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Commit | Line | Data |
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1 | /* REGISTER NAMES */ | |
2 | #define zero r16 | |
3 | #define acc r17 | |
4 | #define i0 r18 | |
5 | #define i1 r19 | |
6 | #define i2 r20 | |
7 | #define i3 r21 | |
8 | #define n r22 | |
9 | #define s r23 | |
10 | #define _ r24 | |
11 | ; r25 | |
12 | #define x r26 //==Xlo==Mh | |
13 | #define t r27 //==Xhi==Ml | |
14 | ; r28 | |
15 | ; r29 | |
16 | ; r30 Zlo | |
17 | ; r31 Zhi | |
18 | ; aliases: | |
19 | #define Xlo r26 | |
20 | #define Xhi r27 | |
21 | #define Mh r26 //mod3 vars | |
22 | #define Ml r27 // -"- | |
23 | ||
24 | /* I/O REGISTERS */ | |
25 | OCR0AL = 0x26 | |
26 | DDRB = 0x01 | |
27 | PUEB = 0x03 | |
28 | SPL = 0x3D | |
29 | SPH = 0x3E | |
30 | CCP = 0x3C | |
31 | CLKPSR = 0x36 | |
32 | SMCR = 0x3A | |
33 | TCCR0A = 0x2E | |
34 | TCCR0B = 0x2D | |
35 | TIMSK0 = 0x2B | |
36 | TIFR0 = 0x2A | |
37 | ||
38 | .section .data | |
39 | .byte 0x84, 0x9d, 0xb0, 0x69, 0x9d, 0x84, 0x69, 0x58 | |
40 | .byte 0x75, 0x8c, 0xb0, 0x69, 0x8c, 0x75, 0x69, 0x58 | |
41 | ||
42 | .section .text | |
43 | ||
44 | mod3: ; mod3(Mh.Ml) -> t | |
45 | #define tmp _ | |
46 | ADD (Ml, Mh) | |
47 | CLR (Mh) | |
48 | ADC (Mh, zero, carry) //Mh only holds the carry bit | |
49 | MOV (tmp, Ml) | |
50 | SWAP (tmp) | |
51 | ANDI (tmp, 0x0f) | |
52 | SWAP (Mh) | |
53 | OR (tmp, Mh) | |
54 | ANDI (Ml, 0x0f) | |
55 | ADD (Ml, tmp) | |
56 | MOV (tmp, Ml) | |
57 | LSR (tmp) | |
58 | LSR (tmp) | |
59 | ANDI (Ml, 0x03) | |
60 | ADD (Ml, tmp) | |
61 | MOV (tmp, Ml) | |
62 | LSR (tmp) | |
63 | LSR (tmp) | |
64 | ANDI (Ml, 0x03) | |
65 | ADD (Ml, tmp) | |
66 | CPI (Ml, 3) | |
67 | BRPL (skip) | |
68 | SUBI (Ml, 3) | |
69 | skip:; | |
70 | RET | |
71 | #undef tmp | |
72 | ||
73 | ; definitions to mul-tree readable: | |
74 | .macro always _bit ; nop; for when a test() is not necessary (see tree) | |
75 | .endm | |
76 | .macro never _bit ; nop; for when a test() is not necessary (see tree) | |
77 | .endm | |
78 | .macro test _bit,_jmpto | |
79 | SBRC t, _bit | |
80 | RJMP _jmpto | |
81 | .endm | |
82 | .macro shift16 | |
83 | LSR a2 | |
84 | ROR a1 | |
85 | .endm | |
86 | .macro shift8 ; top three bits don't need to be corrrect, so save cycles by not carrying | |
87 | LSR a1 | |
88 | .endm | |
89 | .macro shift0 ; nop; last shift is common | |
90 | .endm | |
91 | .macro add_shift16 | |
92 | ADD a1, i0 | |
93 | ADC a2, i1 | |
94 | shift16 | |
95 | .endm | |
96 | .macro add_shift8 ; ditto with carrying | |
97 | ADD a1, i0 | |
98 | shift8 | |
99 | .endm | |
100 | .macro add_shift0 ; last shift is common | |
101 | ADD a1, i0 | |
102 | .endm | |
103 | ||
104 | g: ; g(i, t) -> t | |
105 | #define tmp _ | |
106 | ANDI (t, 0x07) | |
107 | MOV (tmp, i2) | |
108 | ANDI (tmp, 3) | |
109 | TST (tmp) | |
110 | CPSE (tmp, zero) | |
111 | SUBI (t, -8) | |
112 | #undef tmp | |
113 | ||
114 | #define tmp _ | |
115 | MOV (tmp, t) //NOTE: must move value away from `t`, as that is also hi(X) | |
116 | tmp = data[tmp];/* | |
117 | LDI Xhi, hi8(data) | |
118 | LDI Xlo, lo8(data) | |
119 | ADD Xlo, tmp ;<-- the offset (formerly `t`) into data[] | |
120 | ADC Xhi, zero | |
121 | LD tmp, X */ | |
