FE8 EvilRN (credit: SEVA)

.thumb

.macro _blh to, reg=r3
    ldr \reg, =\to
    mov lr, \reg
    .short 0xF800
.endm

.set NextRN100, 0x08000C64
.set SVCDivide, 0x080D167C

@ EvilRN (tm) formula: (Credit to SEVA :) )
@ (3*(A^2)) - ((2*(A^3))/100) = TrueRN*100

@ Original routine offset: 0x08000CB8
@ Args: r0 = chance; Returns: r0 = 1 if hit, 0 if miss
RollHitRN:
    push {r4-r5, lr}

    mov r4, r0

    _blh NextRN100 @ r0 = A

    mov r1, r0 @ r1 = A
    mul r1, r0 @ r1 = A^2

    lsl r5, r1, #1 @ r5 = 2*(A^2)
    add r5, r1 @ r5 = 3*(A^2)

    mul r1, r0 @ r1 = A^3

    lsl r0, r1, #1 @ r0 = 2*(A^3)
    mov r1, #100 @ r1 = 100

    mul r4, r1 @ r4 = Chance*100 (doing it here since we have 100 loaded in a register)

    _blh SVCDivide @ r0 = (2*(A^3))/100

    sub r1, r5, r0 @ r1 = (3*(A^2)) - ((2*(A^3))/100)

    mov r0, #0 @ r0 = False by default

    @ Comparing Chance*100 to TrueRN*100
    cmp r4, r1
    ble End

    mov r0, #1

End:
    pop {r4-r5}

    pop {r1}
    bx r1