Function fix

src/e9patch/e9alloc.cpp:67–82

* Restore interval-tree invariants after a node after child node modification. */

 * Restore interval-tree invariants after a node after child node modification.
 */
static void fix(Node *n)
{
    if (n == nullptr)
        return;
    Node *l = n->entry.left, *r = n->entry.right;
    intptr_t llb = (l != nullptr? l->lb: INTPTR_MAX);
    intptr_t rub = (r != nullptr? r->ub: INTPTR_MIN);
    n->lb = std::min(llb, n->alloc.lb);
    n->ub = std::max(rub, n->alloc.ub);
    uint64_t lgap = (l == nullptr? 0: l->gap);
    uint64_t rgap = (r == nullptr? 0: r->gap);
    uint64_t gap  = std::max(lgap, rgap);
    gap = std::max(gap, (uint64_t)(l == nullptr? 0: n->alloc.lb - l->ub));
    gap = std::max(gap, (uint64_t)(r == nullptr? 0: r->lb - n->alloc.ub));
    n->gap = gap;
}

/****************************************************************************/
/* INTERVAL TREES                                                           */