Dolphin/Source/DSPSpy/tests/loop_counter_test.ds

; This test checks how LOOP and BLOOP handle their arguments by running loops with the count
; ranging from 0 to 0xffff. The current counter is shown via mail at the top of the screen.
; This test gets slower as the counter gets larger (it runs in O(n^2)).
incdir  "tests"
include "dsp_base.inc"

test_main:
	CLR $acc0
	LRI $ar0, #0
	LRI $ix0, #0
	LRI $ar1, #0
	LRI $ix1, #0

main_loop:
	CLR $acc1
	; Incrementing $acc1 $ac0.l times sets $acc1 to 1 * $ac0.l, which is just $ac0.l
	LOOP $ac0.l
	INC $acc1
	; We are now done looping.  Check that the results match what we want...
	CMP
	JZ check_bloop
	; Did not match.
	IAR $ar0
	LRI $ix0, #1
	CALL send_back

check_bloop:
	CLR $acc1
	; Same deal as above.  Here we only have one instruction that is repeated via BLOOP.
	BLOOP $ac0.l, last_bloop_ins
	; TODO: This NOP is needed for things to behave properly; if the last_bloop_ins label
	; is immediately after the BLOOP instruction things break on real hardware.
	; There's no reason to do this normally though since the LOOP instruction does the same thing
	; without needing to provide a label. But it's worth checking eventually (along with how these
	; instructions behave when a 2-word long instruction is at the end).
	NOP
last_bloop_ins:
	INC $acc1
	; We are now done looping.  Check that the results match what we want...
	CMP
	JZ advance_main_loop
	; Did not match.
	IAR $ar1
	LRI $ix1, #1
	CALL send_back

advance_main_loop:
	; Report progress as mail
	SI @DMBH, #0
	SR @DMBL, $ac0.l
	SI @DIRQ, #0x0001

	; Move on to the next value.
	; CMPIS (and CMPI) check the middle of the accumulator, so CMPIS $acc0, #1
	; checks if the full accumulator is 0x10000 - which is our end point.
	INC $acc0
	CMPIS $ac0.m, #1
	JNZ main_loop

	; Done with the test.  $ar0, $ix0, $ar1, and $ix1 should all be 0.
	CALL send_back

	; We're done, DO NOT DELETE THIS LINE
	JMP end_of_test