X64 Crankshaft: Add inline one-element cache for Instanceof.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
===================================================================
--- src/x64/lithium-codegen-x64.cc	(revision 7107)
+++ src/x64/lithium-codegen-x64.cc	(working copy)
@@ -1823,24 +1823,50 @@
                                   LInstanceOfKnownGlobal* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() {
-      codegen()->DoDeferredLInstanceOfKnownGlobal(instr_);
+      codegen()->DoDeferredLInstanceOfKnownGlobal(instr_, &map_check_);
     }
 
+    Label* map_check() { return &map_check_; }
+
    private:
     LInstanceOfKnownGlobal* instr_;
+    Label map_check_;
   };
 
 
   DeferredInstanceOfKnownGlobal* deferred;
   deferred = new DeferredInstanceOfKnownGlobal(this, instr);
 
-  Label false_result;
+  Label done, false_result;
   Register object = ToRegister(instr->InputAt(0));
 
   // A Smi is not an instance of anything.
   __ JumpIfSmi(object, &false_result);
 
-  // Null is not an instance of anything.
+  // 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.
+  NearLabel cache_miss;
+  // Use a temp register to avoid memory operands with variable lengths.
+  Register map = ToRegister(instr->TempAt(0));
+  __ movq(map, FieldOperand(object, HeapObject::kMapOffset));
+  __ bind(deferred->map_check());  // Label for calculating code patching.
+  __ Move(kScratchRegister, Factory::the_hole_value());
+  __ cmpq(map, kScratchRegister);  // Patched to cached map.
+  __ j(not_equal, &cache_miss);
+  // Patched to load either true or false.
+  __ LoadRoot(ToRegister(instr->result()), Heap::kTheHoleValueRootIndex);
+#ifdef DEBUG
+  // Check that the code size between patch label and patch sites is invariant.
+  Label end_of_patched_code;
+  __ bind(&end_of_patched_code);
+  ASSERT(true);
+#endif
+  __ jmp(&done);
+
+  // 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.
   __ CompareRoot(object, Heap::kNullValueRootIndex);
   __ j(equal, &false_result);
 
@@ -1851,17 +1877,26 @@
   __ LoadRoot(ToRegister(instr->result()), Heap::kFalseValueRootIndex);
 
   __ bind(deferred->exit());
+  __ bind(&done);
 }
 
 
-void LCodeGen::DoDeferredLInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr) {
+void LCodeGen::DoDeferredLInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
+                                                Label* map_check) {
   __ PushSafepointRegisters();
+  InstanceofStub::Flags flags = static_cast<InstanceofStub::Flags>(
+      InstanceofStub::kNoFlags | InstanceofStub::kCallSiteInlineCheck);
+  InstanceofStub stub(flags);
 
-  InstanceofStub stub(InstanceofStub::kNoFlags);
-
   __ push(ToRegister(instr->InputAt(0)));
   __ Push(instr->function());
-  __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+  Register temp = ToRegister(instr->TempAt(0));
+  ASSERT(temp.is(rdi));
+  static const int kAdditionalDelta = 16;
+  int delta =
+      masm_->SizeOfCodeGeneratedSince(map_check) + kAdditionalDelta;
+  __ movq(temp, Immediate(delta));
+  __ push(temp);
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   __ movq(kScratchRegister, rax);
   __ PopSafepointRegisters();