aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/libraries/luajit-2.0/src/lj_dispatch.c
blob: 38fd1709619ce82a0d26d1dcf5ec3acd3432f57d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
/*
** Instruction dispatch handling.
** Copyright (C) 2005-2011 Mike Pall. See Copyright Notice in luajit.h
*/

#define lj_dispatch_c
#define LUA_CORE

#include "lj_obj.h"
#include "lj_err.h"
#include "lj_debug.h"
#include "lj_state.h"
#include "lj_frame.h"
#include "lj_bc.h"
#include "lj_ff.h"
#if LJ_HASJIT
#include "lj_jit.h"
#endif
#include "lj_trace.h"
#include "lj_dispatch.h"
#include "lj_vm.h"
#include "luajit.h"

/* Bump GG_NUM_ASMFF in lj_dispatch.h as needed. Ugly. */
LJ_STATIC_ASSERT(GG_NUM_ASMFF == FF_NUM_ASMFUNC);

/* -- Dispatch table management ------------------------------------------- */

/* Initialize instruction dispatch table and hot counters. */
void lj_dispatch_init(GG_State *GG)
{
  uint32_t i;
  ASMFunction *disp = GG->dispatch;
  for (i = 0; i < GG_LEN_SDISP; i++)
    disp[GG_LEN_DDISP+i] = disp[i] = makeasmfunc(lj_bc_ofs[i]);
  for (i = GG_LEN_SDISP; i < GG_LEN_DDISP; i++)
    disp[i] = makeasmfunc(lj_bc_ofs[i]);
  /* The JIT engine is off by default. luaopen_jit() turns it on. */
  disp[BC_FORL] = disp[BC_IFORL];
  disp[BC_ITERL] = disp[BC_IITERL];
  disp[BC_LOOP] = disp[BC_ILOOP];
  disp[BC_FUNCF] = disp[BC_IFUNCF];
  disp[BC_FUNCV] = disp[BC_IFUNCV];
  GG->g.bc_cfunc_ext = GG->g.bc_cfunc_int = BCINS_AD(BC_FUNCC, LUA_MINSTACK, 0);
  for (i = 0; i < GG_NUM_ASMFF; i++)
    GG->bcff[i] = BCINS_AD(BC__MAX+i, 0, 0);
}

#if LJ_HASJIT
/* Initialize hotcount table. */
void lj_dispatch_init_hotcount(global_State *g)
{
  int32_t hotloop = G2J(g)->param[JIT_P_hotloop];
  HotCount start = (HotCount)(hotloop*HOTCOUNT_LOOP - 1);
  HotCount *hotcount = G2GG(g)->hotcount;
  uint32_t i;
  for (i = 0; i < HOTCOUNT_SIZE; i++)
    hotcount[i] = start;
}
#endif

/* Internal dispatch mode bits. */
#define DISPMODE_JIT	0x01	/* JIT compiler on. */
#define DISPMODE_REC	0x02	/* Recording active. */
#define DISPMODE_INS	0x04	/* Override instruction dispatch. */
#define DISPMODE_CALL	0x08	/* Override call dispatch. */
#define DISPMODE_RET	0x08	/* Override return dispatch. */

/* Update dispatch table depending on various flags. */
void lj_dispatch_update(global_State *g)
{
  uint8_t oldmode = g->dispatchmode;
  uint8_t mode = 0;
#if LJ_HASJIT
  mode |= (G2J(g)->flags & JIT_F_ON) ? DISPMODE_JIT : 0;
  mode |= G2J(g)->state != LJ_TRACE_IDLE ?
	    (DISPMODE_REC|DISPMODE_INS|DISPMODE_CALL) : 0;
#endif
  mode |= (g->hookmask & (LUA_MASKLINE|LUA_MASKCOUNT)) ? DISPMODE_INS : 0;
  mode |= (g->hookmask & LUA_MASKCALL) ? DISPMODE_CALL : 0;
  mode |= (g->hookmask & LUA_MASKRET) ? DISPMODE_RET : 0;
  if (oldmode != mode) {  /* Mode changed? */
    ASMFunction *disp = G2GG(g)->dispatch;
    ASMFunction f_forl, f_iterl, f_loop, f_funcf, f_funcv;
    g->dispatchmode = mode;

