Megamorphic KeyedLoadIC needs special handling for vector ics.

src/ic/arm/ic-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/codegen.h"
 #include "src/ic/ic.h"
@@ skipping 509 matching lines @@
                                  Map::kHasNamedInterceptor, &slow);
 
   // If the receiver is a fast-case object, check the stub cache. Otherwise
   // probe the dictionary.
   __ ldr(r3, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
   __ ldr(r4, FieldMemOperand(r3, HeapObject::kMapOffset));
   __ LoadRoot(ip, Heap::kHashTableMapRootIndex);
   __ cmp(r4, ip);
   __ b(eq, &probe_dictionary);
 
+
+  if (FLAG_vector_ics) {
+    // When vector ics are in use, the handlers in the stub cache expect a
+    // vector and slot. Since we won't change the IC from any downstream
+    // misses, a dummy vector can be used.
+    Register vector = VectorLoadICDescriptor::VectorRegister();
+    Register slot = VectorLoadICDescriptor::SlotRegister();
+    DCHECK(!AreAliased(vector, slot, r4, r5, r6, r9));
+    Handle<TypeFeedbackVector> dummy_vector = Handle<TypeFeedbackVector>::cast(
+        masm->isolate()->factory()->keyed_load_dummy_vector());
+    int int_slot = dummy_vector->GetIndex(FeedbackVectorICSlot(0));
+    __ LoadRoot(vector, Heap::kKeyedLoadDummyVectorRootIndex);
+    __ mov(slot, Operand(Smi::FromInt(int_slot)));
+  }
+
   Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
       Code::ComputeHandlerFlags(Code::LOAD_IC));
   masm->isolate()->stub_cache()->GenerateProbe(
-      masm, Code::LOAD_IC, flags, false, receiver, key, r3, r4, r5, r6);
+      masm, Code::KEYED_LOAD_IC, flags, false, receiver, key, r4, r5, r6, r9);
   // Cache miss.
   GenerateMiss(masm);
 
   // Do a quick inline probe of the receiver's dictionary, if it
   // exists.
   __ bind(&probe_dictionary);
   // r3: elements
   __ ldr(r0, FieldMemOperand(receiver, HeapObject::kMapOffset));
   __ ldrb(r0, FieldMemOperand(r0, Map::kInstanceTypeOffset));
   GenerateGlobalInstanceTypeCheck(masm, r0, &slow);
@@ skipping 422 matching lines @@
     patcher.EmitCondition(ne);
   } else {
     DCHECK(Assembler::GetCondition(branch_instr) == ne);
     patcher.EmitCondition(eq);
   }
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM