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BSD 4_1c_2 release
[unix-history] / usr / src / lib / pcc / order.c
static char *sccsid ="@(#)order.c 1.1 (Berkeley) 12/15/82";
# include "mfile2"
int maxargs = { -1 };
stoasg( p, o ) register NODE *p; {
/* should the assignment op p be stored,
given that it lies as the right operand of o
(or the left, if o==UNARY MUL) */
/*
if( p->in.op == INCR || p->in.op == DECR ) return;
if( o==UNARY MUL && p->in.left->in.op == REG && !isbreg(p->in.left->tn.rval) ) SETSTO(p,INAREG);
*/
}
deltest( p ) register NODE *p; {
/* should we delay the INCR or DECR operation p */
p = p->in.left;
return( p->in.op == REG || p->in.op == NAME || p->in.op == OREG );
}
autoincr( p ) NODE *p; {
register NODE *q = p->in.left, *r;
if( q->in.op == INCR && (r=q->in.left)->in.op == REG &&
ISPTR(q->in.type) && p->in.type == DECREF(q->in.type) &&
tlen(p) == q->in.right->tn.lval ) return(1);
return(0);
}
mkadrs(p) register NODE *p; {
register o;
o = p->in.op;
if( asgop(o) ){
if( p->in.left->in.su >= p->in.right->in.su ){
if( p->in.left->in.op == UNARY MUL ){
SETSTO( p->in.left->in.left, INTEMP );
}
else if( p->in.left->in.op == FLD && p->in.left->in.left->in.op == UNARY MUL ){
SETSTO( p->in.left->in.left->in.left, INTEMP );
}
else { /* should be only structure assignment */
SETSTO( p->in.left, INTEMP );
}
}
else SETSTO( p->in.right, INTEMP );
}
else {
if( p->in.left->in.su > p->in.right->in.su ){
SETSTO( p->in.left, INTEMP );
}
else {
SETSTO( p->in.right, INTEMP );
}
}
}
notoff( t, r, off, cp) CONSZ off; char *cp; {
/* is it legal to make an OREG or NAME entry which has an
/* offset of off, (from a register of r), if the
/* resulting thing had type t */
/* if( r == R0 ) return( 1 ); /* NO */
return(0); /* YES */
}
# define max(x,y) ((x)<(y)?(y):(x))
sucomp( p ) register NODE *p; {
/* set the su field in the node to the sethi-ullman
number, or local equivalent */
register o, ty, sul, sur, r;
o = p->in.op;
ty = optype( o );
p->in.su = szty( p->in.type ); /* 2 for float or double, else 1 */;
if( ty == LTYPE ){
if( o == OREG ){
r = p->tn.rval;
/* oreg cost is (worst case) 1 + number of temp registers used */
if( R2TEST(r) ){
if( R2UPK1(r)!=100 && istreg(R2UPK1(r)) ) ++p->in.su;
if( istreg(R2UPK2(r)) ) ++p->in.su;
}
else {
if( istreg( r ) ) ++p->in.su;
}
}
if( p->in.su == szty(p->in.type) &&
(p->in.op!=REG || !istreg(p->tn.rval)) &&
(p->in.type==INT || p->in.type==UNSIGNED || p->in.type==DOUBLE) )
p->in.su = 0;
return;
}
else if( ty == UTYPE ){
switch( o ) {
case UNARY CALL:
case UNARY STCALL:
p->in.su = fregs; /* all regs needed */
return;
default:
p->in.su = p->in.left->in.su + (szty( p->in.type ) > 1 ? 2 : 0) ;
return;
}
}
/* If rhs needs n, lhs needs m, regular su computation */
sul = p->in.left->in.su;
sur = p->in.right->in.su;
if( o == ASSIGN ){
/* computed by doing right, then left (if not in mem), then doing it */
p->in.su = max(sur,sul+1);
return;
}
if( o == CALL || o == STCALL ){
/* in effect, takes all free registers */
p->in.su = fregs;
return;
}
if( o == STASG ){
/* right, then left */
p->in.su = max( max( 1+sul, sur), fregs );
return;
}
if( asgop(o) ){
/* computed by doing right, doing left address, doing left, op, and store */
p->in.su = max(sur,sul+2);
/*
if( o==ASG MUL || o==ASG DIV || o==ASG MOD) p->in.su = max(p->in.su,fregs);
*/
return;
}
switch( o ){
case ANDAND:
case OROR:
case QUEST:
case COLON:
case COMOP:
p->in.su = max( max(sul,sur), 1);
return;
case PLUS:
case OR:
case ER:
/* commutative ops; put harder on left */
