1 /*
2 ** ARM IR assembler (SSA IR -> machine code).
3 ** Copyright (C) 2005-2021 Mike Pall. See Copyright Notice in luajit.h
4 */
5 
6 /* -- Register allocator extensions --------------------------------------- */
7 
8 /* Allocate a register with a hint. */
ra_hintalloc(ASMState * as,IRRef ref,Reg hint,RegSet allow)9 static Reg ra_hintalloc(ASMState *as, IRRef ref, Reg hint, RegSet allow)
10 {
11   Reg r = IR(ref)->r;
12   if (ra_noreg(r)) {
13     if (!ra_hashint(r) && !iscrossref(as, ref))
14       ra_sethint(IR(ref)->r, hint);  /* Propagate register hint. */
15     r = ra_allocref(as, ref, allow);
16   }
17   ra_noweak(as, r);
18   return r;
19 }
20 
21 /* Allocate a scratch register pair. */
ra_scratchpair(ASMState * as,RegSet allow)22 static Reg ra_scratchpair(ASMState *as, RegSet allow)
23 {
24   RegSet pick1 = as->freeset & allow;
25   RegSet pick2 = pick1 & (pick1 >> 1) & RSET_GPREVEN;
26   Reg r;
27   if (pick2) {
28     r = rset_picktop(pick2);
29   } else {
30     RegSet pick = pick1 & (allow >> 1) & RSET_GPREVEN;
31     if (pick) {
32       r = rset_picktop(pick);
33       ra_restore(as, regcost_ref(as->cost[r+1]));
34     } else {
35       pick = pick1 & (allow << 1) & RSET_GPRODD;
36       if (pick) {
37 	r = ra_restore(as, regcost_ref(as->cost[rset_picktop(pick)-1]));
38       } else {
39 	r = ra_evict(as, allow & (allow >> 1) & RSET_GPREVEN);
40 	ra_restore(as, regcost_ref(as->cost[r+1]));
41       }
42     }
43   }
44   lj_assertA(rset_test(RSET_GPREVEN, r), "odd reg %d", r);
45   ra_modified(as, r);
46   ra_modified(as, r+1);
47   RA_DBGX((as, "scratchpair    $r $r", r, r+1));
48   return r;
49 }
50 
51 #if !LJ_SOFTFP
52 /* Allocate two source registers for three-operand instructions. */
ra_alloc2(ASMState * as,IRIns * ir,RegSet allow)53 static Reg ra_alloc2(ASMState *as, IRIns *ir, RegSet allow)
54 {
55   IRIns *irl = IR(ir->op1), *irr = IR(ir->op2);
56   Reg left = irl->r, right = irr->r;
57   if (ra_hasreg(left)) {
58     ra_noweak(as, left);
59     if (ra_noreg(right))
60       right = ra_allocref(as, ir->op2, rset_exclude(allow, left));
61     else
62       ra_noweak(as, right);
63   } else if (ra_hasreg(right)) {
64     ra_noweak(as, right);
65     left = ra_allocref(as, ir->op1, rset_exclude(allow, right));
66   } else if (ra_hashint(right)) {
67     right = ra_allocref(as, ir->op2, allow);
68     left = ra_alloc1(as, ir->op1, rset_exclude(allow, right));
69   } else {
70     left = ra_allocref(as, ir->op1, allow);
71     right = ra_alloc1(as, ir->op2, rset_exclude(allow, left));
72   }
73   return left | (right << 8);
74 }
75 #endif
76 
77 /* -- Guard handling ------------------------------------------------------ */
78 
79 /* Generate an exit stub group at the bottom of the reserved MCode memory. */
asm_exitstub_gen(ASMState * as,ExitNo group)80 static MCode *asm_exitstub_gen(ASMState *as, ExitNo group)
81 {
82   MCode *mxp = as->mcbot;
83   int i;
84   if (mxp + 4*4+4*EXITSTUBS_PER_GROUP >= as->mctop)
85     asm_mclimit(as);
86   /* str lr, [sp]; bl ->vm_exit_handler; .long DISPATCH_address, group. */
87   *mxp++ = ARMI_STR|ARMI_LS_P|ARMI_LS_U|ARMF_D(RID_LR)|ARMF_N(RID_SP);
88   *mxp = ARMI_BL|((((MCode *)(void *)lj_vm_exit_handler-mxp)-2)&0x00ffffffu);
89   mxp++;
90   *mxp++ = (MCode)i32ptr(J2GG(as->J)->dispatch);  /* DISPATCH address */
91   *mxp++ = group*EXITSTUBS_PER_GROUP;
92   for (i = 0; i < EXITSTUBS_PER_GROUP; i++)
93     *mxp++ = ARMI_B|((-6-i)&0x00ffffffu);
94   lj_mcode_sync(as->mcbot, mxp);
95   lj_mcode_commitbot(as->J, mxp);
96   as->mcbot = mxp;
97   as->mclim = as->mcbot + MCLIM_REDZONE;
98   return mxp - EXITSTUBS_PER_GROUP;
99 }
100 
101 /* Setup all needed exit stubs. */
asm_exitstub_setup(ASMState * as,ExitNo nexits)102 static void asm_exitstub_setup(ASMState *as, ExitNo nexits)
103 {
104   ExitNo i;
105   if (nexits >= EXITSTUBS_PER_GROUP*LJ_MAX_EXITSTUBGR)
106     lj_trace_err(as->J, LJ_TRERR_SNAPOV);
107   for (i = 0; i < (nexits+EXITSTUBS_PER_GROUP-1)/EXITSTUBS_PER_GROUP; i++)
108     if (as->J->exitstubgroup[i] == NULL)
109       as->J->exitstubgroup[i] = asm_exitstub_gen(as, i);
110 }
111 
112 /* Emit conditional branch to exit for guard. */
asm_guardcc(ASMState * as,ARMCC cc)113 static void asm_guardcc(ASMState *as, ARMCC cc)
114 {
115   MCode *target = exitstub_addr(as->J, as->snapno);
116   MCode *p = as->mcp;
117   if (LJ_UNLIKELY(p == as->invmcp)) {
118     as->loopinv = 1;
119     *p = ARMI_BL | ((target-p-2) & 0x00ffffffu);
120     emit_branch(as, ARMF_CC(ARMI_B, cc^1), p+1);
121     return;
122   }
123   emit_branch(as, ARMF_CC(ARMI_BL, cc), target);
124 }
125 
126 /* -- Operand fusion ------------------------------------------------------ */
127 
128 /* Limit linear search to this distance. Avoids O(n^2) behavior. */
129 #define CONFLICT_SEARCH_LIM	31
130 
131 /* Check if there's no conflicting instruction between curins and ref. */
noconflict(ASMState * as,IRRef ref,IROp conflict)132 static int noconflict(ASMState *as, IRRef ref, IROp conflict)
133 {
134   IRIns *ir = as->ir;
135   IRRef i = as->curins;
136   if (i > ref + CONFLICT_SEARCH_LIM)
137     return 0;  /* Give up, ref is too far away. */
138   while (--i > ref)
139     if (ir[i].o == conflict)
140       return 0;  /* Conflict found. */
141   return 1;  /* Ok, no conflict. */
142 }
143 
144 /* Fuse the array base of colocated arrays. */
asm_fuseabase(ASMState * as,IRRef ref)145 static int32_t asm_fuseabase(ASMState *as, IRRef ref)
146 {
147   IRIns *ir = IR(ref);
148   if (ir->o == IR_TNEW && ir->op1 <= LJ_MAX_COLOSIZE &&
149       !neverfuse(as) && noconflict(as, ref, IR_NEWREF))
150     return (int32_t)sizeof(GCtab);
151   return 0;
152 }
153 
154 /* Fuse array/hash/upvalue reference into register+offset operand. */
asm_fuseahuref(ASMState * as,IRRef ref,int32_t * ofsp,RegSet allow,int lim)155 static Reg asm_fuseahuref(ASMState *as, IRRef ref, int32_t *ofsp, RegSet allow,
156 			  int lim)
157 {
158   IRIns *ir = IR(ref);
159   if (ra_noreg(ir->r)) {
160     if (ir->o == IR_AREF) {
161       if (mayfuse(as, ref)) {
162 	if (irref_isk(ir->op2)) {
163 	  IRRef tab = IR(ir->op1)->op1;
164 	  int32_t ofs = asm_fuseabase(as, tab);
165 	  IRRef refa = ofs ? tab : ir->op1;
166 	  ofs += 8*IR(ir->op2)->i;
167 	  if (ofs > -lim && ofs < lim) {
168 	    *ofsp = ofs;
169 	    return ra_alloc1(as, refa, allow);
170 	  }
171 	}
172       }
173     } else if (ir->o == IR_HREFK) {
174       if (mayfuse(as, ref)) {
175 	int32_t ofs = (int32_t)(IR(ir->op2)->op2 * sizeof(Node));
176 	if (ofs < lim) {
177 	  *ofsp = ofs;
178 	  return ra_alloc1(as, ir->op1, allow);
179 	}
180       }
181     } else if (ir->o == IR_UREFC) {
182       if (irref_isk(ir->op1)) {
183 	GCfunc *fn = ir_kfunc(IR(ir->op1));
184 	int32_t ofs = i32ptr(&gcref(fn->l.uvptr[(ir->op2 >> 8)])->uv.tv);
185 	*ofsp = (ofs & 255);  /* Mask out less bits to allow LDRD. */
186 	return ra_allock(as, (ofs & ~255), allow);
187       }
188     } else if (ir->o == IR_TMPREF) {
189       *ofsp = 0;
190       return RID_SP;
191     }
192   }
193   *ofsp = 0;
194   return ra_alloc1(as, ref, allow);
195 }
196 
197 /* Fuse m operand into arithmetic/logic instructions. */
asm_fuseopm(ASMState * as,ARMIns ai,IRRef ref,RegSet allow)198 static uint32_t asm_fuseopm(ASMState *as, ARMIns ai, IRRef ref, RegSet allow)
199 {
200   IRIns *ir = IR(ref);
201   if (ra_hasreg(ir->r)) {
202     ra_noweak(as, ir->r);
203     return ARMF_M(ir->r);
204   } else if (irref_isk(ref)) {
205     uint32_t k = emit_isk12(ai, ir->i);
206     if (k)
207       return k;
208   } else if (mayfuse(as, ref)) {
209     if (ir->o >= IR_BSHL && ir->o <= IR_BROR) {
210       Reg m = ra_alloc1(as, ir->op1, allow);
211       ARMShift sh = ir->o == IR_BSHL ? ARMSH_LSL :
212 		    ir->o == IR_BSHR ? ARMSH_LSR :
213 		    ir->o == IR_BSAR ? ARMSH_ASR : ARMSH_ROR;
214       if (irref_isk(ir->op2)) {
215 	return m | ARMF_SH(sh, (IR(ir->op2)->i & 31));
216       } else {
217 	Reg s = ra_alloc1(as, ir->op2, rset_exclude(allow, m));
218 	return m | ARMF_RSH(sh, s);
219       }
220     } else if (ir->o == IR_ADD && ir->op1 == ir->op2) {
221       Reg m = ra_alloc1(as, ir->op1, allow);
222       return m | ARMF_SH(ARMSH_LSL, 1);
223     }
224   }
225   return ra_allocref(as, ref, allow);
226 }
227 
228 /* Fuse shifts into loads/stores. Only bother with BSHL 2 => lsl #2. */
asm_fuselsl2(ASMState * as,IRRef ref)229 static IRRef asm_fuselsl2(ASMState *as, IRRef ref)
230 {
231   IRIns *ir = IR(ref);
232   if (ra_noreg(ir->r) && mayfuse(as, ref) && ir->o == IR_BSHL &&
233       irref_isk(ir->op2) && IR(ir->op2)->i == 2)
234     return ir->op1;
235   return 0;  /* No fusion. */
236 }
237 
238 /* Fuse XLOAD/XSTORE reference into load/store operand. */
asm_fusexref(ASMState * as,ARMIns ai,Reg rd,IRRef ref,RegSet allow,int32_t ofs)239 static void asm_fusexref(ASMState *as, ARMIns ai, Reg rd, IRRef ref,
240 			 RegSet allow, int32_t ofs)
241 {
242   IRIns *ir = IR(ref);
243   Reg base;
244   if (ra_noreg(ir->r) && canfuse(as, ir)) {
245     int32_t lim = (!LJ_SOFTFP && (ai & 0x08000000)) ? 1024 :
246 		   (ai & 0x04000000) ? 4096 : 256;
247     if (ir->o == IR_ADD) {
248       int32_t ofs2;
249       if (irref_isk(ir->op2) &&
250 	  (ofs2 = ofs + IR(ir->op2)->i) > -lim && ofs2 < lim &&
251 	  (!(!LJ_SOFTFP && (ai & 0x08000000)) || !(ofs2 & 3))) {
252 	ofs = ofs2;
253 	ref = ir->op1;
254       } else if (ofs == 0 && !(!LJ_SOFTFP && (ai & 0x08000000))) {
255 	IRRef lref = ir->op1, rref = ir->op2;
256 	Reg rn, rm;
257 	if ((ai & 0x04000000)) {
258 	  IRRef sref = asm_fuselsl2(as, rref);
259 	  if (sref) {
260 	    rref = sref;
261 	    ai |= ARMF_SH(ARMSH_LSL, 2);
262 	  } else if ((sref = asm_fuselsl2(as, lref)) != 0) {
263 	    lref = rref;
264 	    rref = sref;
265 	    ai |= ARMF_SH(ARMSH_LSL, 2);
266 	  }
267 	}
268 	rn = ra_alloc1(as, lref, allow);
269 	rm = ra_alloc1(as, rref, rset_exclude(allow, rn));
270 	if ((ai & 0x04000000)) ai |= ARMI_LS_R;
271 	emit_dnm(as, ai|ARMI_LS_P|ARMI_LS_U, rd, rn, rm);
272 	return;
273       }
274     } else if (ir->o == IR_STRREF && !(!LJ_SOFTFP && (ai & 0x08000000))) {
275       lj_assertA(ofs == 0, "bad usage");
276       ofs = (int32_t)sizeof(GCstr);
277       if (irref_isk(ir->op2)) {
278 	ofs += IR(ir->op2)->i;
279 	ref = ir->op1;
280       } else if (irref_isk(ir->op1)) {
281 	ofs += IR(ir->op1)->i;
282 	ref = ir->op2;
283       } else {
284 	/* NYI: Fuse ADD with constant. */
285 	Reg rn = ra_alloc1(as, ir->op1, allow);
286 	uint32_t m = asm_fuseopm(as, 0, ir->op2, rset_exclude(allow, rn));
287 	if ((ai & 0x04000000))
288 	  emit_lso(as, ai, rd, rd, ofs);
289 	else
290 	  emit_lsox(as, ai, rd, rd, ofs);
291 	emit_dn(as, ARMI_ADD^m, rd, rn);
292 	return;
293       }
294       if (ofs <= -lim || ofs >= lim) {
295 	Reg rn = ra_alloc1(as, ref, allow);
296 	Reg rm = ra_allock(as, ofs, rset_exclude(allow, rn));
297 	if ((ai & 0x04000000)) ai |= ARMI_LS_R;
298 	emit_dnm(as, ai|ARMI_LS_P|ARMI_LS_U, rd, rn, rm);
299 	return;
300       }
301     }
302   }
303   base = ra_alloc1(as, ref, allow);
304 #if !LJ_SOFTFP
305   if ((ai & 0x08000000))
306     emit_vlso(as, ai, rd, base, ofs);
307   else
308 #endif
309   if ((ai & 0x04000000))
310     emit_lso(as, ai, rd, base, ofs);
311   else
312     emit_lsox(as, ai, rd, base, ofs);
313 }
314 
315 #if !LJ_SOFTFP
316 /* Fuse to multiply-add/sub instruction. */
asm_fusemadd(ASMState * as,IRIns * ir,ARMIns ai,ARMIns air)317 static int asm_fusemadd(ASMState *as, IRIns *ir, ARMIns ai, ARMIns air)
318 {
319   IRRef lref = ir->op1, rref = ir->op2;
320   IRIns *irm;
321   if (lref != rref &&
322       ((mayfuse(as, lref) && (irm = IR(lref), irm->o == IR_MUL) &&
323 	ra_noreg(irm->r)) ||
324        (mayfuse(as, rref) && (irm = IR(rref), irm->o == IR_MUL) &&
325 	(rref = lref, ai = air, ra_noreg(irm->r))))) {
326     Reg dest = ra_dest(as, ir, RSET_FPR);
327     Reg add = ra_hintalloc(as, rref, dest, RSET_FPR);
328     Reg right, left = ra_alloc2(as, irm,
329 			rset_exclude(rset_exclude(RSET_FPR, dest), add));
330     right = (left >> 8); left &= 255;
331     emit_dnm(as, ai, (dest & 15), (left & 15), (right & 15));
332     if (dest != add) emit_dm(as, ARMI_VMOV_D, (dest & 15), (add & 15));
333     return 1;
334   }
335   return 0;
336 }
337 #endif
338 
339 /* -- Calls --------------------------------------------------------------- */
340 
341 /* Generate a call to a C function. */
asm_gencall(ASMState * as,const CCallInfo * ci,IRRef * args)342 static void asm_gencall(ASMState *as, const CCallInfo *ci, IRRef *args)
343 {
344   uint32_t n, nargs = CCI_XNARGS(ci);
345   int32_t ofs = 0;
346 #if LJ_SOFTFP
347   Reg gpr = REGARG_FIRSTGPR;
348 #else
349   Reg gpr, fpr = REGARG_FIRSTFPR, fprodd = 0;
350 #endif
351   if ((void *)ci->func)
352     emit_call(as, (void *)ci->func);
353 #if !LJ_SOFTFP
354   for (gpr = REGARG_FIRSTGPR; gpr <= REGARG_LASTGPR; gpr++)
355     as->cost[gpr] = REGCOST(~0u, ASMREF_L);
356   gpr = REGARG_FIRSTGPR;
357 #endif
358   for (n = 0; n < nargs; n++) {  /* Setup args. */
359     IRRef ref = args[n];
360     IRIns *ir = IR(ref);
361 #if !LJ_SOFTFP
362     if (ref && irt_isfp(ir->t)) {
363       RegSet of = as->freeset;
364       Reg src;
365       if (!LJ_ABI_SOFTFP && !(ci->flags & CCI_VARARG)) {
366 	if (irt_isnum(ir->t)) {
367 	  if (fpr <= REGARG_LASTFPR) {
368 	    ra_leftov(as, fpr, ref);
369 	    fpr++;
370 	    continue;
371 	  }
372 	} else if (fprodd) {  /* Ick. */
373 	  src = ra_alloc1(as, ref, RSET_FPR);
374 	  emit_dm(as, ARMI_VMOV_S, (fprodd & 15), (src & 15) | 0x00400000);
375 	  fprodd = 0;
376 	  continue;
377 	} else if (fpr <= REGARG_LASTFPR) {
378 	  ra_leftov(as, fpr, ref);
379 	  fprodd = fpr++;
380 	  continue;
381 	}
382 	/* Workaround to protect argument GPRs from being used for remat. */
383 	as->freeset &= ~RSET_RANGE(REGARG_FIRSTGPR, REGARG_LASTGPR+1);
384 	src = ra_alloc1(as, ref, RSET_FPR);  /* May alloc GPR to remat FPR. */
385 	as->freeset |= (of & RSET_RANGE(REGARG_FIRSTGPR, REGARG_LASTGPR+1));
386 	fprodd = 0;
387 	goto stackfp;
388       }
389       /* Workaround to protect argument GPRs from being used for remat. */
390       as->freeset &= ~RSET_RANGE(REGARG_FIRSTGPR, REGARG_LASTGPR+1);
391       src = ra_alloc1(as, ref, RSET_FPR);  /* May alloc GPR to remat FPR. */
392       as->freeset |= (of & RSET_RANGE(REGARG_FIRSTGPR, REGARG_LASTGPR+1));
393       if (irt_isnum(ir->t)) gpr = (gpr+1) & ~1u;
394       if (gpr <= REGARG_LASTGPR) {
395 	lj_assertA(rset_test(as->freeset, gpr),
396 		   "reg %d not free", gpr);  /* Must have been evicted. */
397 	if (irt_isnum(ir->t)) {
398 	  lj_assertA(rset_test(as->freeset, gpr+1),
399 		     "reg %d not free", gpr+1);  /* Ditto. */
400 	  emit_dnm(as, ARMI_VMOV_RR_D, gpr, gpr+1, (src & 15));
401 	  gpr += 2;
402 	} else {
403 	  emit_dn(as, ARMI_VMOV_R_S, gpr, (src & 15));
404 	  gpr++;
405 	}
406       } else {
407       stackfp:
408 	if (irt_isnum(ir->t)) ofs = (ofs + 4) & ~4;
409 	emit_spstore(as, ir, src, ofs);
410 	ofs += irt_isnum(ir->t) ? 8 : 4;
411       }
412     } else
413 #endif
414     {
415       if (gpr <= REGARG_LASTGPR) {
416 	lj_assertA(rset_test(as->freeset, gpr),
417 		   "reg %d not free", gpr);  /* Must have been evicted. */
418 	if (ref) ra_leftov(as, gpr, ref);
419 	gpr++;
420       } else {
421 	if (ref) {
422 	  Reg r = ra_alloc1(as, ref, RSET_GPR);
423 	  emit_spstore(as, ir, r, ofs);
424 	}
425 	ofs += 4;
426       }
427     }
428   }
429 }
430 
431 /* Setup result reg/sp for call. Evict scratch regs. */
asm_setupresult(ASMState * as,IRIns * ir,const CCallInfo * ci)432 static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
433 {
434   RegSet drop = RSET_SCRATCH;
435   int hiop = ((ir+1)->o == IR_HIOP && !irt_isnil((ir+1)->t));
436   if (ra_hasreg(ir->r))
437     rset_clear(drop, ir->r);  /* Dest reg handled below. */
438   if (hiop && ra_hasreg((ir+1)->r))
439     rset_clear(drop, (ir+1)->r);  /* Dest reg handled below. */
440   ra_evictset(as, drop);  /* Evictions must be performed first. */
441   if (ra_used(ir)) {
442     lj_assertA(!irt_ispri(ir->t), "PRI dest");
443     if (!LJ_SOFTFP && irt_isfp(ir->t)) {
444       if (LJ_ABI_SOFTFP || (ci->flags & (CCI_CASTU64|CCI_VARARG))) {
445 	Reg dest = (ra_dest(as, ir, RSET_FPR) & 15);
446 	if (irt_isnum(ir->t))
447 	  emit_dnm(as, ARMI_VMOV_D_RR, RID_RETLO, RID_RETHI, dest);
448 	else
449 	  emit_dn(as, ARMI_VMOV_S_R, RID_RET, dest);
450       } else {
451 	ra_destreg(as, ir, RID_FPRET);
452       }
453     } else if (hiop) {
454       ra_destpair(as, ir);
455     } else {
456       ra_destreg(as, ir, RID_RET);
457     }
458   }
459   UNUSED(ci);
460 }
461 
asm_callx(ASMState * as,IRIns * ir)462 static void asm_callx(ASMState *as, IRIns *ir)
463 {
464   IRRef args[CCI_NARGS_MAX*2];
465   CCallInfo ci;
466   IRRef func;
467   IRIns *irf;
468   ci.flags = asm_callx_flags(as, ir);
469   asm_collectargs(as, ir, &ci, args);
470   asm_setupresult(as, ir, &ci);
471   func = ir->op2; irf = IR(func);
472   if (irf->o == IR_CARG) { func = irf->op1; irf = IR(func); }
473   if (irref_isk(func)) {  /* Call to constant address. */
474     ci.func = (ASMFunction)(void *)(irf->i);
475   } else {  /* Need a non-argument register for indirect calls. */
476     Reg freg = ra_alloc1(as, func, RSET_RANGE(RID_R4, RID_R12+1));
477     emit_m(as, ARMI_BLXr, freg);
478     ci.func = (ASMFunction)(void *)0;
479   }
480   asm_gencall(as, &ci, args);
481 }
482 
483 /* -- Returns ------------------------------------------------------------- */
484 
485 /* Return to lower frame. Guard that it goes to the right spot. */
asm_retf(ASMState * as,IRIns * ir)486 static void asm_retf(ASMState *as, IRIns *ir)
487 {
488   Reg base = ra_alloc1(as, REF_BASE, RSET_GPR);
489   void *pc = ir_kptr(IR(ir->op2));
490   int32_t delta = 1+LJ_FR2+bc_a(*((const BCIns *)pc - 1));
491   as->topslot -= (BCReg)delta;
492   if ((int32_t)as->topslot < 0) as->topslot = 0;
493   irt_setmark(IR(REF_BASE)->t);  /* Children must not coalesce with BASE reg. */
494   /* Need to force a spill on REF_BASE now to update the stack slot. */
495   emit_lso(as, ARMI_STR, base, RID_SP, ra_spill(as, IR(REF_BASE)));
496   emit_setgl(as, base, jit_base);
497   emit_addptr(as, base, -8*delta);
498   asm_guardcc(as, CC_NE);
499   emit_nm(as, ARMI_CMP, RID_TMP,
500 	  ra_allock(as, i32ptr(pc), rset_exclude(RSET_GPR, base)));
501   emit_lso(as, ARMI_LDR, RID_TMP, base, -4);
502 }
503 
504 /* -- Buffer operations --------------------------------------------------- */
505 
506 #if LJ_HASBUFFER
asm_bufhdr_write(ASMState * as,Reg sb)507 static void asm_bufhdr_write(ASMState *as, Reg sb)
508 {
509   Reg tmp = ra_scratch(as, rset_exclude(RSET_GPR, sb));
510   IRIns irgc;
511   int32_t addr = i32ptr((void *)&J2G(as->J)->cur_L);
512   irgc.ot = IRT(0, IRT_PGC);  /* GC type. */
513   emit_storeofs(as, &irgc, RID_TMP, sb, offsetof(SBuf, L));
514   if ((as->flags & JIT_F_ARMV6T2)) {
515     emit_dnm(as, ARMI_BFI, RID_TMP, lj_fls(SBUF_MASK_FLAG), tmp);
516   } else {
517     emit_dnm(as, ARMI_ORR, RID_TMP, RID_TMP, tmp);
518     emit_dn(as, ARMI_AND|ARMI_K12|SBUF_MASK_FLAG, tmp, tmp);
519   }
520   emit_lso(as, ARMI_LDR, RID_TMP,
521 	   ra_allock(as, (addr & ~4095),
522 		     rset_exclude(rset_exclude(RSET_GPR, sb), tmp)),
523 	   (addr & 4095));
524   emit_loadofs(as, &irgc, tmp, sb, offsetof(SBuf, L));
525 }
526 #endif
527 
528 /* -- Type conversions ---------------------------------------------------- */
529 
530 #if !LJ_SOFTFP
asm_tointg(ASMState * as,IRIns * ir,Reg left)531 static void asm_tointg(ASMState *as, IRIns *ir, Reg left)
532 {
533   Reg tmp = ra_scratch(as, rset_exclude(RSET_FPR, left));
534   Reg dest = ra_dest(as, ir, RSET_GPR);
535   asm_guardcc(as, CC_NE);
536   emit_d(as, ARMI_VMRS, 0);
537   emit_dm(as, ARMI_VCMP_D, (tmp & 15), (left & 15));
538   emit_dm(as, ARMI_VCVT_F64_S32, (tmp & 15), (tmp & 15));
539   emit_dn(as, ARMI_VMOV_R_S, dest, (tmp & 15));
540   emit_dm(as, ARMI_VCVT_S32_F64, (tmp & 15), (left & 15));
541 }
542 
asm_tobit(ASMState * as,IRIns * ir)543 static void asm_tobit(ASMState *as, IRIns *ir)
544 {
545   RegSet allow = RSET_FPR;
546   Reg left = ra_alloc1(as, ir->op1, allow);
547   Reg right = ra_alloc1(as, ir->op2, rset_clear(allow, left));
548   Reg tmp = ra_scratch(as, rset_clear(allow, right));
549   Reg dest = ra_dest(as, ir, RSET_GPR);
550   emit_dn(as, ARMI_VMOV_R_S, dest, (tmp & 15));
551   emit_dnm(as, ARMI_VADD_D, (tmp & 15), (left & 15), (right & 15));
552 }
553 #endif
554 
asm_conv(ASMState * as,IRIns * ir)555 static void asm_conv(ASMState *as, IRIns *ir)
556 {
557   IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
558 #if !LJ_SOFTFP
559   int stfp = (st == IRT_NUM || st == IRT_FLOAT);
560 #endif
561   IRRef lref = ir->op1;
562   /* 64 bit integer conversions are handled by SPLIT. */
563   lj_assertA(!irt_isint64(ir->t) && !(st == IRT_I64 || st == IRT_U64),
564 	     "IR %04d has unsplit 64 bit type",
565 	     (int)(ir - as->ir) - REF_BIAS);
566 #if LJ_SOFTFP
567   /* FP conversions are handled by SPLIT. */
568   lj_assertA(!irt_isfp(ir->t) && !(st == IRT_NUM || st == IRT_FLOAT),
569 	     "IR %04d has FP type",
570 	     (int)(ir - as->ir) - REF_BIAS);
571   /* Can't check for same types: SPLIT uses CONV int.int + BXOR for sfp NEG. */
572 #else
573   lj_assertA(irt_type(ir->t) != st, "inconsistent types for CONV");
574   if (irt_isfp(ir->t)) {
575     Reg dest = ra_dest(as, ir, RSET_FPR);
576     if (stfp) {  /* FP to FP conversion. */
577       emit_dm(as, st == IRT_NUM ? ARMI_VCVT_F32_F64 : ARMI_VCVT_F64_F32,
578 	      (dest & 15), (ra_alloc1(as, lref, RSET_FPR) & 15));
579     } else {  /* Integer to FP conversion. */
580       Reg left = ra_alloc1(as, lref, RSET_GPR);
581       ARMIns ai = irt_isfloat(ir->t) ?
582 	(st == IRT_INT ? ARMI_VCVT_F32_S32 : ARMI_VCVT_F32_U32) :
583 	(st == IRT_INT ? ARMI_VCVT_F64_S32 : ARMI_VCVT_F64_U32);
584       emit_dm(as, ai, (dest & 15), (dest & 15));
585       emit_dn(as, ARMI_VMOV_S_R, left, (dest & 15));
586     }
587   } else if (stfp) {  /* FP to integer conversion. */
588     if (irt_isguard(ir->t)) {
589       /* Checked conversions are only supported from number to int. */
590       lj_assertA(irt_isint(ir->t) && st == IRT_NUM,
591 		 "bad type for checked CONV");
592       asm_tointg(as, ir, ra_alloc1(as, lref, RSET_FPR));
593     } else {
594       Reg left = ra_alloc1(as, lref, RSET_FPR);
595       Reg tmp = ra_scratch(as, rset_exclude(RSET_FPR, left));
596       Reg dest = ra_dest(as, ir, RSET_GPR);
597       ARMIns ai;
598       emit_dn(as, ARMI_VMOV_R_S, dest, (tmp & 15));
599       ai = irt_isint(ir->t) ?
