if (get_opt_global_cse())
set_irg_pinned(irg, op_pin_state_floats);
- set_irg_outs_inconsistent(irg);
set_irg_doms_inconsistent(irg);
- set_irg_loopinfo_inconsistent(irg);
/* Clean the value_table in irg for the CSE. */
new_identities(irg);
current_ir_graph = rem;
}
-/**
- * Block-Walker: uses dominance depth to mark dead blocks.
- */
-static void kill_dead_blocks(ir_node *block, void *env)
-{
- (void) env;
-
- if (get_Block_dom_depth(block) < 0) {
- /*
- * Note that the new dominance code correctly handles
- * the End block, i.e. it is always reachable from Start
- */
- set_Block_dead(block);
- }
-}
-
-/* Applies local optimizations (see iropt.h) to all nodes reachable from node n. */
-void local_optimize_graph(ir_graph *irg)
+static void enqueue_node(ir_node *node, pdeq *waitq)
{
- ir_graph *rem = current_ir_graph;
- current_ir_graph = irg;
-
- if (get_irg_dom_state(irg) == dom_consistent)
- irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
-
- do_local_optimize(get_irg_end(irg));
-
- current_ir_graph = rem;
+ if (get_irn_link(node) == waitq)
+ return;
+ pdeq_putr(waitq, node);
+ set_irn_link(node, waitq);
}
/**
foreach_out_edge(n, edge) {
ir_node *succ = get_edge_src_irn(edge);
- if (get_irn_link(succ) != waitq) {
- pdeq_putr(waitq, succ);
- set_irn_link(succ, waitq);
- }
+ enqueue_node(succ, waitq);
if (get_irn_mode(succ) == mode_T) {
/* A mode_T node has Proj's. Because most optimizations
run on the Proj's we have to enqueue them also. */
}
}
+/**
+ * Block-Walker: uses dominance depth to mark dead blocks.
+ */
+static void find_unreachable_blocks(ir_node *block, void *env)
+{
+ pdeq *waitq = (pdeq*) env;
+
+ if (get_Block_dom_depth(block) < 0) {
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *end = get_irg_end(irg);
+
+ const ir_edge_t *edge;
+ foreach_block_succ(block, edge) {
+ const ir_edge_t *edge2;
+ ir_node *succ_block = get_edge_src_irn(edge);
+ enqueue_node(succ_block, waitq);
+ foreach_out_edge(succ_block, edge2) {
+ ir_node *succ = get_edge_src_irn(edge2);
+ if (is_Phi(succ))
+ enqueue_node(succ, waitq);
+ }
+ }
+ enqueue_node(end, waitq);
+ }
+}
+
+/* Applies local optimizations (see iropt.h) to all nodes reachable from node n. */
+void local_optimize_graph(ir_graph *irg)
+{
+ ir_graph *rem = current_ir_graph;
+ current_ir_graph = irg;
+
+ do_local_optimize(get_irg_end(irg));
+
+ current_ir_graph = rem;
+}
+
/**
* Data flow optimization walker.
- * Optimizes all nodes and enqueue it's users
+ * Optimizes all nodes and enqueue its users
* if done.
*/
static void opt_walker(ir_node *n, void *env)
{
- pdeq *waitq = env;
+ pdeq *waitq = (pdeq*)env;
ir_node *optimized;
optimized = optimize_in_place_2(n);
}
}
+/**
+ * Return the number of non-Bad predecessors of the given node.
+ */
+static int count_non_bads(ir_node *node)
+{
+ int arity = get_irn_arity(node);
+ int count = 0;
+ int i;
+ for (i = 0; i < arity; ++i) {
+ if (!is_Bad(get_irn_n(node, i)))
+ ++count;
+ }
+ return count;
+}
+
+/**
+ * Block-walker, remove Bad block predecessors and shorten Phis.
+ * Phi links must be uptodate.
