Move NumberToStringStub::GenerateLookupNumberStringCache to the MacroAssembler.

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 2fb0f74b0b5bbd833089c4b659425473012a05ba..96fa4fc49630424093eaa29874c118e95c34a115 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -2264,6 +2264,90 @@ void MacroAssembler::Test(const Operand& src, Smi* source) {
 // ----------------------------------------------------------------------------
 
 
+void MacroAssembler::LookupNumberStringCache(Register object,
+                                             Register result,
+                                             Register scratch1,
+                                             Register scratch2,
+                                             Label* not_found) {
+  // Use of registers. Register result is used as a temporary.
+  Register number_string_cache = result;
+  Register mask = scratch1;
+  Register scratch = scratch2;
+
+  // 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.
+  SmiToInteger32(
+      mask, FieldOperand(number_string_cache, FixedArray::kLengthOffset));
+  shrl(mask, Immediate(1));
+  subq(mask, Immediate(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);
+  CheckMap(object,
+           isolate()->factory()->heap_number_map(),
+           not_found,
+           DONT_DO_SMI_CHECK);
+
+  STATIC_ASSERT(8 == kDoubleSize);
+  movl(scratch, FieldOperand(object, HeapNumber::kValueOffset + 4));
+  xor_(scratch, FieldOperand(object, HeapNumber::kValueOffset));
+  and_(scratch, mask);
+  // Each entry in string cache consists of two pointer sized fields,
+  // but times_twice_pointer_size (multiplication by 16) scale factor
+  // is not supported by addrmode on x64 platform.
+  // So we have to premultiply entry index before lookup.
+  shl(scratch, Immediate(kPointerSizeLog2 + 1));
+
+  Register index = scratch;
+  Register probe = mask;
+  movq(probe,
+       FieldOperand(number_string_cache,
+                    index,
+                    times_1,
+                    FixedArray::kHeaderSize));
+  JumpIfSmi(probe, not_found);
+  movsd(xmm0, FieldOperand(object, HeapNumber::kValueOffset));
+  ucomisd(xmm0, FieldOperand(probe, HeapNumber::kValueOffset));
+  j(parity_even, not_found);  // Bail out if NaN is involved.
+  j(not_equal, not_found);  // The cache did not contain this value.
+  jmp(&load_result_from_cache);
+
+  bind(&is_smi);
+  SmiToInteger32(scratch, object);
+  and_(scratch, mask);
+  // Each entry in string cache consists of two pointer sized fields,
+  // but times_twice_pointer_size (multiplication by 16) scale factor
+  // is not supported by addrmode on x64 platform.
+  // So we have to premultiply entry index before lookup.
+  shl(scratch, Immediate(kPointerSizeLog2 + 1));
+
+  // Check if the entry is the smi we are looking for.
+  cmpq(object,
+       FieldOperand(number_string_cache,
+                    index,
+                    times_1,
+                    FixedArray::kHeaderSize));
+  j(not_equal, not_found);
+
+  // Get the result from the cache.
+  bind(&load_result_from_cache);
+  movq(result,
+       FieldOperand(number_string_cache,
+                    index,
+                    times_1,
+                    FixedArray::kHeaderSize + kPointerSize));
+  IncrementCounter(isolate()->counters()->number_to_string_native(), 1);
+}
+
+
 void MacroAssembler::JumpIfNotString(Register object,
                                      Register object_map,
                                      Label* not_string,