/*
* code for the end of a function
* deals with struct return here
* The return value is in (or pointed to by) RETREG.
*/
void
efcode(void)
{
struct symtab *sp;
extern int gotnr;
TWORD t;
NODE *p, *r, *l;
int typ, ssz, rno;
gotnr = 0; /* new number for next fun */
sp = cftnsp;
t = DECREF(sp->stype);
if (t != STRTY && t != UNIONTY)
return;
/* XXX should have one routine for this */
ngpr = nsse = 0;
if ((typ = argtyp(t, sp->sdf, sp->sap)) == STRREG || typ == STRCPX) {
/* Cast to long pointer and move to the registers */
/* XXX can overrun struct size */
/* XXX check carefully for SSE members */
if ((ssz = tsize(t, sp->sdf, sp->sap)) > SZLONG*2)
cerror("efcode1");
if (typ == STRCPX) {
t = DOUBLE;
rno = XMM0;
} else {
t = LONG;
rno = RAX;
}
if (ssz > SZLONG) {
p = block(REG, NIL, NIL, INCREF(t), 0, 0);
regno(p) = RAX;
p = buildtree(UMUL, buildtree(PLUS, p, bcon(1)), NIL);
ecomp(movtoreg(p, rno+1));
}
p = block(REG, NIL, NIL, INCREF(t), 0, 0);
regno(p) = RAX;
p = buildtree(UMUL, p, NIL);
ecomp(movtoreg(p, rno));
} else if (typ == STRMEM) {
r = block(REG, NIL, NIL, INCREF(t), sp->sdf, sp->sap);
regno(r) = RAX;
r = buildtree(UMUL, r, NIL);
l = tempnode(stroffset, INCREF(t), sp->sdf, sp->sap);
l = buildtree(UMUL, l, NIL);
ecomp(buildtree(ASSIGN, l, r));
l = block(REG, NIL, NIL, LONG, 0, 0);
regno(l) = RAX;
r = tempnode(stroffset, LONG, 0, 0);
ecomp(buildtree(ASSIGN, l, r));
} else
cerror("efcode");
}
/*
* Called with a function call with arguments as argument.
* This is done early in buildtree() and only done once.
* Returns p.
*/
NODE *
funcode(NODE *p)
{
NODE *l, *r;
TWORD t;
int i;
nsse = ngpr = nrsp = 0;
/* Check if hidden arg needed */
/* If so, add it in pass2 */
if ((l = p->n_left)->n_type == INCREF(FTN)+STRTY ||
l->n_type == INCREF(FTN)+UNIONTY) {
int ssz = tsize(BTYPE(l->n_type), l->n_df, l->n_ap);
if (ssz > 2*SZLONG)
ngpr++;
}
/* Convert just regs to assign insn's */
p->n_right = argput(p->n_right);
/* Must sort arglist so that STASG ends up first */
/* This avoids registers being clobbered */
while (argsort(p->n_right))
;
/* Check if there are varargs */
if (nsse || l->n_df == NULL || l->n_df->dfun == NULL) {
; /* Need RAX */
} else {
union arglist *al = l->n_df->dfun;
for (; al->type != TELLIPSIS; al++) {
if ((t = al->type) == TNULL)
return p; /* No need */
if (ISSOU(BTYPE(t)))
al++;
for (i = 0; t > BTMASK; t = DECREF(t))
if (ISARY(t) || ISFTN(t))
i++;
if (i)
al++;
}
}
/* Always emit number of SSE regs used */
l = movtoreg(bcon(nsse), RAX);
if (p->n_right->n_op != CM) {
p->n_right = block(CM, l, p->n_right, INT, 0, 0);
} else {
for (r = p->n_right; r->n_left->n_op == CM; r = r->n_left)
;
r->n_left = block(CM, l, r->n_left, INT, 0, 0);
}
return p;
}
/*
* Do the "hard work" in assigning correct destination for arguments.
* Also convert arguments < INT to inte (default argument promotions).
* XXX - should be dome elsewhere.
*/
static NODE *
argput(NODE *p)
{
NODE *q;
TWORD ty;
int typ, r, ssz;
if (p->n_op == CM) {
p->n_left = argput(p->n_left);
p->n_right = argput(p->n_right);
return p;
}
/* first arg may be struct return pointer */
/* XXX - check if varargs; setup al */
switch (typ = argtyp(p->n_type, p->n_df, p->n_ap)) {
case INTEGER:
case SSE:
if (typ == SSE)
r = XMM0 + nsse++;
else
r = argregsi[ngpr++];
if (p->n_type < INT || p->n_type == BOOL)
p = cast(p, INT, 0);
p = movtoreg(p, r);
break;
case X87:
r = nrsp;
nrsp += SZLDOUBLE;
p = movtomem(p, r, STKREG);
break;
case SSEMEM:
r = nrsp;
nrsp += SZDOUBLE;
p = movtomem(p, r, STKREG);
break;
case INTMEM:
r = nrsp;
nrsp += SZLONG;
p = movtomem(p, r, STKREG);
break;
case STRCPX:
case STRREG: /* Struct in registers */
/* Cast to long pointer and move to the registers */
/* XXX can overrun struct size */
/* XXX check carefully for SSE members */
ssz = tsize(p->n_type, p->n_df, p->n_ap);
if (typ == STRCPX) {
ty = DOUBLE;
r = XMM0 + nsse++;
} else {
ty = LONG;
r = argregsi[ngpr++];
}
if (ssz <= SZLONG) {
q = cast(p->n_left, INCREF(ty), 0);
nfree(p);
q = buildtree(UMUL, q, NIL);
p = movtoreg(q, r);
} else if (ssz <= SZLONG*2) {
NODE *ql, *qr;
qr = cast(ccopy(p->n_left), INCREF(ty), 0);
qr = movtoreg(buildtree(UMUL, qr, NIL), r);
ql = cast(p->n_left, INCREF(ty), 0);
ql = buildtree(UMUL, buildtree(PLUS, ql, bcon(1)), NIL);
r = (typ == STRCPX ? XMM0 + nsse++ : argregsi[ngpr++]);
ql = movtoreg(ql, r);
nfree(p);
p = buildtree(CM, ql, qr);
} else
cerror("STRREG");
break;
case STRMEM: {
struct symtab s;
NODE *l, *t;
q = buildtree(UMUL, p->n_left, NIL);
s.stype = p->n_type;
s.squal = 0;
s.sdf = p->n_df;
s.sap = p->n_ap;
s.soffset = nrsp;
s.sclass = AUTO;
nrsp += tsize(p->n_type, p->n_df, p->n_ap);
l = block(REG, NIL, NIL, PTR+STRTY, 0, 0);
l->n_lval = 0;
regno(l) = STKREG;
t = block(NAME, NIL, NIL, p->n_type, p->n_df, p->n_ap);
t->n_sp = &s;
t = stref(block(STREF, l, t, 0, 0, 0));
t = (buildtree(ASSIGN, t, q));
nfree(p);
p = t->n_left;
nfree(t);
break;
}
default:
cerror("argument %d", typ);
}
return p;
}