static INLINE void do_local_optimize(ir_node *n) {
/* Handle graph state */
assert(get_irg_phase_state(current_ir_graph) != phase_building);
+
if (get_opt_global_cse())
set_irg_pinned(current_ir_graph, op_pin_state_floats);
if (get_irg_outs_state(current_ir_graph) == outs_consistent)
set_irg_dom_inconsistent(current_ir_graph);
set_irg_loopinfo_inconsistent(current_ir_graph);
-
/* Clean the value_table in irg for the CSE. */
del_identities(current_ir_graph->value_table);
current_ir_graph->value_table = new_identities();
current_ir_graph = rem;
}
+/**
+ * Block-Walker: uses dominance depth to mark dead blocks.
+ */
+static void kill_dead_blocks(ir_node *block, void *env)
+{
+ if (get_Block_dom_depth(block) < 0)
+ set_Block_dead(block);
+}
+
void
local_optimize_graph (ir_graph *irg) {
ir_graph *rem = current_ir_graph;
current_ir_graph = irg;
+ if (get_irg_dom_state(current_ir_graph) == dom_consistent)
+ irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
+
do_local_optimize(irg->end);
current_ir_graph = rem;
}
/**
- * Get this new node, before the old node is forgotton.
+ * Get this new node, before the old node is forgotten.
*/
static INLINE ir_node *
-get_new_node (ir_node * n)
-{
+get_new_node (ir_node * n) {
return n->link;
}
/* arity changing: set new predecessors without bad nodes */
if (new_irn_arity < old_irn_arity) {
/* Get new predecessor array. We do not resize the array, as we must
- keep the old one to update Phis. */
+ keep the old one to update Phis. */
new_in = NEW_ARR_D (ir_node *, current_ir_graph->obst, (new_irn_arity+1));
/* set new predecessors in array */
new_in[0] = NULL;
new_irn_n = 1;
for (i = 0; i < old_irn_arity; i++) {
- irn = get_irn_n(n, i);
- if (!is_Bad(irn)) {
- new_in[new_irn_n] = irn;
- is_backedge(n, i) ? set_backedge(n, new_irn_n-1) : set_not_backedge(n, new_irn_n-1);
- new_irn_n++;
- }
+ irn = get_irn_n(n, i);
+ if (!is_Bad(irn)) {
+ new_in[new_irn_n] = irn;
+ is_backedge(n, i) ? set_backedge(n, new_irn_n-1) : set_not_backedge(n, new_irn_n-1);
+ new_irn_n++;
+ }
}
//ARR_SETLEN(int, n->attr.block.backedge, new_irn_arity);
ARR_SHRINKLEN(n->attr.block.backedge, new_irn_arity);
/* Relink Phi predecessors if count of predecessors changed */
if (old_irn_arity != ARR_LEN(get_irn_in(block))) {
/* set new predecessors in array
- n->in[0] remains the same block */
+ n->in[0] remains the same block */
new_irn_arity = 1;
for(i = 1; i < old_irn_arity; i++)
- if (!is_Bad((ir_node *)old_in[i])) {
- n->in[new_irn_arity] = n->in[i];
- is_backedge(n, i) ? set_backedge(n, new_irn_arity) : set_not_backedge(n, new_irn_arity);
- new_irn_arity++;
- }
+ if (!is_Bad((ir_node *)old_in[i])) {
+ n->in[new_irn_arity] = n->in[i];
+ is_backedge(n, i) ? set_backedge(n, new_irn_arity) : set_not_backedge(n, new_irn_arity);
+ new_irn_arity++;
+ }
ARR_SETLEN(ir_node *, n->in, new_irn_arity);
ARR_SETLEN(int, n->attr.phi_backedge, new_irn_arity);
/*--------------------------------------------------------------------*/
-/* Funcionality for inlining */
+/* Functionality for inlining */
/*--------------------------------------------------------------------*/
/**
} inline_irg_env;
/**
- * Allocate a new nvironment for inlining.
+ * Allocate a new environment for inlining.
*/
static inline_irg_env *new_inline_irg_env(void) {
inline_irg_env *env = xmalloc(sizeof(*env));
/**
* Returns non-zero, is a block is not reachable from Start.
+ *
+ * @param block the block to test
*/
static int
is_Block_unreachable(ir_node *block) {
*
* We have to avoid calls to get_nodes_block() here
* because the graph is floating.
