static void
add_cf_node(nir_cf_node *cf, struct set *invariants)
{
if (cf->type == nir_cf_node_if) {
nir_if *if_stmt = nir_cf_node_as_if(cf);
add_src(&if_stmt->condition, invariants);
}
if (cf->parent)
add_cf_node(cf->parent, invariants);
}
static bool
dead_cf_list(struct exec_list *list, bool *list_ends_in_jump)
{
bool progress = false;
*list_ends_in_jump = false;
nir_cf_node *prev = NULL;
foreach_list_typed(nir_cf_node, cur, node, list) {
switch (cur->type) {
case nir_cf_node_block: {
nir_block *block = nir_cf_node_as_block(cur);
if (dead_cf_block(block)) {
/* We just deleted the if or loop after this block, so we may have
* deleted the block before or after it -- which one is an
* implementation detail. Therefore, to recover the place we were
* at, we have to use the previous cf_node.
*/
if (prev) {
cur = nir_cf_node_next(prev);
} else {
cur = exec_node_data(nir_cf_node, exec_list_get_head(list),
node);
}
block = nir_cf_node_as_block(cur);
progress = true;
}
if (ends_in_jump(block)) {
*list_ends_in_jump = true;
if (!exec_node_is_tail_sentinel(cur->node.next)) {
remove_after_cf_node(cur);
return true;
}
}
break;
}
case nir_cf_node_if: {
nir_if *if_stmt = nir_cf_node_as_if(cur);
bool then_ends_in_jump, else_ends_in_jump;
progress |= dead_cf_list(&if_stmt->then_list, &then_ends_in_jump);
progress |= dead_cf_list(&if_stmt->else_list, &else_ends_in_jump);
if (then_ends_in_jump && else_ends_in_jump) {
*list_ends_in_jump = true;
nir_block *next = nir_cf_node_as_block(nir_cf_node_next(cur));
if (!exec_list_is_empty(&next->instr_list) ||
!exec_node_is_tail_sentinel(next->cf_node.node.next)) {
remove_after_cf_node(cur);
return true;
}
}
break;
}
case nir_cf_node_loop: {
nir_loop *loop = nir_cf_node_as_loop(cur);
bool dummy;
progress |= dead_cf_list(&loop->body, &dummy);
break;
}
default:
unreachable("unknown cf node type");
}
prev = cur;
}
return progress;
}