/*
* 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;
}
/*
* 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;
}
/*
* 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);
}
/*
* 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);
}