122 | MOV (t, tmp) | |
123 | #undef tmp | |
124 | ||
125 | #define a1 x | |
126 | #define a2 _ | |
127 | #define a0 t | |
128 | CLR (a2) | |
129 | CLR (a1) | |
130 | ||
131 | /* decision tree multiplication saves cycles and (hopefully) reduces code size | |
132 | _xxx? | |
133 | / \ | |
134 | _xx?0 _xx1? | |
135 | | | | |
136 | _x?00 _x?01 | |
137 | / \ / \ | |
138 | _?000 _?100 _?001 _?101 | |
139 | / \ / \ | / \ | |
140 | _0000 _1000 _0100 _1100 _1001 _0101 _1101 | |
141 | | | | | | | | | |
142 | ... ... ... ... ... ... ... | |
143 | | | | | | | | | |
144 | B0 58 84 8C 69 75 9D */ | |
145 | test (0, m____1) | |
146 | m____0: shift16 | |
147 | never (1) | |
148 | m___00: shift16 | |
149 | test (2, m__100) | |
150 | m__000: shift16 | |
151 | test (3, m_1000) | |
152 | m_0000: shift16 | |
153 | always (4) | |
154 | add_shift16 | |
155 | always (5) | |
156 | add_shift8 | |
157 | never (6) | |
158 | shift8 | |
159 | always (7) | |
160 | add_shift0 | |
161 | RJMP (end_mul) // calc'd 0xb0 | |
162 | ||
163 | m_1000: add_shift16 | |
164 | always (4) | |
165 | add_shift16 | |
166 | never (5) | |
167 | shift8 | |
168 | always (6) | |
169 | add_shift8 | |
170 | never (7) | |
171 | shift0 | |
172 | RJMP (end_mul) // calc'd 0x58 | |
173 | ||
174 | m__100: add_shift16 | |
175 | test (3, m_1100) | |
176 | m_0100: shift16 | |
177 | RJMP (upper_8) //'ll calc 0x84 | |
178 | ||
179 | m_1100: add_shift16 | |
180 | upper_8: /* used twice, so deduplicated */ | |
181 | never (4) | |
182 | shift16 | |
183 | never (5) | |
184 | shift8 | |
185 | never (6) | |
186 | shift8 | |
187 | always (7) | |
188 | add_shift0 | |
189 | RJMP (end_mul) // calc'd 0x8c | |
190 | ||
191 | m____1: add_shift16 | |
192 | never (1) | |
193 | m___01: shift16 | |
194 | test (2, m__101) | |
195 | m__001: shift16 | |
196 | always (3) | |
197 | m_1001: add_shift16 | |
198 | never (4) | |
199 | shift16 | |
200 | always (5) | |
201 | add_shift8 | |
202 | always (6) | |
203 | add_shift8 | |
204 | never (7) | |
205 | shift0 | |
206 | RJMP (end_mul) // calc'd 0x69 | |
207 | ||
208 | m__101: add_shift16 | |
209 | test (3, m_1101) | |
210 | m_0101: shift16 | |
211 | always (4) | |
212 | add_shift16 | |
213 | always (5) | |
214 | add_shift8 | |
215 | always (6) | |
216 | add_shift8 | |
217 | never (7) | |
218 | shift0 | |
219 | RJMP (end_mul) // calc'd 0x75 | |
220 | ||
221 | m_1101: add_shift16 | |
222 | always (4) | |
223 | add_shift16 | |
224 | never (5) | |
225 | shift8 | |
226 | never (6) | |
227 | shift8 | |
228 | always (7) | |
229 | add_shift0 | |
230 | // calc'd 0x9d | |
231 | ||
232 | end_mul: | |
233 | LSR (a1) //final shift is a common operation for all | |
234 | ||
235 | MOV (t, a1) //TODO: use a1 in main() directly | |
236 | #undef a0 | |
237 | #undef a1 | |
238 | #undef a2 | |
239 | RET //TODO: replace CALL/RET with IJMP? (requires undoing goto-mul-hack) | |
240 | ||
241 | main: | |
242 | CLR (zero) | |
243 | CLR (i0) | |
244 | CLR (i1) | |
245 | CLR (i2) | |
246 | CLR (i3) | |
247 | //TODO: setup stack pointer, portb, clock, sleep mode, timer0 | |
248 | RJMP sample | |
249 | sample: //TODO: this will probably become the timer0 overflow interrupt handler | |
250 | MOV (n, i2) | |
251 | LSL (n) | |
