[builtins] Simplify String constructor code.

src/arm64/macro-assembler-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/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 2047 matching lines @@
 
   AssertNotSmi(object);
 
   UseScratchRegisterScope temps(this);
   Register temp = temps.AcquireX();
   Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
   JumpIfNotRoot(temp, Heap::kHeapNumberMapRootIndex, on_not_heap_number);
 }
 
 
-void MacroAssembler::LookupNumberStringCache(Register object,
-                                             Register result,
-                                             Register scratch1,
-                                             Register scratch2,
-                                             Register scratch3,
-                                             Label* not_found) {
-  DCHECK(!AreAliased(object, result, scratch1, scratch2, scratch3));
-
-  // Use of registers. Register result is used as a temporary.
-  Register number_string_cache = result;
-  Register mask = scratch3;
-
-  // Load the number string cache.
-  LoadRoot(number_string_cache, Heap::kNumberStringCacheRootIndex);
-
-  // Make the hash mask from the length of the number string cache. It
-  // contains two elements (number and string) for each cache entry.
-  Ldrsw(mask, UntagSmiFieldMemOperand(number_string_cache,
-                                      FixedArray::kLengthOffset));
-  Asr(mask, mask, 1);  // Divide length by two.
-  Sub(mask, mask, 1);  // Make mask.
-
-  // Calculate the entry in the number string cache. The hash value in the
-  // number string cache for smis is just the smi value, and the hash for
-  // doubles is the xor of the upper and lower words. See
-  // Heap::GetNumberStringCache.
-  Label is_smi;
-  Label load_result_from_cache;
-
-  JumpIfSmi(object, &is_smi);
-  JumpIfNotHeapNumber(object, not_found);
-
-  STATIC_ASSERT(kDoubleSize == (kWRegSize * 2));
-  Add(scratch1, object, HeapNumber::kValueOffset - kHeapObjectTag);
-  Ldp(scratch1.W(), scratch2.W(), MemOperand(scratch1));
-  Eor(scratch1, scratch1, scratch2);
-  And(scratch1, scratch1, mask);
-
-  // Calculate address of entry in string cache: each entry consists of two
-  // pointer sized fields.
-  Add(scratch1, number_string_cache,
-      Operand(scratch1, LSL, kPointerSizeLog2 + 1));
-
-  Register probe = mask;
-  Ldr(probe, FieldMemOperand(scratch1, FixedArray::kHeaderSize));
-  JumpIfSmi(probe, not_found);
-  Ldr(d0, FieldMemOperand(object, HeapNumber::kValueOffset));
-  Ldr(d1, FieldMemOperand(probe, HeapNumber::kValueOffset));
-  Fcmp(d0, d1);
-  B(ne, not_found);
-  B(&load_result_from_cache);
-
-  Bind(&is_smi);
-  Register scratch = scratch1;
-  And(scratch, mask, Operand::UntagSmi(object));
-  // Calculate address of entry in string cache: each entry consists
-  // of two pointer sized fields.
-  Add(scratch, number_string_cache,
-      Operand(scratch, LSL, kPointerSizeLog2 + 1));
-
-  // Check if the entry is the smi we are looking for.
-  Ldr(probe, FieldMemOperand(scratch, FixedArray::kHeaderSize));
-  Cmp(object, probe);
-  B(ne, not_found);
-
-  // Get the result from the cache.
-  Bind(&load_result_from_cache);
-  Ldr(result, FieldMemOperand(scratch, FixedArray::kHeaderSize + kPointerSize));
-  IncrementCounter(isolate()->counters()->number_to_string_native(), 1,
-                   scratch1, scratch2);
-}
-
-
 void MacroAssembler::TryRepresentDoubleAsInt(Register as_int,
                                              FPRegister value,
                                              FPRegister scratch_d,
                                              Label* on_successful_conversion,
                                              Label* on_failed_conversion) {
   // Convert to an int and back again, then compare with the original value.
   Fcvtzs(as_int, value);
   Scvtf(scratch_d, as_int);
   Fcmp(value, scratch_d);
 
@@ skipping 2969 matching lines @@
 }
 
 
 #undef __
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64