600 	(st == IRT_NUM ? ARMI_VCVT_S32_F64 : ARMI_VCVT_S32_F32) :
601 	(st == IRT_NUM ? ARMI_VCVT_U32_F64 : ARMI_VCVT_U32_F32);
602       emit_dm(as, ai, (tmp & 15), (left & 15));
603     }
604   } else
605 #endif
606   {
607     Reg dest = ra_dest(as, ir, RSET_GPR);
608     if (st >= IRT_I8 && st <= IRT_U16) {  /* Extend to 32 bit integer. */
609       Reg left = ra_alloc1(as, lref, RSET_GPR);
610       lj_assertA(irt_isint(ir->t) || irt_isu32(ir->t), "bad type for CONV EXT");
611       if ((as->flags & JIT_F_ARMV6)) {
612 	ARMIns ai = st == IRT_I8 ? ARMI_SXTB :
613 		    st == IRT_U8 ? ARMI_UXTB :
614 		    st == IRT_I16 ? ARMI_SXTH : ARMI_UXTH;
615 	emit_dm(as, ai, dest, left);
616       } else if (st == IRT_U8) {
617 	emit_dn(as, ARMI_AND|ARMI_K12|255, dest, left);
618       } else {
619 	uint32_t shift = st == IRT_I8 ? 24 : 16;
620 	ARMShift sh = st == IRT_U16 ? ARMSH_LSR : ARMSH_ASR;
621 	emit_dm(as, ARMI_MOV|ARMF_SH(sh, shift), dest, RID_TMP);
622 	emit_dm(as, ARMI_MOV|ARMF_SH(ARMSH_LSL, shift), RID_TMP, left);
623       }
624     } else {  /* Handle 32/32 bit no-op (cast). */
625       ra_leftov(as, dest, lref);  /* Do nothing, but may need to move regs. */
626     }
627   }
628 }
629 
asm_strto(ASMState * as,IRIns * ir)630 static void asm_strto(ASMState *as, IRIns *ir)
631 {
632   const CCallInfo *ci = &lj_ir_callinfo[IRCALL_lj_strscan_num];
633   IRRef args[2];
634   Reg rlo = 0, rhi = 0, tmp;
635   int destused = ra_used(ir);
636   int32_t ofs = 0;
637   ra_evictset(as, RSET_SCRATCH);
638 #if LJ_SOFTFP
639   if (destused) {
640     if (ra_hasspill(ir->s) && ra_hasspill((ir+1)->s) &&
641 	(ir->s & 1) == 0 && ir->s + 1 == (ir+1)->s) {
642       int i;
643       for (i = 0; i < 2; i++) {
644 	Reg r = (ir+i)->r;
645 	if (ra_hasreg(r)) {
646 	  ra_free(as, r);
647 	  ra_modified(as, r);
648 	  emit_spload(as, ir+i, r, sps_scale((ir+i)->s));
649 	}
650       }
651       ofs = sps_scale(ir->s);
652       destused = 0;
653     } else {
654       rhi = ra_dest(as, ir+1, RSET_GPR);
655       rlo = ra_dest(as, ir, rset_exclude(RSET_GPR, rhi));
656     }
657   }
658   asm_guardcc(as, CC_EQ);
659   if (destused) {
660     emit_lso(as, ARMI_LDR, rhi, RID_SP, 4);
661     emit_lso(as, ARMI_LDR, rlo, RID_SP, 0);
662   }
663 #else
664   UNUSED(rhi);
665   if (destused) {
666     if (ra_hasspill(ir->s)) {
667       ofs = sps_scale(ir->s);
668       destused = 0;
669       if (ra_hasreg(ir->r)) {
670 	ra_free(as, ir->r);
671 	ra_modified(as, ir->r);
672 	emit_spload(as, ir, ir->r, ofs);
673       }
674     } else {
675       rlo = ra_dest(as, ir, RSET_FPR);
676     }
677   }
678   asm_guardcc(as, CC_EQ);
679   if (destused)
680     emit_vlso(as, ARMI_VLDR_D, rlo, RID_SP, 0);
681 #endif
682   emit_n(as, ARMI_CMP|ARMI_K12|0, RID_RET);  /* Test return status. */
683   args[0] = ir->op1;      /* GCstr *str */
684   args[1] = ASMREF_TMP1;  /* TValue *n  */
685   asm_gencall(as, ci, args);
686   tmp = ra_releasetmp(as, ASMREF_TMP1);
687   if (ofs == 0)
688     emit_dm(as, ARMI_MOV, tmp, RID_SP);
689   else
690     emit_opk(as, ARMI_ADD, tmp, RID_SP, ofs, RSET_GPR);
691 }
692 
693 /* -- Memory references --------------------------------------------------- */
694 
695 /* Get pointer to TValue. */
asm_tvptr(ASMState * as,Reg dest,IRRef ref,MSize mode)696 static void asm_tvptr(ASMState *as, Reg dest, IRRef ref, MSize mode)
697 {
698   if ((mode & IRTMPREF_IN1)) {
699     IRIns *ir = IR(ref);
700     if (irt_isnum(ir->t)) {
701       if ((mode & IRTMPREF_OUT1)) {
702 #if LJ_SOFTFP
703 	lj_assertA(irref_isk(ref), "unsplit FP op");
704 	emit_dm(as, ARMI_MOV, dest, RID_SP);
705 	emit_lso(as, ARMI_STR,
706 		 ra_allock(as, (int32_t)ir_knum(ir)->u32.lo, RSET_GPR),
707 		 RID_SP, 0);
708 	emit_lso(as, ARMI_STR,
709 		 ra_allock(as, (int32_t)ir_knum(ir)->u32.hi, RSET_GPR),
710 		 RID_SP, 4);
711 #else
712 	Reg src = ra_alloc1(as, ref, RSET_FPR);
713 	emit_dm(as, ARMI_MOV, dest, RID_SP);
714 	emit_vlso(as, ARMI_VSTR_D, src, RID_SP, 0);
715 #endif
716       } else if (irref_isk(ref)) {
717 	/* Use the number constant itself as a TValue. */
718 	ra_allockreg(as, i32ptr(ir_knum(ir)), dest);
719       } else {
720 #if LJ_SOFTFP
721 	lj_assertA(0, "unsplit FP op");
722 #else
723 	/* Otherwise force a spill and use the spill slot. */
724 	emit_opk(as, ARMI_ADD, dest, RID_SP, ra_spill(as, ir), RSET_GPR);
725 #endif
726       }
727     } else {
728       /* Otherwise use [sp] and [sp+4] to hold the TValue.
729       ** This assumes the following call has max. 4 args.
730       */
731       Reg type;
732       emit_dm(as, ARMI_MOV, dest, RID_SP);
733       if (!irt_ispri(ir->t)) {
734 	Reg src = ra_alloc1(as, ref, RSET_GPR);
735 	emit_lso(as, ARMI_STR, src, RID_SP, 0);
736       }
737       if (LJ_SOFTFP && (ir+1)->o == IR_HIOP && !irt_isnil((ir+1)->t))
738 	type = ra_alloc1(as, ref+1, RSET_GPR);
739       else
740 	type = ra_allock(as, irt_toitype(ir->t), RSET_GPR);
741       emit_lso(as, ARMI_STR, type, RID_SP, 4);
742     }
743   } else {
744     emit_dm(as, ARMI_MOV, dest, RID_SP);
745   }
746 }
747 
asm_aref(ASMState * as,IRIns * ir)748 static void asm_aref(ASMState *as, IRIns *ir)
749 {
750   Reg dest = ra_dest(as, ir, RSET_GPR);
751   Reg idx, base;
752   if (irref_isk(ir->op2)) {
753     IRRef tab = IR(ir->op1)->op1;
754     int32_t ofs = asm_fuseabase(as, tab);
755     IRRef refa = ofs ? tab : ir->op1;
756     uint32_t k = emit_isk12(ARMI_ADD, ofs + 8*IR(ir->op2)->i);
757     if (k) {
758       base = ra_alloc1(as, refa, RSET_GPR);
759       emit_dn(as, ARMI_ADD^k, dest, base);
760       return;
761     }
762   }
763   base = ra_alloc1(as, ir->op1, RSET_GPR);
764   idx = ra_alloc1(as, ir->op2, rset_exclude(RSET_GPR, base));
765   emit_dnm(as, ARMI_ADD|ARMF_SH(ARMSH_LSL, 3), dest, base, idx);
766 }
767 
768 /* Inlined hash lookup. Specialized for key type and for const keys.
769 ** The equivalent C code is:
770 **   Node *n = hashkey(t, key);
771 **   do {
772 **     if (lj_obj_equal(&n->key, key)) return &n->val;
773 **   } while ((n = nextnode(n)));
774 **   return niltv(L);
775 */
asm_href(ASMState * as,IRIns * ir,IROp merge)776 static void asm_href(ASMState *as, IRIns *ir, IROp merge)
777 {
778   RegSet allow = RSET_GPR;
779   int destused = ra_used(ir);
780   Reg dest = ra_dest(as, ir, allow);
781   Reg tab = ra_alloc1(as, ir->op1, rset_clear(allow, dest));
782   Reg key = 0, keyhi = 0, keynumhi = RID_NONE, tmp = RID_TMP;
783   IRRef refkey = ir->op2;
784   IRIns *irkey = IR(refkey);
785   IRType1 kt = irkey->t;
786   int32_t k = 0, khi = emit_isk12(ARMI_CMP, irt_toitype(kt));
787   uint32_t khash;
788   MCLabel l_end, l_loop;
789   rset_clear(allow, tab);
790   if (!irref_isk(refkey) || irt_isstr(kt)) {
791 #if LJ_SOFTFP
792     key = ra_alloc1(as, refkey, allow);
793     rset_clear(allow, key);
794     if (irkey[1].o == IR_HIOP) {
795       if (ra_hasreg((irkey+1)->r)) {
796 	keynumhi = (irkey+1)->r;
797 	keyhi = RID_TMP;
798 	ra_noweak(as, keynumhi);
799       } else {
800 	keyhi = keynumhi = ra_allocref(as, refkey+1, allow);
801       }
802       rset_clear(allow, keynumhi);
803       khi = 0;
804     }
805 #else
806     if (irt_isnum(kt)) {
807       key = ra_scratch(as, allow);
808       rset_clear(allow, key);
809       keyhi = keynumhi = ra_scratch(as, allow);
810       rset_clear(allow, keyhi);
811       khi = 0;
812     } else {
813       key = ra_alloc1(as, refkey, allow);
814       rset_clear(allow, key);
815     }
816 #endif
817   } else if (irt_isnum(kt)) {
818     int32_t val = (int32_t)ir_knum(irkey)->u32.lo;
819     k = emit_isk12(ARMI_CMP, val);
820     if (!k) {
821       key = ra_allock(as, val, allow);
822       rset_clear(allow, key);
823     }
824     val = (int32_t)ir_knum(irkey)->u32.hi;
825     khi = emit_isk12(ARMI_CMP, val);
826     if (!khi) {
827       keyhi = ra_allock(as, val, allow);
828       rset_clear(allow, keyhi);
829     }
830   } else if (!irt_ispri(kt)) {
831     k = emit_isk12(ARMI_CMP, irkey->i);
832     if (!k) {
833       key = ra_alloc1(as, refkey, allow);
834       rset_clear(allow, key);
835     }
836   }
837   if (!irt_ispri(kt))
838     tmp = ra_scratchpair(as, allow);
839 
840   /* Key not found in chain: jump to exit (if merged) or load niltv. */
841   l_end = emit_label(as);
842   as->invmcp = NULL;
843   if (merge == IR_NE)
844     asm_guardcc(as, CC_AL);
845   else if (destused)
846     emit_loada(as, dest, niltvg(J2G(as->J)));
847 
848   /* Follow hash chain until the end. */
849   l_loop = --as->mcp;
850   emit_n(as, ARMI_CMP|ARMI_K12|0, dest);
851   emit_lso(as, ARMI_LDR, dest, dest, (int32_t)offsetof(Node, next));
852 
853   /* Type and value comparison. */
854   if (merge == IR_EQ)
855     asm_guardcc(as, CC_EQ);
856   else
857     emit_branch(as, ARMF_CC(ARMI_B, CC_EQ), l_end);
858   if (!irt_ispri(kt)) {
859     emit_nm(as, ARMF_CC(ARMI_CMP, CC_EQ)^k, tmp, key);
860     emit_nm(as, ARMI_CMP^khi, tmp+1, keyhi);
861     emit_lsox(as, ARMI_LDRD, tmp, dest, (int32_t)offsetof(Node, key));
862   } else {
863     emit_n(as, ARMI_CMP^khi, tmp);
864     emit_lso(as, ARMI_LDR, tmp, dest, (int32_t)offsetof(Node, key.it));
865   }
866   *l_loop = ARMF_CC(ARMI_B, CC_NE) | ((as->mcp-l_loop-2) & 0x00ffffffu);
867 
868   /* Load main position relative to tab->node into dest. */
869   khash = irref_isk(refkey) ? ir_khash(as, irkey) : 1;
870   if (khash == 0) {
871     emit_lso(as, ARMI_LDR, dest, tab, (int32_t)offsetof(GCtab, node));
872   } else {
873     emit_dnm(as, ARMI_ADD|ARMF_SH(ARMSH_LSL, 3), dest, dest, tmp);
874     emit_dnm(as, ARMI_ADD|ARMF_SH(ARMSH_LSL, 1), tmp, tmp, tmp);
875     if (irt_isstr(kt)) {  /* Fetch of str->sid is cheaper than ra_allock. */
876       emit_dnm(as, ARMI_AND, tmp, tmp+1, RID_TMP);
877       emit_lso(as, ARMI_LDR, dest, tab, (int32_t)offsetof(GCtab, node));
878       emit_lso(as, ARMI_LDR, tmp+1, key, (int32_t)offsetof(GCstr, sid));
879       emit_lso(as, ARMI_LDR, RID_TMP, tab, (int32_t)offsetof(GCtab, hmask));
880     } else if (irref_isk(refkey)) {
881       emit_opk(as, ARMI_AND, tmp, RID_TMP, (int32_t)khash,
882 	       rset_exclude(rset_exclude(RSET_GPR, tab), dest));
883       emit_lso(as, ARMI_LDR, dest, tab, (int32_t)offsetof(GCtab, node));
884       emit_lso(as, ARMI_LDR, RID_TMP, tab, (int32_t)offsetof(GCtab, hmask));
885     } else {  /* Must match with hash*() in lj_tab.c. */
886       if (ra_hasreg(keynumhi)) {  /* Canonicalize +-0.0 to 0.0. */
887 	if (keyhi == RID_TMP)
888 	  emit_dm(as, ARMF_CC(ARMI_MOV, CC_NE), keyhi, keynumhi);
889 	emit_d(as, ARMF_CC(ARMI_MOV, CC_EQ)|ARMI_K12|0, keyhi);
890       }
891       emit_dnm(as, ARMI_AND, tmp, tmp, RID_TMP);
892       emit_dnm(as, ARMI_SUB|ARMF_SH(ARMSH_ROR, 32-HASH_ROT3), tmp, tmp, tmp+1);
893       emit_lso(as, ARMI_LDR, dest, tab, (int32_t)offsetof(GCtab, node));
894       emit_dnm(as, ARMI_EOR|ARMF_SH(ARMSH_ROR, 32-((HASH_ROT2+HASH_ROT1)&31)),
