MIPS sample code to test EzMIPS functionality

This is a sample MIPS assembler code used to test EzMIPS functionality. All MIPS instructions and pseudo-instructions supported are tested for correct operation.

Launch EzMIPS, copy the following MIPS code and paste it into EzMIPS. Assemble, Run.

# .......................................................... #

.text
main:
# .................. initialize some registers ............. #


    li $2, 2
    li $3, 0x3
    li $4, 4
    li $5, 5
    li $6, 6
    la $7, var_word01

# .......................................................... #

    add $0, $5, $5
    
    addi $10, $3, 0xfff4 # sign-extend(0xfff4) = 0xfffffff4)
    addi $0, $3, 0xfff4
    
    addiu $0, $3, 4
    addu $0, $5, $5
    
    and $0, $5, $3

    andi $10, $3, -1      # -1 = 0xffff (ie NOT sign-extended)
    andi $0, $2, 0xff

#    beq     $10, $2, exit
#    bge     $5, $2, exit
#    bgez    $5, exit
#    bgezal  $5, exit
#    bgt     $10, $2, exit
#    bgtz    $5, exit
#    ble     $10, $2, exit
#    blez    $5, exit
#    blt     $5, $8, exit
#    bltz    $5, exit
#    bltzal  $5, exit
#    bne     $10, $2, main

#    break

    div $4, $0
    divu $3, $0

#    j main
#    jal exit
#    jr $ra

# ......................... la ............................. #

    la $0, var_word01    # actually testing ori instruction
    la $0, main          # actually testing ori instruction  
    la $10, var_word01

# .......................................................... #

    lb $0, ($10)
    lbu $0,  1($10)

    li $0, 0x12345       # actually testing ori instruction
    li $zero, 7          # actually testing ori instruction
    li $0, 9             # actually testing ori instruction

    lui $0, 0x100

# ....................... lw ............................... #


    lw $0, ($7)
    lw $0, var_byte01
#   lw $12, var_half1    # Runtime exception at 0x00400084:
                         # fetch address not aligned on word
                         # boundary 0x10010002

    lw $0, var_byte02
    lw $0, var_word01
    lw $0, var_half02

# ..................... mfhi, mflo ......................... #
    
    # div $s, $t: $LO = $s/$t, $HI = $s%$t
    div $5, $2          # 5\2 => $LO = 2 & $HI = 1
    
    mfhi $0
    mflo $0

# .......................................................... #

    move $0, $2          # actually testing addu instruction

    mul $0, $2, $5
    mult $2, $5          # $LO = $s * $t
    multu $2, $5         # $LO = $s * $t
    nop
    
# .......................................................... #

    nor $0, $2, $5
    or $0, $2, $5

    ori $10, $2, -1      # -1 = 0xffff (ie NOT sign-extended)
    ori $0, $2, -1

    sb $10, 0($7)

# .......................................................... #

#   sll $10, $2, -2      # invalid 16-bit immediate value <-2>
    sll $0, $2, 2

#   li $3, 40
#   sllv $14, $2, $3     # sllv: the number of bits to shift
                         # is given by the low order 5 bits 
                         # of Rs (ie max 31)
    sllv $0, $2, $3

# .......................................................... #

    slt $0, $2, $5
    slti $0, $2, 3
    sltiu $0, $2, 3
    sltu $0, $2, $5

# .......................................................... #
    
    sra $0, $5, 1

#   li $3, 33
#   srav $14, $6, $3     # srav: the number of bits to shift
                         # is given by the low order 5 bits 
                         # of Rs (ie max 31)
    srav $0, $5, $2

# .......................................................... #

#   srl     $10, $2, -4  # invalid 16-bit immediate value <-4>
    srl     $0, $6, 1

# .......................................................... #

    li $3, 33
    srlv $14, $6, $3     # srlv: the number of bits to shift
                         # is given by the low order 5 bits 
                         # of Rs (ie max 31)
    srlv $0, $5, $2

# .......................................................... #
    
    sub $0, $2, $5
    subu $0, $5, $2
#   li $2, 0xffffffff    
#   sub $12, $5, $2
#   subu $13, $5, $2

# .......................................................... #

    sw $10, 0($gp)
#   sw $10, 1($gp)       # Runtime exception at 0x00400100:
#   sw $10, 2($gp)       # store address not aligned on word
#   sw $10, 3($gp)       # boundary 0x1000800_

    sw $10, var_word01

exit:
    li $v0, 2
    syscall              # Warn. | line 169   | syscall <2> not supported
    
    xor $0, $5, $3

    xori $20, $s7, -1    # -1 = 0xffff (ie NOT sign-extended)
    xori $0, $s7, 100

# ........................................................ #

.data

var_byte01: .byte 0xaa
var_half01: .half 0xbbcc
var_byte02: .byte 0xaa
var_word01: .word 0x12345678
var_half02: .half 0xddee

# ........................................................ #

Please let me know of any suggestions or bugs regarding the code above.

Regards,

Antonis