    /* Hotcount if JIT is on, but not while recording. */
    if ((mode & (DISPMODE_JIT|DISPMODE_REC)) == DISPMODE_JIT) {
      f_forl = makeasmfunc(lj_bc_ofs[BC_FORL]);
      f_iterl = makeasmfunc(lj_bc_ofs[BC_ITERL]);
      f_loop = makeasmfunc(lj_bc_ofs[BC_LOOP]);
      f_funcf = makeasmfunc(lj_bc_ofs[BC_FUNCF]);
      f_funcv = makeasmfunc(lj_bc_ofs[BC_FUNCV]);
    } else {  /* Otherwise use the non-hotcounting instructions. */
      f_forl = disp[GG_LEN_DDISP+BC_IFORL];
      f_iterl = disp[GG_LEN_DDISP+BC_IITERL];
      f_loop = disp[GG_LEN_DDISP+BC_ILOOP];
      f_funcf = makeasmfunc(lj_bc_ofs[BC_IFUNCF]);
      f_funcv = makeasmfunc(lj_bc_ofs[BC_IFUNCV]);
    }
    /* Init static counting instruction dispatch first (may be copied below). */
    disp[GG_LEN_DDISP+BC_FORL] = f_forl;
    disp[GG_LEN_DDISP+BC_ITERL] = f_iterl;
    disp[GG_LEN_DDISP+BC_LOOP] = f_loop;

    /* Set dynamic instruction dispatch. */
    if ((oldmode ^ mode) & (DISPMODE_REC|DISPMODE_INS)) {
      /* Need to update the whole table. */
      if (!(mode & (DISPMODE_REC|DISPMODE_INS))) {  /* No ins dispatch? */
	/* Copy static dispatch table to dynamic dispatch table. */
	memcpy(&disp[0], &disp[GG_LEN_DDISP], GG_LEN_SDISP*sizeof(ASMFunction));
	/* Overwrite with dynamic return dispatch. */
	if ((mode & DISPMODE_RET)) {
	  disp[BC_RETM] = lj_vm_rethook;
	  disp[BC_RET] = lj_vm_rethook;
	  disp[BC_RET0] = lj_vm_rethook;
	  disp[BC_RET1] = lj_vm_rethook;
	}
      } else {
	/* The recording dispatch also checks for hooks. */
	ASMFunction f = (mode & DISPMODE_REC) ? lj_vm_record : lj_vm_inshook;
	uint32_t i;
	for (i = 0; i < GG_LEN_SDISP; i++)
	  disp[i] = f;
      }
    } else if (!(mode & (DISPMODE_REC|DISPMODE_INS))) {
      /* Otherwise set dynamic counting ins. */
      disp[BC_FORL] = f_forl;
      disp[BC_ITERL] = f_iterl;
      disp[BC_LOOP] = f_loop;
      /* Set dynamic return dispatch. */
      if ((mode & DISPMODE_RET)) {
	disp[BC_RETM] = lj_vm_rethook;
	disp[BC_RET] = lj_vm_rethook;
	disp[BC_RET0] = lj_vm_rethook;
	disp[BC_RET1] = lj_vm_rethook;
      } else {
	disp[BC_RETM] = disp[GG_LEN_DDISP+BC_RETM];
	disp[BC_RET] = disp[GG_LEN_DDISP+BC_RET];
	disp[BC_RET0] = disp[GG_LEN_DDISP+BC_RET0];
	disp[BC_RET1] = disp[GG_LEN_DDISP+BC_RET1];
      }
    }

    /* Set dynamic call dispatch. */
    if ((oldmode ^ mode) & DISPMODE_CALL) {  /* Update the whole table? */
      uint32_t i;
      if ((mode & 8) == 0) {  /* No call hooks? */
	for (i = GG_LEN_SDISP; i < GG_LEN_DDISP; i++)
	  disp[i] = makeasmfunc(lj_bc_ofs[i]);
      } else {
	for (i = GG_LEN_SDISP; i < GG_LEN_DDISP; i++)
	  disp[i] = lj_vm_callhook;
      }
    }
    if (!(mode & DISPMODE_CALL)) {  /* Overwrite dynamic counting ins. */
      disp[BC_FUNCF] = f_funcf;
      disp[BC_FUNCV] = f_funcv;
    }

