MIPS: Fixed a bug in CopyBytes() and new test cases for MIPS macro assembler.

src/mips/macro-assembler-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 3202 matching lines @@
     lw(tmp, FieldMemOperand(src, i * kPointerSize));
     sw(tmp, FieldMemOperand(dst, i * kPointerSize));
   }
 }
 
 
 void MacroAssembler::CopyBytes(Register src,
                                Register dst,
                                Register length,
                                Register scratch) {
-  Label align_loop, align_loop_1, word_loop, byte_loop, byte_loop_1, done;
+  Label align_loop_1, word_loop, byte_loop, byte_loop_1, done;
 
   // Align src before copying in word size chunks.
-  bind(&align_loop);
-  Branch(&done, eq, length, Operand(zero_reg));
+  Branch(&byte_loop, le, length, Operand(kPointerSize));
   bind(&align_loop_1);
   And(scratch, src, kPointerSize - 1);
   Branch(&word_loop, eq, scratch, Operand(zero_reg));
   lbu(scratch, MemOperand(src));
   Addu(src, src, 1);
   sb(scratch, MemOperand(dst));
   Addu(dst, dst, 1);
   Subu(length, length, Operand(1));
-  Branch(&byte_loop_1, ne, length, Operand(zero_reg));
+  Branch(&align_loop_1, ne, length, Operand(zero_reg));
 
   // Copy bytes in word size chunks.
   bind(&word_loop);
   if (emit_debug_code()) {
     And(scratch, src, kPointerSize - 1);
     Assert(eq, kExpectingAlignmentForCopyBytes,
         scratch, Operand(zero_reg));
   }
   Branch(&byte_loop, lt, length, Operand(kPointerSize));
   lw(scratch, MemOperand(src));
@@ skipping 2445 matching lines @@
        opcode == BGTZL);
   opcode = (cond == eq) ? BEQ : BNE;
   instr = (instr & ~kOpcodeMask) | opcode;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS