Get rid of the unused native code StringAddStub.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 758d35f3a61e2ec1cad0cdced7ffe253d4a14b89..75ef1ff968d7596a99a03e5ebf4b292efbce593a 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -350,7 +350,7 @@ void BinaryOpWithAllocationSiteStub::InitializeInterfaceDescriptor(
 }
 
 
-void NewStringAddStub::InitializeInterfaceDescriptor(
+void StringAddStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { r1, r0 };
@@ -4433,362 +4433,6 @@ void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
 }
 
 
-void StringAddStub::Generate(MacroAssembler* masm) {
-  Label call_runtime, call_builtin;
-  Builtins::JavaScript builtin_id = Builtins::ADD;
-
-  Counters* counters = masm->isolate()->counters();
-
-  // Stack on entry:
-  // sp[0]: second argument (right).
-  // sp[4]: first argument (left).
-
-  // Load the two arguments.
-  __ ldr(r0, MemOperand(sp, 1 * kPointerSize));  // First argument.
-  __ ldr(r1, MemOperand(sp, 0 * kPointerSize));  // Second argument.
-
-  // Make sure that both arguments are strings if not known in advance.
-  // Otherwise, at least one of the arguments is definitely a string,
-  // and we convert the one that is not known to be a string.
-  if ((flags_ & STRING_ADD_CHECK_BOTH) == STRING_ADD_CHECK_BOTH) {
-    ASSERT((flags_ & STRING_ADD_CHECK_LEFT) == STRING_ADD_CHECK_LEFT);
-    ASSERT((flags_ & STRING_ADD_CHECK_RIGHT) == STRING_ADD_CHECK_RIGHT);
-    __ JumpIfEitherSmi(r0, r1, &call_runtime);
-    // Load instance types.
-    __ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
-    __ ldr(r5, FieldMemOperand(r1, HeapObject::kMapOffset));
-    __ ldrb(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
-    __ ldrb(r5, FieldMemOperand(r5, Map::kInstanceTypeOffset));
-    STATIC_ASSERT(kStringTag == 0);
-    // If either is not a string, go to runtime.
-    __ tst(r4, Operand(kIsNotStringMask));
-    __ tst(r5, Operand(kIsNotStringMask), eq);
-    __ b(ne, &call_runtime);
-  } else if ((flags_ & STRING_ADD_CHECK_LEFT) == STRING_ADD_CHECK_LEFT) {
-    ASSERT((flags_ & STRING_ADD_CHECK_RIGHT) == 0);
-    GenerateConvertArgument(
-        masm, 1 * kPointerSize, r0, r2, r3, r4, r5, &call_builtin);
-    builtin_id = Builtins::STRING_ADD_RIGHT;
-  } else if ((flags_ & STRING_ADD_CHECK_RIGHT) == STRING_ADD_CHECK_RIGHT) {
-    ASSERT((flags_ & STRING_ADD_CHECK_LEFT) == 0);
-    GenerateConvertArgument(
-        masm, 0 * kPointerSize, r1, r2, r3, r4, r5, &call_builtin);
-    builtin_id = Builtins::STRING_ADD_LEFT;
-  }
-
-  // Both arguments are strings.
-  // r0: first string
-  // r1: second string
-  // r4: first string instance type (if flags_ == NO_STRING_ADD_FLAGS)
-  // r5: second string instance type (if flags_ == NO_STRING_ADD_FLAGS)
-  {
-    Label strings_not_empty;
-    // Check if either of the strings are empty. In that case return the other.
-    __ ldr(r2, FieldMemOperand(r0, String::kLengthOffset));
-    __ ldr(r3, FieldMemOperand(r1, String::kLengthOffset));
-    STATIC_ASSERT(kSmiTag == 0);
-    __ cmp(r2, Operand(Smi::FromInt(0)));  // Test if first string is empty.
-    __ mov(r0, Operand(r1), LeaveCC, eq);  // If first is empty, return second.
-    STATIC_ASSERT(kSmiTag == 0);
-     // Else test if second string is empty.
-    __ cmp(r3, Operand(Smi::FromInt(0)), ne);
-    __ b(ne, &strings_not_empty);  // If either string was empty, return r0.
-
-    __ IncrementCounter(counters->string_add_native(), 1, r2, r3);
-    __ add(sp, sp, Operand(2 * kPointerSize));
-    __ Ret();
-
-    __ bind(&strings_not_empty);
-  }
-
-  __ SmiUntag(r2);
-  __ SmiUntag(r3);
-  // Both strings are non-empty.
-  // r0: first string
-  // r1: second string
-  // r2: length of first string
-  // r3: length of second string
-  // r4: first string instance type (if flags_ == NO_STRING_ADD_FLAGS)
-  // r5: second string instance type (if flags_ == NO_STRING_ADD_FLAGS)
-  // Look at the length of the result of adding the two strings.
-  Label string_add_flat_result, longer_than_two;
-  // Adding two lengths can't overflow.
-  STATIC_ASSERT(String::kMaxLength < String::kMaxLength * 2);
-  __ add(r6, r2, Operand(r3));
-  // Use the string table when adding two one character strings, as it
-  // helps later optimizations to return a string here.
-  __ cmp(r6, Operand(2));
-  __ b(ne, &longer_than_two);
-
-  // Check that both strings are non-external ASCII strings.
-  if ((flags_ & STRING_ADD_CHECK_BOTH) != STRING_ADD_CHECK_BOTH) {
-    __ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
-    __ ldr(r5, FieldMemOperand(r1, HeapObject::kMapOffset));
-    __ ldrb(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
-    __ ldrb(r5, FieldMemOperand(r5, Map::kInstanceTypeOffset));
-  }
-  __ JumpIfBothInstanceTypesAreNotSequentialAscii(r4, r5, r6, r3,
-                                                  &call_runtime);
-
-  // Get the two characters forming the sub string.
-  __ ldrb(r2, FieldMemOperand(r0, SeqOneByteString::kHeaderSize));
-  __ ldrb(r3, FieldMemOperand(r1, SeqOneByteString::kHeaderSize));
-
-  // Try to lookup two character string in string table. If it is not found
-  // just allocate a new one.
-  Label make_two_character_string;
-  StringHelper::GenerateTwoCharacterStringTableProbe(
-      masm, r2, r3, r6, r0, r4, r5, r9, &make_two_character_string);
-  __ IncrementCounter(counters->string_add_native(), 1, r2, r3);
-  __ add(sp, sp, Operand(2 * kPointerSize));
-  __ Ret();
-
-  __ bind(&make_two_character_string);
-  // Resulting string has length 2 and first chars of two strings
-  // are combined into single halfword in r2 register.
-  // So we can fill resulting string without two loops by a single
-  // halfword store instruction (which assumes that processor is
-  // in a little endian mode)
-  __ mov(r6, Operand(2));
-  __ AllocateAsciiString(r0, r6, r4, r5, r9, &call_runtime);
-  __ strh(r2, FieldMemOperand(r0, SeqOneByteString::kHeaderSize));
-  __ IncrementCounter(counters->string_add_native(), 1, r2, r3);
-  __ add(sp, sp, Operand(2 * kPointerSize));
-  __ Ret();
-
-  __ bind(&longer_than_two);
-  // Check if resulting string will be flat.
-  __ cmp(r6, Operand(ConsString::kMinLength));
-  __ b(lt, &string_add_flat_result);
-  // Handle exceptionally long strings in the runtime system.
-  STATIC_ASSERT((String::kMaxLength & 0x80000000) == 0);
-  ASSERT(IsPowerOf2(String::kMaxLength + 1));
-  // kMaxLength + 1 is representable as shifted literal, kMaxLength is not.
-  __ cmp(r6, Operand(String::kMaxLength + 1));
-  __ b(hs, &call_runtime);
-
-  // If result is not supposed to be flat, allocate a cons string object.
-  // If both strings are ASCII the result is an ASCII cons string.
-  if ((flags_ & STRING_ADD_CHECK_BOTH) != STRING_ADD_CHECK_BOTH) {
-    __ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
-    __ ldr(r5, FieldMemOperand(r1, HeapObject::kMapOffset));
-    __ ldrb(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
-    __ ldrb(r5, FieldMemOperand(r5, Map::kInstanceTypeOffset));
-  }
-  Label non_ascii, allocated, ascii_data;
-  STATIC_ASSERT(kTwoByteStringTag == 0);
-  __ tst(r4, Operand(kStringEncodingMask));
-  __ tst(r5, Operand(kStringEncodingMask), ne);
-  __ b(eq, &non_ascii);
-
-  // Allocate an ASCII cons string.
-  __ bind(&ascii_data);
-  __ AllocateAsciiConsString(r3, r6, r4, r5, &call_runtime);
-  __ bind(&allocated);
-  // Fill the fields of the cons string.
-  Label skip_write_barrier, after_writing;
-  ExternalReference high_promotion_mode = ExternalReference::
-      new_space_high_promotion_mode_active_address(masm->isolate());
-  __ mov(r4, Operand(high_promotion_mode));
-  __ ldr(r4, MemOperand(r4, 0));
-  __ cmp(r4, Operand::Zero());
-  __ b(eq, &skip_write_barrier);
-
-  __ str(r0, FieldMemOperand(r3, ConsString::kFirstOffset));
-  __ RecordWriteField(r3,
-                      ConsString::kFirstOffset,
-                      r0,
-                      r4,
-                      kLRHasNotBeenSaved,
-                      kDontSaveFPRegs);
-  __ str(r1, FieldMemOperand(r3, ConsString::kSecondOffset));
-  __ RecordWriteField(r3,
-                      ConsString::kSecondOffset,
-                      r1,
-                      r4,
-                      kLRHasNotBeenSaved,
-                      kDontSaveFPRegs);
-  __ jmp(&after_writing);
-
-  __ bind(&skip_write_barrier);
-  __ str(r0, FieldMemOperand(r3, ConsString::kFirstOffset));
-  __ str(r1, FieldMemOperand(r3, ConsString::kSecondOffset));
-
-  __ bind(&after_writing);
-
-  __ mov(r0, Operand(r3));
-  __ IncrementCounter(counters->string_add_native(), 1, r2, r3);
-  __ add(sp, sp, Operand(2 * kPointerSize));
-  __ Ret();
-
-  __ bind(&non_ascii);
-  // At least one of the strings is two-byte. Check whether it happens
-  // to contain only one byte characters.
-  // r4: first instance type.
-  // r5: second instance type.
-  __ tst(r4, Operand(kOneByteDataHintMask));
-  __ tst(r5, Operand(kOneByteDataHintMask), ne);
-  __ b(ne, &ascii_data);
-  __ eor(r4, r4, Operand(r5));
-  STATIC_ASSERT(kOneByteStringTag != 0 && kOneByteDataHintTag != 0);
-  __ and_(r4, r4, Operand(kOneByteStringTag | kOneByteDataHintTag));
-  __ cmp(r4, Operand(kOneByteStringTag | kOneByteDataHintTag));
-  __ b(eq, &ascii_data);
-
-  // Allocate a two byte cons string.
-  __ AllocateTwoByteConsString(r3, r6, r4, r5, &call_runtime);
-  __ jmp(&allocated);
-
-  // We cannot encounter sliced strings or cons strings here since:
-  STATIC_ASSERT(SlicedString::kMinLength >= ConsString::kMinLength);
-  // Handle creating a flat result from either external or sequential strings.
-  // Locate the first characters' locations.
-  // r0: first string
-  // r1: second string
-  // r2: length of first string
-  // r3: length of second string
-  // r4: first string instance type (if flags_ == NO_STRING_ADD_FLAGS)
-  // r5: second string instance type (if flags_ == NO_STRING_ADD_FLAGS)
-  // r6: sum of lengths.
-  Label first_prepared, second_prepared;
-  __ bind(&string_add_flat_result);
-  if ((flags_ & STRING_ADD_CHECK_BOTH) != STRING_ADD_CHECK_BOTH) {
-    __ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
-    __ ldr(r5, FieldMemOperand(r1, HeapObject::kMapOffset));
-    __ ldrb(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
-    __ ldrb(r5, FieldMemOperand(r5, Map::kInstanceTypeOffset));
-  }
-
-  // Check whether both strings have same encoding
-  __ eor(ip, r4, Operand(r5));
-  ASSERT(__ ImmediateFitsAddrMode1Instruction(kStringEncodingMask));
-  __ tst(ip, Operand(kStringEncodingMask));
-  __ b(ne, &call_runtime);
-
-  STATIC_ASSERT(kSeqStringTag == 0);
-  __ tst(r4, Operand(kStringRepresentationMask));
-  STATIC_ASSERT(SeqOneByteString::kHeaderSize == SeqTwoByteString::kHeaderSize);
-  __ add(r6,
-         r0,
-         Operand(SeqOneByteString::kHeaderSize - kHeapObjectTag),
-         LeaveCC,
-         eq);
-  __ b(eq, &first_prepared);
-  // External string: rule out short external string and load string resource.
-  STATIC_ASSERT(kShortExternalStringTag != 0);
-  __ tst(r4, Operand(kShortExternalStringMask));
-  __ b(ne, &call_runtime);
-  __ ldr(r6, FieldMemOperand(r0, ExternalString::kResourceDataOffset));
-  __ bind(&first_prepared);
-
-  STATIC_ASSERT(kSeqStringTag == 0);
-  __ tst(r5, Operand(kStringRepresentationMask));
-  STATIC_ASSERT(SeqOneByteString::kHeaderSize == SeqTwoByteString::kHeaderSize);
-  __ add(r1,
-         r1,
-         Operand(SeqOneByteString::kHeaderSize - kHeapObjectTag),
-         LeaveCC,
-         eq);
-  __ b(eq, &second_prepared);
-  // External string: rule out short external string and load string resource.
