cycle->elems[idx++] = pairs[cur_pair_idx].out_reg;
cycle->n_elems++;
- pairs[cur_pair_idx].checked = 1;
n_pairs_done++;
}
else {
/* we are there where we started -> CYCLE */
cycle->type = PERM_CYCLE;
}
+
+ /* mark the pair as checked */
+ pairs[cur_pair_idx].checked = 1;
}
return cycle;
* copy and swap operations to permute registers.
*
* @param irn The perm node
+ * @param block The block the perm node belongs to
* @param walk_env The environment
*/
-static void lower_perms_walker(ir_node *irn, void *walk_env) {
+static void lower_perm_node(ir_node *irn, void *walk_env) {
const be_node_factory_t *fact;
const arch_register_class_t *reg_class;
const arch_env_t *arch_env;
const ir_edge_t *edge;
perm_cycle_t *cycle;
int n, i, pn, do_copy;
- ir_node *block, *arg, *res, *sched_point, *in[2];
+ ir_node *sched_point, *block, *in[2];
+ ir_node *arg1, *arg2, *res1, *res2;
ir_node *cpyxchg = NULL;
+ if (is_Block(irn))
+ return;
+
fact = env->chord_env->main_env->node_factory;
arch_env = env->chord_env->main_env->arch_env;
do_copy = env->do_copy;
mod = env->dbg_module;
+ block = get_nodes_block(irn);
- /* check if perm */
- if (is_Proj(irn) || ! is_Perm(arch_env, irn))
+ /* check if perm
+ Note: A Proj on a Perm will cause is_Perm()
+ also to return true */
+ if (is_Proj(irn) || ! is_Perm(arch_env, irn))
return;
- block = get_nodes_block(irn);
-
/*
Get the schedule predecessor node to the perm
NOTE: This works with auto-magic. If we insert the
should be ok.
*/
sched_point = sched_prev(irn);
+ DBG((mod, LEVEL_1, "sched point is %+F\n", sched_point));
assert(sched_point && "Perm is not scheduled or has no predecessor");
n = get_irn_arity(irn);
the IN node. */
for (i = 0; i < n; i++) {
if (pairs[i].in_reg->index == pairs[i].out_reg->index) {
- DBG((mod, LEVEL_1, "removing equal perm register pair (%+F, %+F, %s)\n",
- pairs[i].in_node, pairs[i].out_node, pairs[i].out_reg->name));
- /* If scheduling point and in-node are the same, then get the scheduling
- pred of this node, otherwise we would break the scheduling list */
- if (sched_point == pairs[i].in_node) {
- sched_point = sched_prev(sched_point);
+ DBG((mod, LEVEL_1, "%+F removing equal perm register pair (%+F, %+F, %s)\n",
+ irn, pairs[i].in_node, pairs[i].out_node, pairs[i].out_reg->name));
+
+ /* We have to check for a special case:
+ The in-node could be a Proj from a Perm. In this case,
+ we need to correct the projnum */
+ if (is_Perm(arch_env, pairs[i].in_node) && is_Proj(pairs[i].in_node)) {
+ set_Proj_proj(pairs[i].out_node, get_Proj_proj(pairs[i].in_node));
}
+
/* remove the proj from the schedule */
sched_remove(pairs[i].out_node);
- /* remove the argument from schedule */
- sched_remove(pairs[i].in_node);
-
/* exchange the proj with the argument */
- exchange(pairs[i].out_node, pairs[i].in_node);
-
- /* add the argument after the magic scheduling point */
- sched_add_after(sched_point, pairs[i].in_node);
+ edges_reroute(pairs[i].out_node, pairs[i].in_node, env->chord_env->irg);
pairs[i].checked = 1;
}
cycle = calloc(1, sizeof(*cycle));
cycle = get_perm_cycle(cycle, pairs, n, i);
+ /* We don't need to do anything if we have a Perm with two
+ elements which represents a cycle, because those nodes
+ already represent exchange nodes */
+ if (n == 2 && cycle->type == PERM_CYCLE) {
+ free(cycle);
+ continue;
+ }
+
