Tweaks to SubStringStub

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6133 matching lines @@
   __ LoadRoot(t0, Heap::kEmptyStringRootIndex);
   __ Branch(&runtime, ne, t1, Operand(t0));
   __ lw(t1, FieldMemOperand(v0, ConsString::kFirstOffset));
   // Update instance type.
   __ lw(a1, FieldMemOperand(t1, HeapObject::kMapOffset));
   __ lbu(a1, FieldMemOperand(a1, Map::kInstanceTypeOffset));
   __ jmp(&underlying_unpacked);
 
   __ bind(&sliced_string);
   // Sliced string.  Fetch parent and correct start index by offset.
+  __ lw(t1, FieldMemOperand(v0, SlicedString::kParentOffset));
   __ lw(t0, FieldMemOperand(v0, SlicedString::kOffsetOffset));
-  __ lw(t1, FieldMemOperand(v0, SlicedString::kParentOffset));
   __ sra(t0, t0, 1);  // Add offset to index.
   __ Addu(a3, a3, t0);
   // Update instance type.
   __ lw(a1, FieldMemOperand(t1, HeapObject::kMapOffset));
   __ lbu(a1, FieldMemOperand(a1, Map::kInstanceTypeOffset));
   __ jmp(&underlying_unpacked);
 
   __ bind(&seq_or_external_string);
   // Sequential or external string.  Just move string to the expected register.
   __ mov(t1, v0);
@@ skipping 17 matching lines @@
     STATIC_ASSERT((kStringEncodingMask & kAsciiStringTag) != 0);
     STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
     __ And(t0, a1, Operand(kStringEncodingMask));
     __ Branch(&two_byte_slice, eq, t0, Operand(zero_reg));
     __ AllocateAsciiSlicedString(v0, a2, t2, t3, &runtime);
     __ jmp(&set_slice_header);
     __ bind(&two_byte_slice);
     __ AllocateTwoByteSlicedString(v0, a2, t2, t3, &runtime);
     __ bind(&set_slice_header);
     __ sll(a3, a3, 1);
+    __ sw(t1, FieldMemOperand(v0, SlicedString::kParentOffset));
     __ sw(a3, FieldMemOperand(v0, SlicedString::kOffsetOffset));
-    __ sw(t1, FieldMemOperand(v0, SlicedString::kParentOffset));
     __ jmp(&return_v0);
 
     __ bind(&copy_routine);
   }
 
   // t1: underlying subject string
   // a1: instance type of underlying subject string
   // a2: length
   // a3: adjusted start index (untagged)
   Label two_byte_sequential, sequential_string, allocate_result;
@@ skipping 1464 matching lines @@
   __ Ret(USE_DELAY_SLOT);
   __ mov(v0, a0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS