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researchv9-SUN3(old)

#ifndef lint
static	char sccsid[] = "@(#)allo.c 1.1 86/02/03 SMI";
#endif
# include "cpass2.h"

NODE resc[3];

int busy[REGSZ];

int maxa, mina, maxb, minb, maxc, minc;

# ifndef ALLO0
allo0()
{ /* free everything */

	register i;

	maxa = maxb = -1;
	mina = minb = 0;

	REGLOOP(i){
		busy[i] = 0;
		if( rstatus[i] & STAREG ){
			if( maxa<0 ) mina = i;
			maxa = i;
		}
		if( rstatus[i] & STBREG ){
			if( maxb<0 ) minb = i;
			maxb = i;
		}
		if( rstatus[i] & STCREG ){
			if( maxc<0 ) minc = i;
			maxc = i;
		}
	}
}
# endif

# define TBUSY 01000

# ifndef ALLO
allo( p, q ) 
	NODE *p; struct optab *q; 
{

	register n, i, j;
#ifdef VAX
	int either;
#endif

	n = q->needs;
#ifdef VAX
	either = ( EITHER & n );
#endif  
	i = 0;

	while( n & NACOUNT ){
		resc[i].in.op = REG;
		resc[i].tn.rval = freereg( p, n&NAMASK );
		resc[i].tn.lval = 0;
		resc[i].in.name = "";
		n -= NAREG;
		++i;
	}

#ifdef VAX
	if (either) { /* all or nothing at all */
		for( j = 0; j < i; j++ )
			if( resc[j].tn.rval < 0 ) { /* nothing */
				i = 0;
				break;
			}
		if( i != 0 ) goto ok; /* all */
	}
#endif

	while( n & NBCOUNT ){
		resc[i].in.op = REG;
		resc[i].tn.rval = freereg( p, n&NBMASK );
		resc[i].tn.lval = 0;
		resc[i].in.name = "";
		n -= NBREG;
		++i;
	}
#ifdef VAX
	if (either) { /* all or nothing at all */
		for( j = 0; j < i; j++ )
			if( resc[j].tn.rval < 0 ) { /* nothing */
				i = 0;
				break;
			}
		if( i != 0 ) goto ok; /* all */
	}
#endif

	while( n & NCCOUNT ){
		resc[i].in.op = REG;
		resc[i].tn.rval = freereg( p, n&NCMASK );
		resc[i].tn.lval = 0;
		resc[i].in.name = "";
		n -= NCREG;
		++i;
	}
#ifdef VAX
	if (either) { /* all or nothing at all */
		for( j = 0; j < i; j++ )
			if( resc[j].tn.rval < 0 ) { /* nothing */
				i = 0;
				break;
			}
		if( i != 0 ) goto ok; /* all */
	}
#endif

	if( n & NTMASK ){
		resc[i].in.op = OREG;
		resc[i].tn.rval = TMPREG;
		if( p->in.op == STCALL || p->in.op == STARG || p->in.op == UNARY STCALL || p->in.op == STASG ){
			resc[i].tn.lval = freetemp( (SZCHAR*p->stn.stsize + (SZINT-1))/SZINT );
		} else {
			resc[i].tn.lval = freetemp( (n&NTMASK)/NTEMP );
		}
		resc[i].in.name = "";

		resc[i].tn.lval = BITOOR(resc[i].tn.lval);
		++i;
	}

	/* turn off "temporarily busy" bit */

	ok:
	REGLOOP(j){
		busy[j] &= ~TBUSY;
	}

	for( j=0; j<i; ++j ) 
		if( resc[j].tn.rval < 0 ) return(0);

	return(1);
}
# endif

extern unsigned int offsz;

# ifndef FREETEMP
freetemp( k )
{ 
    /* allocate k integers worth of temp space */
    /* we also make the convention that, if the number of words is more than 1,
    /* it must be aligned for storing doubles... */

# ifndef BACKTEMP
	int t;

	if( k>1 ){
		SETOFF( tmpoff, ALDOUBLE );
	}

	t = tmpoff;
	tmpoff += k*SZINT;
	if( tmpoff > maxoff ) maxoff = tmpoff;
	if( tmpoff >= offsz )
		cerror( "stack overflow" );
	if( tmpoff-baseoff > maxtemp ) maxtemp = tmpoff-baseoff;
	return(t);

