-
Notifications
You must be signed in to change notification settings - Fork 0
/
rega.c
696 lines (643 loc) · 13.9 KB
/
rega.c
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
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
#include "all.h"
#ifdef TEST_PMOV
#undef assert
#define assert(x) assert_test(#x, x)
#endif
typedef struct RMap RMap;
struct RMap {
int t[Tmp0];
int r[Tmp0];
int w[Tmp0]; /* wait list, for unmatched hints */
BSet b[1];
int n;
};
static bits regu; /* registers used */
static Tmp *tmp; /* function temporaries */
static Mem *mem; /* function mem references */
static struct {
Ref src, dst;
int cls;
} pm[Tmp0]; /* parallel move constructed */
static int npm; /* size of pm */
static int loop; /* current loop level */
static uint stmov; /* stats: added moves */
static uint stblk; /* stats: added blocks */
static int *
hint(int t)
{
return &tmp[phicls(t, tmp)].hint.r;
}
static void
sethint(int t, int r)
{
Tmp *p;
p = &tmp[phicls(t, tmp)];
if (p->hint.r == -1 || p->hint.w > loop) {
p->hint.r = r;
p->hint.w = loop;
tmp[t].visit = -1;
}
}
static void
rcopy(RMap *ma, RMap *mb)
{
memcpy(ma->t, mb->t, sizeof ma->t);
memcpy(ma->r, mb->r, sizeof ma->r);
memcpy(ma->w, mb->w, sizeof ma->w);
bscopy(ma->b, mb->b);
ma->n = mb->n;
}
static int
rfind(RMap *m, int t)
{
int i;
for (i=0; i<m->n; i++)
if (m->t[i] == t)
return m->r[i];
return -1;
}
static Ref
rref(RMap *m, int t)
{
int r, s;
r = rfind(m, t);
if (r == -1) {
s = tmp[t].slot;
assert(s != -1 && "should have spilled");
return SLOT(s);
} else
return TMP(r);
}
static void
radd(RMap *m, int t, int r)
{
assert((t >= Tmp0 || t == r) && "invalid temporary");
assert(((T.gpr0 <= r && r < T.gpr0 + T.ngpr)
|| (T.fpr0 <= r && r < T.fpr0 + T.nfpr))
&& "invalid register");
assert(!bshas(m->b, t) && "temporary has mapping");
assert(!bshas(m->b, r) && "register already allocated");
assert(m->n <= T.ngpr+T.nfpr && "too many mappings");
bsset(m->b, t);
bsset(m->b, r);
m->t[m->n] = t;
m->r[m->n] = r;
m->n++;
regu |= BIT(r);
}
static Ref
ralloctry(RMap *m, int t, int try)
{
bits regs;
int h, r, r0, r1;
if (t < Tmp0) {
assert(bshas(m->b, t));
return TMP(t);
}
if (bshas(m->b, t)) {
r = rfind(m, t);
assert(r != -1);
return TMP(r);
}
r = tmp[t].visit;
if (r == -1 || bshas(m->b, r))
r = *hint(t);
if (r == -1 || bshas(m->b, r)) {
if (try)
return R;
regs = tmp[phicls(t, tmp)].hint.m;
regs |= m->b->t[0];
if (KBASE(tmp[t].cls) == 0) {
r0 = T.gpr0;
r1 = r0 + T.ngpr;
} else {
r0 = T.fpr0;
r1 = r0 + T.nfpr;
}
for (r=r0; r<r1; r++)
if (!(regs & BIT(r)))
goto Found;
for (r=r0; r<r1; r++)
if (!bshas(m->b, r))
goto Found;
die("no more regs");
}
Found:
radd(m, t, r);
