X87: Reland Vector ICs: platform support for vector-based stores.

port 40fbed06 (r30581)

original commit message:

    The last changes for vector store functionality, they are in 3 areas:

    1) The new vector [keyed] store code stubs - implementation.
    2) IC and handler compiler adjustments
    3) Odds and ends. A change in ast.cc, a test update, a small Oracle fix.

BUG=

Review URL: https://codereview.chromium.org/1311413007

Cr-Commit-Position: refs/heads/master@{#30612}

src/ic/x87/access-compiler-x87.cc

@@ -30,7 +30,8 @@ Register* PropertyAccessCompiler::store_calling_convention() {
   // receiver, name, scratch1, scratch2, scratch3.
   Register receiver = StoreDescriptor::ReceiverRegister();
   Register name = StoreDescriptor::NameRegister();
-  DCHECK(ebx.is(StoreTransitionDescriptor::MapRegister()));
+  DCHECK(FLAG_vector_stores ||
+         ebx.is(StoreTransitionDescriptor::MapRegister()));
   static Register registers[] = {receiver, name, ebx, edi, no_reg};
   return registers;
 }

src/ic/x87/handler-compiler-x87.cc

@@ -304,13 +304,24 @@ static void StoreIC_PushArgs(MacroAssembler* masm) {
   Register name = StoreDescriptor::NameRegister();
   Register value = StoreDescriptor::ValueRegister();
 
-  DCHECK(!ebx.is(receiver) && !ebx.is(name) && !ebx.is(value));
-
-  __ pop(ebx);
-  __ push(receiver);
-  __ push(name);
-  __ push(value);
-  __ push(ebx);
+  if (FLAG_vector_stores) {
+    Register slot = VectorStoreICDescriptor::SlotRegister();
+    Register vector = VectorStoreICDescriptor::VectorRegister();
+
+    __ xchg(receiver, Operand(esp, 0));
+    __ push(name);
+    __ push(value);
+    __ push(slot);
+    __ push(vector);
+    __ push(receiver);  // which contains the return address.
+  } else {
+    DCHECK(!ebx.is(receiver) && !ebx.is(name) && !ebx.is(value));
+    __ pop(ebx);
+    __ push(receiver);
+    __ push(name);
+    __ push(value);
+    __ push(ebx);
+  }
 }
 
 
@@ -319,7 +330,7 @@ void NamedStoreHandlerCompiler::GenerateSlow(MacroAssembler* masm) {
   StoreIC_PushArgs(masm);
 
   // Do tail-call to runtime routine.
-  __ TailCallRuntime(Runtime::kStoreIC_Slow, 3, 1);
+  __ TailCallRuntime(Runtime::kStoreIC_Slow, FLAG_vector_stores ? 5 : 3, 1);
 }
 
 
@@ -328,7 +339,8 @@ void ElementHandlerCompiler::GenerateStoreSlow(MacroAssembler* masm) {
   StoreIC_PushArgs(masm);
 
   // Do tail-call to runtime routine.
-  __ TailCallRuntime(Runtime::kKeyedStoreIC_Slow, 3, 1);
+  __ TailCallRuntime(Runtime::kKeyedStoreIC_Slow, FLAG_vector_stores ? 5 : 3,
+                     1);
 }
 
 
@@ -352,10 +364,16 @@ void NamedStoreHandlerCompiler::GenerateRestoreName(Handle<Name> name) {
 
 void NamedStoreHandlerCompiler::GeneratePushMap(Register map_reg,
                                                 Register scratch) {
-  // Get the return address, push the argument and then continue.
-  __ pop(scratch);
+  //       current               after GeneratePushMap
+  // -------------------------------------------------
+  //       ret addr              slot
+  //       vector                vector
+  // sp -> slot                  map
+  //                       sp -> ret addr
+  //
+  __ xchg(map_reg, Operand(esp, 0));
+  __ xchg(map_reg, Operand(esp, 2 * kPointerSize));
   __ push(map_reg);
-  __ push(scratch);
 }
 
 
@@ -575,6 +593,7 @@ void NamedStoreHandlerCompiler::FrontendFooter(Handle<Name> name, Label* miss) {
     Label success;
     __ jmp(&success);
     GenerateRestoreName(miss, name);
+    if (IC::ICUseVector(kind())) PopVectorAndSlot();
     TailCallBuiltin(masm(), MissBuiltin(kind()));
     __ bind(&success);
   }

src/ic/x87/ic-compiler-x87.cc

@@ -112,7 +112,10 @@ Handle<Code> PropertyICCompiler::CompileKeyedStorePolymorphic(
       Label next_map;
       __ j(not_equal, &next_map, Label::kNear);
       Handle<WeakCell> cell = Map::WeakCellForMap(transitioned_maps->at(i));
-      __ LoadWeakValue(transition_map(), cell, &miss);
+      Register transition_map = scratch1();
+      DCHECK(!FLAG_vector_stores &&
+             transition_map.is(StoreTransitionDescriptor::MapRegister()));
+      __ LoadWeakValue(transition_map, cell, &miss);
       __ jmp(handler_stubs->at(i), RelocInfo::CODE_TARGET);
       __ bind(&next_map);
     }

src/ic/x87/ic-x87.cc

@@ -577,7 +577,7 @@ void KeyedStoreIC::GenerateMegamorphic(MacroAssembler* masm,
   Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
       Code::ComputeHandlerFlags(Code::STORE_IC));
   masm->isolate()->stub_cache()->GenerateProbe(masm, Code::STORE_IC, flags,
-                                               receiver, key, ebx, no_reg);
+                                               receiver, key, edi, no_reg);
 
   if (FLAG_vector_stores) {
     __ pop(VectorStoreICDescriptor::VectorRegister());
@@ -734,6 +734,12 @@ void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm,
 
 
 void StoreIC::GenerateMegamorphic(MacroAssembler* masm) {
+  if (FLAG_vector_stores) {
+    // This shouldn't be called.
+    __ int3();
+    return;
+  }
+
   // Return address is on the stack.
   Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
       Code::ComputeHandlerFlags(Code::STORE_IC));
@@ -787,22 +793,32 @@ void StoreIC::GenerateNormal(MacroAssembler* masm) {
   Register receiver = StoreDescriptor::ReceiverRegister();
   Register name = StoreDescriptor::NameRegister();
   Register value = StoreDescriptor::ValueRegister();
-  Register dictionary = ebx;
-
-  __ mov(dictionary, FieldOperand(receiver, JSObject::kPropertiesOffset));
+  Register vector = VectorStoreICDescriptor::VectorRegister();
+  Register slot = VectorStoreICDescriptor::SlotRegister();
 
   // A lot of registers are needed for storing to slow case
   // objects. Push and restore receiver but rely on
   // GenerateDictionaryStore preserving the value and name.
   __ push(receiver);
+  if (FLAG_vector_stores) {
+    __ push(vector);
+    __ push(slot);
+  }
+
+  Register dictionary = ebx;
+  __ mov(dictionary, FieldOperand(receiver, JSObject::kPropertiesOffset));
   GenerateDictionaryStore(masm, &restore_miss, dictionary, name, value,
                           receiver, edi);
-  __ Drop(1);
+  __ Drop(FLAG_vector_stores ? 3 : 1);
   Counters* counters = masm->isolate()->counters();
   __ IncrementCounter(counters->store_normal_hit(), 1);
   __ ret(0);
 
   __ bind(&restore_miss);
+  if (FLAG_vector_stores) {
+    __ pop(slot);
+    __ pop(vector);
+  }
   __ pop(receiver);
   __ IncrementCounter(counters->store_normal_miss(), 1);
   GenerateMiss(masm);

src/ic/x87/stub-cache-x87.cc

@@ -25,6 +25,9 @@ static void ProbeTable(Isolate* isolate, MacroAssembler* masm,
   ExternalReference map_offset(isolate->stub_cache()->map_reference(table));
 
   Label miss;
+  bool is_vector_store =
+      IC::ICUseVector(ic_kind) &&
+      (ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC);
 
   // Multiply by 3 because there are 3 fields per entry (name, code, map).
   __ lea(offset, Operand(offset, offset, times_2, 0));
@@ -56,19 +59,28 @@ static void ProbeTable(Isolate* isolate, MacroAssembler* masm,
     }
 #endif
 