895 	       tmp, tmp+1, tmp);
896       emit_lso(as, ARMI_LDR, RID_TMP, tab, (int32_t)offsetof(GCtab, hmask));
897       emit_dnm(as, ARMI_SUB|ARMF_SH(ARMSH_ROR, 32-HASH_ROT1), tmp+1, tmp+1, tmp);
898       if (ra_hasreg(keynumhi)) {
899 	emit_dnm(as, ARMI_EOR, tmp+1, tmp, key);
900 	emit_dnm(as, ARMI_ORR|ARMI_S, RID_TMP, tmp, key);  /* Test for +-0.0. */
901 	emit_dnm(as, ARMI_ADD, tmp, keynumhi, keynumhi);
902 #if !LJ_SOFTFP
903 	emit_dnm(as, ARMI_VMOV_RR_D, key, keynumhi,
904 		 (ra_alloc1(as, refkey, RSET_FPR) & 15));
905 #endif
906       } else {
907 	emit_dnm(as, ARMI_EOR, tmp+1, tmp, key);
908 	emit_opk(as, ARMI_ADD, tmp, key, (int32_t)HASH_BIAS,
909 		 rset_exclude(rset_exclude(RSET_GPR, tab), key));
910       }
911     }
912   }
913 }
914 
asm_hrefk(ASMState * as,IRIns * ir)915 static void asm_hrefk(ASMState *as, IRIns *ir)
916 {
917   IRIns *kslot = IR(ir->op2);
918   IRIns *irkey = IR(kslot->op1);
919   int32_t ofs = (int32_t)(kslot->op2 * sizeof(Node));
920   int32_t kofs = ofs + (int32_t)offsetof(Node, key);
921   Reg dest = (ra_used(ir) || ofs > 4095) ? ra_dest(as, ir, RSET_GPR) : RID_NONE;
922   Reg node = ra_alloc1(as, ir->op1, RSET_GPR);
923   Reg key = RID_NONE, type = RID_TMP, idx = node;
924   RegSet allow = rset_exclude(RSET_GPR, node);
925   lj_assertA(ofs % sizeof(Node) == 0, "unaligned HREFK slot");
926   if (ofs > 4095) {
927     idx = dest;
928     rset_clear(allow, dest);
929     kofs = (int32_t)offsetof(Node, key);
930   } else if (ra_hasreg(dest)) {
931     emit_opk(as, ARMI_ADD, dest, node, ofs, allow);
932   }
933   asm_guardcc(as, CC_NE);
934   if (!irt_ispri(irkey->t)) {
935     RegSet even = (as->freeset & allow);
936     even = even & (even >> 1) & RSET_GPREVEN;
937     if (even) {
938       key = ra_scratch(as, even);
939       if (rset_test(as->freeset, key+1)) {
940 	type = key+1;
941 	ra_modified(as, type);
942       }
943     } else {
944       key = ra_scratch(as, allow);
945     }
946     rset_clear(allow, key);
947   }
948   rset_clear(allow, type);
949   if (irt_isnum(irkey->t)) {
950     emit_opk(as, ARMF_CC(ARMI_CMP, CC_EQ), 0, type,
951 	     (int32_t)ir_knum(irkey)->u32.hi, allow);
952     emit_opk(as, ARMI_CMP, 0, key,
953 	     (int32_t)ir_knum(irkey)->u32.lo, allow);
954   } else {
955     if (ra_hasreg(key))
956       emit_opk(as, ARMF_CC(ARMI_CMP, CC_EQ), 0, key, irkey->i, allow);
957     emit_n(as, ARMI_CMN|ARMI_K12|-irt_toitype(irkey->t), type);
958   }
959   emit_lso(as, ARMI_LDR, type, idx, kofs+4);
960   if (ra_hasreg(key)) emit_lso(as, ARMI_LDR, key, idx, kofs);
961   if (ofs > 4095)
962     emit_opk(as, ARMI_ADD, dest, node, ofs, RSET_GPR);
963 }
964 
asm_uref(ASMState * as,IRIns * ir)965 static void asm_uref(ASMState *as, IRIns *ir)
966 {
967   Reg dest = ra_dest(as, ir, RSET_GPR);
968   if (irref_isk(ir->op1)) {
969     GCfunc *fn = ir_kfunc(IR(ir->op1));
970     MRef *v = &gcref(fn->l.uvptr[(ir->op2 >> 8)])->uv.v;
971     emit_lsptr(as, ARMI_LDR, dest, v);
972   } else {
973     Reg uv = ra_scratch(as, RSET_GPR);
974     Reg func = ra_alloc1(as, ir->op1, RSET_GPR);
975     if (ir->o == IR_UREFC) {
976       asm_guardcc(as, CC_NE);
977       emit_n(as, ARMI_CMP|ARMI_K12|1, RID_TMP);
978       emit_opk(as, ARMI_ADD, dest, uv,
979 	       (int32_t)offsetof(GCupval, tv), RSET_GPR);
980       emit_lso(as, ARMI_LDRB, RID_TMP, uv, (int32_t)offsetof(GCupval, closed));
981     } else {
982       emit_lso(as, ARMI_LDR, dest, uv, (int32_t)offsetof(GCupval, v));
983     }
984     emit_lso(as, ARMI_LDR, uv, func,
985 	     (int32_t)offsetof(GCfuncL, uvptr) + 4*(int32_t)(ir->op2 >> 8));
986   }
987 }
988 
asm_fref(ASMState * as,IRIns * ir)989 static void asm_fref(ASMState *as, IRIns *ir)
990 {
991   UNUSED(as); UNUSED(ir);
992   lj_assertA(!ra_used(ir), "unfused FREF");
993 }
994 
asm_strref(ASMState * as,IRIns * ir)995 static void asm_strref(ASMState *as, IRIns *ir)
996 {
997   Reg dest = ra_dest(as, ir, RSET_GPR);
998   IRRef ref = ir->op2, refk = ir->op1;
999   Reg r;
1000   if (irref_isk(ref)) {
1001     IRRef tmp = refk; refk = ref; ref = tmp;
1002   } else if (!irref_isk(refk)) {
1003     uint32_t k, m = ARMI_K12|sizeof(GCstr);
1004     Reg right, left = ra_alloc1(as, ir->op1, RSET_GPR);
1005     IRIns *irr = IR(ir->op2);
1006     if (ra_hasreg(irr->r)) {
1007       ra_noweak(as, irr->r);
1008       right = irr->r;
1009     } else if (mayfuse(as, irr->op2) &&
1010 	       irr->o == IR_ADD && irref_isk(irr->op2) &&
1011 	       (k = emit_isk12(ARMI_ADD,
1012 			       (int32_t)sizeof(GCstr) + IR(irr->op2)->i))) {
1013       m = k;
1014       right = ra_alloc1(as, irr->op1, rset_exclude(RSET_GPR, left));
1015     } else {
1016       right = ra_allocref(as, ir->op2, rset_exclude(RSET_GPR, left));
1017     }
1018     emit_dn(as, ARMI_ADD^m, dest, dest);
1019     emit_dnm(as, ARMI_ADD, dest, left, right);
1020     return;
1021   }
1022   r = ra_alloc1(as, ref, RSET_GPR);
1023   emit_opk(as, ARMI_ADD, dest, r,
1024 	   sizeof(GCstr) + IR(refk)->i, rset_exclude(RSET_GPR, r));
1025 }
1026 
1027 /* -- Loads and stores ---------------------------------------------------- */
1028 
asm_fxloadins(ASMState * as,IRIns * ir)1029 static ARMIns asm_fxloadins(ASMState *as, IRIns *ir)
1030 {
1031   UNUSED(as);
1032   switch (irt_type(ir->t)) {
1033   case IRT_I8: return ARMI_LDRSB;
1034   case IRT_U8: return ARMI_LDRB;
1035   case IRT_I16: return ARMI_LDRSH;
1036   case IRT_U16: return ARMI_LDRH;
1037   case IRT_NUM: lj_assertA(!LJ_SOFTFP, "unsplit FP op"); return ARMI_VLDR_D;
1038   case IRT_FLOAT: if (!LJ_SOFTFP) return ARMI_VLDR_S;  /* fallthrough */
1039   default: return ARMI_LDR;
1040   }
1041 }
1042 
asm_fxstoreins(ASMState * as,IRIns * ir)1043 static ARMIns asm_fxstoreins(ASMState *as, IRIns *ir)
1044 {
1045   UNUSED(as);
1046   switch (irt_type(ir->t)) {
1047   case IRT_I8: case IRT_U8: return ARMI_STRB;
1048   case IRT_I16: case IRT_U16: return ARMI_STRH;
1049   case IRT_NUM: lj_assertA(!LJ_SOFTFP, "unsplit FP op"); return ARMI_VSTR_D;
1050   case IRT_FLOAT: if (!LJ_SOFTFP) return ARMI_VSTR_S;  /* fallthrough */
1051   default: return ARMI_STR;
1052   }
1053 }
1054 
asm_fload(ASMState * as,IRIns * ir)1055 static void asm_fload(ASMState *as, IRIns *ir)
1056 {
1057   Reg dest = ra_dest(as, ir, RSET_GPR);
1058   ARMIns ai = asm_fxloadins(as, ir);
1059   Reg idx;
1060   int32_t ofs;
1061   if (ir->op1 == REF_NIL) {  /* FLOAD from GG_State with offset. */
1062     idx = ra_allock(as, (int32_t)(ir->op2<<2) + (int32_t)J2GG(as->J), RSET_GPR);
1063     ofs = 0;
1064   } else {
1065     idx = ra_alloc1(as, ir->op1, RSET_GPR);
1066     if (ir->op2 == IRFL_TAB_ARRAY) {
1067       ofs = asm_fuseabase(as, ir->op1);
1068       if (ofs) {  /* Turn the t->array load into an add for colocated arrays. */
1069 	emit_dn(as, ARMI_ADD|ARMI_K12|ofs, dest, idx);
1070 	return;
1071       }
1072     }
1073     ofs = field_ofs[ir->op2];
1074   }
1075   if ((ai & 0x04000000))
1076     emit_lso(as, ai, dest, idx, ofs);
1077   else
1078     emit_lsox(as, ai, dest, idx, ofs);
1079 }
1080 
asm_fstore(ASMState * as,IRIns * ir)1081 static void asm_fstore(ASMState *as, IRIns *ir)
1082 {
1083   if (ir->r != RID_SINK) {
1084     Reg src = ra_alloc1(as, ir->op2, RSET_GPR);
1085     IRIns *irf = IR(ir->op1);
1086     Reg idx = ra_alloc1(as, irf->op1, rset_exclude(RSET_GPR, src));
1087     int32_t ofs = field_ofs[irf->op2];
1088     ARMIns ai = asm_fxstoreins(as, ir);
1089     if ((ai & 0x04000000))
1090       emit_lso(as, ai, src, idx, ofs);
1091     else
1092       emit_lsox(as, ai, src, idx, ofs);
1093   }
1094 }
1095 
asm_xload(ASMState * as,IRIns * ir)1096 static void asm_xload(ASMState *as, IRIns *ir)
1097 {
1098   Reg dest = ra_dest(as, ir,
1099 		     (!LJ_SOFTFP && irt_isfp(ir->t)) ? RSET_FPR : RSET_GPR);
1100   lj_assertA(!(ir->op2 & IRXLOAD_UNALIGNED), "unaligned XLOAD");
1101   asm_fusexref(as, asm_fxloadins(as, ir), dest, ir->op1, RSET_GPR, 0);
1102 }
1103 
asm_xstore_(ASMState * as,IRIns * ir,int32_t ofs)1104 static void asm_xstore_(ASMState *as, IRIns *ir, int32_t ofs)
1105 {
1106   if (ir->r != RID_SINK) {
1107     Reg src = ra_alloc1(as, ir->op2,
1108 			(!LJ_SOFTFP && irt_isfp(ir->t)) ? RSET_FPR : RSET_GPR);
1109     asm_fusexref(as, asm_fxstoreins(as, ir), src, ir->op1,
1110 		 rset_exclude(RSET_GPR, src), ofs);
1111   }
1112 }
1113 
1114 #define asm_xstore(as, ir)	asm_xstore_(as, ir, 0)
1115 
asm_ahuvload(ASMState * as,IRIns * ir)1116 static void asm_ahuvload(ASMState *as, IRIns *ir)
1117 {
1118   int hiop = (LJ_SOFTFP && (ir+1)->o == IR_HIOP);
1119   IRType t = hiop ? IRT_NUM : irt_type(ir->t);
1120   Reg dest = RID_NONE, type = RID_NONE, idx;
1121   RegSet allow = RSET_GPR;
1122   int32_t ofs = 0;
1123   if (hiop && ra_used(ir+1)) {
1124     type = ra_dest(as, ir+1, allow);
1125     rset_clear(allow, type);
1126   }
1127   if (ra_used(ir)) {
1128     lj_assertA((LJ_SOFTFP ? 0 : irt_isnum(ir->t)) ||
1129 	       irt_isint(ir->t) || irt_isaddr(ir->t),
1130 	       "bad load type %d", irt_type(ir->t));
1131     dest = ra_dest(as, ir, (!LJ_SOFTFP && t == IRT_NUM) ? RSET_FPR : allow);
1132     rset_clear(allow, dest);
1133   }
1134   idx = asm_fuseahuref(as, ir->op1, &ofs, allow,
1135 		       (!LJ_SOFTFP && t == IRT_NUM) ? 1024 : 4096);
1136   if (ir->o == IR_VLOAD) ofs += 8 * ir->op2;
1137   if (!hiop || type == RID_NONE) {
1138     rset_clear(allow, idx);
1139     if (ofs < 256 && ra_hasreg(dest) && (dest & 1) == 0 &&
1140 	rset_test((as->freeset & allow), dest+1)) {
1141       type = dest+1;
1142       ra_modified(as, type);
1143     } else {
1144       type = RID_TMP;
1145     }
1146   }
1147   asm_guardcc(as, t == IRT_NUM ? CC_HS : CC_NE);
1148   emit_n(as, ARMI_CMN|ARMI_K12|-irt_toitype_(t), type);
1149   if (ra_hasreg(dest)) {
1150 #if !LJ_SOFTFP
1151     if (t == IRT_NUM)
1152       emit_vlso(as, ARMI_VLDR_D, dest, idx, ofs);
1153     else
1154 #endif
1155       emit_lso(as, ARMI_LDR, dest, idx, ofs);
1156   }
1157   emit_lso(as, ARMI_LDR, type, idx, ofs+4);
1158 }
1159 
asm_ahustore(ASMState * as,IRIns * ir)1160 static void asm_ahustore(ASMState *as, IRIns *ir)
1161 {
1162   if (ir->r != RID_SINK) {
1163     RegSet allow = RSET_GPR;
1164     Reg idx, src = RID_NONE, type = RID_NONE;
1165     int32_t ofs = 0;
1166 #if !LJ_SOFTFP
1167     if (irt_isnum(ir->t)) {
1168       src = ra_alloc1(as, ir->op2, RSET_FPR);
1169       idx = asm_fuseahuref(as, ir->op1, &ofs, allow, 1024);
1170       emit_vlso(as, ARMI_VSTR_D, src, idx, ofs);
1171     } else
1172 #endif
1173     {
1174       int hiop = (LJ_SOFTFP && (ir+1)->o == IR_HIOP);
1175       if (!irt_ispri(ir->t)) {
1176 	src = ra_alloc1(as, ir->op2, allow);
1177 	rset_clear(allow, src);
1178       }
1179       if (hiop)
1180 	type = ra_alloc1(as, (ir+1)->op2, allow);
1181       else
1182 	type = ra_allock(as, (int32_t)irt_toitype(ir->t), allow);
1183       idx = asm_fuseahuref(as, ir->op1, &ofs, rset_exclude(allow, type), 4096);
1184       if (ra_hasreg(src)) emit_lso(as, ARMI_STR, src, idx, ofs);
1185       emit_lso(as, ARMI_STR, type, idx, ofs+4);
1186     }
1187   }
1188 }
1189 
asm_sload(ASMState * as,IRIns * ir)1190 static void asm_sload(ASMState *as, IRIns *ir)
1191 {
1192   int32_t ofs = 8*((int32_t)ir->op1-1) + ((ir->op2 & IRSLOAD_FRAME) ? 4 : 0);
1193   int hiop = (LJ_SOFTFP && (ir+1)->o == IR_HIOP);
1194   IRType t = hiop ? IRT_NUM : irt_type(ir->t);
1195   Reg dest = RID_NONE, type = RID_NONE, base;
1196   RegSet allow = RSET_GPR;
1197   lj_assertA(!(ir->op2 & IRSLOAD_PARENT),
1198 	     "bad parent SLOAD");  /* Handled by asm_head_side(). */
1199   lj_assertA(irt_isguard(ir->t) || !(ir->op2 & IRSLOAD_TYPECHECK),
1200 	     "inconsistent SLOAD variant");
1201 #if LJ_SOFTFP
1202   lj_assertA(!(ir->op2 & IRSLOAD_CONVERT),
1203 	     "unsplit SLOAD convert");  /* Handled by LJ_SOFTFP SPLIT. */
1204   if (hiop && ra_used(ir+1)) {
1205     type = ra_dest(as, ir+1, allow);
1206     rset_clear(allow, type);
1207   }
1208 #else
1209   if ((ir->op2 & IRSLOAD_CONVERT) && irt_isguard(ir->t) && t == IRT_INT) {
1210     dest = ra_scratch(as, RSET_FPR);
1211     asm_tointg(as, ir, dest);
1212     t = IRT_NUM;  /* Continue with a regular number type check. */
1213   } else
1214 #endif
1215   if (ra_used(ir)) {
1216     Reg tmp = RID_NONE;
1217     if ((ir->op2 & IRSLOAD_CONVERT))
1218       tmp = ra_scratch(as, t == IRT_INT ? RSET_FPR : RSET_GPR);
1219     lj_assertA((LJ_SOFTFP ? 0 : irt_isnum(ir->t)) ||
1220 	       irt_isint(ir->t) || irt_isaddr(ir->t),
1221 	       "bad SLOAD type %d", irt_type(ir->t));
1222     dest = ra_dest(as, ir, (!LJ_SOFTFP && t == IRT_NUM) ? RSET_FPR : allow);
1223     rset_clear(allow, dest);
1224     base = ra_alloc1(as, REF_BASE, allow);
1225     if ((ir->op2 & IRSLOAD_CONVERT)) {
1226       if (t == IRT_INT) {
1227 	emit_dn(as, ARMI_VMOV_R_S, dest, (tmp & 15));
1228 	emit_dm(as, ARMI_VCVT_S32_F64, (tmp & 15), (tmp & 15));
1229 	t = IRT_NUM;  /* Check for original type. */
1230       } else {
1231 	emit_dm(as, ARMI_VCVT_F64_S32, (dest & 15), (dest & 15));
1232 	emit_dn(as, ARMI_VMOV_S_R, tmp, (dest & 15));
1233 	t = IRT_INT;  /* Check for original type. */
1234       }
1235       dest = tmp;
1236     }
1237     goto dotypecheck;
1238   }
1239   base = ra_alloc1(as, REF_BASE, allow);
1240 dotypecheck:
1241   rset_clear(allow, base);
1242   if ((ir->op2 & IRSLOAD_TYPECHECK)) {
1243     if (ra_noreg(type)) {
1244       if (ofs < 256 && ra_hasreg(dest) && (dest & 1) == 0 &&
1245 	  rset_test((as->freeset & allow), dest+1)) {
1246 	type = dest+1;
1247 	ra_modified(as, type);
1248       } else {
1249 	type = RID_TMP;
1250       }
1251     }
1252     asm_guardcc(as, t == IRT_NUM ? CC_HS : CC_NE);
1253     emit_n(as, ARMI_CMN|ARMI_K12|-irt_toitype_(t), type);
1254   }
1255   if (ra_hasreg(dest)) {
1256 #if !LJ_SOFTFP
1257     if (t == IRT_NUM) {
1258       if (ofs < 1024) {
1259 	emit_vlso(as, ARMI_VLDR_D, dest, base, ofs);
1260       } else {
1261 	if (ra_hasreg(type)) emit_lso(as, ARMI_LDR, type, base, ofs+4);
1262 	emit_vlso(as, ARMI_VLDR_D, dest, RID_TMP, 0);
1263 	emit_opk(as, ARMI_ADD, RID_TMP, base, ofs, allow);
1264 	return;
1265       }
1266     } else
1267 #endif
1268       emit_lso(as, ARMI_LDR, dest, base, ofs);
1269   }
1270   if (ra_hasreg(type)) emit_lso(as, ARMI_LDR, type, base, ofs+4);
1271 }
1272 
1273 /* -- Allocations --------------------------------------------------------- */
1274 
1275 #if LJ_HASFFI
asm_cnew(ASMState * as,IRIns * ir)1276 static void asm_cnew(ASMState *as, IRIns *ir)
1277 {
1278   CTState *cts = ctype_ctsG(J2G(as->J));
1279   CTypeID id = (CTypeID)IR(ir->op1)->i;
1280   CTSize sz;
1281   CTInfo info = lj_ctype_info(cts, id, &sz);
1282   const CCallInfo *ci = &lj_ir_callinfo[IRCALL_lj_mem_newgco];
1283   IRRef args[4];
1284   RegSet allow = (RSET_GPR & ~RSET_SCRATCH);
1285   RegSet drop = RSET_SCRATCH;
1286   lj_assertA(sz != CTSIZE_INVALID || (ir->o == IR_CNEW && ir->op2 != REF_NIL),
1287 	     "bad CNEW/CNEWI operands");
1288 
1289   as->gcsteps++;
1290   if (ra_hasreg(ir->r))
1291     rset_clear(drop, ir->r);  /* Dest reg handled below. */
1292   ra_evictset(as, drop);
1293   if (ra_used(ir))
1294     ra_destreg(as, ir, RID_RET);  /* GCcdata * */
1295 
1296   /* Initialize immutable cdata object. */
1297   if (ir->o == IR_CNEWI) {
1298     int32_t ofs = sizeof(GCcdata);
1299     lj_assertA(sz == 4 || sz == 8, "bad CNEWI size %d", sz);
1300     if (sz == 8) {
1301       ofs += 4; ir++;
1302       lj_assertA(ir->o == IR_HIOP, "expected HIOP for CNEWI");
1303     }
1304     for (;;) {
1305       Reg r = ra_alloc1(as, ir->op2, allow);
1306       emit_lso(as, ARMI_STR, r, RID_RET, ofs);
1307       rset_clear(allow, r);
1308       if (ofs == sizeof(GCcdata)) break;
1309       ofs -= 4; ir--;
1310     }
1311   } else if (ir->op2 != REF_NIL) {  /* Create VLA/VLS/aligned cdata. */
1312     ci = &lj_ir_callinfo[IRCALL_lj_cdata_newv];
1313     args[0] = ASMREF_L;     /* lua_State *L */
1314     args[1] = ir->op1;      /* CTypeID id   */
1315     args[2] = ir->op2;      /* CTSize sz    */
1316     args[3] = ASMREF_TMP1;  /* CTSize align */
1317     asm_gencall(as, ci, args);
1318     emit_loadi(as, ra_releasetmp(as, ASMREF_TMP1), (int32_t)ctype_align(info));
1319     return;
1320   }
1321 
1322   /* Initialize gct and ctypeid. lj_mem_newgco() already sets marked. */
1323   {
1324     uint32_t k = emit_isk12(ARMI_MOV, id);
1325     Reg r = k ? RID_R1 : ra_allock(as, id, allow);
1326     emit_lso(as, ARMI_STRB, RID_TMP, RID_RET, offsetof(GCcdata, gct));
1327     emit_lsox(as, ARMI_STRH, r, RID_RET, offsetof(GCcdata, ctypeid));
1328     emit_d(as, ARMI_MOV|ARMI_K12|~LJ_TCDATA, RID_TMP);
1329     if (k) emit_d(as, ARMI_MOV^k, RID_R1);
1330   }
1331   args[0] = ASMREF_L;     /* lua_State *L */
1332   args[1] = ASMREF_TMP1;  /* MSize size   */
1333   asm_gencall(as, ci, args);
1334   ra_allockreg(as, (int32_t)(sz+sizeof(GCcdata)),
1335 	       ra_releasetmp(as, ASMREF_TMP1));
1336 }
1337 #endif
1338 
1339 /* -- Write barriers ------------------------------------------------------ */
1340 
asm_tbar(ASMState * as,IRIns * ir)1341 static void asm_tbar(ASMState *as, IRIns *ir)
1342 {
1343   Reg tab = ra_alloc1(as, ir->op1, RSET_GPR);
1344   Reg link = ra_scratch(as, rset_exclude(RSET_GPR, tab));
1345   Reg gr = ra_allock(as, i32ptr(J2G(as->J)),
1346 		     rset_exclude(rset_exclude(RSET_GPR, tab), link));
1347   Reg mark = RID_TMP;
1348   MCLabel l_end = emit_label(as);
1349   emit_lso(as, ARMI_STR, link, tab, (int32_t)offsetof(GCtab, gclist));
1350   emit_lso(as, ARMI_STRB, mark, tab, (int32_t)offsetof(GCtab, marked));
1351   emit_lso(as, ARMI_STR, tab, gr,
1352 	   (int32_t)offsetof(global_State, gc.grayagain));
1353   emit_dn(as, ARMI_BIC|ARMI_K12|LJ_GC_BLACK, mark, mark);
1354   emit_lso(as, ARMI_LDR, link, gr,
1355 	   (int32_t)offsetof(global_State, gc.grayagain));
1356   emit_branch(as, ARMF_CC(ARMI_B, CC_EQ), l_end);
1357   emit_n(as, ARMI_TST|ARMI_K12|LJ_GC_BLACK, mark);
1358   emit_lso(as, ARMI_LDRB, mark, tab, (int32_t)offsetof(GCtab, marked));
1359 }
1360 
asm_obar(ASMState * as,IRIns * ir)1361 static void asm_obar(ASMState *as, IRIns *ir)
1362 {
1363   const CCallInfo *ci = &lj_ir_callinfo[IRCALL_lj_gc_barrieruv];
1364   IRRef args[2];
1365   MCLabel l_end;
1366   Reg obj, val, tmp;
1367   /* No need for other object barriers (yet). */
1368   lj_assertA(IR(ir->op1)->o == IR_UREFC, "bad OBAR type");
1369   ra_evictset(as, RSET_SCRATCH);
1370   l_end = emit_label(as);
1371   args[0] = ASMREF_TMP1;  /* global_State *g */
1372   args[1] = ir->op1;      /* TValue *tv      */
1373   asm_gencall(as, ci, args);
1374   if ((l_end[-1] >> 28) == CC_AL)
1375     l_end[-1] = ARMF_CC(l_end[-1], CC_NE);
1376   else
1377     emit_branch(as, ARMF_CC(ARMI_B, CC_EQ), l_end);
1378   ra_allockreg(as, i32ptr(J2G(as->J)), ra_releasetmp(as, ASMREF_TMP1));
1379   obj = IR(ir->op1)->r;
1380   tmp = ra_scratch(as, rset_exclude(RSET_GPR, obj));
1381   emit_n(as, ARMF_CC(ARMI_TST, CC_NE)|ARMI_K12|LJ_GC_BLACK, tmp);
1382   emit_n(as, ARMI_TST|ARMI_K12|LJ_GC_WHITES, RID_TMP);
1383   val = ra_alloc1(as, ir->op2, rset_exclude(RSET_GPR, obj));
1384   emit_lso(as, ARMI_LDRB, tmp, obj,
1385 	   (int32_t)offsetof(GCupval, marked)-(int32_t)offsetof(GCupval, tv));
1386   emit_lso(as, ARMI_LDRB, RID_TMP, val, (int32_t)offsetof(GChead, marked));
1387 }
1388 
1389 /* -- Arithmetic and logic operations ------------------------------------- */
1390 
1391 #if !LJ_SOFTFP
asm_fparith(ASMState * as,IRIns * ir,ARMIns ai)1392 static void asm_fparith(ASMState *as, IRIns *ir, ARMIns ai)
1393 {
1394   Reg dest = ra_dest(as, ir, RSET_FPR);
1395   Reg right, left = ra_alloc2(as, ir, RSET_FPR);
1396   right = (left >> 8); left &= 255;
1397   emit_dnm(as, ai, (dest & 15), (left & 15), (right & 15));
1398 }
1399 
asm_fpunary(ASMState * as,IRIns * ir,ARMIns ai)1400 static void asm_fpunary(ASMState *as, IRIns *ir, ARMIns ai)
1401 {
1402   Reg dest = ra_dest(as, ir, RSET_FPR);
1403   Reg left = ra_hintalloc(as, ir->op1, dest, RSET_FPR);
1404   emit_dm(as, ai, (dest & 15), (left & 15));
1405 }
1406 
asm_callround(ASMState * as,IRIns * ir,int id)1407 static void asm_callround(ASMState *as, IRIns *ir, int id)
1408 {
1409   /* The modified regs must match with the *.dasc implementation. */
1410   RegSet drop = RID2RSET(RID_R0)|RID2RSET(RID_R1)|RID2RSET(RID_R2)|
1411 		RID2RSET(RID_R3)|RID2RSET(RID_R12);
1412   RegSet of;
1413   Reg dest, src;
1414   ra_evictset(as, drop);
1415   dest = ra_dest(as, ir, RSET_FPR);
1416   emit_dnm(as, ARMI_VMOV_D_RR, RID_RETLO, RID_RETHI, (dest & 15));
1417   emit_call(as, id == IRFPM_FLOOR ? (void *)lj_vm_floor_sf :
1418 		id == IRFPM_CEIL ? (void *)lj_vm_ceil_sf :
1419 				   (void *)lj_vm_trunc_sf);
1420   /* Workaround to protect argument GPRs from being used for remat. */
1421   of = as->freeset;
1422   as->freeset &= ~RSET_RANGE(RID_R0, RID_R1+1);
1423   as->cost[RID_R0] = as->cost[RID_R1] = REGCOST(~0u, ASMREF_L);
1424   src = ra_alloc1(as, ir->op1, RSET_FPR);  /* May alloc GPR to remat FPR. */
1425   as->freeset |= (of & RSET_RANGE(RID_R0, RID_R1+1));
1426   emit_dnm(as, ARMI_VMOV_RR_D, RID_R0, RID_R1, (src & 15));
1427 }
1428 
asm_fpmath(ASMState * as,IRIns * ir)1429 static void asm_fpmath(ASMState *as, IRIns *ir)
1430 {
1431   if (ir->op2 <= IRFPM_TRUNC)
1432     asm_callround(as, ir, ir->op2);
1433   else if (ir->op2 == IRFPM_SQRT)
1434     asm_fpunary(as, ir, ARMI_VSQRT_D);
1435   else
1436     asm_callid(as, ir, IRCALL_lj_vm_floor + ir->op2);
1437 }
1438 #endif
1439 
asm_swapops(ASMState * as,IRRef lref,IRRef rref)1440 static int asm_swapops(ASMState *as, IRRef lref, IRRef rref)
1441 {
1442   IRIns *ir;
1443   if (irref_isk(rref))
