This code serves as a built-in function library of Mx Language of Compiler Project of ACM Honored Class

Built by Ficos 16/5/2 All rights reserved.

All test passed.

1. fix a bug in func_parseInt, where the previous version cannot parse negative integer (but this situation does not appear in any test cases)
2. add func__stringLeq, func__stringGeq, func__stringNeq and func__stringLarge
3. Now when calling func__toString and func__stringConcatenate you don't need to save any register other than $v0, $v1(if you used them)
4. you don't need to call "_buffer_init" function before entering the source main function!!!

1.func__getInt will read input until \n, for I call MIPS sysfunc indeed.

1. Just paste all of this in front of your MIPS code

	FunctionName	|		args
	--------------|--------

1. func__print |$a0: the string
2. func__println |$a0: the string
3. func__getString |---
4. func__getInt |---
5. func__toString |$a0: the integer
6. func__string.length |$a0: the string
7. func__string.substring | $a0: the string, $a1: left pos(int), $a2: right pos(int)
8. func__string.parseInt |$a0: the string
9. func__string.ord |$a0: the string, $a1: pos(int)
10. func__array.size |$a0: the array
11. func__stringConcatenate | $a0: left string, $a1: right string
12. func__stringIsEqual | $a0: left string, $a1: right string
13. func__stringLess | $a0: left string, $a1: right string
14. func__stringLeq | $a0: left string, $a1: right string
15. func__stringGeq | $a0: left string, $a1: right string
16. func__stringNeq | $a0: left string, $a1: right string
17. func__stringLarge | $a0: left string, $a1: right string

1. args placed in $a0, $a1, $a2
2. return in $v0
3. follow the MIPS calling convention, be careful on regs when calling these functions
4. all used regs are presented in the front of the function

1. string object is simply a register contains the initial address of the string

2. front of every initial address of a string are a word containing the length of the string e.g.

       .data
     		  .word 6
    	 str: .asciiz "hello\n"
    		  .align 2
   

3. every string ends with '\0', which is not counted in the length

1. front of every initial address of a array are a word containing the size of the array