push(Immediate(Smi::FromInt(1)));  // Smi(1) undicates slow check
   __ push(eax);  // Array
   __ mov(eax, FieldOperand(eax, FixedArray::kLengthOffset));
@@ -1035,12 +1030,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ cmp(edx, FieldOperand(ecx, HeapObject::kMapOffset));
   __ j(equal, &update_each, Label::kNear);
 
-  // We might get here from TurboFan or Crankshaft when something in the
-  // for-in loop body deopts and only now notice in fullcodegen, that we
-  // can now longer use the enum cache, i.e. left fast mode. So better record
-  // this information here, in case we later OSR back into this loop or
-  // reoptimize the whole function w/o rerunning the loop with the slow
-  // mode object in fullcodegen (which would result in a deopt loop).
+  // We need to filter the key, record slow-path here.
+  int const vector_index = SmiFromSlot(slot)->value();
   __ EmitLoadTypeFeedbackVector(edx);
   __ mov(FieldOperand(edx, FixedArray::OffsetOfElementAt(vector_index)),
          Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate())));