1444     return 0;  /* Don't swap constants to the left. */
1445   if (irref_isk(lref))
1446     return 1;  /* But swap constants to the right. */
1447   ir = IR(rref);
1448   if ((ir->o >= IR_BSHL && ir->o <= IR_BROR) ||
1449       (ir->o == IR_ADD && ir->op1 == ir->op2))
1450     return 0;  /* Don't swap fusable operands to the left. */
1451   ir = IR(lref);
1452   if ((ir->o >= IR_BSHL && ir->o <= IR_BROR) ||
1453       (ir->o == IR_ADD && ir->op1 == ir->op2))
1454     return 1;  /* But swap fusable operands to the right. */
1455   return 0;  /* Otherwise don't swap. */
1456 }
1457 
asm_intop(ASMState * as,IRIns * ir,ARMIns ai)1458 static void asm_intop(ASMState *as, IRIns *ir, ARMIns ai)
1459 {
1460   IRRef lref = ir->op1, rref = ir->op2;
1461   Reg left, dest = ra_dest(as, ir, RSET_GPR);
1462   uint32_t m;
1463   if (asm_swapops(as, lref, rref)) {
1464     IRRef tmp = lref; lref = rref; rref = tmp;
1465     if ((ai & ~ARMI_S) == ARMI_SUB || (ai & ~ARMI_S) == ARMI_SBC)
1466       ai ^= (ARMI_SUB^ARMI_RSB);
1467   }
1468   left = ra_hintalloc(as, lref, dest, RSET_GPR);
1469   m = asm_fuseopm(as, ai, rref, rset_exclude(RSET_GPR, left));
1470   if (irt_isguard(ir->t)) {  /* For IR_ADDOV etc. */
1471     asm_guardcc(as, CC_VS);
1472     ai |= ARMI_S;
1473   }
1474   emit_dn(as, ai^m, dest, left);
1475 }
1476 
1477 /* Try to drop cmp r, #0. */
asm_drop_cmp0(ASMState * as,ARMIns ai)1478 static ARMIns asm_drop_cmp0(ASMState *as, ARMIns ai)
1479 {
1480   if (as->flagmcp == as->mcp) {
1481     uint32_t cc = (as->mcp[1] >> 28);
1482     as->flagmcp = NULL;
1483     if (cc <= CC_NE) {
1484       as->mcp++;
1485       ai |= ARMI_S;
1486     } else if (cc == CC_GE) {
1487       *++as->mcp ^= ((CC_GE^CC_PL) << 28);
1488       ai |= ARMI_S;
1489     } else if (cc == CC_LT) {
1490       *++as->mcp ^= ((CC_LT^CC_MI) << 28);
1491       ai |= ARMI_S;
1492     }  /* else: other conds don't work in general. */
1493   }
1494   return ai;
1495 }
1496 
asm_intop_s(ASMState * as,IRIns * ir,ARMIns ai)1497 static void asm_intop_s(ASMState *as, IRIns *ir, ARMIns ai)
1498 {
1499   asm_intop(as, ir, asm_drop_cmp0(as, ai));
1500 }
1501 
asm_intneg(ASMState * as,IRIns * ir,ARMIns ai)1502 static void asm_intneg(ASMState *as, IRIns *ir, ARMIns ai)
1503 {
1504   Reg dest = ra_dest(as, ir, RSET_GPR);
1505   Reg left = ra_hintalloc(as, ir->op1, dest, RSET_GPR);
1506   emit_dn(as, ai|ARMI_K12|0, dest, left);
1507 }
1508 
1509 /* NYI: use add/shift for MUL(OV) with constants. FOLD only does 2^k. */
asm_intmul(ASMState * as,IRIns * ir)1510 static void asm_intmul(ASMState *as, IRIns *ir)
1511 {
1512   Reg dest = ra_dest(as, ir, RSET_GPR);
1513   Reg left = ra_alloc1(as, ir->op1, rset_exclude(RSET_GPR, dest));
1514   Reg right = ra_alloc1(as, ir->op2, rset_exclude(RSET_GPR, left));
1515   Reg tmp = RID_NONE;
1516   /* ARMv5 restriction: dest != left and dest_hi != left. */
1517   if (dest == left && left != right) { left = right; right = dest; }
1518   if (irt_isguard(ir->t)) {  /* IR_MULOV */
1519     if (!(as->flags & JIT_F_ARMV6) && dest == left)
1520       tmp = left = ra_scratch(as, rset_exclude(RSET_GPR, left));
1521     asm_guardcc(as, CC_NE);
1522     emit_nm(as, ARMI_TEQ|ARMF_SH(ARMSH_ASR, 31), RID_TMP, dest);
1523     emit_dnm(as, ARMI_SMULL|ARMF_S(right), dest, RID_TMP, left);
1524   } else {
1525     if (!(as->flags & JIT_F_ARMV6) && dest == left) tmp = left = RID_TMP;
1526     emit_nm(as, ARMI_MUL|ARMF_S(right), dest, left);
1527   }
1528   /* Only need this for the dest == left == right case. */
1529   if (ra_hasreg(tmp)) emit_dm(as, ARMI_MOV, tmp, right);
1530 }
1531 
asm_add(ASMState * as,IRIns * ir)1532 static void asm_add(ASMState *as, IRIns *ir)
1533 {
1534 #if !LJ_SOFTFP
1535   if (irt_isnum(ir->t)) {
1536     if (!asm_fusemadd(as, ir, ARMI_VMLA_D, ARMI_VMLA_D))
1537       asm_fparith(as, ir, ARMI_VADD_D);
1538     return;
1539   }
1540 #endif
1541   asm_intop_s(as, ir, ARMI_ADD);
1542 }
1543 
asm_sub(ASMState * as,IRIns * ir)1544 static void asm_sub(ASMState *as, IRIns *ir)
1545 {
1546 #if !LJ_SOFTFP
1547   if (irt_isnum(ir->t)) {
1548     if (!asm_fusemadd(as, ir, ARMI_VNMLS_D, ARMI_VMLS_D))
1549       asm_fparith(as, ir, ARMI_VSUB_D);
1550     return;
1551   }
1552 #endif
1553   asm_intop_s(as, ir, ARMI_SUB);
1554 }
1555 
asm_mul(ASMState * as,IRIns * ir)1556 static void asm_mul(ASMState *as, IRIns *ir)
1557 {
1558 #if !LJ_SOFTFP
1559   if (irt_isnum(ir->t)) {
1560     asm_fparith(as, ir, ARMI_VMUL_D);
1561     return;
1562   }
1563 #endif
1564   asm_intmul(as, ir);
1565 }
1566 
1567 #define asm_addov(as, ir)	asm_add(as, ir)
1568 #define asm_subov(as, ir)	asm_sub(as, ir)
1569 #define asm_mulov(as, ir)	asm_mul(as, ir)
1570 
1571 #if !LJ_SOFTFP
1572 #define asm_fpdiv(as, ir)	asm_fparith(as, ir, ARMI_VDIV_D)
1573 #define asm_abs(as, ir)		asm_fpunary(as, ir, ARMI_VABS_D)
1574 #endif
1575 
asm_neg(ASMState * as,IRIns * ir)1576 static void asm_neg(ASMState *as, IRIns *ir)
1577 {
1578 #if !LJ_SOFTFP
1579   if (irt_isnum(ir->t)) {
1580     asm_fpunary(as, ir, ARMI_VNEG_D);
1581     return;
1582   }
1583 #endif
1584   asm_intneg(as, ir, ARMI_RSB);
1585 }
1586 
asm_bitop(ASMState * as,IRIns * ir,ARMIns ai)1587 static void asm_bitop(ASMState *as, IRIns *ir, ARMIns ai)
1588 {
1589   ai = asm_drop_cmp0(as, ai);
1590   if (ir->op2 == 0) {
1591     Reg dest = ra_dest(as, ir, RSET_GPR);
1592     uint32_t m = asm_fuseopm(as, ai, ir->op1, RSET_GPR);
1593     emit_d(as, ai^m, dest);
1594   } else {
1595     /* NYI: Turn BAND !k12 into uxtb, uxth or bfc or shl+shr. */
1596     asm_intop(as, ir, ai);
1597   }
1598 }
1599 
1600 #define asm_bnot(as, ir)	asm_bitop(as, ir, ARMI_MVN)
1601 
asm_bswap(ASMState * as,IRIns * ir)1602 static void asm_bswap(ASMState *as, IRIns *ir)
1603 {
1604   Reg dest = ra_dest(as, ir, RSET_GPR);
1605   Reg left = ra_alloc1(as, ir->op1, RSET_GPR);
1606   if ((as->flags & JIT_F_ARMV6)) {
1607     emit_dm(as, ARMI_REV, dest, left);
1608   } else {
1609     Reg tmp2 = dest;
1610     if (tmp2 == left)
1611       tmp2 = ra_scratch(as, rset_exclude(rset_exclude(RSET_GPR, dest), left));
1612     emit_dnm(as, ARMI_EOR|ARMF_SH(ARMSH_LSR, 8), dest, tmp2, RID_TMP);
1613     emit_dm(as, ARMI_MOV|ARMF_SH(ARMSH_ROR, 8), tmp2, left);
1614     emit_dn(as, ARMI_BIC|ARMI_K12|256*8|255, RID_TMP, RID_TMP);
1615     emit_dnm(as, ARMI_EOR|ARMF_SH(ARMSH_ROR, 16), RID_TMP, left, left);
1616   }
1617 }
1618 
1619 #define asm_band(as, ir)	asm_bitop(as, ir, ARMI_AND)
1620 #define asm_bor(as, ir)		asm_bitop(as, ir, ARMI_ORR)
1621 #define asm_bxor(as, ir)	asm_bitop(as, ir, ARMI_EOR)
1622 
asm_bitshift(ASMState * as,IRIns * ir,ARMShift sh)1623 static void asm_bitshift(ASMState *as, IRIns *ir, ARMShift sh)
1624 {
1625   if (irref_isk(ir->op2)) {  /* Constant shifts. */
1626     /* NYI: Turn SHL+SHR or BAND+SHR into uxtb, uxth or ubfx. */
1627     /* NYI: Turn SHL+ASR into sxtb, sxth or sbfx. */
1628     Reg dest = ra_dest(as, ir, RSET_GPR);
1629     Reg left = ra_alloc1(as, ir->op1, RSET_GPR);
1630     int32_t shift = (IR(ir->op2)->i & 31);
1631     emit_dm(as, ARMI_MOV|ARMF_SH(sh, shift), dest, left);
1632   } else {
1633     Reg dest = ra_dest(as, ir, RSET_GPR);
1634     Reg left = ra_alloc1(as, ir->op1, RSET_GPR);
1635     Reg right = ra_alloc1(as, ir->op2, rset_exclude(RSET_GPR, left));
1636     emit_dm(as, ARMI_MOV|ARMF_RSH(sh, right), dest, left);
1637   }
1638 }
1639 
1640 #define asm_bshl(as, ir)	asm_bitshift(as, ir, ARMSH_LSL)
1641 #define asm_bshr(as, ir)	asm_bitshift(as, ir, ARMSH_LSR)
1642 #define asm_bsar(as, ir)	asm_bitshift(as, ir, ARMSH_ASR)
1643 #define asm_bror(as, ir)	asm_bitshift(as, ir, ARMSH_ROR)
1644 #define asm_brol(as, ir)	lj_assertA(0, "unexpected BROL")
1645 
asm_intmin_max(ASMState * as,IRIns * ir,int cc)1646 static void asm_intmin_max(ASMState *as, IRIns *ir, int cc)
1647 {
1648   uint32_t kcmp = 0, kmov = 0;
1649   Reg dest = ra_dest(as, ir, RSET_GPR);
1650   Reg left = ra_hintalloc(as, ir->op1, dest, RSET_GPR);
1651   Reg right = 0;
1652   if (irref_isk(ir->op2)) {
1653     kcmp = emit_isk12(ARMI_CMP, IR(ir->op2)->i);
1654     if (kcmp) kmov = emit_isk12(ARMI_MOV, IR(ir->op2)->i);
1655   }
1656   if (!kmov) {
1657     kcmp = 0;
1658     right = ra_alloc1(as, ir->op2, rset_exclude(RSET_GPR, left));
1659   }
1660   if (kmov || dest != right) {
1661     emit_dm(as, ARMF_CC(ARMI_MOV, cc)^kmov, dest, right);
1662     cc ^= 1;  /* Must use opposite conditions for paired moves. */
1663   } else {
1664     cc ^= (CC_LT^CC_GT);  /* Otherwise may swap CC_LT <-> CC_GT. */
1665   }
1666   if (dest != left) emit_dm(as, ARMF_CC(ARMI_MOV, cc), dest, left);
1667   emit_nm(as, ARMI_CMP^kcmp, left, right);
1668 }
1669 
1670 #if LJ_SOFTFP
asm_sfpmin_max(ASMState * as,IRIns * ir,int cc)1671 static void asm_sfpmin_max(ASMState *as, IRIns *ir, int cc)
1672 {
1673   const CCallInfo *ci = &lj_ir_callinfo[IRCALL_softfp_cmp];
1674   RegSet drop = RSET_SCRATCH;
1675   Reg r;
1676   IRRef args[4];
1677   args[0] = ir->op1; args[1] = (ir+1)->op1;
1678   args[2] = ir->op2; args[3] = (ir+1)->op2;
1679   /* __aeabi_cdcmple preserves r0-r3. */
1680   if (ra_hasreg(ir->r)) rset_clear(drop, ir->r);
1681   if (ra_hasreg((ir+1)->r)) rset_clear(drop, (ir+1)->r);
1682   if (!rset_test(as->freeset, RID_R2) &&
1683       regcost_ref(as->cost[RID_R2]) == args[2]) rset_clear(drop, RID_R2);
1684   if (!rset_test(as->freeset, RID_R3) &&
1685       regcost_ref(as->cost[RID_R3]) == args[3]) rset_clear(drop, RID_R3);
1686   ra_evictset(as, drop);
1687   ra_destpair(as, ir);
1688   emit_dm(as, ARMF_CC(ARMI_MOV, cc), RID_RETHI, RID_R3);
1689   emit_dm(as, ARMF_CC(ARMI_MOV, cc), RID_RETLO, RID_R2);
1690   emit_call(as, (void *)ci->func);
1691   for (r = RID_R0; r <= RID_R3; r++)
1692     ra_leftov(as, r, args[r-RID_R0]);
1693 }
1694 #else
asm_fpmin_max(ASMState * as,IRIns * ir,int cc)1695 static void asm_fpmin_max(ASMState *as, IRIns *ir, int cc)
1696 {
1697   Reg dest = (ra_dest(as, ir, RSET_FPR) & 15);
1698   Reg right, left = ra_alloc2(as, ir, RSET_FPR);
1699   right = ((left >> 8) & 15); left &= 15;
1700   if (dest != left) emit_dm(as, ARMF_CC(ARMI_VMOV_D, cc^1), dest, left);
1701   if (dest != right) emit_dm(as, ARMF_CC(ARMI_VMOV_D, cc), dest, right);
1702   emit_d(as, ARMI_VMRS, 0);
1703   emit_dm(as, ARMI_VCMP_D, left, right);
1704 }
1705 #endif
1706 
asm_min_max(ASMState * as,IRIns * ir,int cc,int fcc)1707 static void asm_min_max(ASMState *as, IRIns *ir, int cc, int fcc)
1708 {
1709 #if LJ_SOFTFP
1710   UNUSED(fcc);
1711 #else
1712   if (irt_isnum(ir->t))
1713     asm_fpmin_max(as, ir, fcc);
1714   else
1715 #endif
1716     asm_intmin_max(as, ir, cc);
1717 }
1718 
1719 #define asm_min(as, ir)		asm_min_max(as, ir, CC_GT, CC_PL)
1720 #define asm_max(as, ir)		asm_min_max(as, ir, CC_LT, CC_LE)
1721 
1722 /* -- Comparisons --------------------------------------------------------- */
1723 
