[compiler] Introduce code stubs for string relational comparisons.

src/arm64/code-stubs-arm64.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_ARM64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/ic/handler-compiler.h"
@@ skipping 3450 matching lines @@
   __ Bind(&loop);
   __ Ldrb(scratch1, MemOperand(left, index));
   __ Ldrb(scratch2, MemOperand(right, index));
   __ Cmp(scratch1, scratch2);
   __ B(ne, chars_not_equal);
   __ Add(index, index, 1);
   __ Cbnz(index, &loop);
 }
 
 
-void StringCompareStub::Generate(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  //  -- x1    : left
-  //  -- x0    : right
-  //  -- lr    : return address
-  // -----------------------------------
-  __ AssertString(x1);
-  __ AssertString(x0);
-
-  Label not_same;
-  __ Cmp(x0, x1);
-  __ B(ne, &not_same);
-  __ Mov(x0, Smi::FromInt(EQUAL));
-  __ IncrementCounter(isolate()->counters()->string_compare_native(), 1, x3,
-                      x4);
-  __ Ret();
-
-  __ Bind(&not_same);
-
-  // Check that both objects are sequential one-byte strings.
-  Label runtime;
-  __ JumpIfEitherIsNotSequentialOneByteStrings(x1, x0, x12, x13, &runtime);
-
-  // Compare flat one-byte strings natively.
-  __ IncrementCounter(isolate()->counters()->string_compare_native(), 1, x3,
-                      x4);
-  StringHelper::GenerateCompareFlatOneByteStrings(masm, x1, x0, x12, x13, x14,
-                                                  x15);
-
-  // Call the runtime.
-  // Returns -1 (less), 0 (equal), or 1 (greater) tagged as a small integer.
-  __ Bind(&runtime);
-  __ Push(x1, x0);
-  __ TailCallRuntime(Runtime::kStringCompare);
-}
-
-
 void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- x1    : left
   //  -- x0    : right
   //  -- lr    : return address
   // -----------------------------------
 
   // Load x2 with the allocation site.  We stick an undefined dummy value here
   // and replace it with the real allocation site later when we instantiate this
   // stub in BinaryOpICWithAllocationSiteStub::GetCodeCopyFromTemplate().
@@ skipping 2492 matching lines @@
                            return_value_operand, NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64