# else
	tmpoff += k*SZINT;
	if( k>1 ) {
		SETOFF( tmpoff, ALDOUBLE );
	}
	if( tmpoff > maxoff ) maxoff = tmpoff;
#ifndef VAX
	if (tmpoff >= TMPMAX) 
		uerror( "stack overflow: too many local variables");
#endif
	if( tmpoff >= offsz )
		cerror( "stack overflow" );
	if( tmpoff-baseoff > maxtemp ) maxtemp = tmpoff-baseoff;
	return( -tmpoff );
# endif
}
#endif

freereg( p, n ) 
	NODE *p;
{
	/* allocate a register of type n */
	/* p gives the type, if floating */

	register j;

	/* not general; means that only one register (the result) OK for call */
	if( callop(p->in.op) ){
		j = callreg(p);
		if( usable( p, n, j ) ) return( j );
		/* have allocated callreg first */
	}
	j = p->in.rall & ~MUSTDO;
	if( j!=NOPREF && usable(p,n,j) ){ /* needed and not allocated */
		return( j );
	}
	if( n&NAMASK ){
		for( j=mina; j<=maxa; ++j ) if( rstatus[j]&STAREG ){
			if( usable(p,n,j) ){
				return( j );
			}
		}
	}
	else if( n &NBMASK ){
		for( j=minb; j<=maxb; ++j ) if( rstatus[j]&STBREG ){
			if( usable(p,n,j) ){
				return(j);
			}
		}
	}
	else if( n &NCMASK ){
		for( j=minc; j<=maxc; ++j ) if( rstatus[j]&STCREG ){
			if( usable(p,n,j) ){
				return(j);
			}
		}
	}

	return( -1 );
}

# ifndef USABLE
usable( p, n, r ) 
	NODE *p; 
{
	/* decide if register r is usable in tree p to satisfy need n */

	/* checks, for the moment */
	if ( !istreg(r) ) cerror( "usable asked about nontemp register" );

	if ( busy[r] > 1 ) return(0);
	if ( isbreg(r) ){
		if ( n&(NAMASK|NCMASK) ) return(0);
	} else if  ( iscreg(r) ){
		if ( n&(NAMASK|NBMASK) ) return(0);
	} else {
		if ( n & (NBMASK|NCMASK) ) return(0);
	}
	if ((n&NAMASK) && needpair(r, p->in.type) ){ /* only do the pairing for real regs */
		if ( r&01 ) return(0);
		if ( !istreg(r+1) ) return( 0 );
		if ( busy[r+1] > 1 ) return( 0 );
		if ( ( busy[r] == 0 || shareit( p, r, n ) )
		  && ( busy[r+1] == 0  || shareit( p, r+1, n ) ) ){
			busy[r] |= TBUSY;
			busy[r+1] |= TBUSY;
			return(1);
		} else 
			return(0);
	}
	if ( busy[r] == 0 ) {
		busy[r] |= TBUSY;
		return(1);
	}

	/* busy[r] is 1: is there chance for sharing */
	return( shareit( p, r, n ) );

}
# endif

shareit( p, r, n ) 
	NODE *p; 
{
	/* can we make register r available by sharing from p
	   given that the need is n */
	if( (n&(NASL|NBSL|NCSL)) && ushare( getlr(p,'L'), r ) ) return(1);
	if( (n&(NASR|NBSR|NCSR)) && ushare( getlr(p,'R'), r ) ) return(1);
	return(0);
}

ushare( p, r ) 
    NODE *p; 
{
    /*  can we find a register r to share in subtree p? */
    switch(optype(p->in.op)) {
    case LTYPE:
	break;
    case UTYPE:
	return ushare(p->in.left, r);
    case BITYPE:
	return ushare(p->in.left, r) || ushare(p->in.right, r);
    }
    if( p->in.op == OREG ){
	if(R2TEST(p->tn.rval))
	    return( r==R2UPK1(p->tn.rval) || r==R2UPK2(p->tn.rval) );
	return( r == p->tn.rval );
    }
    if( p->in.op == REG ){
	return( r == p->tn.rval || 
	    ( needpair(r, p->in.type) && r==p->tn.rval+1 ) );
    }
    return(0);
}

