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#include "all.h"
void
liveon(BSet *v, Blk *b, Blk *s)
{
Phi *p;
uint a;
bscopy(v, s->in);
for (p=s->phi; p; p=p->link)
if (rtype(p->to) == RTmp)
bsclr(v, p->to.val);
for (p=s->phi; p; p=p->link)
for (a=0; a<p->narg; a++)
if (p->blk[a] == b)
if (rtype(p->arg[a]) == RTmp)
bsset(v, p->arg[a].val);
}
static int
phitmp(int t, Tmp *tmp)
{
int tp;
tp = tmp[t].phi;
return tp ? tp : t;
}
static void
phifix(int t1, int *phi, Tmp *tmp)
{
int t, t2;
/* detect temporaries arguments
* of the same phi node that
* interfere and separate them
*/
t = phitmp(t1, tmp);
t2 = phi[t];
if (t2 && t2 != t1) {
if (t != t1) {
tmp[t1].phi = t1;
t = t1;
} else {
tmp[t2].phi = t2;
phi[t2] = t2;
}
}
phi[t] = t1;
}
static void
bset(Ref r, Blk *b, int *nlv, int *phi, Tmp *tmp)
{
if (rtype(r) != RTmp)
return;
bsset(b->gen, r.val);
phifix(r.val, phi, tmp);
if (!bshas(b->in, r.val)) {
nlv[KBASE(tmp[r.val].cls)]++;
bsset(b->in, r.val);
}
}
/* liveness analysis
* requires rpo computation
*/
void
filllive(Fn *f)
{
Blk *b;
Ins *i;
int k, t, m[2], n, chg, nlv[2];
int *phi;
BSet u[1], v[1];
Mem *ma;
bsinit(u, f->ntmp);
bsinit(v, f->ntmp);
phi = emalloc(f->ntmp * sizeof phi[0]);
for (b=f->start; b; b=b->link) {
bsinit(b->in, f->ntmp);
bsinit(b->out, f->ntmp);
bsinit(b->gen, f->ntmp);
}
chg = 1;
Again:
for (n=f->nblk-1; n>=0; n--) {
b = f->rpo[n];
bscopy(u, b->out);
if (b->s1) {
liveon(v, b, b->s1);
bsunion(b->out, v);
}
if (b->s2) {
liveon(v, b, b->s2);
bsunion(b->out, v);
}
chg |= !bsequal(b->out, u);
memset(phi, 0, f->ntmp * sizeof phi[0]);
memset(nlv, 0, sizeof nlv);
bscopy(b->in, b->out);
for (t=0; bsiter(b->in, &t); t++) {
phifix(t, phi, f->tmp);
nlv[KBASE(f->tmp[t].cls)]++;
}
if (rtype(b->jmp.arg) == RCall) {
assert(bscount(b->in) == 0 && nlv[0] == 0 && nlv[1] == 0);
b->in->t[0] |= retregs(b->jmp.arg, nlv);
} else
bset(b->jmp.arg, b, nlv, phi, f->tmp);
for (k=0; k<2; k++)
b->nlive[k] = nlv[k];
for (i=&b->ins[b->nins]; i!=b->ins;) {
if ((--i)->op == OCall && rtype(i->arg[1]) == RCall) {
b->in->t[0] &= ~retregs(i->arg[1], m);
for (k=0; k<2; k++)
nlv[k] -= m[k];
if (nlv[0] + NISave > b->nlive[0])
b->nlive[0] = nlv[0] + NISave;
if (nlv[1] + NFSave > b->nlive[1])
b->nlive[1] = nlv[1] + NFSave;
b->in->t[0] |= argregs(i->arg[1], m);
for (k=0; k<2; k++)
nlv[k] += m[k];
}
if (!req(i->to, R)) {
assert(rtype(i->to) == RTmp);
t = i->to.val;
if (bshas(b->in, i->to.val))
nlv[KBASE(f->tmp[t].cls)]--;
bsset(b->gen, t);
bsclr(b->in, t);
phi[phitmp(t, f->tmp)] = 0;
}
for (k=0; k<2; k++)
switch (rtype(i->arg[k])) {
case RMem:
ma = &f->mem[i->arg[k].val];
bset(ma->base, b, nlv, phi, f->tmp);
bset(ma->index, b, nlv, phi, f->tmp);
break;
default:
bset(i->arg[k], b, nlv, phi, f->tmp);
break;
}
for (k=0; k<2; k++)
if (nlv[k] > b->nlive[k])
b->nlive[k] = nlv[k];
}
}
if (chg) {
chg = 0;
goto Again;
}
free(phi);
if (debug['L']) {
fprintf(stderr, "\n> Liveness analysis:\n");
for (b=f->start; b; b=b->link) {
fprintf(stderr, "\t%-10sin: ", b->name);
dumpts(b->in, f->tmp, stderr);
fprintf(stderr, "\t out: ");
dumpts(b->out, f->tmp, stderr);
fprintf(stderr, "\t gen: ");
dumpts(b->gen, f->tmp, stderr);
fprintf(stderr, "\t live: ");
fprintf(stderr, "%d %d\n", b->nlive[0], b->nlive[1]);
}
}
}
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