-  STATIC_ASSERT(kShortExternalStringTag != 0);
-  __ tst(r5, Operand(kShortExternalStringMask));
-  __ b(ne, &call_runtime);
-  __ ldr(r1, FieldMemOperand(r1, ExternalString::kResourceDataOffset));
-  __ bind(&second_prepared);
-
-  Label non_ascii_string_add_flat_result;
-  // r6: first character of first string
-  // r1: first character of second string
-  // r2: length of first string.
-  // r3: length of second string.
-  // Both strings have the same encoding.
-  STATIC_ASSERT(kTwoByteStringTag == 0);
-  __ tst(r5, Operand(kStringEncodingMask));
-  __ b(eq, &non_ascii_string_add_flat_result);
-
-  __ add(r2, r2, Operand(r3));
-  __ AllocateAsciiString(r0, r2, r4, r5, r9, &call_runtime);
-  __ sub(r2, r2, Operand(r3));
-  __ add(r5, r0, Operand(SeqOneByteString::kHeaderSize - kHeapObjectTag));
-  // r0: result string.
-  // r6: first character of first string.
-  // r1: first character of second string.
-  // r2: length of first string.
-  // r3: length of second string.
-  // r5: first character of result.
-  StringHelper::GenerateCopyCharacters(masm, r5, r6, r2, r4, true);
-  // r5: next character of result.
-  StringHelper::GenerateCopyCharacters(masm, r5, r1, r3, r4, true);
-  __ IncrementCounter(counters->string_add_native(), 1, r2, r3);
-  __ add(sp, sp, Operand(2 * kPointerSize));
-  __ Ret();
-
-  __ bind(&non_ascii_string_add_flat_result);
-  __ add(r2, r2, Operand(r3));
-  __ AllocateTwoByteString(r0, r2, r4, r5, r9, &call_runtime);
-  __ sub(r2, r2, Operand(r3));
-  __ add(r5, r0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
-  // r0: result string.
-  // r6: first character of first string.
-  // r1: first character of second string.
-  // r2: length of first string.
-  // r3: length of second string.
-  // r5: first character of result.
-  StringHelper::GenerateCopyCharacters(masm, r5, r6, r2, r4, false);
-  // r5: next character of result.
-  StringHelper::GenerateCopyCharacters(masm, r5, r1, r3, r4, false);
-  __ IncrementCounter(counters->string_add_native(), 1, r2, r3);
-  __ add(sp, sp, Operand(2 * kPointerSize));
-  __ Ret();
-
-  // Just jump to runtime to add the two strings.
-  __ bind(&call_runtime);
-  __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
-
-  if (call_builtin.is_linked()) {
-    __ bind(&call_builtin);
-    __ InvokeBuiltin(builtin_id, JUMP_FUNCTION);
-  }
-}
-
-
-void StringAddStub::GenerateRegisterArgsPush(MacroAssembler* masm) {
-  __ push(r0);
-  __ push(r1);
-}
-
-
-void StringAddStub::GenerateRegisterArgsPop(MacroAssembler* masm) {
-  __ pop(r1);
-  __ pop(r0);
-}
-
-
-void StringAddStub::GenerateConvertArgument(MacroAssembler* masm,
-                                            int stack_offset,
-                                            Register arg,
-                                            Register scratch1,
-                                            Register scratch2,
-                                            Register scratch3,
-                                            Register scratch4,
-                                            Label* slow) {
-  // First check if the argument is already a string.
-  Label not_string, done;
-  __ JumpIfSmi(arg, &not_string);
-  __ CompareObjectType(arg, scratch1, scratch1, FIRST_NONSTRING_TYPE);
-  __ b(lt, &done);
-
-  // Check the number to string cache.
-  __ bind(&not_string);
-  // Puts the cached result into scratch1.
-  __ LookupNumberStringCache(arg, scratch1, scratch2, scratch3, scratch4, slow);
-  __ mov(arg, scratch1);
-  __ str(arg, MemOperand(sp, stack_offset));
-  __ bind(&done);
-}
-
-
 void ICCompareStub::GenerateSmis(MacroAssembler* masm) {
   ASSERT(state_ == CompareIC::SMI);
   Label miss;