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d16005f8 PC |
1 | /* |
2 | * Copyright (C) 2014-2020 Paul Cercueil <paul@crapouillou.net> | |
3 | * | |
4 | * This library is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU Lesser General Public | |
6 | * License as published by the Free Software Foundation; either | |
7 | * version 2.1 of the License, or (at your option) any later version. | |
8 | * | |
9 | * This library is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * Lesser General Public License for more details. | |
13 | */ | |
14 | ||
15 | #include "debug.h" | |
16 | #include "memmanager.h" | |
17 | #include "regcache.h" | |
18 | ||
19 | #include <lightning.h> | |
20 | #include <stdbool.h> | |
21 | #include <stddef.h> | |
22 | ||
23 | struct native_register { | |
24 | bool used, loaded, dirty, output, extend, extended, locked; | |
25 | s8 emulated_register; | |
26 | }; | |
27 | ||
28 | struct regcache { | |
29 | struct lightrec_state *state; | |
30 | struct native_register lightrec_regs[NUM_REGS + NUM_TEMPS]; | |
31 | }; | |
32 | ||
33 | static const char * mips_regs[] = { | |
34 | "zero", | |
35 | "at", | |
36 | "v0", "v1", | |
37 | "a0", "a1", "a2", "a3", | |
38 | "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", | |
39 | "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7", | |
40 | "t8", "t9", | |
41 | "k0", "k1", | |
42 | "gp", "sp", "fp", "ra", | |
43 | "lo", "hi", | |
44 | }; | |
45 | ||
46 | const char * lightrec_reg_name(u8 reg) | |
47 | { | |
48 | return mips_regs[reg]; | |
49 | } | |
50 | ||
51 | static inline u8 lightrec_reg_number(const struct regcache *cache, | |
52 | const struct native_register *nreg) | |
53 | { | |
54 | return (u8) (((uintptr_t) nreg - (uintptr_t) cache->lightrec_regs) | |
55 | / sizeof(*nreg)); | |
56 | } | |
57 | ||
58 | static inline u8 lightrec_reg_to_lightning(const struct regcache *cache, | |
59 | const struct native_register *nreg) | |
60 | { | |
61 | u8 offset = lightrec_reg_number(cache, nreg); | |
62 | return offset < NUM_REGS ? JIT_V(offset) : JIT_R(offset - NUM_REGS); | |
63 | } | |
64 | ||
65 | static inline struct native_register * lightning_reg_to_lightrec( | |
66 | struct regcache *cache, u8 reg) | |
67 | { | |
68 | if ((JIT_V0 > JIT_R0 && reg >= JIT_V0) || | |
69 | (JIT_V0 < JIT_R0 && reg < JIT_R0)) { | |
70 | if (JIT_V1 > JIT_V0) | |
71 | return &cache->lightrec_regs[reg - JIT_V0]; | |
72 | else | |
73 | return &cache->lightrec_regs[JIT_V0 - reg]; | |
74 | } else { | |
75 | if (JIT_R1 > JIT_R0) | |
76 | return &cache->lightrec_regs[NUM_REGS + reg - JIT_R0]; | |
77 | else | |
78 | return &cache->lightrec_regs[NUM_REGS + JIT_R0 - reg]; | |
79 | } | |
80 | } | |
81 | ||
82 | static struct native_register * alloc_temp(struct regcache *cache) | |
83 | { | |
84 | unsigned int i; | |
85 | ||
86 | /* We search the register list in reverse order. As temporaries are | |
87 | * meant to be used only in the emitter functions, they can be mapped to | |
88 | * caller-saved registers, as they won't have to be saved back to | |
89 | * memory. */ | |
90 | for (i = ARRAY_SIZE(cache->lightrec_regs); i; i--) { | |
91 | struct native_register *nreg = &cache->lightrec_regs[i - 1]; | |
92 | if (!nreg->used && !nreg->loaded && !nreg->dirty) | |
93 | return nreg; | |
94 | } | |
95 | ||
96 | for (i = ARRAY_SIZE(cache->lightrec_regs); i; i--) { | |
