# COS235- HW4
# Nicholas Pease
# 31 OCT 2024
.data:
    inputUInt: .space 32
    dots: .asciz ".."

.text:
main:
    li a7, 5 # input unsigned int (A)
    la a0, inputUInt
    ecall
    mv a1, a0 # a1 = A

    li a7, 5 # input unsigned int (B)
    la a0, inputUInt
    ecall
    mv a2, a0
    # a2 = B

    # CALL RECURSIVE FUNCTION
    jal kapow
    jal kapow

    # PRINT RETURN VALUE
    li a7, 34
    ecall

    mv t0, a0
    li a0, 9
    li a7, 11
    ecall
    mv a0, t0

    li a7, 1
    ecall

    jal newline

    li a7, 10
    ecall # Exit program


kapow:
    # A0 = return
    # A1 = A, X 
    # A2 = B, Y
    # A3 = Saved
    # t0 = Loop
    # t1 = Temporary

    addi sp, sp, -16
    sw a3, 12(sp)
    sw ra, 8(sp)
    sw a1, 4(sp)
    sw a2, 0(sp) # save all values before run

    li t0, 0 # loop counter (0)
    li a7, 4 # print string
    la a0, dots # print dots

    kapow_forLoop:
        ecall
        addi t0, t0, 1
        bne t0,a2,kapow_forLoop
    # END FOR LOOP

    li a0, 32
    li a7, 11
    ecall

    li a7, 1 # print int
    mv a0, a2 # print Y
    ecall

    jal newline # print newline

    li a0, 1
    blt a0, a2, kapow_gt1 # if Y > 1, jump
    blt zero, a2, kapow_gt0 # if Y > 0, jump
        # others y < 0
        j kapow_return

    kapow_gt0:
        mv a0, a1 # return X
        j kapow_return

    kapow_gt1:
        li t0, 2
        div a2,a2,t0 # Y = Y / 2
        jal kapow # recursive call
        mv a3, a0 # a3 = first return value
        lw t1, 0(sp) # load original Y (t1)
        li t0, 2 # remainder number (t0)
        rem t0,t1,t0 # t0 = Y (t1) % 2 (t0)
        add a2, t0, a2# Y = prevY + y%2
        jal kapow
        mul a0, a3, a0 # return = x * y

    kapow_return:
        lw a3, 12(sp)
        lw ra, 8(sp)
        lw a1, 4(sp)
        lw a2, 0(sp)
        addi sp, sp, 16
        ret

newline:
    mv t0, a0
    li a0, 10
    li a7, 11
    ecall
    mv a0, t0
    ret