sethint(t, r);
tmp[t].visit = r;
h = *hint(t);
if (h != -1 && h != r)
m->w[h] = t;
return TMP(r);
}
static inline Ref
ralloc(RMap *m, int t)
{
return ralloctry(m, t, 0);
}
static int
rfree(RMap *m, int t)
{
int i, r;
assert(t >= Tmp0 || !(BIT(t) & T.rglob));
if (!bshas(m->b, t))
return -1;
for (i=0; m->t[i] != t; i++)
assert(i+1 < m->n);
r = m->r[i];
bsclr(m->b, t);
bsclr(m->b, r);
m->n--;
memmove(&m->t[i], &m->t[i+1], (m->n-i) * sizeof m->t[0]);
memmove(&m->r[i], &m->r[i+1], (m->n-i) * sizeof m->r[0]);
assert(t >= Tmp0 || t == r);
return r;
}
static void
mdump(RMap *m)
{
int i;
for (i=0; i<m->n; i++)
if (m->t[i] >= Tmp0)
fprintf(stderr, " (%s, R%d)",
tmp[m->t[i]].name,
m->r[i]);
fprintf(stderr, "\n");
}
static void
pmadd(Ref src, Ref dst, int k)
{
if (npm == Tmp0)
die("cannot have more moves than registers");
pm[npm].src = src;
pm[npm].dst = dst;
pm[npm].cls = k;
npm++;
}
enum PMStat { ToMove, Moving, Moved };
static int
pmrec(enum PMStat *status, int i, int *k)
{
int j, c;
/* note, this routine might emit
* too many large instructions
*/
if (req(pm[i].src, pm[i].dst)) {
status[i] = Moved;
return -1;
}
// assert(KBASE(pm[i].cls) == KBASE(*k));
assert((Kw|Kl) == Kl && (Ks|Kd) == Kd);
*k |= pm[i].cls;
for (j=0; j<npm; j++)
if (req(pm[j].dst, pm[i].src))
break;
switch (j == npm ? Moved : status[j]) {
case Moving:
c = j; /* start of cycle */
emit(Oswap, *k, R, pm[i].src, pm[i].dst);
break;
case ToMove:
status[i] = Moving;
c = pmrec(status, j, k);
if (c == i) {
c = -1; /* end of cycle */
break;
}
if (c != -1) {
emit(Oswap, *k, R, pm[i].src, pm[i].dst);
break;
}
/* fall through */
case Moved:
c = -1;
emit(Ocopy, pm[i].cls, pm[i].dst, pm[i].src, R);
break;
}
status[i] = Moved;
return c;
}
static void
pmgen()
{
int i;
enum PMStat *status;
status = alloc(npm * sizeof status[0]);
assert(!npm || status[npm-1] == ToMove);
for (i=0; i<npm; i++)
if (status[i] == ToMove)
pmrec(status, i, (int[]){pm[i].cls});
}
static void
move(int r, Ref to, RMap *m)
{
int n, t, r1;
r1 = req(to, R) ? -1 : rfree(m, to.val);
if (bshas(m->b, r)) {
/* r is used and not by to */
assert(r1 != r);
for (n=0; m->r[n] != r; n++)
assert(n+1 < m->n);
t = m->t[n];
rfree(m, t);
bsset(m->b, r);
ralloc(m, t);
bsclr(m->b, r);
}
t = req(to, R) ? r : to.val;
radd(m, t, r);
}
static int
regcpy(Ins *i)
{
return i->op == Ocopy && isreg(i->arg[0]);
}
static Ins *
dopm(Blk *b, Ins *i, RMap *m)
{
RMap m0;
int n, r, r1, t, s;
Ins *i1, *ip;
bits def;
m0 = *m; /* okay since we don't use m0.b */
m0.b->t = 0;
i1 = ++i;
do {
i--;
move(i->arg[0].val, i->to, m);
} while (i != b->ins && regcpy(i-1));
assert(m0.n <= m->n);
if (i != b->ins && (i-1)->op == Ocall) {
