[stubs] Refactor StringCompareStub and use it for HStringCompareAndBranch.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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_X64
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/cpu-profiler.h"
@@ skipping 981 matching lines @@
     case CodeStub::RegExpExec: {
       RegExpExecStub stub(isolate());
       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
       break;
     }
     case CodeStub::SubString: {
       SubStringStub stub(isolate());
       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
       break;
     }
-    case CodeStub::StringCompare: {
-      StringCompareStub stub(isolate());
-      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
-      break;
-    }
     default:
       UNREACHABLE();
   }
 }
 
 
 void LCodeGen::DoUnknownOSRValue(LUnknownOSRValue* instr) {
   GenerateOsrPrologue();
 }
 
@@ skipping 1467 matching lines @@
   }
   __ movp(temp, FieldOperand(input, HeapObject::kMapOffset));
   __ testb(FieldOperand(temp, Map::kBitFieldOffset),
            Immediate(1 << Map::kIsUndetectable));
   EmitBranch(instr, not_zero);
 }
 
 
 void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
   DCHECK(ToRegister(instr->context()).is(rsi));
-  Token::Value op = instr->op();
+  DCHECK(ToRegister(instr->left()).is(rdx));
+  DCHECK(ToRegister(instr->right()).is(rax));
 
-  Handle<Code> ic =
-      CodeFactory::CompareIC(isolate(), op, Strength::WEAK).code();
-  CallCode(ic, RelocInfo::CODE_TARGET, instr);
-
-  Condition condition = TokenToCondition(op, false);
+  Handle<Code> code = CodeFactory::StringCompare(isolate()).code();
+  CallCode(code, RelocInfo::CODE_TARGET, instr);
   __ testp(rax, rax);
 
-  EmitBranch(instr, condition);
+  EmitBranch(instr, TokenToCondition(instr->op(), false));
 }
 
 
 static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
   InstanceType from = instr->from();
   InstanceType to = instr->to();
   if (from == FIRST_TYPE) return to;
   DCHECK(from == to || to == LAST_TYPE);
   return from;
 }
@@ skipping 3407 matching lines @@
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64