Optimize instanceof further...

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2010 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 1682 matching lines @@
   Register reg = ToRegister(instr->input());
   int true_block = instr->true_block_id();
   int false_block = instr->false_block_id();
 
   __ cmp(FieldOperand(reg, HeapObject::kMapOffset), instr->map());
   EmitBranch(true_block, false_block, equal);
 }
 
 
 void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
-  // Object and function are in fixed registers eax and edx.
+  // Object and function are in fixed registers defined by the stub.
   InstanceofStub stub(InstanceofStub::kArgsInRegisters);
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
 
   NearLabel true_value, done;
   __ test(eax, Operand(eax));
   __ j(zero, &true_value);
   __ mov(ToRegister(instr->result()), Factory::false_value());
   __ jmp(&done);
   __ bind(&true_value);
   __ mov(ToRegister(instr->result()), Factory::true_value());
   __ bind(&done);
 }
 
 
 void LCodeGen::DoInstanceOfAndBranch(LInstanceOfAndBranch* instr) {
   int true_block = chunk_->LookupDestination(instr->true_block_id());
   int false_block = chunk_->LookupDestination(instr->false_block_id());
 
   InstanceofStub stub(InstanceofStub::kArgsInRegisters);
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   __ test(eax, Operand(eax));
   EmitBranch(true_block, false_block, zero);
 }
 
 
+void LCodeGen::DoInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr) {
+  class DeferredInstanceOfKnownGlobal: public LDeferredCode {
+   public:
+    DeferredInstanceOfKnownGlobal(LCodeGen* codegen,
+                                  LInstanceOfKnownGlobal* instr)
+        : LDeferredCode(codegen), instr_(instr) { }
+    virtual void Generate() {
+      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 done, false_result;
+  Register object = ToRegister(instr->input());
+  Register temp = ToRegister(instr->temp());
+
+  // A Smi is not instance of anything.
+  __ test(object, Immediate(kSmiTagMask));
+  __ j(zero, &false_result, not_taken);
+
+  // This is the inlined call site instanceof cache. The two occourences of the
+  // hole value will be patched to the last map/result pair generated by the
+  // instanceof stub.
+  NearLabel cache_miss;
+  Register map = ToRegister(instr->temp());
+  __ mov(map, FieldOperand(object, HeapObject::kMapOffset));
+  __ bind(deferred->map_check());  // Label for calculating code patching.
+  __ cmp(map, Factory::the_hole_value());  // Patched to cached map.
+  __ j(not_equal, &cache_miss, not_taken);
+  __ mov(eax, Factory::the_hole_value());  // Patched to either true or false.
+  __ jmp(&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.
+  __ cmp(object, Factory::null_value());
+  __ j(equal, &false_result);
+
+  // String values is not instance of anything.
+  Condition is_string = masm_->IsObjectStringType(object, temp, temp);
+  __ j(is_string, &false_result);
+
+  // 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);
+}
+
+
+void LCodeGen::DoDeferredLInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
+                                                Label* map_check) {
+  __ PushSafepointRegisters();
+
+  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);
+
+  // Get the temp register reserved by the instruction. This needs to be edi 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());
+  ASSERT(temp.is(edi));
+  __ mov(InstanceofStub::right(), Immediate(instr->function()));
+  InstanceofStub stub(flags);

[Mads Ager (chromium), 2011/01/05 09:59:26]

Can you move this declaration up to where the flags are defined to make it clear
what they are used for?

[Søren Thygesen Gjesse, 2011/01/05 11:11:01]

Done.

+  static const int kAdditionalDelta = 13;
+  int delta = masm_->SizeOfCodeGeneratedSince(map_check) + kAdditionalDelta;
+  Label before_push_delta;
+  __ bind(&before_push_delta);
+  __ mov(temp, Immediate(delta));
+  __ mov(Operand(esp, EspIndexForPushAll(temp) * kPointerSize), temp);
+  __ call(stub.GetCode(), RelocInfo::CODE_TARGET);
+  ASSERT_EQ(kAdditionalDelta,
+            masm_->SizeOfCodeGeneratedSince(&before_push_delta));
+  RecordSafepointWithRegisters(
+      instr->pointer_map(), 0, Safepoint::kNoDeoptimizationIndex);
+  // Put the result value into the eax slot and restore all registers.
+  __ mov(Operand(esp, EspIndexForPushAll(eax) * kPointerSize), eax);
+
+  __ PopSafepointRegisters();
+}
+
+
 static Condition ComputeCompareCondition(Token::Value op) {
   switch (op) {
     case Token::EQ_STRICT:
     case Token::EQ:
       return equal;
     case Token::LT:
       return less;
     case Token::GT:
       return greater;
     case Token::LTE:
@@ skipping 1528 matching lines @@
   ASSERT(!environment->HasBeenRegistered());
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal