/*
* Compare two trees; return 1 if equal and 0 if not.
*/
int
treecmp(NODE *p1, NODE *p2)
{
if (p1->n_op != p2->n_op)
return 0;
switch (p1->n_op) {
case SCONV:
case UMUL:
return treecmp(p1->n_left, p2->n_left);
case OREG:
if (getlval(p1) != getlval(p2) || p1->n_rval != p2->n_rval)
return 0;
break;
case NAME:
case ICON:
if (strcmp(p1->n_name, p2->n_name))
return 0;
/* FALLTHROUGH */
if (getlval(p1) != getlval(p2))
return 0;
break;
case TEMP:
#ifdef notyet
/* SSA will put assignment in separate register */
/* Help out by accepting different regs here */
if (xssa)
break;
#endif
case REG:
if (p1->n_rval != p2->n_rval)
return 0;
break;
case LS:
case RS:
case PLUS:
case MINUS:
case MUL:
case DIV:
if (treecmp(p1->n_left, p2->n_left) == 0 ||
treecmp(p1->n_right, p2->n_right) == 0)
return 0;
break;
default:
return 0;
}
return 1;
}
static int
inctree(NODE *p)
{
if (p->n_op == MINUS && p->n_left->n_op == ASSIGN &&
p->n_left->n_right->n_op == PLUS &&
treecmp(p->n_left->n_left, p->n_left->n_right->n_left) &&
p->n_right->n_op == ICON && p->n_right->n_lval == 1 &&
p->n_left->n_right->n_right->n_op == ICON &&
p->n_left->n_right->n_right->n_lval == 1) {
/* post-increment by 1; (r0)+ */
if (isreg(p->n_left->n_left)) /* Ignore if index not in reg */
return 1;
}
return 0;
}
long treestack_push(Dataptr matrix, Treestack *sp, const Branch *const barray, const long root)
{
long i; /* loop counter */
Branch *stacktree = NULL; /* current tree on stack */
long stackroot; /* root of current tree */
/* return before push if not a new topology */
/* check backwards as similar trees may be discovered together */
for (i = sp->next - 1; i >= 0; i--) {
stacktree = sp->stack[i].tree;
stackroot = sp->stack[i].root;
if (treecmp(matrix, stacktree, stackroot, barray, root) == 0) return 0;
}
/* topology is new so must be pushed */
dopush(matrix, sp, barray, root);
return 1;
} /* end treestack_push() */
/*
* Try to find constructs like "a = a + 1;" and match them together
* with instructions like "incl a" or "addl $1,a".
*
* Level assignment for priority:
* left right prio
* - - -
* direct direct 1
* direct REG 2
* direct OREG 3
* OREG direct 4
* OREG REG 5
* OREG OREG 6
*/
int
findmops(NODE *p, int cookie)
{
extern int *qtable[];
struct optab *q;
int i, sh, shl, shr, lvl = 10;
NODE *l, *r;
int *ixp;
struct optab *qq = NULL; /* XXX gcc */
int idx = 0, gol = 0, gor = 0;
shl = shr = 0;
F2DEBUG(("findmops tree: %s\n", prcook(cookie)));
F2WALK(p);
l = getlr(p, 'L');
r = getlr(p, 'R');
/* See if this is a usable tree to work with */
/* Currently only check for leaves */
if (optype(r->n_op) != BITYPE || treecmp(l, r->n_left) == 0)
return FFAIL;
F2DEBUG(("findmops is useable\n"));
/* We can try to find a match. Use right op */
ixp = qtable[r->n_op];
l = getlr(r, 'L');
r = getlr(r, 'R');
for (i = 0; ixp[i] >= 0; i++) {
q = &table[ixp[i]];
F2DEBUG(("findmops: ixp %d\n", ixp[i]));
if (!acceptable(q)) /* target-dependent filter */
continue;
if (ttype(l->n_type, q->ltype) == 0 ||
ttype(r->n_type, q->rtype) == 0)
continue; /* Types must be correct */
F2DEBUG(("findmops got types\n"));
switch (cookie) {
case FOREFF:
if ((q->visit & FOREFF) == 0)
continue; /* Not only for side effects */
break;
case FORCC:
if ((q->visit & FORCC) == 0)
continue; /* Not only for side effects */
break;
default:
if ((cookie & q->visit) == 0)
continue; /* Won't match requested shape */
if (((cookie & INREGS & q->lshape) == 0) || !isreg(l))
continue; /* Bad return register */
break;
}
F2DEBUG(("findmops cookie\n"));
/*
* left shape must match left node.
*/
if ((shl = tshape(l, q->lshape)) != SRDIR && (shl != SROREG))
continue;
F2DEBUG(("findmops lshape %s\n", srtyp[shl]));
F2WALK(l);
if ((shr = chcheck(r, q->rshape, 0)) == SRNOPE)
continue;
F2DEBUG(("findmops rshape %s\n", srtyp[shr]));
/*
* Only allow RLEFT. XXX
*/
if ((q->rewrite & (RLEFT|RRIGHT)) != RLEFT)
continue;
F2DEBUG(("rewrite OK\n"));
F2WALK(r);
if (q->needs & REWRITE)
break; /* Done here */
if (lvl <= (shl + shr))
continue;
lvl = shl + shr;
qq = q;
idx = ixp[i];
gol = shl;
gor = shr;
}
if (lvl == 10)
return FFAIL;
F2DEBUG(("findmops entry %d(%s,%s)\n", idx, srtyp[gol], srtyp[gor]));
/*
* Now we're here and have a match. left is semi-direct and
* right may be anything.
*/
sh = -1;
sh = shswitch(sh, p->n_left, qq->lshape, cookie,
qq->rewrite & RLEFT, gol);
sh = shswitch(sh, r, qq->rshape, cookie, 0, gor);
if (sh == -1) {
if (cookie & (FOREFF|FORCC))
sh = 0;
else
sh = ffs(cookie & qq->visit & INREGS)-1;
}
F2DEBUG(("findmops done: node %p class %d\n", p, sh));
/* Trickery: Set table index on assign to op instead */
/* gencode() will remove useless nodes */
p->n_su = MKIDX(idx, 0);
p->n_su |= ISMOPS; /* XXX tell gencode to reduce the right tree */
SCLASS(p->n_su, sh);
return sh;
}