def = T.retregs((i-1)->arg[1], 0) | T.rglob;
for (r=0; T.rsave[r]>=0; r++)
if (!(BIT(T.rsave[r]) & def))
move(T.rsave[r], R, m);
}
for (npm=0, n=0; n<m->n; n++) {
t = m->t[n];
s = tmp[t].slot;
r1 = m->r[n];
r = rfind(&m0, t);
if (r != -1)
pmadd(TMP(r1), TMP(r), tmp[t].cls);
else if (s != -1)
pmadd(TMP(r1), SLOT(s), tmp[t].cls);
}
for (ip=i; ip<i1; ip++) {
if (!req(ip->to, R))
rfree(m, ip->to.val);
r = ip->arg[0].val;
if (rfind(m, r) == -1)
radd(m, r, r);
}
pmgen();
return i;
}
static int
prio1(Ref r1, Ref r2)
{
/* trivial heuristic to begin with,
* later we can use the distance to
* the definition instruction
*/
(void) r2;
return *hint(r1.val) != -1;
}
static void
insert(Ref *r, Ref **rs, int p)
{
int i;
rs[i = p] = r;
while (i-- > 0 && prio1(*r, *rs[i])) {
rs[i+1] = rs[i];
rs[i] = r;
}
}
static void
doblk(Blk *b, RMap *cur)
{
int t, x, r, rf, rt, nr;
bits rs;
Ins *i, *i1;
Mem *m;
Ref *ra[4];
for (r=0; bsiter(b->out, &r) && r<Tmp0; r++)
radd(cur, r, r);
if (rtype(b->jmp.arg) == RTmp)
b->jmp.arg = ralloc(cur, b->jmp.arg.val);
curi = &insb[NIns];
for (i1=&b->ins[b->nins]; i1!=b->ins;) {
emiti(*--i1);
i = curi;
rf = -1;
switch (i->op) {
case Ocall:
rs = T.argregs(i->arg[1], 0) | T.rglob;
for (r=0; T.rsave[r]>=0; r++)
if (!(BIT(T.rsave[r]) & rs))
rfree(cur, T.rsave[r]);
break;
case Ocopy:
if (regcpy(i)) {
curi++;
i1 = dopm(b, i1, cur);
stmov += i+1 - curi;
continue;
}
if (isreg(i->to))
if (rtype(i->arg[0]) == RTmp)
sethint(i->arg[0].val, i->to.val);
/* fall through */
default:
if (!req(i->to, R)) {
assert(rtype(i->to) == RTmp);
r = i->to.val;
if (r < Tmp0 && (BIT(r) & T.rglob))
break;
rf = rfree(cur, r);
if (rf == -1) {
assert(!isreg(i->to));
curi++;
continue;
}
i->to = TMP(rf);
}
break;
}
for (x=0, nr=0; x<2; x++)
switch (rtype(i->arg[x])) {
case RMem:
m = &mem[i->arg[x].val];
if (rtype(m->base) == RTmp)
insert(&m->base, ra, nr++);
if (rtype(m->index) == RTmp)
insert(&m->index, ra, nr++);
break;
case RTmp:
insert(&i->arg[x], ra, nr++);
break;
}
for (r=0; r<nr; r++)
*ra[r] = ralloc(cur, ra[r]->val);
if (i->op == Ocopy && req(i->to, i->arg[0]))
curi++;
/* try to change the register of a hinted
* temporary if rf is available */
if (rf != -1 && (t = cur->w[rf]) != 0)
if (!bshas(cur->b, rf) && *hint(t) == rf
&& (rt = rfree(cur, t)) != -1) {
tmp[t].visit = -1;
ralloc(cur, t);
assert(bshas(cur->b, rf));
emit(Ocopy, tmp[t].cls, TMP(rt), TMP(rf), R);
stmov += 1;
cur->w[rf] = 0;
for (r=0; r<nr; r++)
if (req(*ra[r], TMP(rt)))
*ra[r] = TMP(rf);
/* one could iterate this logic with
* the newly freed rt, but in this case
* the above loop must be changed */
}
}
b->nins = &insb[NIns] - curi;
