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#include "ir.h"
static void
porec(struct block ***rpo, struct block *b)
{
if (wasvisited(b)) return;
markvisited(b);
if (b->s2) porec(rpo, b->s2);
if (b->s1) porec(rpo, b->s1);
*--*rpo = b;
}
void
sortrpo(struct function *fn)
{
static struct block **rpobuf;
struct block **rpoend, **rpo, *blk, *next;
int i, ndead;
xbgrow(&rpobuf, fn->nblk);
rpo = rpoend = rpobuf + fn->nblk,
startbbvisit();
fn->entry->id = 0;
porec(&rpo, fn->entry);
ndead = rpo - rpobuf;
if (ndead > 0) for (blk = fn->entry->lprev; blk != fn->entry; blk = next) {
next = blk->lprev;
if (!wasvisited(blk)) {
for (int i = 0; i < blk->ins.n; ++i) {
/* if unreachable block has alloca pseudo-instrs, move them to the entry
* to be able to delete it */
if (oisalloca(instrtab[blk->ins.p[i]].op)) {
vpush(&fn->entry->ins, blk->ins.p[i]);
}
}
for (int i = 0; i < blk->npred; ++i)
assert(!wasvisited(blkpred(blk, i)));
freeblk(fn, blk);
--ndead;
}
}
for (i = 1, ++rpo; rpo < rpoend; ++rpo, ++i) {
rpo[-1]->lnext = rpo[0];
rpo[0]->lprev = rpo[-1];
rpo[0]->id = i;
}
fn->entry->lprev = rpo[-1];
rpo[-1]->lnext = fn->entry;
}
/* vim:set ts=3 sw=3 expandtab: */
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