Question

Translate the following C code to MIPS assembly code.

Question 1)

int counter = 0;

void change_global(int value)

{

counter = counter + value;

}

void main()

{

change_global(5);

change_global(10);

}

Answer 1

The MIPS assembly code will be: .file     1 ""    .section .mdebug.abi32  .previous       .nan    legacy  .module fp=32   .module nooddspreg      .abicalls       .globl  counter         .section        .bss,"aw",@nobits       .align  2       .type   counter, @object        .size   counter, 4 counter:     .space  4       .text   .align  2       .globl  change_global   .set    nomips16        .set    nomicromips     .ent    change_global   .type   change_global, @function change_global:         .frame  $fp,8,$31               # vars= 0, regs= 1/0, args= 0, gp= 0    .mask   0x40000000,-4   .fmask  0x00000000,0    .set    noreorder       .cpload $25     .set    nomacro         addiu   $sp,$sp,-8      sw      $fp,4($sp)      move    $fp,$sp         sw      $4,8($fp)       lw      $2,%got(counter)($28)   movz    $31,$31,$0      nop     lw      $3,0($2)        lw      $2,8($fp)       nop     addu    $3,$3,$2        lw      $2,%got(counter)($28)   nop     sw      $3,0($2)        nop     move    $sp,$fp         lw      $fp,4($sp)      addiu   $sp,$sp,8       j       $31     nop     .set    macro   .set    reorder         .end    change_global   .size   change_global, .-change_global  .align  2       .globl  main    .set    nomips16        .set    nomicromips     .ent    main    .type   main, @function main:   .frame  $fp,32,$31              # vars= 0, regs= 2/0, args= 16, gp= 8   .mask   0xc0000000,-4   .fmask  0x00000000,0    .set    noreorder       .cpload $25     .set    nomacro         addiu   $sp,$sp,-32     sw      $31,28($sp)     sw      $fp,24($sp)     move    $fp,$sp         .cprestore      16      movz    $31,$31,$0      li      $4,5                    # 0x5   lw      $2,%got(change_global)($28)     nop     move    $25,$2  .reloc  1f,R_MIPS_JALR,change_global 1: jalr    $25     nop     lw      $28,16($fp)     li      $4,10                   # 0xa   lw      $2,%got(change_global)($28)     nop     move    $25,$2  .reloc  1f,R_MIPS_JALR,change_global 1: jalr    $25     nop     lw      $28,16($fp)     nop     move    $sp,$fp         lw      $31,28($sp)     lw      $fp,24($sp)     addiu   $sp,$sp,32      j       $31     nop     .set    macro   .set    reorder         .end    main    .size   main, .-main    .ident  "GCC: (Ubuntu 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609"