+ */
+static void block_remove_bads(ir_node *block, void *env)
+{
+ int *changed = (int *)env;
+ int i, j;
+ ir_node **new_in, *new_block, *phi;
+ const int max = get_irn_arity(block);
+ const int new_max = count_non_bads(block);
+ assert(max >= new_max);
+
+ if (is_Bad(block) || max == new_max)
+ return;
+
+ new_in = ALLOCAN(ir_node*, new_max);
+ *changed = 1;
+
+ assert(get_Block_dom_depth(block) >= 0);
+
+ /* 1. Create a new block without Bad inputs */
+ for (i = j = 0; i < max; ++i) {
+ ir_node *block_pred = get_irn_n(block, i);
+ if (!is_Bad(block_pred)) {
+ new_in[j++] = block_pred;
+ }
+ }
+ assert(j == new_max);
+
+ /* If the end block is unreachable, it might have zero predecessors. */
+ if (new_max == 0) {
+ ir_node *end_block = get_irg_end_block(get_irn_irg(block));
+ if (block == end_block) {
+ set_irn_in(block, new_max, new_in);
+ return;
+ }
+ }
+
+ new_block = new_r_Block(get_irn_irg(block), new_max, new_in);
+
+ /* 2. Remove inputs on Phis, where the block input is Bad. */
+ phi = get_Block_phis(block);
+ if (phi != NULL) {
+ do {
+ ir_node *next = get_Phi_next(phi);
+ if (get_irn_arity(phi) != new_max) {
+ ir_node *new_phi;
+
+ for (i = j = 0; i < max; ++i) {
+ ir_node *block_pred = get_irn_n(block, i);
+
+ if (!is_Bad(block_pred)) {
+ ir_node *pred = get_irn_n(phi, i);
+ new_in[j++] = pred;
+ }
+ }
+ assert(j == new_max);
+
+ new_phi = new_r_Phi(new_block, new_max, new_in, get_irn_mode(phi));
+ exchange(phi, new_phi);
+ }
+ phi = next;
+ } while (phi != NULL);
+ }
+
+ exchange(block, new_block);
+}
+
+/* Remove Bad nodes from Phi and Block inputs.
+ *
+ * Precondition: No unreachable code.
+ * Postcondition: No Bad nodes.
+ */
+static int remove_Bads(ir_graph *irg)
+{
+ int changed = 0;
+ /* build phi list per block */
+ irg_walk_graph(irg, firm_clear_block_phis, firm_collect_block_phis, NULL);
+
+ /* actually remove Bads */
+ irg_block_walk_graph(irg, NULL, block_remove_bads, (void *)&changed);
+
+ return changed;
+}
+
/* Applies local optimizations to all nodes in the graph until fixpoint. */
int optimize_graph_df(ir_graph *irg)
{
state = edges_assure(irg);
- if (get_opt_global_cse())
- set_irg_pinned(irg, op_pin_state_floats);
-
/* Clean the value_table in irg for the CSE. */
new_identities(irg);
- if (get_irg_dom_state(irg) == dom_consistent)
- irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
+ if (get_opt_global_cse()) {
+ set_irg_pinned(irg, op_pin_state_floats);
+ }
+
+ /* The following enables unreachable code elimination (=Blocks may be
+ * Bad). */
+ set_irg_state(irg, IR_GRAPH_STATE_BAD_BLOCK);
/* invalidate info */
- set_irg_outs_inconsistent(irg);
set_irg_doms_inconsistent(irg);
- set_irg_loopinfo_inconsistent(irg);
ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
+ /* Calculate dominance so we can kill unreachable code */
+ assure_doms(irg);
+
/* walk over the graph, but don't touch keep-alives */
irg_walk_graph(irg, NULL, opt_walker, waitq);
* so if it's not empty, the graph has been changed */
changed = !pdeq_empty(waitq);
- /* finish the wait queue */
- while (! pdeq_empty(waitq)) {
- ir_node *n = pdeq_getl(waitq);
- if (! is_Bad(n))
+ while (!pdeq_empty(waitq)) {
+ /* finish the wait queue */
+ while (! pdeq_empty(waitq)) {
+ ir_node *n = (ir_node*)pdeq_getl(waitq);
opt_walker(n, waitq);
+ }
+ /* Calculate dominance so we can kill unreachable code */
+ compute_doms(irg);
+ irg_block_walk_graph(irg, NULL, find_unreachable_blocks, waitq);
}
+ set_irg_doms_inconsistent(irg);
del_pdeq(waitq);
if (! state)
edges_deactivate(irg);
+ if (remove_Bads(irg)) {
+ edges_deactivate(irg);
+ }
+
/* Finally kill BAD and doublets from the keep alives.
Doing this AFTER edges where deactivated saves cycles */
- end = get_irg_end(irg);
+ end = get_irg_end(irg);
remove_End_Bads_and_doublets(end);
+ clear_irg_state(irg, IR_GRAPH_STATE_BAD_BLOCK);
+
current_ir_graph = rem;
return changed;
}
projects / libfirm / blobdiff