//todo: - iff PERM_CYCLE && do_copy -> determine free temp reg and insert copy to/from it before/after
// the copy cascade (this reduces the cycle into a chain)
/* build copy/swap nodes from back to front */
for (i = cycle->n_elems - 2; i >= 0; i--) {
- arg = get_node_for_register(pairs, n, cycle->elems[i], 0);
- res = get_node_for_register(pairs, n, cycle->elems[i + 1], 1);
+ arg1 = get_node_for_register(pairs, n, cycle->elems[i], 0);
+ arg2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 0);
+
+ res1 = get_node_for_register(pairs, n, cycle->elems[i], 1);
+ res2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 1);
/*
If we have a cycle and don't copy: we need to create exchange nodes
OUT_2 = out node with register i
*/
if (cycle->type == PERM_CYCLE && !do_copy) {
- in[0] = arg;
- in[1] = get_node_for_register(pairs, n, cycle->elems[i + 1], 0);
+ in[0] = arg1;
+ in[1] = arg2;
- DBG((mod, LEVEL_1, "creating exchange node (%+F, %s) <-> (%+F, %s)\n",
- arg, cycle->elems[i]->name, res, cycle->elems[i + 1]->name));
+ DBG((mod, LEVEL_1, "%+F creating exchange node (%+F, %s) and (%+F, %s) with\n",
+ irn, arg1, cycle->elems[i]->name, arg2, cycle->elems[i + 1]->name));
+ DBG((mod, LEVEL_1, "%+F (%+F, %s) and (%+F, %s)\n",
+ irn, res1, cycle->elems[i]->name, res2, cycle->elems[i + 1]->name));
cpyxchg = new_Perm(fact, reg_class, env->chord_env->irg, block, 2, in);
- set_Proj_pred(res, cpyxchg);
- set_Proj_proj(res, 0);
- set_Proj_pred(get_node_for_register(pairs, n, cycle->elems[i], 1), cpyxchg);
- set_Proj_proj(get_node_for_register(pairs, n, cycle->elems[i], 1), 1);
+
+ sched_remove(res1);
+ sched_remove(res2);
+
+ set_Proj_pred(res2, cpyxchg);
+ set_Proj_proj(res2, 0);
+ set_Proj_pred(res1, cpyxchg);
+ set_Proj_proj(res1, 1);
+
+ sched_add_after(sched_point, res1);
+ sched_add_after(sched_point, res2);
+
+ arch_set_irn_register(arch_env, res2, cycle->elems[i + 1]);
+ arch_set_irn_register(arch_env, res1, cycle->elems[i]);
}
else {
- DBG((mod, LEVEL_1, "creating copy node (%+F, %s) -> (%+F, %s)\n",
- arg, cycle->elems[i]->name, res, cycle->elems[i + 1]->name));
+ DBG((mod, LEVEL_1, "%+F creating copy node (%+F, %s) -> (%+F, %s)\n",
+ irn, arg1, cycle->elems[i]->name, res2, cycle->elems[i + 1]->name));
- cpyxchg = new_Copy(fact, reg_class, env->chord_env->irg, block, arg);
+ cpyxchg = new_Copy(fact, reg_class, env->chord_env->irg, block, arg1);
arch_set_irn_register(arch_env, cpyxchg, cycle->elems[i + 1]);
/* remove the proj from the schedule */
- sched_remove(res);
+ sched_remove(res2);
/* exchange copy node and proj */
- exchange(res, cpyxchg);
+ exchange(res2, cpyxchg);
}
/* insert the copy/exchange node in schedule after the magic schedule node (see above) */
sched_add_after(sched_point, cpyxchg);
+
+ DBG((mod, LEVEL_1, "replacing %+F with %+F, placed new node after %+F\n", irn, cpyxchg, sched_point));
}
// free(cycle->elems);
}
/**
- * Walks over all nodes in an irg and performs perm lowering.
+ * Walks over all blocks in an irg and performs perm lowering.
*
* @param chord_env The chordal environment containing the irg
* @param do_copy 1 == resolve cycles with a free reg if available
env.do_copy = do_copy;
env.dbg_module = firm_dbg_register("ir.be.lower");
- irg_walk_blkwise_graph(chord_env->irg, NULL, lower_perms_walker, &env);
+ irg_walk_blkwise_graph(chord_env->irg, NULL, lower_perm_node, &env);
}
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