[compiler] Introduce code stubs for string relational comparisons.

src/arm/code-stubs-arm.cc

 // Copyright 2012 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_ARM
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 2832 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, Operand(1), SetCC);
   __ b(ne, &loop);
 }
 
 
-void StringCompareStub::Generate(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  //  -- r1    : left
-  //  -- r0    : right
-  //  -- lr    : return address
-  // -----------------------------------
-  __ AssertString(r1);
-  __ AssertString(r0);
-
-  Label not_same;
-  __ cmp(r0, r1);
-  __ b(ne, &not_same);
-  __ mov(r0, Operand(Smi::FromInt(EQUAL)));
-  __ IncrementCounter(isolate()->counters()->string_compare_native(), 1, r1,
-                      r2);
-  __ Ret();
-
-  __ bind(&not_same);
-
-  // Check that both objects are sequential one-byte strings.
-  Label runtime;
-  __ JumpIfNotBothSequentialOneByteStrings(r1, r0, r2, r3, &runtime);
-
-  // Compare flat one-byte strings natively.
-  __ IncrementCounter(isolate()->counters()->string_compare_native(), 1, r2,
-                      r3);
-  StringHelper::GenerateCompareFlatOneByteStrings(masm, r1, r0, r2, r3, r4, r5);
-
-  // Call the runtime; it returns -1 (less), 0 (equal), or 1 (greater)
-  // tagged as a small integer.
-  __ bind(&runtime);
-  __ Push(r1, r0);
-  __ TailCallRuntime(Runtime::kStringCompare);
-}
-
-
 void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r1    : left
   //  -- r0    : right
   //  -- lr    : return address
   // -----------------------------------
 
   // Load r2 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 2728 matching lines @@
                            kStackUnwindSpace, NULL, return_value_operand, NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM