MIPS: Move NumberToStringStub::GenerateLookupNumberStringCache to the MacroAssembler.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 465e8abc59f08d6f3dbc8051e23b8f0ec73a822c..8cac27c549d0b2e5a6a963fdd44f239986765b65 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -4945,6 +4945,86 @@ void MacroAssembler::JumpIfNotHeapNumber(Register object,
 }
 
 
+void MacroAssembler::LookupNumberStringCache(Register object,
+                                             Register result,
+                                             Register scratch1,
+                                             Register scratch2,
+                                             Register scratch3,
+                                             Label* not_found) {
+  // 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.
+  lw(mask, FieldMemOperand(number_string_cache, FixedArray::kLengthOffset));
+  // Divide length by two (length is a smi).
+  sra(mask, mask, kSmiTagSize + 1);
+  Addu(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);
+  CheckMap(object,
+           scratch1,
+           Heap::kHeapNumberMapRootIndex,
+           not_found,
+           DONT_DO_SMI_CHECK);
+
+  STATIC_ASSERT(8 == kDoubleSize);
+  Addu(scratch1,
+       object,
+       Operand(HeapNumber::kValueOffset - kHeapObjectTag));
+  lw(scratch2, MemOperand(scratch1, kPointerSize));
+  lw(scratch1, MemOperand(scratch1, 0));
+  Xor(scratch1, scratch1, Operand(scratch2));
+  And(scratch1, scratch1, Operand(mask));
+
+  // Calculate address of entry in string cache: each entry consists
+  // of two pointer sized fields.
+  sll(scratch1, scratch1, kPointerSizeLog2 + 1);
+  Addu(scratch1, number_string_cache, scratch1);
+
+  Register probe = mask;
+  lw(probe, FieldMemOperand(scratch1, FixedArray::kHeaderSize));
+  JumpIfSmi(probe, not_found);
+  ldc1(f12, FieldMemOperand(object, HeapNumber::kValueOffset));
+  ldc1(f14, FieldMemOperand(probe, HeapNumber::kValueOffset));
+  BranchF(&load_result_from_cache, NULL, eq, f12, f14);
+  Branch(not_found);
+
+  bind(&is_smi);
+  Register scratch = scratch1;
+  sra(scratch, object, 1);   // Shift away the tag.
+  And(scratch, mask, Operand(scratch));
+
+  // Calculate address of entry in string cache: each entry consists
+  // of two pointer sized fields.
+  sll(scratch, scratch, kPointerSizeLog2 + 1);
+  Addu(scratch, number_string_cache, scratch);
+
+  // Check if the entry is the smi we are looking for.
+  lw(probe, FieldMemOperand(scratch, FixedArray::kHeaderSize));
+  Branch(not_found, ne, object, Operand(probe));
+
+  // Get the result from the cache.
+  bind(&load_result_from_cache);
+  lw(result, FieldMemOperand(scratch, FixedArray::kHeaderSize + kPointerSize));
+
+  IncrementCounter(isolate()->counters()->number_to_string_native(),
+                   1,
+                   scratch1,
+                   scratch2);
+}
+
+
 void MacroAssembler::JumpIfNonSmisNotBothSequentialAsciiStrings(
     Register first,
     Register second,