#ifdef VAX
recl2( p ) 
	register NODE *p; 
{
	register r = p->tn.rval;
#ifndef OLD
	int op = p->in.op;
	switch(optype(op))
	case LTYPE:
		break;
	case UTYPE:
		recl2(p->in.left);
		return;
	case BITYPE:
		recl2(p->in.left);
		recl2(p->in.right);
		return;
	}
	if (op == REG && r >= REGSZ)
		op = OREG;
	if( op == REG ) rfree( r, p->in.type );
	else if( op == OREG ) {
		if( R2TEST( r ) ) {
			if( R2UPK1( r ) != 100 ) rfree( R2UPK1( r ), PTR+INT );
			rfree( R2UPK2( r ), INT );
		} else {
			rfree( r, PTR+INT );
		}
	}
#else
	switch(optype(p->in.op))
	case LTYPE:
		break;
	case UTYPE:
		recl2(p->in.left);
		return;
	case BITYPE:
		recl2(p->in.left);
		recl2(p->in.right);
		return;
	}
	if( p->in.op == REG ) rfree( r, p->in.type );
	else if( p->in.op == OREG ) {
		if( R2TEST( r ) ) {
			if( R2UPK1( r ) != 100 ) rfree( R2UPK1( r ), PTR+INT );
			rfree( R2UPK2( r ), INT );
		} else {
			rfree( r, PTR+INT );
		}
	}
#endif
}
#else
recl2( p ) 
	register NODE *p; 
{
	register r = p->tn.rval;
	switch(optype(p->in.op)) {
	case LTYPE:
		break;
	case UTYPE:
		recl2(p->in.left);
		return;
	case BITYPE:
		recl2(p->in.left);
		recl2(p->in.right);
		return;
	}
	if( p->in.op == REG ) rfree( r, p->in.type );
	else if( p->in.op == OREG ) {
		if( R2TEST( r ) ) {
			rfree( R2UPK1( r ), PTR+INT );
			rfree( R2UPK2( r ), INT );
		} else {
			rfree( r, PTR+INT );
		}
	}
}
#endif


int rdebug = 0;

# ifndef RFREE
rfree( r, t ) TWORD t; {
	/* mark register r free, if it is legal to do so */
	/* t is the type */

# ifndef BUG3
	if( rdebug ){
		printf( "rfree( %s ), size %d\n", rnames[r], szty(t) );
	}
# endif

	if( istreg(r) ){
		if( --busy[r] < 0 ) cerror( "register overfreed");
		if( needpair(r,t) ){
			if( (r&01) || (istreg(r)^istreg(r+1)) ) cerror( "illegal free" );
			if( --busy[r+1] < 0 ) cerror( "register overfreed" );
		}
	}
}
# endif

# ifndef RBUSY
rbusy(r,t) 
	TWORD t; 
{
	/* mark register r busy */
	/* t is the type */

# ifndef BUG3
	if( rdebug ){
		printf( "rbusy( %s ), size %d\n", rnames[r], szty(t) );
	}
# endif

	if( istreg(r) ) ++busy[r];
	if( needpair(r,t) ){
		if( istreg(r+1) ) ++busy[r+1];
		if( (r&01) || (istreg(r)^istreg(r+1)) ) cerror( "illegal register pair freed" );
	}
}
# endif

# ifndef BUG3
rwprint( rw ){ /* print rewriting rule */
	register i, flag;
	static char * rwnames[] = {

		"RLEFT",
		"RRIGHT",
		"RESC1",
		"RESC2",
		"RESC3",
		0,
	};

	if( rw == RNULL ){
		print_str( "RNULL" );
		return;
	}

	if( rw == RNOP ){
		print_str( "RNOP" );
		return;
	}

	flag = 0;
	for( i=0; rwnames[i]; ++i ){
		if( rw & (1<<i) ){
			if( flag ) putchar('|');
			++flag;
			print_str( rwnames[i] );
		}
	}
}
# endif

reclaim( p, rw, cookie ) 
	NODE *p;
{
	register NODE **qq;
	register NODE *q;
	register i;
	NODE *recres[5];
	struct respref *r;

	/* get back stuff */

# ifndef BUG3
	if( rdebug ){
		printf( "reclaim( %o, ", p );
		rwprint( rw );
		print_str( ", " );
		prcook( cookie );
		print_str( " )\n" );
	}
# endif

	if( rw == RNOP || ( p->in.op==FREE && rw==RNULL ) ) return;  /* do nothing */

	recl2(p);

	if( callop(p->in.op) ){
		/* check that all scratch regs are free */
		callchk(p);  /* ordinarily, this is the same as allchk() */
	}

	if( rw == RNULL || (cookie&FOREFF) ){ /* totally clobber, leaving nothing */
		tfree(p);
		return;
	}

	/* handle condition codes specially */

	if( (cookie & FORCC) && (rw&(RESFCC|RESCC)) ) {
		/*
		 * result is CC register. Machines with
		 * coprocessors may have more than one (bletch)
		 */
		tfree(p);
		p->in.op = (rw&RESFCC ? FCCODES : CCODES);
		p->tn.lval = 0;
		p->tn.rval = 0;
		return;
	}