#if LJ_HASJIT
    /* Reset hotcounts for JIT off to on transition. */
    if ((mode & DISPMODE_JIT) && !(oldmode & DISPMODE_JIT))
      lj_dispatch_init_hotcount(g);
#endif
  }
}

/* -- JIT mode setting ---------------------------------------------------- */

#if LJ_HASJIT
/* Set JIT mode for a single prototype. */
static void setptmode(global_State *g, GCproto *pt, int mode)
{
  if ((mode & LUAJIT_MODE_ON)) {  /* (Re-)enable JIT compilation. */
    pt->flags &= ~PROTO_NOJIT;
    lj_trace_reenableproto(pt);  /* Unpatch all ILOOP etc. bytecodes. */
  } else {  /* Flush and/or disable JIT compilation. */
    if (!(mode & LUAJIT_MODE_FLUSH))
      pt->flags |= PROTO_NOJIT;
    lj_trace_flushproto(g, pt);  /* Flush all traces of prototype. */
  }
}

/* Recursively set the JIT mode for all children of a prototype. */
static void setptmode_all(global_State *g, GCproto *pt, int mode)
{
  ptrdiff_t i;
  if (!(pt->flags & PROTO_CHILD)) return;
  for (i = -(ptrdiff_t)pt->sizekgc; i < 0; i++) {
    GCobj *o = proto_kgc(pt, i);
    if (o->gch.gct == ~LJ_TPROTO) {
      setptmode(g, gco2pt(o), mode);
      setptmode_all(g, gco2pt(o), mode);
    }
  }
}
#endif

/* Public API function: control the JIT engine. */
int luaJIT_setmode(lua_State *L, int idx, int mode)
{
  global_State *g = G(L);
  int mm = mode & LUAJIT_MODE_MASK;
  lj_trace_abort(g);  /* Abort recording on any state change. */
  /* Avoid pulling the rug from under our own feet. */
  if ((g->hookmask & HOOK_GC))
    lj_err_caller(L, LJ_ERR_NOGCMM);
  switch (mm) {
#if LJ_HASJIT
  case LUAJIT_MODE_ENGINE:
    if ((mode & LUAJIT_MODE_FLUSH)) {
      lj_trace_flushall(L);
    } else {
      if (!(mode & LUAJIT_MODE_ON))
	G2J(g)->flags &= ~(uint32_t)JIT_F_ON;
#if LJ_TARGET_X86ORX64
      else if ((G2J(g)->flags & JIT_F_SSE2))
	G2J(g)->flags |= (uint32_t)JIT_F_ON;
      else
	return 0;  /* Don't turn on JIT compiler without SSE2 support. */
#else
      else
	G2J(g)->flags |= (uint32_t)JIT_F_ON;
#endif
      lj_dispatch_update(g);
    }
    break;
  case LUAJIT_MODE_FUNC:
  case LUAJIT_MODE_ALLFUNC:
  case LUAJIT_MODE_ALLSUBFUNC: {
    cTValue *tv = idx == 0 ? frame_prev(L->base-1) :
		  idx > 0 ? L->base + (idx-1) : L->top + idx;
    GCproto *pt;
    if ((idx == 0 || tvisfunc(tv)) && isluafunc(&gcval(tv)->fn))
      pt = funcproto(&gcval(tv)->fn);  /* Cannot use funcV() for frame slot. */
    else if (tvisproto(tv))
      pt = protoV(tv);
    else
      return 0;  /* Failed. */
    if (mm != LUAJIT_MODE_ALLSUBFUNC)
      setptmode(g, pt, mode);
    if (mm != LUAJIT_MODE_FUNC)
      setptmode_all(g, pt, mode);
    break;
    }
  case LUAJIT_MODE_TRACE:
    if (!(mode & LUAJIT_MODE_FLUSH))
      return 0;  /* Failed. */
    lj_trace_flush(G2J(g), idx);
    break;
#else
  case LUAJIT_MODE_ENGINE:
  case LUAJIT_MODE_FUNC:
  case LUAJIT_MODE_ALLFUNC:
  case LUAJIT_MODE_ALLSUBFUNC:
    UNUSED(idx);
    if ((mode & LUAJIT_MODE_ON))
      return 0;  /* Failed. */
    break;
#endif
  case LUAJIT_MODE_WRAPCFUNC:
    if ((mode & LUAJIT_MODE_ON)) {
      if (idx != 0) {
	cTValue *tv = idx > 0 ? L->base + (idx-1) : L->top + idx;
	if (tvislightud(tv))
	  g->wrapf = (lua_CFunction)lightudV(tv);
	else
	  return 0;  /* Failed. */
      } else {
	return 0;  /* Failed. */
      }
      g->bc_cfunc_ext = BCINS_AD(BC_FUNCCW, 0, 0);
    } else {
      g->bc_cfunc_ext = BCINS_AD(BC_FUNCC, 0, 0);
    }
    break;
  default:
    return 0;  /* Failed. */
  }
  return 1;  /* OK. */
}

