Correctify instanceof and make it optimizable.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index 768531fce36dacd97afa9336b424bbd3282fe8e1..02d8dcbe8a7573bcb799354a46934fba7bcc1249 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -2057,11 +2057,17 @@ void LCodeGen::EmitBranchF(InstrType instr,
 }
 
 
-template<class InstrType>
-void LCodeGen::EmitFalseBranch(InstrType instr,
-                               Condition condition,
-                               Register src1,
-                               const Operand& src2) {
+template <class InstrType>
+void LCodeGen::EmitTrueBranch(InstrType instr, Condition condition,
+                              Register src1, const Operand& src2) {
+  int true_block = instr->TrueDestination(chunk_);
+  __ Branch(chunk_->GetAssemblyLabel(true_block), condition, src1, src2);
+}
+
+
+template <class InstrType>
+void LCodeGen::EmitFalseBranch(InstrType instr, Condition condition,
+                               Register src1, const Operand& src2) {
   int false_block = instr->FalseDestination(chunk_);
   __ Branch(chunk_->GetAssemblyLabel(false_block), condition, src1, src2);
 }
@@ -2651,142 +2657,38 @@ void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
 
 void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
   DCHECK(ToRegister(instr->context()).is(cp));
-  Label true_label, done;
-  DCHECK(ToRegister(instr->left()).is(a0));  // Object is in a0.
-  DCHECK(ToRegister(instr->right()).is(a1));  // Function is in a1.
-  Register result = ToRegister(instr->result());
-  DCHECK(result.is(v0));
-
-  InstanceofStub stub(isolate(), InstanceofStub::kArgsInRegisters);
+  DCHECK(ToRegister(instr->left()).is(InstanceOfDescriptor::LeftRegister()));
+  DCHECK(ToRegister(instr->right()).is(InstanceOfDescriptor::RightRegister()));
+  DCHECK(ToRegister(instr->result()).is(v0));
+  InstanceOfStub stub(isolate());
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
-
-  __ Branch(&true_label, eq, result, Operand(zero_reg));
-  __ li(result, Operand(factory()->false_value()));
-  __ Branch(&done);
-  __ bind(&true_label);
-  __ li(result, Operand(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_;
-  };
-
-  DeferredInstanceOfKnownGlobal* deferred;
-  deferred = new(zone()) DeferredInstanceOfKnownGlobal(this, instr);
-
-  Label done, false_result;
-  Register object = ToRegister(instr->value());
-  Register temp = ToRegister(instr->temp());
-  Register result = ToRegister(instr->result());
-
-  DCHECK(object.is(a0));
-  DCHECK(result.is(v0));
+void LCodeGen::DoHasInPrototypeChainAndBranch(
+    LHasInPrototypeChainAndBranch* instr) {
+  Register const object = ToRegister(instr->object());
+  Register const object_map = scratch0();
+  Register const object_prototype = object_map;
+  Register const prototype = ToRegister(instr->prototype());
 
-  // A Smi is not instance of anything.
-  __ JumpIfSmi(object, &false_result);
-
-  // 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 = temp;
-  __ lw(map, FieldMemOperand(object, HeapObject::kMapOffset));
-
-  Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
-  __ bind(deferred->map_check());  // Label for calculating code patching.
-  // We use Factory::the_hole_value() on purpose instead of loading from the
-  // root array to force relocation to be able to later patch with
-  // the cached map.
-  Handle<Cell> cell = factory()->NewCell(factory()->the_hole_value());
-  __ li(at, Operand(cell));
-  __ lw(at, FieldMemOperand(at, Cell::kValueOffset));
-  __ BranchShort(&cache_miss, ne, map, Operand(at));
-  // We use Factory::the_hole_value() on purpose instead of loading from the
-  // root array to force relocation to be able to later patch
-  // with true or false. The distance from map check has to be constant.
-  __ li(result, Operand(factory()->the_hole_value()), CONSTANT_SIZE);
-  __ Branch(&done);
-
-  // The inlined call site cache did not match. Check null and string before
-  // calling the deferred code.
-  __ bind(&cache_miss);
-  // Null is not instance of anything.
-  __ LoadRoot(temp, Heap::kNullValueRootIndex);
-  __ Branch(&false_result, eq, object, Operand(temp));
-
-  // String values is not instance of anything.
-  Condition cc = __ IsObjectStringType(object, temp, temp);
-  __ Branch(&false_result, cc, temp, Operand(zero_reg));
-
-  // Go to the deferred code.
-  __ Branch(deferred->entry());
-
-  __ bind(&false_result);
-  __ LoadRoot(result, Heap::kFalseValueRootIndex);
-
-  // Here result has either true or false. Deferred code also produces true or
-  // false object.
-  __ bind(deferred->exit());
-  __ bind(&done);
-}
-
-
-void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
-                                               Label* map_check) {
-  Register result = ToRegister(instr->result());
-  DCHECK(result.is(v0));
-
-  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);
-
-  PushSafepointRegistersScope scope(this);
-  LoadContextFromDeferred(instr->context());
-
-  // Get the temp register reserved by the instruction. This needs to be t0 as
-  // its slot of the pushing of safepoint registers is used to communicate the
-  // offset to the location of the map check.
-  Register temp = ToRegister(instr->temp());
-  DCHECK(temp.is(t0));
-  __ li(InstanceofStub::right(), instr->function());
-  static const int kAdditionalDelta = 7;
-  int delta = masm_->InstructionsGeneratedSince(map_check) + kAdditionalDelta;
-  Label before_push_delta;
-  __ bind(&before_push_delta);
-  {
-    Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
-    __ li(temp, Operand(delta * kPointerSize), CONSTANT_SIZE);
-    __ StoreToSafepointRegisterSlot(temp, temp);
-  }
-  CallCodeGeneric(stub.GetCode(),
-                  RelocInfo::CODE_TARGET,
-                  instr,
-                  RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
-  LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
-  safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
-  // Put the result value into the result register slot and
-  // restore all registers.
-  __ StoreToSafepointRegisterSlot(result, result);
+  // 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()) {
+    __ SmiTst(object, at);
+    EmitFalseBranch(instr, eq, at, Operand(zero_reg));
+  }
+  // Loop through the {object}s prototype chain looking for the {prototype}.
+  __ lw(object_map, FieldMemOperand(object, HeapObject::kMapOffset));
+  Label loop;
+  __ bind(&loop);
+  __ lw(object_prototype, FieldMemOperand(object_map, Map::kPrototypeOffset));
+  EmitTrueBranch(instr, eq, object_prototype, Operand(prototype));
+  __ LoadRoot(at, Heap::kNullValueRootIndex);
+  EmitFalseBranch(instr, eq, object_prototype, Operand(at));
+  __ Branch(USE_DELAY_SLOT, &loop);
+  __ lw(object_map, FieldMemOperand(object_prototype, HeapObject::kMapOffset));
 }