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1.1 root 1: static char *sccsid ="%W% (Berkeley) %G%";
2: # include "mfile2"
3:
4: NODE resc[3];
5:
6: int busy[REGSZ];
7:
8: int maxa, mina, maxb, minb;
9:
10: # ifndef ALLO0
11: allo0(){ /* free everything */
12:
13: register i;
14:
15: maxa = maxb = -1;
16: mina = minb = 0;
17:
18: REGLOOP(i){
19: busy[i] = 0;
20: if( rstatus[i] & STAREG ){
21: if( maxa<0 ) mina = i;
22: maxa = i;
23: }
24: if( rstatus[i] & STBREG ){
25: if( maxb<0 ) minb = i;
26: maxb = i;
27: }
28: }
29: }
30: # endif
31:
32: # define TBUSY 01000
33:
34: # ifndef ALLO
35: allo( p, q ) NODE *p; struct optab *q; {
36:
37: register n, i, j;
38: int either;
39:
40: n = q->needs;
41: either = ( EITHER & n );
42: i = 0;
43:
44: while( n & NACOUNT ){
45: resc[i].in.op = REG;
46: resc[i].tn.rval = freereg( p, n&NAMASK );
47: resc[i].tn.lval = 0;
48: #ifdef FLEXNAMES
49: resc[i].in.name = "";
50: #else
51: resc[i].in.name[0] = '\0';
52: #endif
53: n -= NAREG;
54: ++i;
55: }
56:
57: if (either) { /* all or nothing at all */
58: for( j = 0; j < i; j++ )
59: if( resc[j].tn.rval < 0 ) { /* nothing */
60: i = 0;
61: break;
62: }
63: if( i != 0 ) goto ok; /* all */
64: }
65:
66: while( n & NBCOUNT ){
67: resc[i].in.op = REG;
68: resc[i].tn.rval = freereg( p, n&NBMASK );
69: resc[i].tn.lval = 0;
70: #ifdef FLEXNAMES
71: resc[i].in.name = "";
72: #else
73: resc[i].in.name[0] = '\0';
74: #endif
75: n -= NBREG;
76: ++i;
77: }
78: if (either) { /* all or nothing at all */
79: for( j = 0; j < i; j++ )
80: if( resc[j].tn.rval < 0 ) { /* nothing */
81: i = 0;
82: break;
83: }
84: if( i != 0 ) goto ok; /* all */
85: }
86:
87: if( n & NTMASK ){
88: resc[i].in.op = OREG;
89: resc[i].tn.rval = TMPREG;
90: if( p->in.op == STCALL || p->in.op == STARG || p->in.op == UNARY STCALL || p->in.op == STASG ){
91: resc[i].tn.lval = freetemp( (SZCHAR*p->stn.stsize + (SZINT-1))/SZINT );
92: }
93: else {
94: resc[i].tn.lval = freetemp( (n&NTMASK)/NTEMP );
95: }
96: #ifdef FLEXNAMES
97: resc[i].in.name = "";
98: #else
99: resc[i].in.name[0] = '\0';
100: #endif
101:
102: resc[i].tn.lval = BITOOR(resc[i].tn.lval);
103: ++i;
104: }
105:
106: /* turn off "temporarily busy" bit */
107:
108: ok:
109: REGLOOP(j){
110: busy[j] &= ~TBUSY;
111: }
112:
113: for( j=0; j<i; ++j ) if( resc[j].tn.rval < 0 ) return(0);
114: return(1);
115:
116: }
117: # endif
118:
119: extern unsigned int offsz;
120: freetemp( k ){ /* allocate k integers worth of temp space */
121: /* we also make the convention that, if the number of words is more than 1,
122: /* it must be aligned for storing doubles... */
123:
124: # ifndef BACKTEMP
125: int t;
126:
127: if( k>1 ){
128: SETOFF( tmpoff, ALDOUBLE );
129: }
130:
131: t = tmpoff;
132: tmpoff += k*SZINT;
133: if( tmpoff > maxoff ) maxoff = tmpoff;
134: if( tmpoff >= offsz )
135: cerror( "stack overflow" );
136: if( tmpoff-baseoff > maxtemp ) maxtemp = tmpoff-baseoff;
137: return(t);
138:
139: # else
140: tmpoff += k*SZINT;
141: if( k>1 ) {
142: SETOFF( tmpoff, ALDOUBLE );
143: }
144: if( tmpoff > maxoff ) maxoff = tmpoff;
145: if( tmpoff >= offsz )
146: cerror( "stack overflow" );
147: if( tmpoff-baseoff > maxtemp ) maxtemp = tmpoff-baseoff;
148: return( -tmpoff );
149: # endif
150: }
151:
152: freereg( p, n ) NODE *p; {
153: /* allocate a register of type n */