/* Enforce (dynamic) linker error for version mismatches. See luajit.c. */
LUA_API void LUAJIT_VERSION_SYM(void)
{
}

/* -- Hooks --------------------------------------------------------------- */

/* This function can be called asynchronously (e.g. during a signal). */
LUA_API int lua_sethook(lua_State *L, lua_Hook func, int mask, int count)
{
  global_State *g = G(L);
  mask &= HOOK_EVENTMASK;
  if (func == NULL || mask == 0) { mask = 0; func = NULL; }  /* Consistency. */
  g->hookf = func;
  g->hookcount = g->hookcstart = (int32_t)count;
  g->hookmask = (uint8_t)((g->hookmask & ~HOOK_EVENTMASK) | mask);
  lj_trace_abort(g);  /* Abort recording on any hook change. */
  lj_dispatch_update(g);
  return 1;
}

LUA_API lua_Hook lua_gethook(lua_State *L)
{
  return G(L)->hookf;
}

LUA_API int lua_gethookmask(lua_State *L)
{
  return G(L)->hookmask & HOOK_EVENTMASK;
}

LUA_API int lua_gethookcount(lua_State *L)
{
  return (int)G(L)->hookcstart;
}

/* Call a hook. */
static void callhook(lua_State *L, int event, BCLine line)
{
  global_State *g = G(L);
  lua_Hook hookf = g->hookf;
  if (hookf && !hook_active(g)) {
    lua_Debug ar;
    lj_trace_abort(g);  /* Abort recording on any hook call. */
    ar.event = event;
    ar.currentline = line;
    /* Top frame, nextframe = NULL. */
    ar.i_ci = (int)((L->base-1) - tvref(L->stack));
    lj_state_checkstack(L, 1+LUA_MINSTACK);
    hook_enter(g);
    hookf(L, &ar);
    lua_assert(hook_active(g));
    hook_leave(g);
  }
}

/* -- Dispatch callbacks -------------------------------------------------- */

/* Calculate number of used stack slots in the current frame. */
static BCReg cur_topslot(GCproto *pt, const BCIns *pc, uint32_t nres)
{
  BCIns ins = pc[-1];
  if (bc_op(ins) == BC_UCLO)
    ins = pc[bc_j(ins)];
  switch (bc_op(ins)) {
  case BC_CALLM: case BC_CALLMT: return bc_a(ins) + bc_c(ins) + nres-1+1;
  case BC_RETM: return bc_a(ins) + bc_d(ins) + nres-1;
  case BC_TSETM: return bc_a(ins) + nres-1;
  default: return pt->framesize;
  }
}

