.section .text

.global memcpy
memcpy:
    mov x3, x0
0:
    cbz x2, 1f
    ldrb w4, [x1], #1
    strb w4, [x0], #1
    sub x2, x2, #1
    b 0b
1:
    mov x0, x3
    ret

.global memset
memset:
    mov x3, x0
0:
    cbz x2, 1f
    strb w1, [x0], #1
    sub x2, x2, #1
    b 0b
1:
    mov x0, x3
    ret

.global memmove
memmove:
    mov x3, x0
    mov x5, x2

    cmp x0, x1
    b.gt 1f
0:
    cbz x2, 2f
    ldrb w4, [x1], #1
    strb w4, [x0], #1
    sub x2, x2, #1
    b 0b
1:
    sub x5, x5, #1
    cbz x2, 2f
    ldrb w4, [x1, x5]
    strb w4, [x0, x5]
    sub x2, x2, #1
    b 1b
2:
    mov x0, x3
    ret

.global memcmp
memcmp:
    mov x3, xzr
0:
    cbz x2, 1f
    ldrb w3, [x0], #1
    ldrb w4, [x1], #1
    sub w3, w3, w4
    cbnz w3, 1f
    sub x2, x2, #1
    b 0b
1:
    sxtw x0, w3
    mov x0, x3
    ret