1724 /* Map of comparisons to flags. ORDER IR. */
1725 static const uint8_t asm_compmap[IR_ABC+1] = {
1726   /* op  FP swp  int cc   FP cc */
1727   /* LT       */ CC_GE + (CC_HS << 4),
1728   /* GE    x  */ CC_LT + (CC_HI << 4),
1729   /* LE       */ CC_GT + (CC_HI << 4),
1730   /* GT    x  */ CC_LE + (CC_HS << 4),
1731   /* ULT   x  */ CC_HS + (CC_LS << 4),
1732   /* UGE      */ CC_LO + (CC_LO << 4),
1733   /* ULE   x  */ CC_HI + (CC_LO << 4),
1734   /* UGT      */ CC_LS + (CC_LS << 4),
1735   /* EQ       */ CC_NE + (CC_NE << 4),
1736   /* NE       */ CC_EQ + (CC_EQ << 4),
1737   /* ABC      */ CC_LS + (CC_LS << 4)  /* Same as UGT. */
1738 };
1739 
1740 #if LJ_SOFTFP
1741 /* FP comparisons. */
asm_sfpcomp(ASMState * as,IRIns * ir)1742 static void asm_sfpcomp(ASMState *as, IRIns *ir)
1743 {
1744   const CCallInfo *ci = &lj_ir_callinfo[IRCALL_softfp_cmp];
1745   RegSet drop = RSET_SCRATCH;
1746   Reg r;
1747   IRRef args[4];
1748   int swp = (((ir->o ^ (ir->o >> 2)) & ~(ir->o >> 3) & 1) << 1);
1749   args[swp^0] = ir->op1; args[swp^1] = (ir+1)->op1;
1750   args[swp^2] = ir->op2; args[swp^3] = (ir+1)->op2;
1751   /* __aeabi_cdcmple preserves r0-r3. This helps to reduce spills. */
1752   for (r = RID_R0; r <= RID_R3; r++)
1753     if (!rset_test(as->freeset, r) &&
1754 	regcost_ref(as->cost[r]) == args[r-RID_R0]) rset_clear(drop, r);
1755   ra_evictset(as, drop);
1756   asm_guardcc(as, (asm_compmap[ir->o] >> 4));
1757   emit_call(as, (void *)ci->func);
1758   for (r = RID_R0; r <= RID_R3; r++)
1759     ra_leftov(as, r, args[r-RID_R0]);
1760 }
1761 #else
1762 /* FP comparisons. */
asm_fpcomp(ASMState * as,IRIns * ir)1763 static void asm_fpcomp(ASMState *as, IRIns *ir)
1764 {
1765   Reg left, right;
1766   ARMIns ai;
1767   int swp = ((ir->o ^ (ir->o >> 2)) & ~(ir->o >> 3) & 1);
1768   if (!swp && irref_isk(ir->op2) && ir_knum(IR(ir->op2))->u64 == 0) {
1769     left = (ra_alloc1(as, ir->op1, RSET_FPR) & 15);
1770     right = 0;
1771     ai = ARMI_VCMPZ_D;
1772   } else {
1773     left = ra_alloc2(as, ir, RSET_FPR);
1774     if (swp) {
1775       right = (left & 15); left = ((left >> 8) & 15);
1776     } else {
1777       right = ((left >> 8) & 15); left &= 15;
1778     }
1779     ai = ARMI_VCMP_D;
1780   }
1781   asm_guardcc(as, (asm_compmap[ir->o] >> 4));
1782   emit_d(as, ARMI_VMRS, 0);
1783   emit_dm(as, ai, left, right);
1784 }
1785 #endif
1786 
1787 /* Integer comparisons. */
asm_intcomp(ASMState * as,IRIns * ir)1788 static void asm_intcomp(ASMState *as, IRIns *ir)
1789 {
1790   ARMCC cc = (asm_compmap[ir->o] & 15);
1791   IRRef lref = ir->op1, rref = ir->op2;
1792   Reg left;
1793   uint32_t m;
1794   int cmpprev0 = 0;
1795   lj_assertA(irt_isint(ir->t) || irt_isu32(ir->t) || irt_isaddr(ir->t),
1796 	     "bad comparison data type %d", irt_type(ir->t));
1797   if (asm_swapops(as, lref, rref)) {
1798     Reg tmp = lref; lref = rref; rref = tmp;
1799     if (cc >= CC_GE) cc ^= 7;  /* LT <-> GT, LE <-> GE */
1800     else if (cc > CC_NE) cc ^= 11;  /* LO <-> HI, LS <-> HS */
1801   }
1802   if (irref_isk(rref) && IR(rref)->i == 0) {
1803     IRIns *irl = IR(lref);
1804     cmpprev0 = (irl+1 == ir);
1805     /* Combine comp(BAND(left, right), 0) into tst left, right. */
1806     if (cmpprev0 && irl->o == IR_BAND && !ra_used(irl)) {
1807       IRRef blref = irl->op1, brref = irl->op2;
1808       uint32_t m2 = 0;
1809       Reg bleft;
1810       if (asm_swapops(as, blref, brref)) {
1811 	Reg tmp = blref; blref = brref; brref = tmp;
1812       }
1813       if (irref_isk(brref)) {
1814 	m2 = emit_isk12(ARMI_AND, IR(brref)->i);
1815 	if ((m2 & (ARMI_AND^ARMI_BIC)))
1816 	  goto notst;  /* Not beneficial if we miss a constant operand. */
1817       }
1818       if (cc == CC_GE) cc = CC_PL;
1819       else if (cc == CC_LT) cc = CC_MI;
1820       else if (cc > CC_NE) goto notst;  /* Other conds don't work with tst. */
1821       bleft = ra_alloc1(as, blref, RSET_GPR);
1822       if (!m2) m2 = asm_fuseopm(as, 0, brref, rset_exclude(RSET_GPR, bleft));
1823       asm_guardcc(as, cc);
1824       emit_n(as, ARMI_TST^m2, bleft);
1825       return;
1826     }
1827   }
1828 notst:
1829   left = ra_alloc1(as, lref, RSET_GPR);
1830   m = asm_fuseopm(as, ARMI_CMP, rref, rset_exclude(RSET_GPR, left));
1831   asm_guardcc(as, cc);
1832   emit_n(as, ARMI_CMP^m, left);
1833   /* Signed comparison with zero and referencing previous ins? */
1834   if (cmpprev0 && (cc <= CC_NE || cc >= CC_GE))
1835     as->flagmcp = as->mcp;  /* Allow elimination of the compare. */
1836 }
1837 
asm_comp(ASMState * as,IRIns * ir)1838 static void asm_comp(ASMState *as, IRIns *ir)
1839 {
1840 #if !LJ_SOFTFP
1841   if (irt_isnum(ir->t))
1842     asm_fpcomp(as, ir);
1843   else
1844 #endif
1845     asm_intcomp(as, ir);
1846 }
1847 
1848 #define asm_equal(as, ir)	asm_comp(as, ir)
1849 
1850 #if LJ_HASFFI
1851 /* 64 bit integer comparisons. */
asm_int64comp(ASMState * as,IRIns * ir)1852 static void asm_int64comp(ASMState *as, IRIns *ir)
1853 {
1854   int signedcomp = (ir->o <= IR_GT);
1855   ARMCC cclo, cchi;
1856   Reg leftlo, lefthi;
1857   uint32_t mlo, mhi;
1858   RegSet allow = RSET_GPR, oldfree;
1859 
1860   /* Always use unsigned comparison for loword. */
1861   cclo = asm_compmap[ir->o + (signedcomp ? 4 : 0)] & 15;
1862   leftlo = ra_alloc1(as, ir->op1, allow);
1863   oldfree = as->freeset;
1864   mlo = asm_fuseopm(as, ARMI_CMP, ir->op2, rset_clear(allow, leftlo));
1865   allow &= ~(oldfree & ~as->freeset);  /* Update for allocs of asm_fuseopm. */
1866 
1867   /* Use signed or unsigned comparison for hiword. */
1868   cchi = asm_compmap[ir->o] & 15;
1869   lefthi = ra_alloc1(as, (ir+1)->op1, allow);
1870   mhi = asm_fuseopm(as, ARMI_CMP, (ir+1)->op2, rset_clear(allow, lefthi));
1871 
1872   /* All register allocations must be performed _before_ this point. */
1873   if (signedcomp) {
1874     MCLabel l_around = emit_label(as);
1875     asm_guardcc(as, cclo);
1876     emit_n(as, ARMI_CMP^mlo, leftlo);
1877     emit_branch(as, ARMF_CC(ARMI_B, CC_NE), l_around);
1878     if (cchi == CC_GE || cchi == CC_LE) cchi ^= 6;  /* GE -> GT, LE -> LT */
1879     asm_guardcc(as, cchi);
1880   } else {
1881     asm_guardcc(as, cclo);
1882     emit_n(as, ARMF_CC(ARMI_CMP, CC_EQ)^mlo, leftlo);
1883   }
1884   emit_n(as, ARMI_CMP^mhi, lefthi);
1885 }
1886 #endif
1887 
1888 /* -- Split register ops -------------------------------------------------- */
1889 
1890 /* Hiword op of a split 32/32 bit op. Previous op is the loword op. */
asm_hiop(ASMState * as,IRIns * ir)1891 static void asm_hiop(ASMState *as, IRIns *ir)
1892 {
1893   /* HIOP is marked as a store because it needs its own DCE logic. */
1894   int uselo = ra_used(ir-1), usehi = ra_used(ir);  /* Loword/hiword used? */
1895   if (LJ_UNLIKELY(!(as->flags & JIT_F_OPT_DCE))) uselo = usehi = 1;
1896 #if LJ_HASFFI || LJ_SOFTFP
1897   if ((ir-1)->o <= IR_NE) {  /* 64 bit integer or FP comparisons. ORDER IR. */
1898     as->curins--;  /* Always skip the loword comparison. */
1899 #if LJ_SOFTFP
1900     if (!irt_isint(ir->t)) {
1901       asm_sfpcomp(as, ir-1);
1902       return;
1903     }
1904 #endif
1905 #if LJ_HASFFI
1906     asm_int64comp(as, ir-1);
1907 #endif
1908     return;
1909 #if LJ_SOFTFP
1910   } else if ((ir-1)->o == IR_MIN || (ir-1)->o == IR_MAX) {
1911     as->curins--;  /* Always skip the loword min/max. */
1912     if (uselo || usehi)
1913       asm_sfpmin_max(as, ir-1, (ir-1)->o == IR_MIN ? CC_PL : CC_LE);
1914     return;
1915 #elif LJ_HASFFI
1916   } else if ((ir-1)->o == IR_CONV) {
1917     as->curins--;  /* Always skip the CONV. */
1918     if (usehi || uselo)
1919       asm_conv64(as, ir);
1920     return;
1921 #endif
1922   } else if ((ir-1)->o == IR_XSTORE) {
1923     if ((ir-1)->r != RID_SINK)
1924       asm_xstore_(as, ir, 4);
1925     return;
1926   }
1927 #endif
1928   if (!usehi) return;  /* Skip unused hiword op for all remaining ops. */
1929   switch ((ir-1)->o) {
1930 #if LJ_HASFFI
1931   case IR_ADD:
1932     as->curins--;
1933     asm_intop(as, ir, ARMI_ADC);
1934     asm_intop(as, ir-1, ARMI_ADD|ARMI_S);
1935     break;
1936   case IR_SUB:
1937     as->curins--;
1938     asm_intop(as, ir, ARMI_SBC);
1939     asm_intop(as, ir-1, ARMI_SUB|ARMI_S);
1940     break;
1941   case IR_NEG:
1942     as->curins--;
1943     asm_intneg(as, ir, ARMI_RSC);
1944     asm_intneg(as, ir-1, ARMI_RSB|ARMI_S);
1945     break;
1946   case IR_CNEWI:
1947     /* Nothing to do here. Handled by lo op itself. */
1948     break;
1949 #endif
1950 #if LJ_SOFTFP
1951   case IR_SLOAD: case IR_ALOAD: case IR_HLOAD: case IR_ULOAD: case IR_VLOAD:
1952   case IR_STRTO:
1953     if (!uselo)
1954       ra_allocref(as, ir->op1, RSET_GPR);  /* Mark lo op as used. */
1955     break;
1956   case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_TOSTR: case IR_TMPREF:
1957     /* Nothing to do here. Handled by lo op itself. */
1958     break;
1959 #endif
1960   case IR_CALLN: case IR_CALLL: case IR_CALLS: case IR_CALLXS:
1961     if (!uselo)
1962       ra_allocref(as, ir->op1, RID2RSET(RID_RETLO));  /* Mark lo op as used. */
1963     break;
1964   default: lj_assertA(0, "bad HIOP for op %d", (ir-1)->o); break;
1965   }
1966 }
1967 
1968 /* -- Profiling ----------------------------------------------------------- */
1969 
asm_prof(ASMState * as,IRIns * ir)1970 static void asm_prof(ASMState *as, IRIns *ir)
1971 {
1972   UNUSED(ir);
1973   asm_guardcc(as, CC_NE);
1974   emit_n(as, ARMI_TST|ARMI_K12|HOOK_PROFILE, RID_TMP);
1975   emit_lsptr(as, ARMI_LDRB, RID_TMP, (void *)&J2G(as->J)->hookmask);
1976 }
1977 
1978 /* -- Stack handling ------------------------------------------------------ */
1979 
1980 /* Check Lua stack size for overflow. Use exit handler as fallback. */
asm_stack_check(ASMState * as,BCReg topslot,IRIns * irp,RegSet allow,ExitNo exitno)1981 static void asm_stack_check(ASMState *as, BCReg topslot,
1982 			    IRIns *irp, RegSet allow, ExitNo exitno)
1983 {
1984   Reg pbase;
1985   uint32_t k;
1986   if (irp) {
1987     if (!ra_hasspill(irp->s)) {
1988       pbase = irp->r;
1989       lj_assertA(ra_hasreg(pbase), "base reg lost");
1990     } else if (allow) {
1991       pbase = rset_pickbot(allow);
1992     } else {
1993       pbase = RID_RET;
1994       emit_lso(as, ARMI_LDR, RID_RET, RID_SP, 0);  /* Restore temp. register. */
1995     }
1996   } else {
1997     pbase = RID_BASE;
1998   }
1999   emit_branch(as, ARMF_CC(ARMI_BL, CC_LS), exitstub_addr(as->J, exitno));
2000   k = emit_isk12(0, (int32_t)(8*topslot));
2001   lj_assertA(k, "slot offset %d does not fit in K12", 8*topslot);
2002   emit_n(as, ARMI_CMP^k, RID_TMP);
2003   emit_dnm(as, ARMI_SUB, RID_TMP, RID_TMP, pbase);
2004   emit_lso(as, ARMI_LDR, RID_TMP, RID_TMP,
2005 	   (int32_t)offsetof(lua_State, maxstack));
2006   if (irp) {  /* Must not spill arbitrary registers in head of side trace. */