154: /* p gives the type, if floating */
155:
156: register j;
157:
158: /* not general; means that only one register (the result) OK for call */
159: if( callop(p->in.op) ){
160: j = callreg(p);
161: if( usable( p, n, j ) ) return( j );
162: /* have allocated callreg first */
163: }
164: j = p->in.rall & ~MUSTDO;
165: if( j!=NOPREF && usable(p,n,j) ){ /* needed and not allocated */
166: return( j );
167: }
168: if( n&NAMASK ){
169: for( j=mina; j<=maxa; ++j ) if( rstatus[j]&STAREG ){
170: if( usable(p,n,j) ){
171: return( j );
172: }
173: }
174: }
175: else if( n &NBMASK ){
176: for( j=minb; j<=maxb; ++j ) if( rstatus[j]&STBREG ){
177: if( usable(p,n,j) ){
178: return(j);
179: }
180: }
181: }
182:
183: return( -1 );
184: }
185:
186: # ifndef USABLE
187: usable( p, n, r ) NODE *p; {
188: /* decide if register r is usable in tree p to satisfy need n */
189:
190: /* checks, for the moment */
191: if( !istreg(r) ) cerror( "usable asked about nontemp register" );
192:
193: if( busy[r] > 1 ) return(0);
194: if( isbreg(r) ){
195: if( n&NAMASK ) return(0);
196: }
197: else {
198: if( n & NBMASK ) return(0);
199: }
200: if( (n&NAMASK) && (szty(p->in.type) == 2) ){ /* only do the pairing for real regs */
201: if( r&01 ) return(0);
202: if( !istreg(r+1) ) return( 0 );
203: if( busy[r+1] > 1 ) return( 0 );
204: if( busy[r] == 0 && busy[r+1] == 0 ||
205: busy[r+1] == 0 && shareit( p, r, n ) ||
206: busy[r] == 0 && shareit( p, r+1, n ) ){
207: busy[r] |= TBUSY;
208: busy[r+1] |= TBUSY;
209: return(1);
210: }
211: else return(0);
212: }
213: if( busy[r] == 0 ) {
214: busy[r] |= TBUSY;
215: return(1);
216: }
217:
218: /* busy[r] is 1: is there chance for sharing */
219: return( shareit( p, r, n ) );
220:
221: }
222: # endif
223:
224: shareit( p, r, n ) NODE *p; {
225: /* can we make register r available by sharing from p
226: given that the need is n */
227: if( (n&(NASL|NBSL)) && ushare( p, 'L', r ) ) return(1);
228: if( (n&(NASR|NBSR)) && ushare( p, 'R', r ) ) return(1);
229: return(0);
230: }
231:
232: ushare( p, f, r ) NODE *p; {
233: /* can we find a register r to share on the left or right
234: (as f=='L' or 'R', respectively) of p */
235: p = getlr( p, f );
236: if( p->in.op == UNARY MUL ) p = p->in.left;
237: if( p->in.op == OREG ){
238: if( R2TEST(p->tn.rval) ){
239: return( r==R2UPK1(p->tn.rval) || r==R2UPK2(p->tn.rval) );
240: }
241: else return( r == p->tn.rval );
242: }
243: if( p->in.op == REG ){
244: return( r == p->tn.rval || ( szty(p->in.type) == 2 && r==p->tn.rval+1 ) );
245: }
246: return(0);
247: }
248:
249: recl2( p ) register NODE *p; {
250: register r = p->tn.rval;
251: #ifndef OLD
252: int op = p->in.op;
253: if (op == REG && r >= REGSZ)
254: op = OREG;
255: if( op == REG ) rfree( r, p->in.type );
256: else if( op == OREG ) {
257: if( R2TEST( r ) ) {
258: if( R2UPK1( r ) != 100 ) rfree( R2UPK1( r ), PTR+INT );
259: rfree( R2UPK2( r ), INT );
260: }
261: else {
262: rfree( r, PTR+INT );
263: }
264: }
265: #else
266: if( p->in.op == REG ) rfree( r, p->in.type );
267: else if( p->in.op == OREG ) {
268: if( R2TEST( r ) ) {
269: if( R2UPK1( r ) != 100 ) rfree( R2UPK1( r ), PTR+INT );
270: rfree( R2UPK2( r ), INT );
271: }
272: else {
273: rfree( r, PTR+INT );
274: }
275: }
276: #endif
277: }
278:
279: int rdebug = 0;
280:
281: # ifndef RFREE
282: rfree( r, t ) TWORD t; {
