DK64 RNG

MIPS > MATHS/LUA CONVERSION

RNGSomething()
	var_C = -0xC
	var_8 = -8
	var_4 = -4

	[lui $t6, 0x8074]			$t6 = 0x80740000
	[lw $a1, RNG]				$a1 = RNG Value
	[addiu $sp, -0x20]			$sp = $sp - 0x20
	[sw $ra 0x20+var_C($sp)]	mainmemory.write_u32_be($sp + 0x20 + var_C, $ra)
	[li $a0,0]					$a0 = 0x0
	[lui $a3, 0x1DF]			$a3 = 0x01DF0000
	[sw $a0, 0x20+var_8($sp)]	mainmemory.write_u32_be($sp + 0x20 + var_8, $a0)
	[li $a3, 0x1DF5E0D]			$a3 = 0x01DF5E0D
	[li $a2, 0]					$a2 = 0x0
	[jal CycleRNG]				CycleRNG()
	[sw $a1, 0x20+var_4($sp)]	mainmemory.write_u32_be($sp + 0x20 + var_4, $a1)
	[lw $ra, 0x20+var_C($sp)]	$ra = mainmemory.read_u32_be($sp + 0x20 + var_C)
	[lui $a0, 0x8074]			$a0 = 0x80740000
	[addiu $t1, $v1, 1]			$t1 = $v1 + 1
	[li $at, 0xFFFFFFFF]		$at = 0xFFFFFFFF
	[la $a0, RNG]				$a0 = RNG
	[and $v0, $t1, $at]			$v0 = $t1 and $at
	[sw $v0, (RNG-RNG)($a0)]	mainmemory.write_u32_be($a0 + (RNG - RNG), $v0)
	[jr $ra]					jr $ra
	[addiu $sp, 0x20]			$sp = $sp + 0x20
end

CycleRNG()
	arg_0 = 0
	arg_8 = 8
	[sw $a0, arg_0($sp)]		mainmemory.write_u32_be($sp + arg_0, $a0)
	[sw $a1, arg_0+4($sp)]		mainmemory.write_u32_be($sp + arg_0 + 4, $a1)
	[sw $a2, arg_8($sp)]		mainmemory.write_u32_be($sp + arg_8, $a2)
	[sw $a3, arg_8+4($sp)]		mainmemory.write_u32_be($sp + arg_8 + 4, $a3)

	[ld $t7, arg_8($sp)]		$t7 = mainmemory.read_u64_be($sp + arg_8)
	[ld $t6, arg_0($sp)]		$t6 = mainmemory.read_u64_be($sp + arg_0)

	[dmultu $t6, $t7]			LO = [$t6 x $t7](0 > 63) -- Lower 64 bits get placed into LO
	[dmultu $t6, $t7]			HI = [$t6 x $t7](64 > 127) -- Upper 64 bits get placed into HI

	[mflo $v0]					$v0 = LO

	[dsll32 $v1, $v0, 0]		$v1 = $v0 * 2^(32 + 0) -- Bitshift left 32 bits
	[dsra32 $v1, 0]				$v1 = $v1 / 2^(32 + 0) -- Bitshift right 32 bits

	[jr $ra]					jr $ra

	[dsra32 $v0, 0]				$v0 = $v0 / 2^(32 + 0) -- Bitshift right 32 bits
end

SIMPLIFIED
a0 = 0
a1 = rng_value
a2 = 0
a3 = 0x01DF5E0D
sp = sp - 32
t6 = (a0 * (256 ^ 4)) + a1
t7 = (a2 * (256 ^ 4)) + a3
hi = math.floor(t6 * t7 / (256 ^ 8))
lo = (t6 * t7) - (256 ^ 8)(hi)
v0 = lo
v1 = v0
a0 = 0x80740000
t1 = v1 + 1
at = 0xFFFFFFFF
a0 = rng_address
v0 = t1
rng_value = v0
sp = sp + 32

sp = sp - 32
t6 = rng_value
t7 = 0x01DF5E0D
hi = math.floor(t6 * t7 / (256 ^ 4))
lo = (t6 * t7) % (256 ^ 8)
v1 = lo
t1 = v1 + 1
v0 = t1 % (16 ^ 8)
rng_value = v0
sp = sp + 32

rng_value = (((rng_value * 0x01DF5E0D) % (256 ^ 8)) + 1) % (256 ^ 4)