if( p->in.right->in.su > p->in.left->in.su && !istnode(p->in.left) ){
register NODE *temp;
temp = p->in.left;
p->in.left = p->in.right;
p->in.right = temp;
}
break;
}
/* binary op, computed by left, then right, then do op */
p->in.su = max(sul,szty(p->in.right->in.type)+sur);
/*
if( o==MUL||o==DIV||o==MOD) p->in.su = max(p->in.su,fregs);
*/
}
int radebug = 0;
rallo( p, down ) NODE *p; {
/* do register allocation */
register o, type, down1, down2, ty;
if( radebug ) printf( "rallo( %o, %d )\n", p, down );
down2 = NOPREF;
p->in.rall = down;
down1 = ( down &= ~MUSTDO );
ty = optype( o = p->in.op );
type = p->in.type;
if( type == DOUBLE || type == FLOAT ){
if( o == FORCE ) down1 = R0|MUSTDO;
}
else switch( o ) {
case ASSIGN:
down1 = NOPREF;
down2 = down;
break;
/*
case MUL:
case DIV:
case MOD:
down1 = R3|MUSTDO;
down2 = R5|MUSTDO;
break;
case ASG MUL:
case ASG DIV:
case ASG MOD:
p->in.left->in.rall = down1 = R3|MUSTDO;
if( p->in.left->in.op == UNARY MUL ){
rallo( p->in.left->in.left, R4|MUSTDO );
}
else if( p->in.left->in.op == FLD && p->in.left->in.left->in.op == UNARY MUL ){
rallo( p->in.left->in.left->in.left, R4|MUSTDO );
}
else rallo( p->in.left, R3|MUSTDO );
rallo( p->in.right, R5|MUSTDO );
return;
*/
case CALL:
case STASG:
case EQ:
case NE:
case GT:
case GE:
case LT:
case LE:
case NOT:
case ANDAND:
case OROR:
down1 = NOPREF;
break;
case FORCE:
down1 = R0|MUSTDO;
break;
}
if( ty != LTYPE ) rallo( p->in.left, down1 );
if( ty == BITYPE ) rallo( p->in.right, down2 );
}
offstar( p ) register NODE *p; {
if( p->in.op == PLUS ) {
if( p->in.left->in.su == fregs ) {
order( p->in.left, INTAREG|INAREG );
return;
} else if( p->in.right->in.su == fregs ) {
order( p->in.right, INTAREG|INAREG );
return;
}
if( p->in.left->in.op==LS &&
(p->in.left->in.left->in.op!=REG || tlen(p->in.left->in.left)!=sizeof(int) ) ) {
order( p->in.left->in.left, INTAREG|INAREG );
return;
}
if( p->in.right->in.op==LS &&
(p->in.right->in.left->in.op!=REG || tlen(p->in.right->in.left)!=sizeof(int) ) ) {
order( p->in.right->in.left, INTAREG|INAREG );
return;
}
if( p->in.type == (PTR|CHAR) || p->in.type == (PTR|UCHAR) ) {
if( p->in.left->in.op!=REG || tlen(p->in.left)!=sizeof(int) ) {
order( p->in.left, INTAREG|INAREG );
return;
}
else if( p->in.right->in.op!=REG || tlen(p->in.right)!=sizeof(int) ) {
order(p->in.right, INTAREG|INAREG);
return;
}
}
}
if( p->in.op == PLUS || p->in.op == MINUS ){
if( p->in.right->in.op == ICON ){
p = p->in.left;
order( p , INTAREG|INAREG);
return;
}
}
if( p->in.op == UNARY MUL && !canaddr(p) ) {
offstar( p->in.left );
return;
}
order( p, INTAREG|INAREG );
}
setincr( p ) register NODE *p; {
p = p->in.left;
if( p->in.op == UNARY MUL ){
offstar( p );
return( 1 );
}
return( 0 );
}
setbin( p ) register NODE *p; {
register ro, rt;
rt = p->in.right->in.type;
ro = p->in.right->in.op;
if( canaddr( p->in.left ) && !canaddr( p->in.right ) ) { /* address rhs */
if( ro == UNARY MUL ) {
offstar( p->in.right->in.left );
return(1);
} else {
order( p->in.right, INAREG|INTAREG|SOREG );
return(1);
}
}
if( !istnode( p->in.left) ) { /* try putting LHS into a reg */
/* order( p->in.left, logop(p->in.op)?(INAREG|INBREG|INTAREG|INTBREG|SOREG):(INTAREG|INTBREG|SOREG) );*/
order( p->in.left, INAREG|INTAREG|INBREG|INTBREG|SOREG );
return(1);
}
else if( ro == UNARY MUL && rt != CHAR && rt != UCHAR ){
offstar( p->in.right->in.left );
return(1);
}
else if( rt == CHAR || rt == UCHAR || rt == SHORT || rt == USHORT || (ro != REG &&
ro != NAME && ro != OREG && ro != ICON ) ){
order( p->in.right, INAREG|INBREG );
return(1);
}
/*
