Correctify instanceof and make it optimizable.

src/ia32/lithium-codegen-ia32.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.
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 2037 matching lines @@
     __ j(NegateCondition(cc), chunk_->GetAssemblyLabel(right_block));
   } else if (right_block == next_block) {
     __ j(cc, chunk_->GetAssemblyLabel(left_block));
   } else {
     __ j(cc, chunk_->GetAssemblyLabel(left_block));
     __ jmp(chunk_->GetAssemblyLabel(right_block));
   }
 }
 
 
+template <class InstrType>
+void LCodeGen::EmitTrueBranch(InstrType instr, Condition cc) {
+  int true_block = instr->TrueDestination(chunk_);
+  if (cc == no_condition) {
+    __ jmp(chunk_->GetAssemblyLabel(true_block));
+  } else {
+    __ j(cc, chunk_->GetAssemblyLabel(true_block));
+  }
+}
+
+
 template<class InstrType>
 void LCodeGen::EmitFalseBranch(InstrType instr, Condition cc) {
   int false_block = instr->FalseDestination(chunk_);
   if (cc == no_condition) {
     __ jmp(chunk_->GetAssemblyLabel(false_block));
   } else {
     __ j(cc, chunk_->GetAssemblyLabel(false_block));
   }
 }
 
@@ skipping 539 matching lines @@
 
 
 void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
   Register reg = ToRegister(instr->value());
   __ cmp(FieldOperand(reg, HeapObject::kMapOffset), instr->map());
   EmitBranch(instr, equal);
 }
 
 
 void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
-  // Object and function are in fixed registers defined by the stub.
   DCHECK(ToRegister(instr->context()).is(esi));
-  InstanceofStub stub(isolate(), InstanceofStub::kArgsInRegisters);
+  DCHECK(ToRegister(instr->left()).is(InstanceOfDescriptor::LeftRegister()));
+  DCHECK(ToRegister(instr->right()).is(InstanceOfDescriptor::RightRegister()));
+  DCHECK(ToRegister(instr->result()).is(eax));
+  InstanceOfStub stub(isolate());
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
-
-  Label true_value, done;
-  __ test(eax, Operand(eax));
-  __ j(zero, &true_value, Label::kNear);
-  __ mov(ToRegister(instr->result()), factory()->false_value());
-  __ jmp(&done, Label::kNear);
-  __ bind(&true_value);
-  __ mov(ToRegister(instr->result()), factory()->true_value());
-  __ bind(&done);
 }
 
 
-void LCodeGen::DoInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr) {
-  class DeferredInstanceOfKnownGlobal final : public LDeferredCode {
-   public:
-    DeferredInstanceOfKnownGlobal(LCodeGen* codegen,
-                                  LInstanceOfKnownGlobal* instr)
-        : LDeferredCode(codegen), instr_(instr) { }
-    void Generate() override {
-      codegen()->DoDeferredInstanceOfKnownGlobal(instr_, &map_check_);
-    }
-    LInstruction* instr() override { return instr_; }
-    Label* map_check() { return &map_check_; }
-   private:
-    LInstanceOfKnownGlobal* instr_;
-    Label map_check_;
-  };
+void LCodeGen::DoHasInPrototypeChainAndBranch(
+    LHasInPrototypeChainAndBranch* instr) {
+  Register const object = ToRegister(instr->object());
+  Register const object_map = ToRegister(instr->scratch());
+  Register const object_prototype = object_map;
+  Register const prototype = ToRegister(instr->prototype());
 
-  DeferredInstanceOfKnownGlobal* deferred;
-  deferred = new(zone()) DeferredInstanceOfKnownGlobal(this, instr);
+  // The {object} must be a spec object.  It's sufficient to know that {object}
+  // is not a smi, since all other non-spec objects have {null} prototypes and
+  // will be ruled out below.
+  if (instr->hydrogen()->ObjectNeedsSmiCheck()) {
+    __ test(object, Immediate(kSmiTagMask));
+    EmitFalseBranch(instr, zero);
+  }
 