97 | struct native_register *nreg = &cache->lightrec_regs[i - 1]; | |
98 | if (!nreg->used) | |
99 | return nreg; | |
100 | } | |
101 | ||
102 | return NULL; | |
103 | } | |
104 | ||
105 | static struct native_register * find_mapped_reg(struct regcache *cache, | |
106 | u8 reg, bool out) | |
107 | { | |
108 | unsigned int i; | |
109 | ||
110 | for (i = 0; i < ARRAY_SIZE(cache->lightrec_regs); i++) { | |
111 | struct native_register *nreg = &cache->lightrec_regs[i]; | |
112 | if ((!reg || nreg->loaded || nreg->dirty) && | |
113 | nreg->emulated_register == reg && | |
114 | (!out || !nreg->locked)) | |
115 | return nreg; | |
116 | } | |
117 | ||
118 | return NULL; | |
119 | } | |
120 | ||
121 | static struct native_register * alloc_in_out(struct regcache *cache, | |
122 | u8 reg, bool out) | |
123 | { | |
124 | struct native_register *nreg; | |
125 | unsigned int i; | |
126 | ||
127 | /* Try to find if the register is already mapped somewhere */ | |
128 | nreg = find_mapped_reg(cache, reg, out); | |
129 | if (nreg) | |
130 | return nreg; | |
131 | ||
132 | /* Try to allocate a non-dirty, non-loaded register. | |
133 | * Loaded registers may be re-used later, so it's better to avoid | |
134 | * re-using one if possible. */ | |
135 | for (i = 0; i < ARRAY_SIZE(cache->lightrec_regs); i++) { | |
136 | nreg = &cache->lightrec_regs[i]; | |
137 | if (!nreg->used && !nreg->dirty && !nreg->loaded) | |
138 | return nreg; | |
139 | } | |
140 | ||
141 | /* Try to allocate a non-dirty register */ | |
142 | for (i = 0; i < ARRAY_SIZE(cache->lightrec_regs); i++) { | |
143 | nreg = &cache->lightrec_regs[i]; | |
144 | if (!nreg->used && !nreg->dirty) | |
145 | return nreg; | |
146 | } | |
147 | ||
148 | for (i = 0; i < ARRAY_SIZE(cache->lightrec_regs); i++) { | |
149 | nreg = &cache->lightrec_regs[i]; | |
150 | if (!nreg->used) | |
151 | return nreg; | |
152 | } | |
153 | ||
154 | return NULL; | |
155 | } | |
156 | ||
157 | static void lightrec_discard_nreg(struct native_register *nreg) | |
158 | { | |
159 | nreg->extended = false; | |
160 | nreg->loaded = false; | |
161 | nreg->output = false; | |
162 | nreg->dirty = false; | |
163 | nreg->used = false; | |
164 | nreg->locked = false; | |
165 | nreg->emulated_register = -1; | |
166 | } | |
167 | ||
168 | static void lightrec_unload_nreg(struct regcache *cache, jit_state_t *_jit, | |
169 | struct native_register *nreg, u8 jit_reg) | |
170 | { | |
171 | /* If we get a dirty register, store back the old value */ | |
172 | if (nreg->dirty) { | |
173 | s16 offset = offsetof(struct lightrec_state, native_reg_cache) | |
174 | + (nreg->emulated_register << 2); | |
175 | ||
176 | jit_stxi_i(offset, LIGHTREC_REG_STATE, jit_reg); | |
177 | } | |
178 | ||
179 | lightrec_discard_nreg(nreg); | |
180 | } | |
181 | ||
182 | void lightrec_unload_reg(struct regcache *cache, jit_state_t *_jit, u8 jit_reg) | |
183 | { | |
184 | lightrec_unload_nreg(cache, _jit, | |
185 | lightning_reg_to_lightrec(cache, jit_reg), jit_reg); | |
186 | } | |
187 | ||
188 | /* lightrec_lock_reg: the register will be cleaned if dirty, then locked. | |
189 | * A locked register cannot only be used as input, not output. */ | |
190 | void lightrec_lock_reg(struct regcache *cache, jit_state_t *_jit, u8 jit_reg) | |
191 | { | |
192 | struct native_register *reg = lightning_reg_to_lightrec(cache, jit_reg); | |
193 | ||
194 | lightrec_clean_reg(cache, _jit, jit_reg); | |
