.text
        .global amax
amax:
        stmfd   sp!, { r4, r5, r6, lr }
        mov     r4, r0
        mov     r5, r1
        mov     r6, #0
        mov     r0, #0
        cmp     r1, #0
        beq     done
        ldr     r0, [r4]
loop:
        ldr     r2, [r4], #4        @updates r4!!
        add     r6, #1
        cmp     r0, r2
        movlt   r0, r2
        cmp     r5, r6
        bne     loop
        b       done
done:
        ldmfd   sp!, { r4, r5, r6, pc }