-    if (IC::ICUseVector(ic_kind)) {
-      // The vector and slot were pushed onto the stack before starting the
-      // probe, and need to be dropped before calling the handler.
+    // The vector and slot were pushed onto the stack before starting the
+    // probe, and need to be dropped before calling the handler.
+    if (is_vector_store) {
+      // The overlap here is rather embarrassing. One does what one must.
+      Register vector = VectorStoreICDescriptor::VectorRegister();
+      DCHECK(extra.is(VectorStoreICDescriptor::SlotRegister()));
+      __ add(extra, Immediate(Code::kHeaderSize - kHeapObjectTag));
+      __ pop(vector);
+      __ xchg(extra, Operand(esp, 0));
+      // Jump to the first instruction in the code stub.
+      __ ret(0);
+    } else {
       __ pop(LoadWithVectorDescriptor::VectorRegister());
       __ pop(LoadDescriptor::SlotRegister());
+      __ add(extra, Immediate(Code::kHeaderSize - kHeapObjectTag));
+      __ jmp(extra);
     }
 
-    // Jump to the first instruction in the code stub.
-    __ add(extra, Immediate(Code::kHeaderSize - kHeapObjectTag));
-    __ jmp(extra);
-
     __ bind(&miss);
   } else {
+    DCHECK(ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC);
+
     // Save the offset on the stack.
     __ push(offset);
 
@@ -105,21 +117,21 @@ static void ProbeTable(Isolate* isolate, MacroAssembler* masm,
     __ pop(offset);
     __ mov(offset, Operand::StaticArray(offset, times_1, value_offset));
 
-    if (IC::ICUseVector(ic_kind)) {
+    // Jump to the first instruction in the code stub.
+    if (is_vector_store) {
       // The vector and slot were pushed onto the stack before starting the
       // probe, and need to be dropped before calling the handler.
-      Register vector = LoadWithVectorDescriptor::VectorRegister();
-      Register slot = LoadDescriptor::SlotRegister();
-      DCHECK(!offset.is(vector) && !offset.is(slot));
-
+      Register vector = VectorStoreICDescriptor::VectorRegister();
+      DCHECK(offset.is(VectorStoreICDescriptor::SlotRegister()));
+      __ add(offset, Immediate(Code::kHeaderSize - kHeapObjectTag));
       __ pop(vector);
-      __ pop(slot);
+      __ xchg(offset, Operand(esp, 0));
+      __ ret(0);
+    } else {
+      __ add(offset, Immediate(Code::kHeaderSize - kHeapObjectTag));
+      __ jmp(offset);
     }
 
-    // Jump to the first instruction in the code stub.
-    __ add(offset, Immediate(Code::kHeaderSize - kHeapObjectTag));
-    __ jmp(offset);
-
     // Pop at miss.
     __ bind(&miss);
     __ pop(offset);

src/x87/code-stubs-x87.cc

@@ -4269,11 +4269,173 @@ void VectorStoreICStub::GenerateForTrampoline(MacroAssembler* masm) {
 }
 
 
+// value is on the stack already.
+static void HandlePolymorphicStoreCase(MacroAssembler* masm, Register receiver,
+                                       Register key, Register vector,
+                                       Register slot, Register feedback,
+                                       Label* miss) {
+  // feedback initially contains the feedback array
+  Label next, next_loop, prepare_next;
+  Label load_smi_map, compare_map;
+  Label start_polymorphic;
+
+  __ push(receiver);
+  __ push(vector);
+
+  Register receiver_map = receiver;
+  Register cached_map = vector;
+
+  // Receiver might not be a heap object.
+  __ JumpIfSmi(receiver, &load_smi_map);
+  __ mov(receiver_map, FieldOperand(receiver, 0));
+  __ bind(&compare_map);
+  __ mov(cached_map, FieldOperand(feedback, FixedArray::OffsetOfElementAt(0)));
+
+  // A named keyed store might have a 2 element array, all other cases can count
+  // on an array with at least 2 {map, handler} pairs, so they can go right
+  // into polymorphic array handling.
+  __ cmp(receiver_map, FieldOperand(cached_map, WeakCell::kValueOffset));
+  __ j(not_equal, &start_polymorphic);
+
+  // found, now call handler.
+  Register handler = feedback;
+  DCHECK(handler.is(VectorStoreICDescriptor::ValueRegister()));
+  __ mov(handler, FieldOperand(feedback, FixedArray::OffsetOfElementAt(1)));
+  __ pop(vector);
+  __ pop(receiver);
+  __ lea(handler, FieldOperand(handler, Code::kHeaderSize));
+  __ xchg(handler, Operand(esp, 0));
+  __ ret(0);
+
+  // Polymorphic, we have to loop from 2 to N
+
+  // TODO(mvstanton): I think there is a bug here, we are assuming the
+  // array has more than one map/handler pair, but we call this function in the
+  // keyed store with a string key case, where it might be just an array of two
+  // elements.
+
+  __ bind(&start_polymorphic);
+  __ push(key);
+  Register counter = key;
+  __ mov(counter, Immediate(Smi::FromInt(2)));
+  __ bind(&next_loop);
+  __ mov(cached_map, FieldOperand(feedback, counter, times_half_pointer_size,
+                                  FixedArray::kHeaderSize));
+  __ cmp(receiver_map, FieldOperand(cached_map, WeakCell::kValueOffset));
+  __ j(not_equal, &prepare_next);
+  __ mov(handler, FieldOperand(feedback, counter, times_half_pointer_size,
+                               FixedArray::kHeaderSize + kPointerSize));
+  __ pop(key);
+  __ pop(vector);
+  __ pop(receiver);
+  __ lea(handler, FieldOperand(handler, Code::kHeaderSize));
+  __ xchg(handler, Operand(esp, 0));
+  __ ret(0);
+
+  __ bind(&prepare_next);
+  __ add(counter, Immediate(Smi::FromInt(2)));
+  __ cmp(counter, FieldOperand(feedback, FixedArray::kLengthOffset));
+  __ j(less, &next_loop);
+
+  // We exhausted our array of map handler pairs.
+  __ pop(key);
+  __ pop(vector);
+  __ pop(receiver);
+  __ jmp(miss);
+
+  __ bind(&load_smi_map);
+  __ LoadRoot(receiver_map, Heap::kHeapNumberMapRootIndex);
+  __ jmp(&compare_map);
+}
+
+
+static void HandleMonomorphicStoreCase(MacroAssembler* masm, Register receiver,
+                                       Register key, Register vector,
+                                       Register slot, Register weak_cell,
+                                       Label* miss) {
+  // The store ic value is on the stack.
+  DCHECK(weak_cell.is(VectorStoreICDescriptor::ValueRegister()));
+
+  // feedback initially contains the feedback array
+  Label compare_smi_map;
+
+  // Move the weak map into the weak_cell register.
+  Register ic_map = weak_cell;
+  __ mov(ic_map, FieldOperand(weak_cell, WeakCell::kValueOffset));
+
+  // Receiver might not be a heap object.
+  __ JumpIfSmi(receiver, &compare_smi_map);
+  __ cmp(ic_map, FieldOperand(receiver, 0));
+  __ j(not_equal, miss);
+  __ mov(weak_cell, FieldOperand(vector, slot, times_half_pointer_size,
+                                 FixedArray::kHeaderSize + kPointerSize));
+  __ lea(weak_cell, FieldOperand(weak_cell, Code::kHeaderSize));
+  // Put the store ic value back in it's register.
+  __ xchg(weak_cell, Operand(esp, 0));
+  // "return" to the handler.
+  __ ret(0);
+
+  // In microbenchmarks, it made sense to unroll this code so that the call to
+  // the handler is duplicated for a HeapObject receiver and a Smi receiver.
+  __ bind(&compare_smi_map);
+  __ CompareRoot(ic_map, Heap::kHeapNumberMapRootIndex);
+  __ j(not_equal, miss);
+  __ mov(weak_cell, FieldOperand(vector, slot, times_half_pointer_size,
+                                 FixedArray::kHeaderSize + kPointerSize));
+  __ lea(weak_cell, FieldOperand(weak_cell, Code::kHeaderSize));
+  // Put the store ic value back in it's register.
+  __ xchg(weak_cell, Operand(esp, 0));
+  // "return" to the handler.
+  __ ret(0);
+}
+
+
 void VectorStoreICStub::GenerateImpl(MacroAssembler* masm, bool in_frame) {
+  Register receiver = VectorStoreICDescriptor::ReceiverRegister();  // edx
+  Register key = VectorStoreICDescriptor::NameRegister();           // ecx
+  Register value = VectorStoreICDescriptor::ValueRegister();        // eax
+  Register vector = VectorStoreICDescriptor::VectorRegister();      // ebx
+  Register slot = VectorStoreICDescriptor::SlotRegister();          // edi
   Label miss;
 
-  // TODO(mvstanton): Implement.
+  __ push(value);
+
+  Register scratch = value;
+  __ mov(scratch, FieldOperand(vector, slot, times_half_pointer_size,
+                               FixedArray::kHeaderSize));
+
+  // Is it a weak cell?
+  Label try_array;
+  Label not_array, smi_key, key_okay;
+  __ CompareRoot(FieldOperand(scratch, 0), Heap::kWeakCellMapRootIndex);
+  __ j(not_equal, &try_array);
+  HandleMonomorphicStoreCase(masm, receiver, key, vector, slot, scratch, &miss);
+
+  // Is it a fixed array?
+  __ bind(&try_array);
+  __ CompareRoot(FieldOperand(scratch, 0), Heap::kFixedArrayMapRootIndex);
+  __ j(not_equal, &not_array);
+  HandlePolymorphicStoreCase(masm, receiver, key, vector, slot, scratch, &miss);
+
+  __ bind(&not_array);
+  __ CompareRoot(scratch, Heap::kmegamorphic_symbolRootIndex);
+  __ j(not_equal, &miss);
+
+  __ pop(value);
+  __ push(slot);
+  __ push(vector);
+  Code::Flags code_flags = Code::RemoveTypeAndHolderFromFlags(
+      Code::ComputeHandlerFlags(Code::STORE_IC));
+  masm->isolate()->stub_cache()->GenerateProbe(masm, Code::STORE_IC, code_flags,
+                                               receiver, key, slot, no_reg);
+  __ pop(vector);
+  __ pop(slot);
+  Label no_pop_miss;
+  __ jmp(&no_pop_miss);
+
   __ bind(&miss);
+  __ pop(value);
+  __ bind(&no_pop_miss);
   StoreIC::GenerateMiss(masm);
 }
 
@@ -4288,11 +4450,147 @@ void VectorKeyedStoreICStub::GenerateForTrampoline(MacroAssembler* masm) {
 }
 
 
+static void HandlePolymorphicKeyedStoreCase(MacroAssembler* masm,
+                                            Register receiver, Register key,
+                                            Register vector, Register slot,
+                                            Register feedback, Label* miss) {
+  // feedback initially contains the feedback array
+  Label next, next_loop, prepare_next;
+  Label load_smi_map, compare_map;
+  Label transition_call;
+  Label pop_and_miss;
+
+  __ push(receiver);
+  __ push(vector);
+
+  Register receiver_map = receiver;
+  Register cached_map = vector;
+
+  // Receiver might not be a heap object.
+  __ JumpIfSmi(receiver, &load_smi_map);
+  __ mov(receiver_map, FieldOperand(receiver, 0));
+  __ bind(&compare_map);
+
+  // Polymorphic, we have to loop from 0 to N - 1
+  __ push(key);
+  // On the stack we have:
+  // key (esp)
+  // vector
+  // receiver
+  // value
+  Register counter = key;
+  __ mov(counter, Immediate(Smi::FromInt(0)));
+  __ bind(&next_loop);
+  __ mov(cached_map, FieldOperand(feedback, counter, times_half_pointer_size,
+                                  FixedArray::kHeaderSize));
+  __ cmp(receiver_map, FieldOperand(cached_map, WeakCell::kValueOffset));
+  __ j(not_equal, &prepare_next);
+  __ mov(cached_map, FieldOperand(feedback, counter, times_half_pointer_size,
+                                  FixedArray::kHeaderSize + kPointerSize));
+  __ CompareRoot(cached_map, Heap::kUndefinedValueRootIndex);
+  __ j(not_equal, &transition_call);
+  __ mov(feedback, FieldOperand(feedback, counter, times_half_pointer_size,
+                                FixedArray::kHeaderSize + 2 * kPointerSize));
+  __ pop(key);
+  __ pop(vector);
+  __ pop(receiver);
+  __ lea(feedback, FieldOperand(feedback, Code::kHeaderSize));
+  __ xchg(feedback, Operand(esp, 0));
+  __ ret(0);
+
+  __ bind(&transition_call);
+  // Oh holy hell this will be tough.
+  // The map goes in vector register.
+  __ mov(receiver, FieldOperand(cached_map, WeakCell::kValueOffset));
+  // The weak cell may have been cleared.
+  __ JumpIfSmi(receiver, &pop_and_miss);
+  // slot goes on the stack, and holds return address.
+  __ xchg(slot, Operand(esp, 4 * kPointerSize));
+  // Get the handler in value.
+  __ mov(feedback, FieldOperand(feedback, counter, times_half_pointer_size,
+                                FixedArray::kHeaderSize + 2 * kPointerSize));
+  __ lea(feedback, FieldOperand(feedback, Code::kHeaderSize));
+  // Pop key into place.
+  __ pop(key);
+  // Put the return address on top of stack, vector goes in slot.
+  __ xchg(slot, Operand(esp, 0));
+  // put the map on the stack, receiver holds receiver.
+  __ xchg(receiver, Operand(esp, 1 * kPointerSize));
+  // put the vector on the stack, slot holds value.
+  __ xchg(slot, Operand(esp, 2 * kPointerSize));
+  // feedback (value) = value, slot = handler.
+  __ xchg(feedback, slot);
+  __ jmp(slot);
+
+  __ bind(&prepare_next);
+  __ add(counter, Immediate(Smi::FromInt(3)));
+  __ cmp(counter, FieldOperand(feedback, FixedArray::kLengthOffset));
+  __ j(less, &next_loop);
+
+  // We exhausted our array of map handler pairs.
+  __ bind(&pop_and_miss);
+  __ pop(key);
+  __ pop(vector);
+  __ pop(receiver);
+  __ jmp(miss);
+
+  __ bind(&load_smi_map);
+  __ LoadRoot(receiver_map, Heap::kHeapNumberMapRootIndex);
+  __ jmp(&compare_map);
+}
+
+
 void VectorKeyedStoreICStub::GenerateImpl(MacroAssembler* masm, bool in_frame) {
+  Register receiver = VectorStoreICDescriptor::ReceiverRegister();  // edx
+  Register key = VectorStoreICDescriptor::NameRegister();           // ecx
+  Register value = VectorStoreICDescriptor::ValueRegister();        // eax
+  Register vector = VectorStoreICDescriptor::VectorRegister();      // ebx
+  Register slot = VectorStoreICDescriptor::SlotRegister();          // edi
   Label miss;
 