idup(&b->ins, curi, b->nins);
}
/* qsort() comparison function to peel
* loop nests from inside out */
static int
carve(const void *a, const void *b)
{
Blk *ba, *bb;
/* todo, evaluate if this order is really
* better than the simple postorder */
ba = *(Blk**)a;
bb = *(Blk**)b;
if (ba->loop == bb->loop)
return ba->id > bb->id ? -1 : ba->id < bb->id;
return ba->loop > bb->loop ? -1 : +1;
}
/* comparison function to order temporaries
* for allocation at the end of blocks */
static int
prio2(int t1, int t2)
{
if ((tmp[t1].visit ^ tmp[t2].visit) < 0) /* != signs */
return tmp[t1].visit != -1 ? +1 : -1;
if ((*hint(t1) ^ *hint(t2)) < 0)
return *hint(t1) != -1 ? +1 : -1;
return tmp[t1].cost - tmp[t2].cost;
}
/* register allocation
* depends on rpo, phi, cost, (and obviously spill)
*/
void
rega(Fn *fn)
{
int j, t, r, x, rl[Tmp0];
Blk *b, *b1, *s, ***ps, *blist, **blk, **bp;
RMap *end, *beg, cur, old, *m;
Ins *i;
Phi *p;
uint u, n;
Ref src, dst;
/* 1. setup */
stmov = 0;
stblk = 0;
regu = 0;
tmp = fn->tmp;
mem = fn->mem;
blk = alloc(fn->nblk * sizeof blk[0]);
end = alloc(fn->nblk * sizeof end[0]);
beg = alloc(fn->nblk * sizeof beg[0]);
for (n=0; n<fn->nblk; n++) {
bsinit(end[n].b, fn->ntmp);
bsinit(beg[n].b, fn->ntmp);
}
bsinit(cur.b, fn->ntmp);
bsinit(old.b, fn->ntmp);
loop = INT_MAX;
for (t=0; t<fn->ntmp; t++) {
tmp[t].hint.r = t < Tmp0 ? t : -1;
tmp[t].hint.w = loop;
tmp[t].visit = -1;
}
for (bp=blk, b=fn->start; b; b=b->link)
*bp++ = b;
qsort(blk, fn->nblk, sizeof blk[0], carve);
for (b=fn->start, i=b->ins; i<&b->ins[b->nins]; i++)
if (i->op != Ocopy || !isreg(i->arg[0]))
break;
else {
assert(rtype(i->to) == RTmp);
sethint(i->to.val, i->arg[0].val);
}
/* 2. assign registers */
for (bp=blk; bp<&blk[fn->nblk]; bp++) {
b = *bp;
n = b->id;
loop = b->loop;
cur.n = 0;
bszero(cur.b);
memset(cur.w, 0, sizeof cur.w);
for (x=0, t=Tmp0; bsiter(b->out, &t); t++) {
j = x++;
rl[j] = t;
while (j-- > 0 && prio2(t, rl[j]) > 0) {
rl[j+1] = rl[j];
rl[j] = t;
}
}
for (j=0; j<x; j++)
ralloctry(&cur, rl[j], 1);
for (j=0; j<x; j++)
ralloc(&cur, rl[j]);
rcopy(&end[n], &cur);
doblk(b, &cur);
bscopy(b->in, cur.b);
for (p=b->phi; p; p=p->link)
if (rtype(p->to) == RTmp)
bsclr(b->in, p->to.val);
rcopy(&beg[n], &cur);
}
/* 3. emit copies shared by multiple edges
* to the same block */
for (s=fn->start; s; s=s->link) {
if (s->npred <= 1)
continue;
m = &beg[s->id];
/* rl maps a register that is live at the
* beginning of s to the one used in all
* predecessors (if any, -1 otherwise) */
memset(rl, 0, sizeof rl);
/* to find the register of a phi in a
* predecessor, we have to find the
* corresponding argument */
for (p=s->phi; p; p=p->link) {