195 | ||
196 | reg->locked = true; | |
197 | } | |
198 | ||
199 | u8 lightrec_alloc_reg(struct regcache *cache, jit_state_t *_jit, u8 jit_reg) | |
200 | { | |
201 | struct native_register *reg = lightning_reg_to_lightrec(cache, jit_reg); | |
202 | ||
203 | lightrec_unload_nreg(cache, _jit, reg, jit_reg); | |
204 | ||
205 | reg->used = true; | |
206 | return jit_reg; | |
207 | } | |
208 | ||
209 | u8 lightrec_alloc_reg_temp(struct regcache *cache, jit_state_t *_jit) | |
210 | { | |
211 | u8 jit_reg; | |
212 | struct native_register *nreg = alloc_temp(cache); | |
213 | if (!nreg) { | |
214 | /* No free register, no dirty register to free. */ | |
215 | pr_err("No more registers! Abandon ship!\n"); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | jit_reg = lightrec_reg_to_lightning(cache, nreg); | |
220 | lightrec_unload_nreg(cache, _jit, nreg, jit_reg); | |
221 | ||
222 | nreg->used = true; | |
223 | return jit_reg; | |
224 | } | |
225 | ||
226 | u8 lightrec_alloc_reg_out(struct regcache *cache, jit_state_t *_jit, u8 reg) | |
227 | { | |
228 | u8 jit_reg; | |
229 | struct native_register *nreg = alloc_in_out(cache, reg, true); | |
230 | if (!nreg) { | |
231 | /* No free register, no dirty register to free. */ | |
232 | pr_err("No more registers! Abandon ship!\n"); | |
233 | return 0; | |
234 | } | |
235 | ||
236 | jit_reg = lightrec_reg_to_lightning(cache, nreg); | |
237 | ||
238 | /* If we get a dirty register that doesn't correspond to the one | |
239 | * we're requesting, store back the old value */ | |
240 | if (nreg->emulated_register != reg) | |
241 | lightrec_unload_nreg(cache, _jit, nreg, jit_reg); | |
242 | ||
243 | nreg->extend = false; | |
244 | nreg->used = true; | |
245 | nreg->output = true; | |
246 | nreg->emulated_register = reg; | |
247 | return jit_reg; | |
248 | } | |
249 | ||
250 | u8 lightrec_alloc_reg_in(struct regcache *cache, jit_state_t *_jit, u8 reg) | |
251 | { | |
252 | u8 jit_reg; | |
253 | bool reg_changed; | |
254 | struct native_register *nreg = alloc_in_out(cache, reg, false); | |
255 | if (!nreg) { | |
256 | /* No free register, no dirty register to free. */ | |
257 | pr_err("No more registers! Abandon ship!\n"); | |
258 | return 0; | |
259 | } | |
260 | ||
261 | jit_reg = lightrec_reg_to_lightning(cache, nreg); | |
262 | ||
263 | /* If we get a dirty register that doesn't correspond to the one | |
264 | * we're requesting, store back the old value */ | |
265 | reg_changed = nreg->emulated_register != reg; | |
266 | if (reg_changed) | |
267 | lightrec_unload_nreg(cache, _jit, nreg, jit_reg); | |
268 | ||
269 | if (!nreg->loaded && !nreg->dirty && reg != 0) { | |
270 | s16 offset = offsetof(struct lightrec_state, native_reg_cache) | |
271 | + (reg << 2); | |
272 | ||
273 | /* Load previous value from register cache */ | |
274 | jit_ldxi_i(jit_reg, LIGHTREC_REG_STATE, offset); | |
275 | nreg->loaded = true; | |
276 | nreg->extended = true; | |
277 | } | |
278 | ||
279 | /* Clear register r0 before use */ | |
280 | if (reg == 0 && (!nreg->loaded || nreg->dirty)) { | |
281 | jit_movi(jit_reg, 0); | |
282 | nreg->extended = true; | |
283 | nreg->loaded = true; | |
284 | } | |
285 | ||
286 | nreg->used = true; | |
287 | nreg->output = false; | |
288 | nreg->emulated_register = reg; | |
289 | return jit_reg; | |
290 | } | |
291 | ||