-  Label done, false_result;
-  Register object = ToRegister(instr->value());
-  Register temp = ToRegister(instr->temp());
-
-  // A Smi is not an instance of anything.
-  __ JumpIfSmi(object, &false_result, Label::kNear);
-
-  // This is the inlined call site instanceof cache. The two occurences of the
-  // hole value will be patched to the last map/result pair generated by the
-  // instanceof stub.
-  Label cache_miss;
-  Register map = ToRegister(instr->temp());
-  __ mov(map, FieldOperand(object, HeapObject::kMapOffset));
-  __ bind(deferred->map_check());  // Label for calculating code patching.
-  Handle<Cell> cache_cell = factory()->NewCell(factory()->the_hole_value());
-  __ cmp(map, Operand::ForCell(cache_cell));  // Patched to cached map.
-  __ j(not_equal, &cache_miss, Label::kNear);
-  __ mov(eax, factory()->the_hole_value());  // Patched to either true or false.
-  __ jmp(&done, Label::kNear);
-
-  // The inlined call site cache did not match. Check for null and string
-  // before calling the deferred code.
-  __ bind(&cache_miss);
-  // Null is not an instance of anything.
-  __ cmp(object, factory()->null_value());
-  __ j(equal, &false_result, Label::kNear);
-
-  // String values are not instances of anything.
-  Condition is_string = masm_->IsObjectStringType(object, temp, temp);
-  __ j(is_string, &false_result, Label::kNear);
-
-  // Go to the deferred code.
-  __ jmp(deferred->entry());
-
-  __ bind(&false_result);
-  __ mov(ToRegister(instr->result()), factory()->false_value());
-
-  // Here result has either true or false. Deferred code also produces true or
-  // false object.
-  __ bind(deferred->exit());
-  __ bind(&done);
+  // Loop through the {object}s prototype chain looking for the {prototype}.
+  __ mov(object_map, FieldOperand(object, HeapObject::kMapOffset));
+  Label loop;
+  __ bind(&loop);
+  __ mov(object_prototype, FieldOperand(object_map, Map::kPrototypeOffset));
+  __ cmp(object_prototype, prototype);
+  EmitTrueBranch(instr, equal);
+  __ cmp(object_prototype, factory()->null_value());
+  EmitFalseBranch(instr, equal);
+  __ mov(object_map, FieldOperand(object_prototype, HeapObject::kMapOffset));
+  __ jmp(&loop);
 }
 
 
-void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
-                                               Label* map_check) {
-  PushSafepointRegistersScope scope(this);
-
-  InstanceofStub::Flags flags = InstanceofStub::kNoFlags;
-  flags = static_cast<InstanceofStub::Flags>(
-      flags | InstanceofStub::kArgsInRegisters);
-  flags = static_cast<InstanceofStub::Flags>(
-      flags | InstanceofStub::kCallSiteInlineCheck);
-  flags = static_cast<InstanceofStub::Flags>(
-      flags | InstanceofStub::kReturnTrueFalseObject);
-  InstanceofStub stub(isolate(), flags);
-
-  // Get the temp register reserved by the instruction. This needs to be a
-  // register which is pushed last by PushSafepointRegisters as top of the
-  // stack is used to pass the offset to the location of the map check to
-  // the stub.
-  Register temp = ToRegister(instr->temp());
-  DCHECK(MacroAssembler::SafepointRegisterStackIndex(temp) == 0);
-  __ LoadHeapObject(InstanceofStub::right(), instr->function());
-  static const int kAdditionalDelta = 13;
-  int delta = masm_->SizeOfCodeGeneratedSince(map_check) + kAdditionalDelta;
-  __ mov(temp, Immediate(delta));
-  __ StoreToSafepointRegisterSlot(temp, temp);
-  CallCodeGeneric(stub.GetCode(),
-                  RelocInfo::CODE_TARGET,
-                  instr,
-                  RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
-  // Get the deoptimization index of the LLazyBailout-environment that
-  // corresponds to this instruction.
-  LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
-  safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
-
-  // Put the result value into the eax slot and restore all registers.
-  __ StoreToSafepointRegisterSlot(eax, eax);
-}
-
-
 void LCodeGen::DoCmpT(LCmpT* instr) {
   Token::Value op = instr->op();
 
   Handle<Code> ic =
       CodeFactory::CompareIC(isolate(), op, instr->strength()).code();
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 
   Condition condition = ComputeCompareCondition(op);
   Label true_value, done;
   __ test(eax, Operand(eax));
@@ skipping 3108 matching lines @@
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32