Question

7. Translate the following C code to MIPS assembly code. Use a minimum number of instructions. Assume that the values of a,b, i and j are in registers Ss0, Ss1, St0, and St1, respectively. Also, assume that register SS2 holds the base address of the array D. for(i-0; i<a; i++) for(j=0 ; j<b; j++)

Answer 1

Answer: MIPS code:

.file   1 ""
        .section .mdebug.abi32
        .previous
        .nan    legacy
        .module fp=32
        .module nooddspreg
        .abicalls
        .text
        .align  2
        .globl  main
        .set    nomips16
        .set    nomicromips
        .ent    main
        .type   main, @function
main:
        .frame  $fp,432,$31             # vars= 416, regs= 1/0, args= 0, gp= 8
        .mask   0x40000000,-4
        .fmask  0x00000000,0
        .set    noreorder
        .set    nomacro
        addiu   $sp,$sp,-432
        sw      $fp,428($sp)
        move    $fp,$sp
        sw      $0,8($fp)
        b       $L2
        movz    $31,$31,$0
        nop

$L5:
        sw      $0,12($fp)
        b       $L3
        nop

$L4:
        lw      $2,12($fp)
        nop
        sll     $2,$2,2
        lw      $4,8($fp)
        lw      $3,12($fp)
        nop
        addu    $3,$4,$3
        sll     $2,$2,2
        addiu   $4,$fp,8
        addu    $2,$4,$2
        sw      $3,16($2)
        lw      $2,12($fp)
        nop
        addiu   $2,$2,1
        sw      $2,12($fp)
$L3:
        lw      $3,12($fp)
        lw      $2,20($fp)
        nop
        slt     $2,$3,$2
        bne     $2,$0,$L4
        nop

        lw      $2,8($fp)
        nop
        addiu   $2,$2,1
        sw      $2,8($fp)
$L2:
        lw      $3,8($fp)
        lw      $2,16($fp)
        nop
        slt     $2,$3,$2
        bne     $2,$0,$L5
        nop

        move    $2,$0
        move    $sp,$fp
        lw      $fp,428($sp)
        addiu   $sp,$sp,432
        j       $31
        nop

        .set    macro
        .set    reorder
        .end    main
        .size   main, .-main
        .ident  "GCC: (Ubuntu 5.4.0-6ubuntu1~16.04.1) 5.4.0 20160609"