Remove prototype checks for leaf maps in optimized code.

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 66 matching lines @@
       GenerateDeoptJumpTable() &&
       GenerateSafepointTable();
 }
 
 
 void LCodeGen::FinishCode(Handle<Code> code) {
   ASSERT(is_done());
   code->set_stack_slots(GetStackSlotCount());
   code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
   PopulateDeoptimizationData(code);
+  for (int i = 0 ; i < prototype_maps_.length(); i++) {
+    prototype_maps_.at(i)->AddDependentCode(
+        DependentCode::kPrototypeCheckGroup, code);
+  }
 }
 
 
 void LCodeGen::Abort(const char* reason) {
   info()->set_bailout_reason(reason);
   status_ = ABORTED;
 }
 
 
 void LCodeGen::Comment(const char* format, ...) {
@@ skipping 5377 matching lines @@
 void LCodeGen::DoCheckPrototypeMaps(LCheckPrototypeMaps* instr) {
   ASSERT(instr->temp()->Equals(instr->result()));
   Register prototype_reg = ToRegister(instr->temp());
   Register map_reg = ToRegister(instr->temp2());
 
   ZoneList<Handle<JSObject> >* prototypes = instr->prototypes();
   ZoneList<Handle<Map> >* maps = instr->maps();
 
   ASSERT(prototypes->length() == maps->length());
 
-  for (int i = 0; i < prototypes->length(); i++) {
-    __ LoadHeapObject(prototype_reg, prototypes->at(i));
-    __ ldr(map_reg, FieldMemOperand(prototype_reg, HeapObject::kMapOffset));
-    DoCheckMapCommon(map_reg,
-                     maps->at(i),
-                     ALLOW_ELEMENT_TRANSITION_MAPS,
-                     instr->environment());
+  if (instr->hydrogen()->CanOmitPrototypeChecks()) {
+    for (int i = 0; i < maps->length(); i++) {
+      prototype_maps_.Add(maps->at(i), info()->zone());
+    }
+    __ LoadHeapObject(prototype_reg,
+                      prototypes->at(prototypes->length() - 1));
+  } else {
+    for (int i = 0; i < prototypes->length(); i++) {
+      __ LoadHeapObject(prototype_reg, prototypes->at(i));
+      __ ldr(map_reg, FieldMemOperand(prototype_reg, HeapObject::kMapOffset));
+      DoCheckMapCommon(map_reg,
+                       maps->at(i),
+                       ALLOW_ELEMENT_TRANSITION_MAPS,
+                       instr->environment());
+    }
   }
 }
 
 
 void LCodeGen::DoAllocateObject(LAllocateObject* instr) {
   class DeferredAllocateObject: public LDeferredCode {
    public:
     DeferredAllocateObject(LCodeGen* codegen, LAllocateObject* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() { codegen()->DoDeferredAllocateObject(instr_); }
@@ skipping 815 matching lines @@
   __ sub(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal