Move NumberToStringStub::GenerateLookupNumberStringCache to the MacroAssembler.

src/ia32/macro-assembler-ia32.cc

Index: src/ia32/macro-assembler-ia32.cc
diff --git a/src/ia32/macro-assembler-ia32.cc b/src/ia32/macro-assembler-ia32.cc
index 2ae06128a83a6ffea545668e8ce4376b65d24b9b..f8caecd67d877ac965f458dec7e5fc1a4818b4b1 100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -3023,6 +3023,88 @@ void MacroAssembler::LoadPowerOf2(XMMRegister dst,
 }
 
 
+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.
+  mov(mask, FieldOperand(number_string_cache, FixedArray::kLengthOffset));
+  shr(mask, kSmiTagSize + 1);  // Untag length and divide it by two.
+  sub(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 smi_hash_calculated;
+  Label load_result_from_cache;
+  Label not_smi;
+  STATIC_ASSERT(kSmiTag == 0);
+  JumpIfNotSmi(object, &not_smi, Label::kNear);
+  mov(scratch, object);
+  SmiUntag(scratch);
+  jmp(&smi_hash_calculated, Label::kNear);
+  bind(&not_smi);
+  cmp(FieldOperand(object, HeapObject::kMapOffset),
+      isolate()->factory()->heap_number_map());
+  j(not_equal, not_found);
+  STATIC_ASSERT(8 == kDoubleSize);
+  mov(scratch, FieldOperand(object, HeapNumber::kValueOffset));
+  xor_(scratch, FieldOperand(object, HeapNumber::kValueOffset + 4));
+  // Object is heap number and hash is now in scratch. Calculate cache index.
+  and_(scratch, mask);
+  Register index = scratch;
+  Register probe = mask;
+  mov(probe,
+      FieldOperand(number_string_cache,
+                   index,
+                   times_twice_pointer_size,
+                   FixedArray::kHeaderSize));
+  JumpIfSmi(probe, not_found);
+  if (CpuFeatures::IsSupported(SSE2)) {
+    CpuFeatureScope fscope(this, SSE2);
+    movdbl(xmm0, FieldOperand(object, HeapNumber::kValueOffset));
+    ucomisd(xmm0, FieldOperand(probe, HeapNumber::kValueOffset));
+  } else {
+    fld_d(FieldOperand(object, HeapNumber::kValueOffset));
+    fld_d(FieldOperand(probe, HeapNumber::kValueOffset));
+    FCmp();
+  }
+  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, Label::kNear);
+
+  bind(&smi_hash_calculated);
+  // Object is smi and hash is now in scratch. Calculate cache index.
+  and_(scratch, mask);
+  // Check if the entry is the smi we are looking for.
+  cmp(object,
+      FieldOperand(number_string_cache,
+                   index,
+                   times_twice_pointer_size,
+                   FixedArray::kHeaderSize));
+  j(not_equal, not_found);
+
+  // Get the result from the cache.
+  bind(&load_result_from_cache);
+  mov(result,
+      FieldOperand(number_string_cache,
+                   index,
+                   times_twice_pointer_size,
+                   FixedArray::kHeaderSize + kPointerSize));
+  IncrementCounter(isolate()->counters()->number_to_string_native(), 1);
+}
+
+
 void MacroAssembler::JumpIfInstanceTypeIsNotSequentialAscii(
     Register instance_type,
     Register scratch,