/* Instruction dispatch. Used by instr/line/return hooks or when recording. */
void LJ_FASTCALL lj_dispatch_ins(lua_State *L, const BCIns *pc)
{
  ERRNO_SAVE
  GCfunc *fn = curr_func(L);
  GCproto *pt = funcproto(fn);
  void *cf = cframe_raw(L->cframe);
  const BCIns *oldpc = cframe_pc(cf);
  global_State *g = G(L);
  BCReg slots;
  setcframe_pc(cf, pc);
  slots = cur_topslot(pt, pc, cframe_multres_n(cf));
  L->top = L->base + slots;  /* Fix top. */
#if LJ_HASJIT
  {
    jit_State *J = G2J(g);
    if (J->state != LJ_TRACE_IDLE) {
      J->L = L;
      lj_trace_ins(J, pc-1);  /* The interpreter bytecode PC is offset by 1. */
    }
  }
#endif
  if ((g->hookmask & LUA_MASKCOUNT) && g->hookcount == 0) {
    g->hookcount = g->hookcstart;
    callhook(L, LUA_HOOKCOUNT, -1);
    L->top = L->base + slots;  /* Fix top again. */
  }
  if ((g->hookmask & LUA_MASKLINE)) {
    BCPos npc = proto_bcpos(pt, pc) - 1;
    BCPos opc = proto_bcpos(pt, oldpc) - 1;
    BCLine line = lj_debug_line(pt, npc);
    if (pc <= oldpc || opc >= pt->sizebc || line != lj_debug_line(pt, opc)) {
      callhook(L, LUA_HOOKLINE, line);
      L->top = L->base + slots;  /* Fix top again. */
    }
  }
  if ((g->hookmask & LUA_MASKRET) && bc_isret(bc_op(pc[-1])))
    callhook(L, LUA_HOOKRET, -1);
  ERRNO_RESTORE
}

/* Initialize call. Ensure stack space and return # of missing parameters. */
static int call_init(lua_State *L, GCfunc *fn)
{
  if (isluafunc(fn)) {
    GCproto *pt = funcproto(fn);
    int numparams = pt->numparams;
    int gotparams = (int)(L->top - L->base);
    int need = pt->framesize;
    if ((pt->flags & PROTO_VARARG)) need += 1+gotparams;
    lj_state_checkstack(L, (MSize)need);
    numparams -= gotparams;
    return numparams >= 0 ? numparams : 0;
  } else {
    lj_state_checkstack(L, LUA_MINSTACK);
    return 0;
  }
}

/* Call dispatch. Used by call hooks, hot calls or when recording. */
ASMFunction LJ_FASTCALL lj_dispatch_call(lua_State *L, const BCIns *pc)
{
  ERRNO_SAVE
  GCfunc *fn = curr_func(L);
  BCOp op;
  global_State *g = G(L);
#if LJ_HASJIT
  jit_State *J = G2J(g);
#endif
  int missing = call_init(L, fn);
#if LJ_HASJIT
  J->L = L;
  if ((uintptr_t)pc & 1) {  /* Marker for hot call. */
    pc = (const BCIns *)((uintptr_t)pc & ~(uintptr_t)1);
    lj_trace_hot(J, pc);
    goto out;
  } else if (J->state != LJ_TRACE_IDLE &&
	     !(g->hookmask & (HOOK_GC|HOOK_VMEVENT))) {
#ifdef LUA_USE_ASSERT
    ptrdiff_t delta = L->top - L->base;
#endif
    /* Record the FUNC* bytecodes, too. */
    lj_trace_ins(J, pc-1);  /* The interpreter bytecode PC is offset by 1. */
    lua_assert(L->top - L->base == delta);
  }
#endif
  if ((g->hookmask & LUA_MASKCALL)) {
    int i;
    for (i = 0; i < missing; i++)  /* Add missing parameters. */
      setnilV(L->top++);
    callhook(L, LUA_HOOKCALL, -1);
    /* Preserve modifications of missing parameters by lua_setlocal(). */
    while (missing-- > 0 && tvisnil(L->top - 1))
      L->top--;
  }
#if LJ_HASJIT
out:
#endif
  op = bc_op(pc[-1]);  /* Get FUNC* op. */
#if LJ_HASJIT
  /* Use the non-hotcounting variants if JIT is off or while recording. */
  if ((!(J->flags & JIT_F_ON) || J->state != LJ_TRACE_IDLE) &&
      (op == BC_FUNCF || op == BC_FUNCV))
    op = (BCOp)((int)op+(int)BC_IFUNCF-(int)BC_FUNCF);
#endif
  ERRNO_RESTORE
  return makeasmfunc(lj_bc_ofs[op]);  /* Return static dispatch target. */
}