252 | LSL (n) | |
253 | #define tmp _ | |
254 | MOV (tmp, i1) | |
255 | SWAP (tmp) | |
256 | ANDI (tmp, 0x0f) | |
257 | LSR (tmp) | |
258 | LSR (tmp) | |
259 | OR (n, tmp) | |
260 | #undef tmp | |
261 | MOV (s, i3) | |
262 | LSR (s) | |
263 | ROR (s) | |
264 | ANDI (s, 0x80) | |
265 | #define tmp _ | |
266 | MOV (tmp, i2) | |
267 | LSR (tmp) | |
268 | OR (s, tmp) | |
269 | #undef tmp | |
270 | ||
271 | //voice 1: | |
272 | MOV (t, n) | |
273 | RCALL g(); | |
274 | SWAP (t) | |
275 | ANDI (t, 1) | |
276 | MOV (acc, t) | |
277 | ||
278 | //voice 2: | |
279 | #define tmp _ | |
280 | MOV (tmp, i2) | |
281 | LSL (tmp) | |
282 | LSL (tmp) | |
283 | LSL (tmp) | |
284 | MOV (t, i1) | |
285 | SWAP (t) | |
286 | ANDI (t, 0xf) | |
287 | LSR (t) | |
288 | OR (t, tmp) | |
289 | #undef tmp | |
290 | EOR (t, n) | |
291 | RCALL g(); | |
292 | LSR (t) | |
293 | LSR (t) | |
294 | ANDI (t, 3) | |
295 | AND (t, s) | |
296 | ADD (acc, t) | |
297 | ||
298 | //voice 3: | |
299 | MOV (Ml, i2) | |
300 | SWAP (Ml) | |
301 | ANDI (Ml, 0xf0) | |
302 | LSL (Ml) | |
303 | #define tmp _ | |
304 | MOV (tmp, i1) | |
305 | LSR (tmp) | |
306 | LSR (tmp) | |
307 | LSR (tmp) | |
308 | OR (Ml, tmp) | |
309 | #undef tmp | |
310 | MOV (Mh, i3) | |
311 | SWAP (Mh) | |
312 | ANDI (Mh, 0xf0) | |
313 | LSL (Mh) | |
314 | #define tmp _ | |
315 | MOV (tmp, i2) | |
316 | LSR (tmp) | |
317 | LSR (tmp) | |
318 | LSR (tmp) | |
319 | OR (Mh, tmp) | |
320 | #undef tmp | |
321 | RCALL mod3(); | |
322 | ADD (t, n) | |
323 | RCALL g(); | |
324 | LSR (t) | |
325 | LSR (t) | |
326 | ANDI (t, 3) | |
327 | MOV (x, s) | |
328 | INC (x) | |
329 | #define tmp _ | |
330 | MOV (tmp, x) | |
331 | LSR (tmp) | |
332 | LSR (tmp) | |
333 | ADD (tmp, x) | |
334 | ROR (tmp) | |
335 | LSR (tmp) | |
336 | ADD (tmp, x) | |
337 | ROR (tmp) | |
338 | LSR (tmp) | |
339 | ADD (tmp, x) | |
340 | ROR (tmp) | |
341 | LSR (tmp) | |
342 | AND (t, tmp) | |
343 | #undef tmp | |
344 | ADD (acc, t) | |
345 | ||
346 | //voice 4: | |
347 | MOV (Ml, i2) | |
348 | SWAP (Ml) | |
349 | ANDI (Ml, 0xf0) | |
350 | LSL (Ml) | |
351 | LSL (Ml) | |
352 | #define tmp _ | |
353 | MOV (tmp, i1) | |
354 | LSR (tmp) | |
355 | LSR (tmp) | |
356 | OR (Ml, tmp) | |
357 | #undef tmp | |
358 | MOV (Mh, i3) | |
359 | SWAP (Mh) | |
360 | ANDI (Mh, 0xf0) | |
361 | LSL (Mh) | |
362 | LSL (Mh) | |
363 | #define tmp _ | |
364 | MOV (tmp, i2) | |
365 | LSR (tmp) | |
366 | LSR (tmp) | |
367 | OR (Mh, tmp) | |
368 | #undef tmp | |
369 | RCALL mod3(); | |
370 | SUB (t, n) | |
371 | NEG (t) | |
372 | SUBI (t, -8) | |
373 | RCALL g(); | |
374 | LSR (t) | |
375 | ANDI (t, 3) | |
376 | INC (s) | |
377 | #define tmp _ | |
378 | MOV (tmp, s) | |
379 | LSR (tmp) | |
380 | ADD (tmp, s) | |
381 | ROR (tmp) | |
382 | LSR (tmp) | |
383 | LSR (tmp) | |
384 | ADD (tmp, s) | |
385 | ROR (tmp) | |
386 | ADD (tmp, s) | |
387 | ROR (tmp) | |
388 | LSR (tmp) | |
389 | LSR (tmp) | |
390 | AND (t, tmp) | |
391 | #undef tmp | |
392 | ADD (acc, t) | |
393 | ||
394 | putchar(acc<<4); //TODO | |
395 | SUBI (i0, -1) | |
396 | ADC (i1, zero, !i0) //XXX: must use "sbci i1,-1" in the assembly version | |
397 | ADC (i2, zero, !i0&&!i1) // sbci i2,-1 | |
398 | ADC (i3, zero, !i0&&!i1&&!i2) // sbci i3,-1 |