283: /* mark register r free, if it is legal to do so */
284: /* t is the type */
285:
286: # ifndef BUG3
287: if( rdebug ){
288: printf( "rfree( %s ), size %d\n", rnames[r], szty(t) );
289: }
290: # endif
291:
292: if( istreg(r) ){
293: if( --busy[r] < 0 ) cerror( "register overfreed");
294: if( szty(t) == 2 ){
295: if( (r&01) || (istreg(r)^istreg(r+1)) ) cerror( "illegal free" );
296: if( --busy[r+1] < 0 ) cerror( "register overfreed" );
297: }
298: }
299: }
300: # endif
301:
302: # ifndef RBUSY
303: rbusy(r,t) TWORD t; {
304: /* mark register r busy */
305: /* t is the type */
306:
307: # ifndef BUG3
308: if( rdebug ){
309: printf( "rbusy( %s ), size %d\n", rnames[r], szty(t) );
310: }
311: # endif
312:
313: if( istreg(r) ) ++busy[r];
314: if( szty(t) == 2 ){
315: if( istreg(r+1) ) ++busy[r+1];
316: if( (r&01) || (istreg(r)^istreg(r+1)) ) cerror( "illegal register pair freed" );
317: }
318: }
319: # endif
320:
321: # ifndef BUG3
322: rwprint( rw ){ /* print rewriting rule */
323: register i, flag;
324: static char * rwnames[] = {
325:
326: "RLEFT",
327: "RRIGHT",
328: "RESC1",
329: "RESC2",
330: "RESC3",
331: 0,
332: };
333:
334: if( rw == RNULL ){
335: printf( "RNULL" );
336: return;
337: }
338:
339: if( rw == RNOP ){
340: printf( "RNOP" );
341: return;
342: }
343:
344: flag = 0;
345: for( i=0; rwnames[i]; ++i ){
346: if( rw & (1<<i) ){
347: if( flag ) printf( "|" );
348: ++flag;
349: printf( rwnames[i] );
350: }
351: }
352: }
353: # endif
354:
355: reclaim( p, rw, cookie ) NODE *p; {
356: register NODE **qq;
357: register NODE *q;
358: register i;
359: NODE *recres[5];
360: struct respref *r;
361:
362: /* get back stuff */
363:
364: # ifndef BUG3
365: if( rdebug ){
366: printf( "reclaim( %o, ", p );
367: rwprint( rw );
368: printf( ", " );
369: prcook( cookie );
370: printf( " )\n" );
371: }
372: # endif
373:
374: if( rw == RNOP || ( p->in.op==FREE && rw==RNULL ) ) return; /* do nothing */
375:
376: walkf( p, recl2 );
377:
378: if( callop(p->in.op) ){
379: /* check that all scratch regs are free */
380: callchk(p); /* ordinarily, this is the same as allchk() */
381: }
382:
383: if( rw == RNULL || (cookie&FOREFF) ){ /* totally clobber, leaving nothing */
384: tfree(p);
385: return;
386: }
387:
388: /* handle condition codes specially */
389:
390: if( (cookie & FORCC) && (rw&RESCC)) {
391: /* result is CC register */
392: tfree(p);
393: p->in.op = CCODES;
394: p->tn.lval = 0;
395: p->tn.rval = 0;
396: return;
397: }
398:
399: /* locate results */
400:
401: qq = recres;
402:
403: if( rw&RLEFT) *qq++ = getlr( p, 'L' );;
404: if( rw&RRIGHT ) *qq++ = getlr( p, 'R' );
405: if( rw&RESC1 ) *qq++ = &resc[0];
406: if( rw&RESC2 ) *qq++ = &resc[1];
407: if( rw&RESC3 ) *qq++ = &resc[2];
408:
409: if( qq == recres ){
410: cerror( "illegal reclaim");
411: }
412:
413: *qq = NIL;
414:
415: /* now, select the best result, based on the cookie */
416:
417: for( r=respref; r->cform; ++r ){
418: if( cookie & r->cform ){
419: for( qq=recres; (q= *qq) != NIL; ++qq ){
420: if( tshape( q, r->mform ) ) goto gotit;
421: }
422: }
423: }
424:
425: /* we can't do it; die */
426: cerror( "cannot reclaim");
427:
428: gotit:
429:
430: if( p->in.op == STARG ) p = p->in.left; /* STARGs are still STARGS */
431:
432: q->in.type = p->in.type; /* to make multi-register allocations work */