	/* locate results */

	qq = recres;

	if( rw&RLEFT) *qq++ = getlr( p, 'L' );;
	if( rw&RRIGHT ) *qq++ = getlr( p, 'R' );
	if( rw&RESC1 ) *qq++ = &resc[0];
	if( rw&RESC2 ) *qq++ = &resc[1];
	if( rw&RESC3 ) *qq++ = &resc[2];

	if( qq == recres ){
		cerror( "illegal reclaim");
	}

	*qq = NIL;

	/* now, select the best result, based on the cookie */

	for( r=respref; r->cform; ++r ){
		if( cookie & r->cform ){
			for( qq=recres; (q= *qq) != NIL; ++qq ){
				if( tshape( q, r->mform ) ) goto gotit;
			}
		}
	}

	/* we can't do it; die */
	cerror( "cannot reclaim");

	gotit:

	if( p->in.op == STARG ) p = p->in.left;  /* STARGs are still STARGS */

	q->in.type = p->in.type;  /* to make multi-register allocations work */
	q->in.rall = p->in.rall;
		/* maybe there is a better way! */
	q = tcopy(q);
	tfree(p);
	ncopy(p,q);
	q->in.op = FREE;

	/* if the thing is in a register, adjust the type */

	switch( p->in.op ){

	case REG:
#ifdef VAX
		if( !rtyflg ){
			/* the C language requires intermediate results to change type */
			/* this is inefficient or impossible on some machines */
			/* the "T" command in match supresses this type changing */
			if( p->in.type == CHAR || p->in.type == SHORT ) p->in.type = INT;
			else if( p->in.type == UCHAR || p->in.type == USHORT ) p->in.type = UNSIGNED;
			else if( p->in.type == FLOAT ) p->in.type = DOUBLE;
		}
#endif
		if( ! (p->in.rall & MUSTDO ) ) return;  /* unless necessary, ignore it */
		i = p->in.rall & ~MUSTDO;
		if( i & NOPREF ) return;
		if( i != p->tn.rval ){
			if( busy[i] || (needpair(i,p->in.type) && busy[i+1]) ){
				cerror( "faulty register move" );
			}
			rbusy( i, p->in.type );
			rfree( p->tn.rval, p->in.type );
			rmove( i, p->tn.rval, p->in.type );
			p->tn.rval = i;
		}

	case OREG:
#ifdef VAX
		if( p->in.op == REG || !R2TEST(p->tn.rval) ) {
			if( busy[p->tn.rval]>1 && istreg(p->tn.rval) ) cerror( "potential register overwrite");
		} else
			if( (R2UPK1(p->tn.rval) != 100 && busy[R2UPK1(p->tn.rval)]>1 && istreg(R2UPK1(p->tn.rval)) )
				|| (busy[R2UPK2(p->tn.rval)]>1 && istreg(R2UPK2(p->tn.rval)) ) )
			   cerror( "potential register overwrite");
#else
		if( R2TEST(p->tn.rval) ){
			int r1, r2;
			r1 = R2UPK1(p->tn.rval);
			r2 = R2UPK2(p->tn.rval);
			if( (busy[r1]>1 && istreg(r1)) || (busy[r2]>1 && istreg(r2)) ){
				cerror( "potential register overwrite" );
			}
		}
		else if( (busy[p->tn.rval]>1) && istreg(p->tn.rval) ) cerror( "potential register overwrite");
#endif
	}

}

NODE *
tcopy( p ) 
	register NODE *p; 
{
	/* make a fresh copy of p */

	register NODE *q;
	register r;

	ncopy(q=talloc(), p);
	r = p->tn.rval;
	if( p->in.op == REG ) rbusy( r, p->in.type );
	else if( p->in.op == OREG ) {
		if( R2TEST(r) ){
			if( R2UPK1(r) != 100 ) rbusy( R2UPK1(r), PTR+INT );
			rbusy( R2UPK2(r), INT );
		} else {
			rbusy( r, PTR+INT );
		}
	}

	switch( optype(q->in.op) ){

	case BITYPE:
		q->in.right = tcopy(p->in.right);
	case UTYPE:
		q->in.left = tcopy(p->in.left);
	}

	return(q);
}

allchk(){
	/* check to ensure that all register are free */

	register i;

	REGLOOP(i){
		if( istreg(i) && busy[i] ){
			cerror( "register allocation error");
		}
	}

}

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