292 | u8 lightrec_alloc_reg_out_ext(struct regcache *cache, jit_state_t *_jit, u8 reg) | |
293 | { | |
294 | struct native_register *nreg; | |
295 | u8 jit_reg; | |
296 | ||
297 | jit_reg = lightrec_alloc_reg_out(cache, _jit, reg); | |
298 | nreg = lightning_reg_to_lightrec(cache, jit_reg); | |
299 | ||
300 | nreg->extend = true; | |
301 | ||
302 | return jit_reg; | |
303 | } | |
304 | ||
305 | u8 lightrec_alloc_reg_in_ext(struct regcache *cache, jit_state_t *_jit, u8 reg) | |
306 | { | |
307 | struct native_register *nreg; | |
308 | u8 jit_reg; | |
309 | ||
310 | jit_reg = lightrec_alloc_reg_in(cache, _jit, reg); | |
311 | nreg = lightning_reg_to_lightrec(cache, jit_reg); | |
312 | ||
313 | #if __WORDSIZE == 64 | |
314 | if (!nreg->extended) { | |
315 | nreg->extended = true; | |
316 | jit_extr_i(jit_reg, jit_reg); | |
317 | } | |
318 | #endif | |
319 | ||
320 | return jit_reg; | |
321 | } | |
322 | ||
323 | u8 lightrec_request_reg_in(struct regcache *cache, jit_state_t *_jit, | |
324 | u8 reg, u8 jit_reg) | |
325 | { | |
326 | struct native_register *nreg; | |
327 | u16 offset; | |
328 | ||
329 | nreg = find_mapped_reg(cache, reg, false); | |
330 | if (nreg) { | |
331 | jit_reg = lightrec_reg_to_lightning(cache, nreg); | |
332 | nreg->used = true; | |
333 | return jit_reg; | |
334 | } | |
335 | ||
336 | nreg = lightning_reg_to_lightrec(cache, jit_reg); | |
337 | lightrec_unload_nreg(cache, _jit, nreg, jit_reg); | |
338 | ||
339 | /* Load previous value from register cache */ | |
340 | offset = offsetof(struct lightrec_state, native_reg_cache) + (reg << 2); | |
341 | jit_ldxi_i(jit_reg, LIGHTREC_REG_STATE, offset); | |
342 | ||
343 | nreg->extended = true; | |
344 | nreg->used = true; | |
345 | nreg->loaded = true; | |
346 | nreg->emulated_register = reg; | |
347 | ||
348 | return jit_reg; | |
349 | } | |
350 | ||
351 | static void free_reg(struct native_register *nreg) | |
352 | { | |
353 | /* Set output registers as dirty */ | |
354 | if (nreg->used && nreg->output && nreg->emulated_register > 0) | |
355 | nreg->dirty = true; | |
356 | if (nreg->output) | |
357 | nreg->extended = nreg->extend; | |
358 | nreg->used = false; | |
359 | } | |
360 | ||
361 | void lightrec_free_reg(struct regcache *cache, u8 jit_reg) | |
362 | { | |
363 | free_reg(lightning_reg_to_lightrec(cache, jit_reg)); | |
364 | } | |
365 | ||
366 | void lightrec_free_regs(struct regcache *cache) | |
367 | { | |
368 | unsigned int i; | |
369 | ||
370 | for (i = 0; i < ARRAY_SIZE(cache->lightrec_regs); i++) | |
371 | free_reg(&cache->lightrec_regs[i]); | |
372 | } | |
373 | ||
374 | static void clean_reg(jit_state_t *_jit, | |
375 | struct native_register *nreg, u8 jit_reg, bool clean) | |
376 | { | |
377 | if (nreg->dirty) { | |
378 | s16 offset = offsetof(struct lightrec_state, native_reg_cache) | |
379 | + (nreg->emulated_register << 2); | |
380 | ||
381 | jit_stxi_i(offset, LIGHTREC_REG_STATE, jit_reg); | |
382 | nreg->loaded |= nreg->dirty; | |
383 | nreg->dirty ^= clean; | |
384 | } | |
385 | } | |
386 | ||
387 | static void clean_regs(struct regcache *cache, jit_state_t *_jit, bool clean) | |
388 | { | |
389 | unsigned int i; | |
390 | ||
391 | for (i = 0; i < NUM_REGS; i++) | |
392 | clean_reg(_jit, &cache->lightrec_regs[i], JIT_V(i), clean); | |
393 | for (i = 0; i < NUM_TEMPS; i++) { | |
394 | clean_reg(_jit, &cache->lightrec_regs[i + NUM_REGS], | |
395 | JIT_R(i), clean); | |
396 | } | |