433: /* maybe there is a better way! */
434: q = tcopy(q);
435:
436: tfree(p);
437:
438: p->in.op = q->in.op;
439: p->tn.lval = q->tn.lval;
440: p->tn.rval = q->tn.rval;
441: #ifdef FLEXNAMES
442: p->in.name = q->in.name;
443: #ifdef ONEPASS
444: p->in.stalign = q->in.stalign;
445: #endif
446: #else
447: for( i=0; i<NCHNAM; ++i )
448: p->in.name[i] = q->in.name[i];
449: #endif
450:
451: q->in.op = FREE;
452:
453: /* if the thing is in a register, adjust the type */
454:
455: switch( p->in.op ){
456:
457: case REG:
458: if( !rtyflg ){
459: /* the C language requires intermediate results to change type */
460: /* this is inefficient or impossible on some machines */
461: /* the "T" command in match supresses this type changing */
462: if( p->in.type == CHAR || p->in.type == SHORT ) p->in.type = INT;
463: else if( p->in.type == UCHAR || p->in.type == USHORT ) p->in.type = UNSIGNED;
464: else if( p->in.type == FLOAT ) p->in.type = DOUBLE;
465: }
466: if( ! (p->in.rall & MUSTDO ) ) return; /* unless necessary, ignore it */
467: i = p->in.rall & ~MUSTDO;
468: if( i & NOPREF ) return;
469: if( i != p->tn.rval ){
470: if( busy[i] || ( szty(p->in.type)==2 && busy[i+1] ) ){
471: cerror( "faulty register move" );
472: }
473: rbusy( i, p->in.type );
474: rfree( p->tn.rval, p->in.type );
475: rmove( i, p->tn.rval, p->in.type );
476: p->tn.rval = i;
477: }
478:
479: case OREG:
480: if( p->in.op == REG || !R2TEST(p->tn.rval) ) {
481: if( busy[p->tn.rval]>1 && istreg(p->tn.rval) ) cerror( "potential register overwrite");
482: }
483: else
484: if( (R2UPK1(p->tn.rval) != 100 && busy[R2UPK1(p->tn.rval)]>1 && istreg(R2UPK1(p->tn.rval)) )
485: || (busy[R2UPK2(p->tn.rval)]>1 && istreg(R2UPK2(p->tn.rval)) ) )
486: cerror( "potential register overwrite");
487: }
488:
489: }
490:
491: ncopy( q, p ) NODE *p, *q; {
492: /* copy the contents of p into q, without any feeling for
493: the contents */
494: /* this code assume that copying rval and lval does the job;
495: in general, it might be necessary to special case the
496: operator types */
497: register i;
498:
499: q->in.op = p->in.op;
500: q->in.rall = p->in.rall;
501: q->in.type = p->in.type;
502: q->tn.lval = p->tn.lval;
503: q->tn.rval = p->tn.rval;
504: #ifdef FLEXNAMES
505: q->in.name = p->in.name;
506: #ifdef ONEPASS
507: q->in.stalign = p->in.stalign;
508: #endif
509: #else
510: for( i=0; i<NCHNAM; ++i ) q->in.name[i] = p->in.name[i];
511: #endif
512:
513: }
514:
515: NODE *
516: tcopy( p ) register NODE *p; {
517: /* make a fresh copy of p */
518:
519: register NODE *q;
520: register r;
521:
522: ncopy( q=talloc(), p );
523:
524: r = p->tn.rval;
525: if( p->in.op == REG ) rbusy( r, p->in.type );
526: else if( p->in.op == OREG ) {
527: if( R2TEST(r) ){
528: if( R2UPK1(r) != 100 ) rbusy( R2UPK1(r), PTR+INT );
529: rbusy( R2UPK2(r), INT );
530: }
531: else {
532: rbusy( r, PTR+INT );
533: }
534: }
535:
536: switch( optype(q->in.op) ){
537:
538: case BITYPE:
539: q->in.right = tcopy(p->in.right);
540: case UTYPE:
541: q->in.left = tcopy(p->in.left);
542: }
543:
544: return(q);
545: }
546:
547: allchk(){
548: /* check to ensure that all register are free */
549:
550: register i;
551:
552: REGLOOP(i){
553: if( istreg(i) && busy[i] ){
554: cerror( "register allocation error");
555: }
556: }
557:
558: }
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