The MIPS Processor Computer Organization The MIPS Processor Appendix A

The MIPS Processor Computer Organization Assembly Language Symbolic representation of a computer's machine language. more readable than machine language each processor has its own assembly language no two assembly languages are the same.

The MIPS Processor Computer Organization Why Use Assembly Language Primary reason: for speed or size of a critical application compiler may not produce the best instructions have better control over which instructions are used Example: embedded systems or devices

The MIPS Processor Computer Organization Drawbacks of Assembly Language Are not widely used by everyday programmers programs are machine dependent programs are longer than those in a high-level language programs have no structure; hard to read

The MIPS Processor Computer Organization The Assembler Translates assembly language instructions into machine language instructions

The MIPS Processor Computer Organization Translation Symbols can be used before they are defined. A two step translation is required: resolve labels (find memory locations) translate assembly instructions

The MIPS Processor Computer Organization Sample Program # # Prints all primes in the numbers #.text main: li $t0, 1 WHILE: bgt $t0, 100, WHILE_END move $a0, $t0 jal TEST_PRIME beqz $v0, INC1 la $a0, Message move $a1, $t0, jal PRINTF INC1: addi $t0, $t0, 1 j WHILE WHILE_END: li $v0, 10 syscall ###################################.data Message:.asciiz "This number is prime: " NEWLINE:.asciiz "\n"

The MIPS Processor Computer Organization Object File object code - machine instructions, data, and bookkeeping info. can not be executed directly it may refer to routines in other object files Six distinct sections on Unix systems:

The MIPS Processor Computer Organization The Linker linker - combines a collection of object files into an executable file. programs can be split into smaller pieces (files) each file contains logically related routines and data

The MIPS Processor Computer Organization The Loader loader - used to load a program into memory sets the registers initializes the program counter For the MIPS processor: