static void checkreach(Cfg *cfg)
{
Bitset *reach, *kill;
size_t i, j, k;
Reaching *r;
Node *n, *m;
Bb *bb;
r = reaching(cfg);
// dumpcfg(cfg, stdout);
for (i = 0; i < cfg->nbb; i++) {
bb = cfg->bb[i];
if (!bb)
continue;
reach = bsdup(r->in[i]);
kill = mkbs();
for (j = 0; j < bb->nnl; j++) {
n = bb->nl[j];
if (exprop(n) == Oundef) {
bsput(reach, n->nid);
} else {
m = assignee(n);
if (m)
for (k = 0; k < r->ndefs[m->expr.did]; k++)
bsput(kill, r->defs[m->expr.did][k]);
checkundef(n, r, reach, kill);
}
}
bsfree(reach);
bsfree(kill);
}
}
Reaching *reaching(Cfg *cfg)
{
Bitset **in, **out;
Bitset **gen, **kill;
Bitset *bbin, *bbout;
Reaching *reaching;
size_t **defs; /* mapping from did => [def,list] */
size_t *ndefs;
size_t i, j;
int changed;
in = zalloc(cfg->nbb * sizeof(Bb*));
out = zalloc(cfg->nbb * sizeof(Bb*));
gen = zalloc(cfg->nbb * sizeof(Bb*));
kill = zalloc(cfg->nbb * sizeof(Bb*));
defs = zalloc(ndecls * sizeof(size_t*));
ndefs = zalloc(ndecls * sizeof(size_t));
collectdefs(cfg, defs, ndefs);
for (i = 0; i < cfg->nbb; i++) {
in[i] = mkbs();
out[i] = mkbs();
gen[i] = mkbs();
kill[i] = mkbs();
if (cfg->bb[i])
genkill(cfg->bb[i], defs, ndefs, gen[i], kill[i]);
}
do {
changed = 0;
for (i = 0; i < cfg->nbb; i++) {
if (!cfg->bb[i])
continue;
bbin = mkbs();
for (j = 0; bsiter(cfg->bb[i]->pred, &j); j++)
bsunion(bbin, out[j]);
bbout = bsdup(bbin);
bsdiff(bbout, kill[i]);
bsunion(bbout, gen[i]);
if (!bseq(out[i], bbout) || !bseq(in[i], bbin)) {
changed = 1;
bsfree(in[i]);
bsfree(out[i]);
in[i] = bbin;
out[i] = bbout;
}
}
} while (changed);
reaching = xalloc(sizeof(Reaching));
reaching->in = in;
reaching->out = out;
reaching->defs = defs;
reaching->ndefs = ndefs;
return reaching;
}
static Nodes *
circbreak1(ASTNode *n)
{
ASTNode *idx;
BitSet *visit;
ASTNode *m;
int r;
if(n->t == ASTASS && n->n2 != nil && n->n2->t == ASTISUB) {
idx = n->n2->n1;
assert(idx != nil && idx->t == ASTIDX);
if(n->n1->t == ASTSSA && idx->n1->t == ASTSSA && idx->n1->semv == idx->n1->semv->sym->semc[1]) {
visit = bsnew(nvars);
r = findcircles(idx->n1->semv, n->n1->semv, visit);
bsfree(visit);
if(r) {
m = nodedup(n);
m->n2 = nodedup(m->n2);
m->n2->n1 = nodedup(m->n2->n1);
m->n2->n1->n1 = node(ASTSSA, idx->n1->semv->sym->semc[0]);
circbroken++;
return nl(m);
}
}
}
return nl(n);
}
/* copy blocks and create definitions for the primed values as needed */
static void
makenext(void)
{
SemBlock *b, *c;
BitSet *copy;
int i, j, ch;
copy = bsnew(nblocks);
for(i = 0; i < nblocks; i++) {
b = blocks[i];
if(descendsum(b->phi, countnext) + descendsum(b->cont, countnext) > 0)
bsadd(copy, i);
}
do {
ch = 0;
for(i = -1; i = bsiter(copy, i), i >= 0; ) {
b = blocks[i];
for(j = 0; j < b->nto; j++)
ch += bsadd(copy, b->to[j]->idx) == 0;
for(j = 0; j < b->nfrom; j++)
ch += bsadd(copy, b->from[j]->idx) == 0;
}
} while(ch != 0);
dupl = emalloc(nblocks * sizeof(SemBlock *));
for(i = -1; i = bsiter(copy, i), i >= 0; )
dupl[i] = newblock();
for(i = -1; i = bsiter(copy, i), i >= 0; ) {
b = blocks[i];
c = dupl[i];
c->nto = b->nto;
c->to = emalloc(sizeof(SemBlock *) * c->nto);
c->nfrom = b->nfrom;
c->from = emalloc(sizeof(SemBlock *) * c->nfrom);
for(j = 0; j < b->nto; j++) {
c->to[j] = dupl[b->to[j]->idx];
assert(c->to[j] != nil);
}
for(j = 0; j < b->nfrom; j++) {
c->from[j] = dupl[b->from[j]->idx];
assert(c->from[j] != nil);
}
c->phi = mkblock(descend(b->phi, nil, makenext1));
c->cont = mkblock(descend(b->cont, nil, makenext1));
c->jump = mkblock(descend(b->jump, nil, makenext1));
}
for(i = 0; i < nblocks; i++) {
b = blocks[i];
b->phi = mkblock(descend(b->phi, nil, deldefs));
b->cont = mkblock(descend(b->cont, nil, deldefs));
}
bsfree(copy);
}
static void
doif(ASTNode *n, int ctxt)
{
BitSet *g, *k, *kp;
BitSet *g1, *k1, *k1p;
BitSet *g2, *k2, *k2p, *t;
PipeStage *p;
p = stcur;
t = bsnew(p->nvars);
findstages(n->n1, ctxt);
g = p->gen;
k = p->kill;
kp = p->killp;
p->gen = g1 = bsdup(g);
p->kill = k1 = bsdup(k);
p->killp = k1p = bsdup(kp);
findstages(n->n2, ctxt);
p->gen = g2 = bsdup(g);
p->kill = k2 = bsdup(k);
p->killp = k2p = bsdup(kp);
findstages(n->n3, ctxt);
bsunion(g, g1, g);
bsunion(g, g2, g);
bsunion(k, k1, k);
bsunion(k, k2, k);
bsunion(kp, k1p, kp);
bsunion(kp, k2p, kp);
bsminus(t, k1, k2);
addeq(t, &n->n3, 0);
bsunion(g, t, g);
bsminus(t, k2, k1);
addeq(t, &n->n2, 0);
bsunion(g, t, g);
bsminus(t, k1p, k2p);
addeq(t, &n->n3, 1);
bsunion(g, t, g);
bsminus(t, k2p, k1p);
addeq(t, &n->n2, 1);
bsunion(g, t, g);
p->gen = g;
p->kill = k;
p->killp = kp;
bsfree(g1);
bsfree(g2);
bsfree(k1);
bsfree(k2);
bsfree(k1p);
bsfree(k2p);
bsfree(t);
}
static void
circdefs(void)
{
int i;
BitSet *visit;
visit = bsnew(nvars);
for(i = 0; i < nvars; i++) {
bsreset(visit);
if(vars[i] == vars[i]->sym->semc[0] && findcircles(vars[i], vars[i], visit))
error(vars[i]->sym, "combinational loop involving %s", vars[i]->sym->name);
bsreset(visit);
if(vars[i] == vars[i]->sym->semc[1] && findcircles(vars[i], vars[i], visit))
error(vars[i]->sym, "combinational loop involving %s'", vars[i]->sym->name);
}
bsfree(visit);
}
static Nodes *
process(ASTNode *n)
{
Nodes *r, *s, *t;
int ours;
BitSet *ks;
if(n == nil) return nil;
switch(n->t){
case ASTPIPEL:
t = nil;
s = nil;
for(r = n->nl; r != nil; r = r->next)
if(r->n->t == ASTSTATE){
if(stcur == nil) stcur = stlist.next;
else stcur = stcur->next;
assert(stcur != nil && stcur->sym == r->n->sym);
bsreset(killed);
if(s != nil) t = nlcat(t, nl(node(ASTBLOCK, s)));
s = nil;
}else
s = nlcat(s, process(r->n));
if(s != nil) t = nlcat(t, nl(node(ASTBLOCK, s)));
return t;
case ASTSYMB:
if(stcur != nil && n->sym->pipeidx >= 0)
if(bstest(killed, n->sym->pipeidx))
n->sym = stcur->outvars[n->sym->pipeidx];
else
n->sym = stcur->invars[n->sym->pipeidx];
return nl(n);
case ASTPRIME:
ours = 0;
return nl(lvalfix(n, 0, &ours));
case ASTASS:
n = nodedup(n);
n->n2 = onlyone(process(n->n2));
ours = 0;
n->n1 = lvalfix(n->n1, LVAL, &ours);
return nl(n);
case ASTDECL:
return nil;
case ASTBLOCK:
n = nodedup(n);
s = nil;
for(r = n->nl; r != nil; r = r->next)
s = nlcat(s, process(r->n));
n->nl = s;
return nl(n);
case ASTCINT:
case ASTCONST:
return nl(n);
case ASTOP:
case ASTTERN:
n = nodedup(n);
n->n1 = onlyone(process(n->n1));
n->n2 = onlyone(process(n->n2));
n->n3 = onlyone(process(n->n3));
n->n4 = onlyone(process(n->n4));
return nl(n);
case ASTIF:
n = nodedup(n);
n->n1 = onlyone(process(n->n1));
ks = killed;
killed = bsdup(ks);
n->n2 = onlyone(process(n->n2));
bsfree(killed);
killed = ks;
n->n3 = onlyone(process(n->n3));
return nl(n);
default:
warn(n, "process: unknown %A", n->t);
}
return nl(n);
}