if (rtype(p->to) != RTmp
|| (r=rfind(m, p->to.val)) == -1)
continue;
for (u=0; u<p->narg; u++) {
b = p->blk[u];
src = p->arg[u];
if (rtype(src) != RTmp)
continue;
x = rfind(&end[b->id], src.val);
if (x == -1) /* spilled */
continue;
rl[r] = (!rl[r] || rl[r] == x) ? x : -1;
}
if (rl[r] == 0)
rl[r] = -1;
}
/* process non-phis temporaries */
for (j=0; j<m->n; j++) {
t = m->t[j];
r = m->r[j];
if (rl[r] || t < Tmp0 /* todo, remove this */)
continue;
for (bp=s->pred; bp<&s->pred[s->npred]; bp++) {
x = rfind(&end[(*bp)->id], t);
if (x == -1) /* spilled */
continue;
rl[r] = (!rl[r] || rl[r] == x) ? x : -1;
}
if (rl[r] == 0)
rl[r] = -1;
}
npm = 0;
for (j=0; j<m->n; j++) {
t = m->t[j];
r = m->r[j];
x = rl[r];
assert(x != 0 || t < Tmp0 /* todo, ditto */);
if (x > 0 && !bshas(m->b, x)) {
pmadd(TMP(x), TMP(r), tmp[t].cls);
m->r[j] = x;
bsset(m->b, x);
}
}
curi = &insb[NIns];
pmgen();
j = &insb[NIns] - curi;
if (j == 0)
continue;
stmov += j;
s->nins += j;
i = alloc(s->nins * sizeof(Ins));
icpy(icpy(i, curi, j), s->ins, s->nins-j);
s->ins = i;
}
if (debug['R']) {
fprintf(stderr, "\n> Register mappings:\n");
for (n=0; n<fn->nblk; n++) {
b = fn->rpo[n];
fprintf(stderr, "\t%-10s beg", b->name);
mdump(&beg[n]);
fprintf(stderr, "\t end");
mdump(&end[n]);
}
fprintf(stderr, "\n");
}
/* 4. emit remaining copies in new blocks */
blist = 0;
for (b=fn->start;; b=b->link) {
ps = (Blk**[3]){&b->s1, &b->s2, (Blk*[1]){0}};
for (; (s=**ps); ps++) {
npm = 0;
for (p=s->phi; p; p=p->link) {
dst = p->to;
assert(rtype(dst)==RSlot || rtype(dst)==RTmp);
if (rtype(dst) == RTmp) {
r = rfind(&beg[s->id], dst.val);
if (r == -1)
continue;
dst = TMP(r);
}
for (u=0; p->blk[u]!=b; u++)
assert(u+1 < p->narg);
src = p->arg[u];
if (rtype(src) == RTmp)
src = rref(&end[b->id], src.val);
pmadd(src, dst, p->cls);
}
for (t=Tmp0; bsiter(s->in, &t); t++) {
src = rref(&end[b->id], t);
dst = rref(&beg[s->id], t);
pmadd(src, dst, tmp[t].cls);
}
curi = &insb[NIns];
pmgen();
if (curi == &insb[NIns])
continue;
b1 = blknew();
b1->loop = (b->loop+s->loop) / 2;
b1->link = blist;
blist = b1;
fn->nblk++;
(void)!snprintf(b1->name, sizeof(b1->name), "%s_%s", b->name, s->name);
b1->nins = &insb[NIns] - curi;
stmov += b1->nins;
stblk += 1;
idup(&b1->ins, curi, b1->nins);
b1->jmp.type = Jjmp;
b1->s1 = s;
**ps = b1;
}
if (!b->link) {
b->link = blist;
break;
}
}
for (b=fn->start; b; b=b->link)
b->phi = 0;
fn->reg = regu;
if (debug['R']) {
fprintf(stderr, "\n> Register allocation statistics:\n");
fprintf(stderr, "\tnew moves: %d\n", stmov);
fprintf(stderr, "\tnew blocks: %d\n", stblk);
fprintf(stderr, "\n> After register allocation:\n");
printfn(fn, stderr);
}
}