else if( logop(p->in.op) && rt==USHORT ){ /* must get rhs into register */
/*
order( p->in.right, INAREG );
return( 1 );
}
*/
return(0);
}
setstr( p ) register NODE *p; { /* structure assignment */
if( p->in.right->in.op != REG ){
order( p->in.right, INTAREG );
return(1);
}
p = p->in.left;
if( p->in.op != NAME && p->in.op != OREG ){
if( p->in.op != UNARY MUL ) cerror( "bad setstr" );
order( p->in.left, INTAREG );
return( 1 );
}
return( 0 );
}
setasg( p ) register NODE *p; {
/* setup for assignment operator */
if( !canaddr(p->in.right) ) {
if( p->in.right->in.op == UNARY MUL )
offstar(p->in.right->in.left);
else
order( p->in.right, INAREG|INBREG|SOREG );
return(1);
}
if( p->in.left->in.op == UNARY MUL ) {
offstar( p->in.left->in.left );
return(1);
}
if( p->in.left->in.op == FLD && p->in.left->in.left->in.op == UNARY MUL ){
offstar( p->in.left->in.left->in.left );
return(1);
}
/* FLD patch */
if( p->in.left->in.op == FLD && !(p->in.right->in.type==INT || p->in.right->in.type==UNSIGNED)) {
order( p->in.right, INAREG);
return(1);
}
/* end of FLD patch */
return(0);
}
setasop( p ) register NODE *p; {
/* setup for =ops */
register rt, ro;
rt = p->in.right->in.type;
ro = p->in.right->in.op;
if( ro == UNARY MUL && rt != CHAR ){
offstar( p->in.right->in.left );
return(1);
}
if( ( rt == CHAR || rt == SHORT || rt == UCHAR || rt == USHORT ||
( ro != REG && ro != ICON && ro != NAME && ro != OREG ) ) ){
order( p->in.right, INAREG|INBREG );
return(1);
}
/*
if( (p->in.op == ASG LS || p->in.op == ASG RS) && ro != ICON && ro != REG ){
order( p->in.right, INAREG );
return(1);
}
*/
p = p->in.left;
if( p->in.op == FLD ) p = p->in.left;
switch( p->in.op ){
case REG:
case ICON:
case NAME:
case OREG:
return(0);
case UNARY MUL:
if( p->in.left->in.op==OREG )
return(0);
else
offstar( p->in.left );
return(1);
}
cerror( "illegal setasop" );
}
int crslab = 9999; /* Honeywell */
getlab(){
return( crslab-- );
}
deflab( l ){
printf( "L%d:\n", l );
}
genargs( p, ptemp ) register NODE *p, *ptemp; {
register NODE *pasg;
register align;
register size;
register TWORD type;
/* generate code for the arguments */
/* first, do the arguments on the right */
while( p->in.op == CM ){
genargs( p->in.right, ptemp );
p->in.op = FREE;
p = p->in.left;
}
if( p->in.op == STARG ){ /* structure valued argument */
size = p->stn.stsize;
align = p->stn.stalign;
if( p->in.left->in.op == ICON ){
p->in.op = FREE;
p= p->in.left;
}
else {
/* make it look beautiful... */
p->in.op = UNARY MUL;
canon( p ); /* turn it into an oreg */
if( p->in.op != OREG ){
offstar( p->in.left );
canon( p );
if( p->in.op != OREG ){
offstar( p->in.left );
canon( p );
if( p->in.op != OREG ) cerror( "stuck starg" );
}
}
}
ptemp->tn.lval = 0; /* all moves to (sp) */
pasg = talloc();
pasg->in.op = STASG;
pasg->stn.stsize = size;
pasg->stn.stalign = align;
pasg->in.right = p;
pasg->in.left = tcopy( ptemp );
/* the following line is done only with the knowledge
that it will be undone by the STASG node, with the
offset (lval) field retained */
if( p->in.op == OREG ) p->in.op = REG; /* only for temporaries */
order( pasg, FORARG );
ptemp->tn.lval += size;
return;
}
/* ordinary case */
order( p, FORARG );
}
argsize( p ) register NODE *p; {
register t;
t = 0;
if( p->in.op == CM ){
t = argsize( p->in.left );
p = p->in.right;
}
if( p->in.type == DOUBLE || p->in.type == FLOAT ){
SETOFF( t, 4 );
return( t+8 );
}
else if( p->in.op == STARG ){
SETOFF( t, 4 ); /* alignment */
return( t + ((p->stn.stsize+3)/4)*4 ); /* size */
}
else {
SETOFF( t, 4 );
return( t+4 );
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.