-  // TODO(mvstanton): Implement.
+  __ push(value);
+
+  Register scratch = value;
+  __ mov(scratch, FieldOperand(vector, slot, times_half_pointer_size,
+                               FixedArray::kHeaderSize));
+
+  // Is it a weak cell?
+  Label try_array;
+  Label not_array, smi_key, key_okay;
+  __ CompareRoot(FieldOperand(scratch, 0), Heap::kWeakCellMapRootIndex);
+  __ j(not_equal, &try_array);
+  HandleMonomorphicStoreCase(masm, receiver, key, vector, slot, scratch, &miss);
+
+  // Is it a fixed array?
+  __ bind(&try_array);
+  __ CompareRoot(FieldOperand(scratch, 0), Heap::kFixedArrayMapRootIndex);
+  __ j(not_equal, &not_array);
+  HandlePolymorphicKeyedStoreCase(masm, receiver, key, vector, slot, scratch,
+                                  &miss);
+
+  __ bind(&not_array);
+  Label try_poly_name;
+  __ CompareRoot(scratch, Heap::kmegamorphic_symbolRootIndex);
+  __ j(not_equal, &try_poly_name);
+
+  __ pop(value);
+
+  Handle<Code> megamorphic_stub =
+      KeyedStoreIC::ChooseMegamorphicStub(masm->isolate(), GetExtraICState());
+  __ jmp(megamorphic_stub, RelocInfo::CODE_TARGET);
+
+  __ bind(&try_poly_name);
+  // We might have a name in feedback, and a fixed array in the next slot.
+  __ cmp(key, scratch);
+  __ j(not_equal, &miss);
+  // If the name comparison succeeded, we know we have a fixed array with
+  // at least one map/handler pair.
+  __ mov(scratch, FieldOperand(vector, slot, times_half_pointer_size,
+                               FixedArray::kHeaderSize + kPointerSize));
+  HandlePolymorphicStoreCase(masm, receiver, key, vector, slot, scratch, &miss);
+
   __ bind(&miss);
+  __ pop(value);
   KeyedStoreIC::GenerateMiss(masm);
 }