git.gir.st - Chiptunes-pms150c.git/blame_incremental

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Commit	Line	Data
	1	#include <stdio.h>
	2	#include "fakeasm.h"
	3	typedef unsigned char u8;
	4
	5	u8 i0, i1, i2; //MEM
	6	u8 n; //MEM
	7	u8 sample; //MEM
	8	u8 tmp_1; //MEM
	9	u8 acc; //ACC
	10
	11	u8 notes[] = {
	12	0x84, 0x9d, 0xb0, 0x69, 0x9d, 0x84, 0x69, 0x58,
	13	0x75, 0x8c, 0xb0, 0x69, 0x8c, 0x75, 0x69, 0x58
	14	};
	15
	16	u8 mod3hi, mod3lo; //MEM
	17	//todo: can mod3hi be aliased to tmp_1?
	18	void mod3(void) {
	19	MOV (acc,mod3hi)
	20	ADD (mod3lo,acc) // mod3lo = hi+lo
	21	CLEAR (acc)
	22	ADDC0 (acc) // mod3hi, 1bit
	23	SWAP (acc)
	24	MOV (mod3hi, acc)
	25
	26	MOV (acc, mod3lo)
	27	SWAP (acc)
	28	AND (acc, 0xf) // (mod3lo>>4)
	29	XCH (mod3lo) // acc=mod3lo, mod3lo=mod3lo>>4
	30	AND (acc, 0xF) // acc=mod3lo&0xf, mod3lo=mod3lo>>4
	31	ADD (acc, mod3lo) // (mod3lo & 0xF)
	32	ADD (acc, mod3hi)
	33	MOV (mod3lo, acc)
	34
	35	AND (acc, 0x3) // acc = (mod3lo & 0x3)
	36	SR (mod3lo)
	37	SR (mod3lo) // (mod3lo >> 2)
	38	ADD (acc, mod3lo)
	39	MOV (mod3lo, acc)
	40
	41	AND (acc, 0x3) // acc = (mod3lo & 0x3)
	42	SR (mod3lo)
	43	SR (mod3lo) // (mod3lo >> 2)
	44	ADD (acc, mod3lo)
	45
	46	if (acc > 2) { // TODO: acc in [0,1,2,3,4]
	47	SUB (acc,3)
	48	}
	49	}
	50
	51	void g(void){
	52	u8 notes_ix = acc & 0x7;
	53	if(3&i2)
	54	notes_ix += 8;
	55	u8 result = ((i1<<8\|i0)*notes[notes_ix])>>8; // keep hi byte
	56	acc = result;
	57	}
	58	void main(void){
	59	CLEAR (i0)
	60	CLEAR (i1)
	61	CLEAR (i2)
	62	for(;;) {
	63	MOV (acc, i2)// "mov mem,mem"
	64	MOV (n, acc)// does not exist
	65	SL (n)
	66	SL (n)
	67	MOV (acc, i1)
	68	SWAP (acc)
	69	AND (acc, 0xf)
	70	SR (acc)
	71	SR (acc)
	72	OR (n, acc)
	73
	74	MOV (acc, n)
	75	CALL (g)
	76	SWAP (acc)
	77	AND (acc, 0x1)
	78	MOV (sample, acc)
	79
	80	MOV (acc, i2)
	81	SL (acc)
	82	SL (acc)
	83	SL (acc)
	84	MOV (tmp_1, acc) // fresh tmp_1:
	85	MOV (acc, i1)
	86	SWAP (acc)
	87	AND (acc, 0xf)
	88	SR (acc)
	89	OR (acc, tmp_1) // tmp_1 done.
	90	XOR (acc, n)
	91	CALL (g)
	92	SR (acc)
	93	AND (acc, i2)
	94	SR (acc)
	95	AND (acc, 3)
	96	ADD (sample, acc)
	97
	98	MOV (acc, i2)
	99	MOV (mod3hi, acc)
	100	SR (mod3hi)
	101	SR (mod3hi)
	102	SR (mod3hi)
	103	SWAP (acc)
	104	AND (acc, 0xf0)
	105	SL (acc)
	106	MOV (mod3lo, acc)
	107	MOV (acc, i1)
	108	SR (acc)
	109	SR (acc)
	110	SR (acc)
	111	OR (mod3lo, acc)
	112	CALL (mod3)
	113	ADD (acc, n)
	114	CALL (g)
	115	SR (acc)
	116	SR (acc)
	117	MOV (tmp_1, acc) // acc saved in tmp_1; fresh acc
	118	MOV (acc, i2)
	119	// shift-divide by six
	120	// note: i2 is max 0x78; so acc will <= 20. (breaks vor values >=128)
	121	SR (acc)
	122	ADD (acc, i2)
	123	SR (acc)
	124	SR (acc)
	125	ADD (acc, i2)
	126	SR (acc)
	127	SR (acc)
	128	ADD (acc, i2)
	129	SR (acc)
	130	SR (acc)
	131	SR (acc)
	132	// end divide by six
	133	AND (acc, tmp_1) // acc restored from tmp_1
	134	AND (acc, 3)
	135	ADD (sample, acc)
	136
	137	MOV (acc, i2)
	138	MOV (mod3hi, acc)
	139	SR (mod3hi)
	140	SR (mod3hi)
	141	SWAP (acc)
	142	AND (acc, 0xf0)
	143	SL (acc)
	144	SL (acc)
	145	MOV (mod3lo, acc)
	146	MOV (acc, i1)
	147	SR (acc)
	148	SR (acc)
	149	OR (mod3lo, acc)
	150	CALL (mod3)
	151	SUB (acc, n)
	152	SUB (acc, 8)
	153	NEG (acc)
	154	CALL (g)
	155	SR (acc)
	156	MOV (tmp_1, acc) // acc saved in tmp_1; fresh acc
	157	MOV (acc, i2)
	158	// shift-divide by ten
	159	// note: i2 is max 0x78; so acc will <= 12.
	160	INC (i2)
	161	SR (acc)
	162	ADD (acc, i2)
	163	SR (acc)
	164	SR (acc)
	165	SR (acc)
	166	ADD (acc, i2)
	167	SR (acc)
	168	ADD (acc, i2)
	169	SWAP (acc)
	170	DEC (i2)
	171	// end divide by ten
	172	AND (acc, tmp_1) // acc restored from tmp_1
	173	AND (acc, 3)
	174	ADD (sample, acc)
	175
	176	MOV (acc, sample)
	177	SWAP (acc)
	178	putchar(acc);
	179
	180	INC (i0)
	181	i1 += !i0; // ADDC i1
	182	i2 += !i1 && !i0; // ADDC i2
	183
	184	if(i2 == 0x78) break;
	185	}
	186	}