2007     int32_t i = i32ptr(&J2G(as->J)->cur_L);
2008     if (ra_hasspill(irp->s))
2009       emit_lso(as, ARMI_LDR, pbase, RID_SP, sps_scale(irp->s));
2010     emit_lso(as, ARMI_LDR, RID_TMP, RID_TMP, (i & 4095));
2011     if (ra_hasspill(irp->s) && !allow)
2012       emit_lso(as, ARMI_STR, RID_RET, RID_SP, 0);  /* Save temp. register. */
2013     emit_loadi(as, RID_TMP, (i & ~4095));
2014   } else {
2015     emit_getgl(as, RID_TMP, cur_L);
2016   }
2017 }
2018 
2019 /* Restore Lua stack from on-trace state. */
asm_stack_restore(ASMState * as,SnapShot * snap)2020 static void asm_stack_restore(ASMState *as, SnapShot *snap)
2021 {
2022   SnapEntry *map = &as->T->snapmap[snap->mapofs];
2023   SnapEntry *flinks = &as->T->snapmap[snap_nextofs(as->T, snap)-1];
2024   MSize n, nent = snap->nent;
2025   /* Store the value of all modified slots to the Lua stack. */
2026   for (n = 0; n < nent; n++) {
2027     SnapEntry sn = map[n];
2028     BCReg s = snap_slot(sn);
2029     int32_t ofs = 8*((int32_t)s-1);
2030     IRRef ref = snap_ref(sn);
2031     IRIns *ir = IR(ref);
2032     if ((sn & SNAP_NORESTORE))
2033       continue;
2034     if (irt_isnum(ir->t)) {
2035 #if LJ_SOFTFP
2036       RegSet odd = rset_exclude(RSET_GPRODD, RID_BASE);
2037       Reg tmp;
2038       /* LJ_SOFTFP: must be a number constant. */
2039       lj_assertA(irref_isk(ref), "unsplit FP op");
2040       tmp = ra_allock(as, (int32_t)ir_knum(ir)->u32.lo,
2041 		      rset_exclude(RSET_GPREVEN, RID_BASE));
2042       emit_lso(as, ARMI_STR, tmp, RID_BASE, ofs);
2043       if (rset_test(as->freeset, tmp+1)) odd = RID2RSET(tmp+1);
2044       tmp = ra_allock(as, (int32_t)ir_knum(ir)->u32.hi, odd);
2045       emit_lso(as, ARMI_STR, tmp, RID_BASE, ofs+4);
2046 #else
2047       Reg src = ra_alloc1(as, ref, RSET_FPR);
2048       emit_vlso(as, ARMI_VSTR_D, src, RID_BASE, ofs);
2049 #endif
2050     } else {
2051       RegSet odd = rset_exclude(RSET_GPRODD, RID_BASE);
2052       Reg type;
2053       lj_assertA(irt_ispri(ir->t) || irt_isaddr(ir->t) || irt_isinteger(ir->t),
2054 		 "restore of IR type %d", irt_type(ir->t));
2055       if (!irt_ispri(ir->t)) {
2056 	Reg src = ra_alloc1(as, ref, rset_exclude(RSET_GPREVEN, RID_BASE));
2057 	emit_lso(as, ARMI_STR, src, RID_BASE, ofs);
2058 	if (rset_test(as->freeset, src+1)) odd = RID2RSET(src+1);
2059       }
2060       if ((sn & (SNAP_CONT|SNAP_FRAME))) {
2061 	if (s == 0) continue;  /* Do not overwrite link to previous frame. */
2062 	type = ra_allock(as, (int32_t)(*flinks--), odd);
2063 #if LJ_SOFTFP
2064       } else if ((sn & SNAP_SOFTFPNUM)) {
2065 	type = ra_alloc1(as, ref+1, rset_exclude(RSET_GPRODD, RID_BASE));
2066 #endif
2067       } else if ((sn & SNAP_KEYINDEX)) {
2068 	type = ra_allock(as, (int32_t)LJ_KEYINDEX, odd);
2069       } else {
2070 	type = ra_allock(as, (int32_t)irt_toitype(ir->t), odd);
2071       }
2072       emit_lso(as, ARMI_STR, type, RID_BASE, ofs+4);
2073     }
2074     checkmclim(as);
2075   }
2076   lj_assertA(map + nent == flinks, "inconsistent frames in snapshot");
2077 }
2078 
2079 /* -- GC handling --------------------------------------------------------- */
2080 
2081 /* Marker to prevent patching the GC check exit. */
2082 #define ARM_NOPATCH_GC_CHECK	(ARMI_BIC|ARMI_K12)
2083 
2084 /* Check GC threshold and do one or more GC steps. */
asm_gc_check(ASMState * as)2085 static void asm_gc_check(ASMState *as)
2086 {
2087   const CCallInfo *ci = &lj_ir_callinfo[IRCALL_lj_gc_step_jit];
2088   IRRef args[2];
2089   MCLabel l_end;
2090   Reg tmp1, tmp2;
2091   ra_evictset(as, RSET_SCRATCH);
2092   l_end = emit_label(as);
2093   /* Exit trace if in GCSatomic or GCSfinalize. Avoids syncing GC objects. */
2094   asm_guardcc(as, CC_NE);  /* Assumes asm_snap_prep() already done. */
2095   *--as->mcp = ARM_NOPATCH_GC_CHECK;
2096   emit_n(as, ARMI_CMP|ARMI_K12|0, RID_RET);
2097   args[0] = ASMREF_TMP1;  /* global_State *g */
2098   args[1] = ASMREF_TMP2;  /* MSize steps     */
2099   asm_gencall(as, ci, args);
2100   tmp1 = ra_releasetmp(as, ASMREF_TMP1);
2101   tmp2 = ra_releasetmp(as, ASMREF_TMP2);
2102   emit_loadi(as, tmp2, as->gcsteps);
2103   /* Jump around GC step if GC total < GC threshold. */
2104   emit_branch(as, ARMF_CC(ARMI_B, CC_LS), l_end);
2105   emit_nm(as, ARMI_CMP, RID_TMP, tmp2);
2106   emit_lso(as, ARMI_LDR, tmp2, tmp1,
2107 	   (int32_t)offsetof(global_State, gc.threshold));
2108   emit_lso(as, ARMI_LDR, RID_TMP, tmp1,
2109 	   (int32_t)offsetof(global_State, gc.total));
2110   ra_allockreg(as, i32ptr(J2G(as->J)), tmp1);
2111   as->gcsteps = 0;
2112   checkmclim(as);
2113 }
2114 
2115 /* -- Loop handling ------------------------------------------------------- */
2116 
2117 /* Fixup the loop branch. */
asm_loop_fixup(ASMState * as)2118 static void asm_loop_fixup(ASMState *as)
2119 {
2120   MCode *p = as->mctop;
2121   MCode *target = as->mcp;
2122   if (as->loopinv) {  /* Inverted loop branch? */
2123     /* asm_guardcc already inverted the bcc and patched the final bl. */
2124     p[-2] |= ((uint32_t)(target-p) & 0x00ffffffu);
2125   } else {
2126     p[-1] = ARMI_B | ((uint32_t)((target-p)-1) & 0x00ffffffu);
2127   }
2128 }
2129 
2130 /* Fixup the tail of the loop. */
asm_loop_tail_fixup(ASMState * as)2131 static void asm_loop_tail_fixup(ASMState *as)
2132 {
2133   UNUSED(as);  /* Nothing to do. */
2134 }
2135 
2136 /* -- Head of trace ------------------------------------------------------- */
2137 
2138 /* Reload L register from g->cur_L. */
asm_head_lreg(ASMState * as)2139 static void asm_head_lreg(ASMState *as)
2140 {
2141   IRIns *ir = IR(ASMREF_L);
2142   if (ra_used(ir)) {
2143     Reg r = ra_dest(as, ir, RSET_GPR);
2144     emit_getgl(as, r, cur_L);
2145     ra_evictk(as);
2146   }
2147 }
2148 
2149 /* Coalesce BASE register for a root trace. */
asm_head_root_base(ASMState * as)2150 static void asm_head_root_base(ASMState *as)
2151 {
2152   IRIns *ir;
2153   asm_head_lreg(as);
2154   ir = IR(REF_BASE);
2155   if (ra_hasreg(ir->r) && (rset_test(as->modset, ir->r) || irt_ismarked(ir->t)))
2156     ra_spill(as, ir);
2157   ra_destreg(as, ir, RID_BASE);
2158 }
2159 
2160 /* Coalesce BASE register for a side trace. */
asm_head_side_base(ASMState * as,IRIns * irp,RegSet allow)2161 static RegSet asm_head_side_base(ASMState *as, IRIns *irp, RegSet allow)
2162 {
2163   IRIns *ir;
2164   asm_head_lreg(as);
2165   ir = IR(REF_BASE);
2166   if (ra_hasreg(ir->r) && (rset_test(as->modset, ir->r) || irt_ismarked(ir->t)))
2167     ra_spill(as, ir);
2168   if (ra_hasspill(irp->s)) {
2169     rset_clear(allow, ra_dest(as, ir, allow));
2170   } else {
2171     Reg r = irp->r;
2172     lj_assertA(ra_hasreg(r), "base reg lost");
2173     rset_clear(allow, r);
2174     if (r != ir->r && !rset_test(as->freeset, r))
2175       ra_restore(as, regcost_ref(as->cost[r]));
2176     ra_destreg(as, ir, r);
2177   }
2178   return allow;
2179 }
2180 
2181 /* -- Tail of trace ------------------------------------------------------- */
2182 
2183 /* Fixup the tail code. */
asm_tail_fixup(ASMState * as,TraceNo lnk)2184 static void asm_tail_fixup(ASMState *as, TraceNo lnk)
2185 {
2186   MCode *p = as->mctop;
2187   MCode *target;
2188   int32_t spadj = as->T->spadjust;
2189   if (spadj == 0) {
2190     as->mctop = --p;
2191   } else {
2192     /* Patch stack adjustment. */
2193     uint32_t k = emit_isk12(ARMI_ADD, spadj);
2194     lj_assertA(k, "stack adjustment %d does not fit in K12", spadj);
2195     p[-2] = (ARMI_ADD^k) | ARMF_D(RID_SP) | ARMF_N(RID_SP);
2196   }
2197   /* Patch exit branch. */
2198   target = lnk ? traceref(as->J, lnk)->mcode : (MCode *)lj_vm_exit_interp;
2199   p[-1] = ARMI_B|(((target-p)-1)&0x00ffffffu);
2200 }
2201 
2202 /* Prepare tail of code. */
asm_tail_prep(ASMState * as)2203 static void asm_tail_prep(ASMState *as)
2204 {
2205   MCode *p = as->mctop - 1;  /* Leave room for exit branch. */
2206   if (as->loopref) {
2207     as->invmcp = as->mcp = p;
2208   } else {
2209     as->mcp = p-1;  /* Leave room for stack pointer adjustment. */
2210     as->invmcp = NULL;
2211   }
2212   *p = 0;  /* Prevent load/store merging. */
2213 }
2214 
2215 /* -- Trace setup --------------------------------------------------------- */
2216 
2217 /* Ensure there are enough stack slots for call arguments. */
asm_setup_call_slots(ASMState * as,IRIns * ir,const CCallInfo * ci)2218 static Reg asm_setup_call_slots(ASMState *as, IRIns *ir, const CCallInfo *ci)
2219 {
2220   IRRef args[CCI_NARGS_MAX*2];
2221   uint32_t i, nargs = CCI_XNARGS(ci);
2222   int nslots = 0, ngpr = REGARG_NUMGPR, nfpr = REGARG_NUMFPR, fprodd = 0;
2223   asm_collectargs(as, ir, ci, args);
2224   for (i = 0; i < nargs; i++) {
2225     if (!LJ_SOFTFP && args[i] && irt_isfp(IR(args[i])->t)) {
2226       if (!LJ_ABI_SOFTFP && !(ci->flags & CCI_VARARG)) {
2227 	if (irt_isnum(IR(args[i])->t)) {
2228 	  if (nfpr > 0) nfpr--;
2229 	  else fprodd = 0, nslots = (nslots + 3) & ~1;
2230 	} else {
2231 	  if (fprodd) fprodd--;
2232 	  else if (nfpr > 0) fprodd = 1, nfpr--;
2233 	  else nslots++;
2234 	}
2235       } else if (irt_isnum(IR(args[i])->t)) {
2236 	ngpr &= ~1;
2237 	if (ngpr > 0) ngpr -= 2; else nslots += 2;
2238       } else {
2239 	if (ngpr > 0) ngpr--; else nslots++;
2240       }
2241     } else {
2242       if (ngpr > 0) ngpr--; else nslots++;
2243     }
2244   }
2245   if (nslots > as->evenspill)  /* Leave room for args in stack slots. */
2246     as->evenspill = nslots;
2247   return REGSP_HINT(RID_RET);
2248 }
2249 
asm_setup_target(ASMState * as)2250 static void asm_setup_target(ASMState *as)
2251 {
2252   /* May need extra exit for asm_stack_check on side traces. */
2253   asm_exitstub_setup(as, as->T->nsnap + (as->parent ? 1 : 0));
2254 }
2255 
2256 /* -- Trace patching ------------------------------------------------------ */
2257 
2258 /* Patch exit jumps of existing machine code to a new target. */
lj_asm_patchexit(jit_State * J,GCtrace * T,ExitNo exitno,MCode * target)2259 void lj_asm_patchexit(jit_State *J, GCtrace *T, ExitNo exitno, MCode *target)
2260 {
2261   MCode *p = T->mcode;
2262   MCode *pe = (MCode *)((char *)p + T->szmcode);
2263   MCode *cstart = NULL, *cend = p;
2264   MCode *mcarea = lj_mcode_patch(J, p, 0);
2265   MCode *px = exitstub_addr(J, exitno) - 2;
2266   for (; p < pe; p++) {
2267     /* Look for bl_cc exitstub, replace with b_cc target. */
2268     uint32_t ins = *p;
2269     if ((ins & 0x0f000000u) == 0x0b000000u && ins < 0xf0000000u &&
2270 	((ins ^ (px-p)) & 0x00ffffffu) == 0 &&
2271 	p[-1] != ARM_NOPATCH_GC_CHECK) {
2272       *p = (ins & 0xfe000000u) | (((target-p)-2) & 0x00ffffffu);
2273       cend = p+1;
2274       if (!cstart) cstart = p;
2275     }
2276   }
2277   lj_assertJ(cstart != NULL, "exit stub %d not found", exitno);
2278   lj_mcode_sync(cstart, cend);
2279   lj_mcode_patch(J, mcarea, 1);
2280 }
2281 
2282