Exemplo n.º 1
0
/*
 * Fixup struct/unions depending on attributes.
 */
void
gcc_tcattrfix(NODE *p)
{
    struct symtab *sp;
    struct attr *ap;
    int sz, coff, csz, al;

    if ((ap = attr_find(p->n_ap, GCC_ATYP_PACKED)) == NULL)
        return; /* nothing to fix */

    al = ap->iarg(0);

    /* Must repack struct */
    coff = csz = 0;
    for (sp = strmemb(ap); sp; sp = sp->snext) {
        if (sp->sclass & FIELD)
            sz = sp->sclass&FLDSIZ;
        else
            sz = (int)tsize(sp->stype, sp->sdf, sp->sap);
        SETOFF(sz, al);
        sp->soffset = coff;
        coff += sz;
        if (coff > csz)
            csz = coff;
        if (p->n_type == UNIONTY)
            coff = 0;
    }
    SETOFF(csz, al); /* Roundup to whatever */

    ap = attr_find(p->n_ap, ATTR_BASETYP);
    ap->atypsz = csz;
    ap->aalign = al;
}
Exemplo n.º 2
0
/*
 * Fixup struct/unions depending on attributes.
 */
void
gcc_tcattrfix(NODE *p)
{
	struct symtab *sp;
	struct attr *ap;
	int sz, coff, csz, al, oal, mxal;

	if (!ISSOU(p->n_type)) /* only for structs or unions */
		return;
	if ((ap = attr_find(p->n_ap, GCC_ATYP_PACKED)) == NULL)
		return; /* nothing to fix */

	al = ap->iarg(0);
	mxal = 0;

	/* Must repack struct */
	coff = csz = 0;
	for (sp = strmemb(ap); sp; sp = sp->snext) {
		oal = talign(sp->stype, sp->sap);
		if (oal > al)
			oal = al;
		if (mxal < oal)
			mxal = oal;
		if (sp->sclass & FIELD)
			sz = sp->sclass&FLDSIZ;
		else
			sz = (int)tsize(sp->stype, sp->sdf, sp->sap);
		sp->soffset = upoff(sz, oal, &coff);
		if (coff > csz)
			csz = coff;
		if (p->n_type == UNIONTY)
			coff = 0;
	}
	if (mxal < ALCHAR)
		mxal = ALCHAR; /* for bitfields */
	SETOFF(csz, mxal); /* Roundup to whatever */

	ap = attr_find(p->n_ap, ATTR_STRUCT);
	ap->amsize = csz;
	ap = attr_find(p->n_ap, ATTR_ALIGNED);
	ap->iarg(0) = mxal;

}
Exemplo n.º 3
0
/*
 * Watch out for references to static members.
 */
NODE *
cxxstructref(NODE *p, int f, char *n)
{
	struct symtab *sp = strmemb(p->n_ap);

	if (sp == NULL)
		cerror("ref to unknown struct");
	sp = sfind(n, sp);
	while (sp != NULL) {
		if (ISFTN(sp->stype) == 0) {
			if (sp->sclass == STATIC || sp->sclass == USTATIC) {
				tfree(p);
				return nametree(sp);
			}
			break;
		}
		sp = sfind(n, sp->snext);
	}
	return structref(p, f, n);
}
Exemplo n.º 4
0
/*
 * local optimizations, most of which are probably
 * machine independent
 */
NODE *
optim(NODE *p)
{
	int o, ty;
	NODE *sp, *q;
	OFFSZ sz;
	int i;

	if (odebug) return(p);

	ty = coptype(p->n_op);
	if( ty == LTYPE ) return(p);

	if( ty == BITYPE ) p->n_right = optim(p->n_right);
	p->n_left = optim(p->n_left);

	/* collect constants */
again:	o = p->n_op;
	switch(o){

	case SCONV:
		if (concast(p->n_left, p->n_type)) {
			q = p->n_left;
			nfree(p);
			p = q;
			break;
		}
		/* FALLTHROUGH */
	case PCONV:
		if (p->n_type != VOID)
			p = clocal(p);
		break;

	case FORTCALL:
		p->n_right = fortarg( p->n_right );
		break;

	case ADDROF:
		if (LO(p) == TEMP)
			break;
		if( LO(p) != NAME ) cerror( "& error" );

		if( !andable(p->n_left) && !statinit)
			break;

		LO(p) = ICON;

		setuleft:
		/* paint over the type of the left hand side with the type of the top */
		p->n_left->n_type = p->n_type;
		p->n_left->n_df = p->n_df;
		p->n_left->n_ap = p->n_ap;
		q = p->n_left;
		nfree(p);
		p = q;
		break;

	case NOT:
	case UMINUS:
	case COMPL:
		if (LCON(p) && conval(p->n_left, o, p->n_left))
			p = nfree(p);
		break;

	case UMUL:
		/* Do not discard ADDROF TEMP's */
		if (LO(p) == ADDROF && LO(p->n_left) != TEMP) {
			q = p->n_left->n_left;
			nfree(p->n_left);
			nfree(p);
			p = q;
			break;
		}
		if( LO(p) != ICON ) break;
		LO(p) = NAME;
		goto setuleft;

	case RS:
		if (LCON(p) && RCON(p) && conval(p->n_left, o, p->n_right))
			goto zapright;

		sz = tsize(p->n_type, p->n_df, p->n_ap);

		if (LO(p) == RS && RCON(p->n_left) && RCON(p) &&
		    (RV(p) + RV(p->n_left)) < sz) {
			/* two right-shift  by constants */
			RV(p) += RV(p->n_left);
			p->n_left = zapleft(p->n_left);
		}
#if 0
		  else if (LO(p) == LS && RCON(p->n_left) && RCON(p)) {
			RV(p) -= RV(p->n_left);
			if (RV(p) < 0)
				o = p->n_op = LS, RV(p) = -RV(p);
			p->n_left = zapleft(p->n_left);
		}
#endif
		if (RO(p) == ICON) {
			if (RV(p) < 0) {
				RV(p) = -RV(p);
				p->n_op = LS;
				goto again;
			}
#ifdef notyet /* must check for side effects, --a >> 32; */
			if (RV(p) >= tsize(p->n_type, p->n_df, p->n_sue) &&
			    ISUNSIGNED(p->n_type)) { /* ignore signed shifts */
				/* too many shifts */
				tfree(p->n_left);
				nfree(p->n_right);
				p->n_op = ICON; p->n_lval = 0; p->n_sp = NULL;
			} else
#endif
			/* avoid larger shifts than type size */
			if (RV(p) >= sz) {
				RV(p) = RV(p) % sz;
				werror("shift larger than type");
			}
			if (RV(p) == 0)
				p = zapleft(p);
		}
		break;

	case LS:
		if (LCON(p) && RCON(p) && conval(p->n_left, o, p->n_right))
			goto zapright;

		sz = tsize(p->n_type, p->n_df, p->n_ap);

		if (LO(p) == LS && RCON(p->n_left) && RCON(p)) {
			/* two left-shift  by constants */
			RV(p) += RV(p->n_left);
			p->n_left = zapleft(p->n_left);
		}
#if 0
		  else if (LO(p) == RS && RCON(p->n_left) && RCON(p)) {
			RV(p) -= RV(p->n_left);
			p->n_left = zapleft(p->n_left);
		}
#endif
		if (RO(p) == ICON) {
			if (RV(p) < 0) {
				RV(p) = -RV(p);
				p->n_op = RS;
				goto again;
			}
#ifdef notyet /* must check for side effects */
			if (RV(p) >= tsize(p->n_type, p->n_df, p->n_sue)) {
				/* too many shifts */
				tfree(p->n_left);
				nfree(p->n_right);
				p->n_op = ICON; p->n_lval = 0; p->n_sp = NULL;
			} else
#endif
			/* avoid larger shifts than type size */
			if (RV(p) >= sz) {
				RV(p) = RV(p) % sz;
				werror("shift larger than type");
			}
			if (RV(p) == 0)  
				p = zapleft(p);
		}
		break;

	case MINUS:
		if (LCON(p) && RCON(p) && p->n_left->n_sp == p->n_right->n_sp) {
			/* link-time constants, but both are the same */
			/* solve it now by forgetting the symbols */
			p->n_left->n_sp = p->n_right->n_sp = NULL;
		}
		if( !nncon(p->n_right) ) break;
		RV(p) = -RV(p);
		o = p->n_op = PLUS;