397 | } | |
398 | ||
399 | void lightrec_storeback_regs(struct regcache *cache, jit_state_t *_jit) | |
400 | { | |
401 | clean_regs(cache, _jit, false); | |
402 | } | |
403 | ||
404 | void lightrec_clean_regs(struct regcache *cache, jit_state_t *_jit) | |
405 | { | |
406 | clean_regs(cache, _jit, true); | |
407 | } | |
408 | ||
409 | void lightrec_clean_reg(struct regcache *cache, jit_state_t *_jit, u8 jit_reg) | |
410 | { | |
411 | struct native_register *reg = lightning_reg_to_lightrec(cache, jit_reg); | |
412 | clean_reg(_jit, reg, jit_reg, true); | |
413 | } | |
414 | ||
415 | void lightrec_clean_reg_if_loaded(struct regcache *cache, jit_state_t *_jit, | |
416 | u8 reg, bool unload) | |
417 | { | |
418 | struct native_register *nreg; | |
419 | u8 jit_reg; | |
420 | ||
421 | nreg = find_mapped_reg(cache, reg, false); | |
422 | if (nreg) { | |
423 | jit_reg = lightrec_reg_to_lightning(cache, nreg); | |
424 | ||
425 | if (unload) | |
426 | lightrec_unload_nreg(cache, _jit, nreg, jit_reg); | |
427 | else | |
428 | clean_reg(_jit, nreg, jit_reg, true); | |
429 | } | |
430 | } | |
431 | ||
432 | struct native_register * lightrec_regcache_enter_branch(struct regcache *cache) | |
433 | { | |
434 | struct native_register *backup; | |
435 | ||
436 | backup = lightrec_malloc(cache->state, MEM_FOR_LIGHTREC, | |
437 | sizeof(cache->lightrec_regs)); | |
438 | memcpy(backup, &cache->lightrec_regs, sizeof(cache->lightrec_regs)); | |
439 | ||
440 | return backup; | |
441 | } | |
442 | ||
443 | void lightrec_regcache_leave_branch(struct regcache *cache, | |
444 | struct native_register *regs) | |
445 | { | |
446 | memcpy(&cache->lightrec_regs, regs, sizeof(cache->lightrec_regs)); | |
447 | lightrec_free(cache->state, MEM_FOR_LIGHTREC, | |
448 | sizeof(cache->lightrec_regs), regs); | |
449 | } | |
450 | ||
451 | void lightrec_regcache_reset(struct regcache *cache) | |
452 | { | |
453 | memset(&cache->lightrec_regs, 0, sizeof(cache->lightrec_regs)); | |
454 | } | |
455 | ||
456 | struct regcache * lightrec_regcache_init(struct lightrec_state *state) | |
457 | { | |
458 | struct regcache *cache; | |
459 | ||
460 | cache = lightrec_calloc(state, MEM_FOR_LIGHTREC, sizeof(*cache)); | |
461 | if (!cache) | |
462 | return NULL; | |
463 | ||
464 | cache->state = state; | |
465 | ||
466 | return cache; | |
467 | } | |
468 | ||
469 | void lightrec_free_regcache(struct regcache *cache) | |
470 | { | |
471 | return lightrec_free(cache->state, MEM_FOR_LIGHTREC, | |
472 | sizeof(*cache), cache); | |
473 | } | |
474 | ||
475 | void lightrec_regcache_mark_live(struct regcache *cache, jit_state_t *_jit) | |
476 | { | |
477 | struct native_register *nreg; | |
478 | unsigned int i; | |
479 | ||
480 | #ifdef _WIN32 | |
481 | /* FIXME: GNU Lightning on Windows seems to use our mapped registers as | |
482 | * temporaries. Until the actual bug is found and fixed, unconditionally | |
483 | * mark our registers as live here. */ | |
484 | for (i = 0; i < NUM_REGS; i++) { | |
485 | nreg = &cache->lightrec_regs[i]; | |
486 | ||
487 | if (nreg->used || nreg->loaded || nreg->dirty) | |
488 | jit_live(JIT_V(i)); | |
489 | } | |
490 | #endif | |
491 | ||
492 | for (i = 0; i < NUM_TEMPS; i++) { | |
493 | nreg = &cache->lightrec_regs[NUM_REGS + i]; | |
494 | ||
495 | if (nreg->used || nreg->loaded || nreg->dirty) | |
496 | jit_live(JIT_R(i)); | |
497 | } | |
498 | } |