	case MUL:
		/*
		 * Check for u=(x-y)+z; where all vars are pointers to
		 * the same struct. This has two advantages:
		 * 1: avoid a mul+div
		 * 2: even if not allowed, people may get surprised if this
		 *    calculation do not give correct result if using
		 *    unaligned structs.
		 */
		if (p->n_type == INTPTR && RCON(p) &&
		    LO(p) == DIV && RCON(p->n_left) &&
		    RV(p) == RV(p->n_left) &&
		    LO(p->n_left) == MINUS) {
			q = p->n_left->n_left;
			if (q->n_left->n_type == PTR+STRTY &&
			    q->n_right->n_type == PTR+STRTY &&
			    strmemb(q->n_left->n_ap) ==
			    strmemb(q->n_right->n_ap)) {
				p = zapleft(p);
				p = zapleft(p);
			}
		}
		/* FALLTHROUGH */
	case PLUS:
	case AND:
	case OR:
	case ER:
		/* commutative ops; for now, just collect constants */
		/* someday, do it right */
		if( nncon(p->n_left) || ( LCON(p) && !RCON(p) ) )
			SWAP( p->n_left, p->n_right );
		/* make ops tower to the left, not the right */
		if( RO(p) == o ){
			NODE *t1, *t2, *t3;
			t1 = p->n_left;
			sp = p->n_right;
			t2 = sp->n_left;
			t3 = sp->n_right;
			/* now, put together again */
			p->n_left = sp;
			sp->n_left = t1;
			sp->n_right = t2;
			sp->n_type = p->n_type;
			p->n_right = t3;
			}
		if(o == PLUS && LO(p) == MINUS && RCON(p) && RCON(p->n_left) &&
		   conval(p->n_right, MINUS, p->n_left->n_right)){
			zapleft:

			q = p->n_left->n_left;
			nfree(p->n_left->n_right);
			nfree(p->n_left);
			p->n_left = q;
		}
		if( RCON(p) && LO(p)==o && RCON(p->n_left) &&
		    conval( p->n_right, o, p->n_left->n_right ) ){
			goto zapleft;
			}
		else if( LCON(p) && RCON(p) && conval( p->n_left, o, p->n_right ) ){
			zapright:
			nfree(p->n_right);
			q = makety(p->n_left, p->n_type, p->n_qual,
			    p->n_df, p->n_ap);
			nfree(p);
			p = clocal(q);
			break;
			}

		/* change muls to shifts */

		if( o == MUL && nncon(p->n_right) && (i=ispow2(RV(p)))>=0){
			if( i == 0 ) { /* multiplication by 1 */
				goto zapright;
				}
			o = p->n_op = LS;
			p->n_right->n_type = INT;
			p->n_right->n_df = NULL;
			RV(p) = i;
			}

		/* change +'s of negative consts back to - */
		if( o==PLUS && nncon(p->n_right) && RV(p)<0 ){
			RV(p) = -RV(p);
			o = p->n_op = MINUS;
			}

		/* remove ops with RHS 0 */
		if ((o == PLUS || o == MINUS || o == OR || o == ER) &&
		    nncon(p->n_right) && RV(p) == 0) {
			goto zapright;
		}
		break;

	case DIV:
		if( nncon( p->n_right ) && p->n_right->n_lval == 1 )
			goto zapright;
		if (LCON(p) && RCON(p) && conval(p->n_left, DIV, p->n_right))
			goto zapright;
		if (RCON(p) && ISUNSIGNED(p->n_type) && (i=ispow2(RV(p))) > 0) {
			p->n_op = RS;
			RV(p) = i;
			q = p->n_right;
			if(tsize(q->n_type, q->n_df, q->n_ap) > SZINT)
				p->n_right = makety(q, INT, 0, 0, 0);

			break;
		}
		break;

	case MOD:
		if (RCON(p) && ISUNSIGNED(p->n_type) && ispow2(RV(p)) > 0) {
			p->n_op = AND;
			RV(p) = RV(p) -1;
			break;
		}
		break;

	case EQ:
	case NE:
	case LT:
	case LE:
	case GT:
	case GE:
	case ULT:
	case ULE:
	case UGT:
	case UGE:
		if( !LCON(p) ) break;

		/* exchange operands */

		sp = p->n_left;
		p->n_left = p->n_right;
		p->n_right = sp;
		p->n_op = revrel[p->n_op - EQ ];
		break;

#ifdef notyet
	case ASSIGN:
		/* Simple test to avoid two branches */
		if (RO(p) != NE)
			break;
		q = p->n_right;
		if (RCON(q) && RV(q) == 0 && LO(q) == AND &&
		    RCON(q->n_left) && (i = ispow2(RV(q->n_left))) &&
		    q->n_left->n_type == INT) {
			q->n_op = RS;
			RV(q) = i;
		}
		break;
#endif
	}

	return(p);
	}