+ *
+ * move_out_of_loops() expects that place_floats_early() have placed
+ * all "living" nodes into a living block. That's why we must
+ * move nodes in dead block with "live" successors into a valid
+ * block.
+ * We move them just into the same block as it's successor (or
+ * in case of a Phi into the effective use block). For Phi successors,
+ * this may still be a dead block, but then there is no real use, as
+ * the control flow will be dead later.
*/
static void
place_floats_early(ir_node *n, pdeq *worklist)
{
- int i, start, irn_arity;
+ int i, irn_arity;
/* we must not run into an infinite loop */
- assert (irn_not_visited(n));
+ assert(irn_not_visited(n));
mark_irn_visited(n);
/* Place floating nodes. */
if (get_irn_pinned(n) == op_pin_state_floats) {
- int depth = 0;
- ir_node *b = NULL; /* The block to place this node in */
- int bad_recursion = is_Block_unreachable(get_irn_n(n, -1));
+ ir_node *curr_block = get_irn_n(n, -1);
+ int in_dead_block = is_Block_unreachable(curr_block);
+ int depth = 0;
+ ir_node *b = NULL; /* The block to place this node in */
assert(get_irn_op(n) != op_Block);
/* find the block for this node. */
irn_arity = get_irn_arity(n);
for (i = 0; i < irn_arity; i++) {
- ir_node *dep = get_irn_n(n, i);
- ir_node *dep_block;
-
- if ((irn_not_visited(dep))
- && (get_irn_pinned(dep) == op_pin_state_floats)) {
- place_floats_early(dep, worklist);
+ ir_node *pred = get_irn_n(n, i);
+ ir_node *pred_block;
+
+ if ((irn_not_visited(pred))
+ && (get_irn_pinned(pred) == op_pin_state_floats)) {
+
+ /*
+ * If the current node is NOT in a dead block, but one of its
+ * predecessors is, we must move the predecessor to a live block.
+ * Such thing can happen, if global CSE chose a node from a dead block.
+ * We move it simple to our block.
+ * Note that neither Phi nor End nodes are floating, so we don't
+ * need to handle them here.
+ */
+ if (! in_dead_block) {
+ if (get_irn_pinned(pred) == op_pin_state_floats &&
+ is_Block_unreachable(get_irn_n(pred, -1)))
+ set_nodes_block(pred, curr_block);
+ }
+ place_floats_early(pred, worklist);
}
/*
* A node in the Bad block must stay in the bad block,
* so don't compute a new block for it.
*/
- if (bad_recursion)
+ if (in_dead_block)
continue;
/* Because all loops contain at least one op_pin_state_pinned node, now all
our inputs are either op_pin_state_pinned or place_early() has already
been finished on them. We do not have any unfinished inputs! */
- dep_block = get_irn_n(dep, -1);
- if ((!is_Block_dead(dep_block)) &&
- (get_Block_dom_depth(dep_block) > depth)) {
- b = dep_block;
- depth = get_Block_dom_depth(dep_block);
+ pred_block = get_irn_n(pred, -1);
+ if ((!is_Block_dead(pred_block)) &&
+ (get_Block_dom_depth(pred_block) > depth)) {
+ b = pred_block;
+ depth = get_Block_dom_depth(pred_block);
}
/* Avoid that the node is placed in the Start block */
if ((depth == 1) && (get_Block_dom_depth(get_irn_n(n, -1)) > 1)) {
set_nodes_block(n, b);
}
- /* Add predecessors of non floating nodes on worklist. */
- start = (get_irn_op(n) == op_Block) ? 0 : -1;
+ /*
+ * Add predecessors of non floating nodes and non-floating predecessors
+ * of floating nodes to worklist and fix their blocks if the are in dead block.
+ */
irn_arity = get_irn_arity(n);
- for (i = start; i < irn_arity; i++) {
- ir_node *pred = get_irn_n(n, i);
- if (irn_not_visited(pred)) {
- pdeq_putr (worklist, pred);
+
+ if (get_irn_op(n) == op_End) {
+ /*
+ * Simplest case: End node. Predecessors are keep-alives,
+ * no need to move out of dead block.
+ */
+ for (i = -1; i < irn_arity; ++i) {
+ ir_node *pred = get_irn_n(n, i);
+ if (irn_not_visited(pred))
+ pdeq_putr(worklist, pred);
+ }
+ }
+ else if (is_Block(n)) {
+ /*
+ * Blocks: Predecessors are control flow, no need to move
+ * them out of dead block.
+ */
+ for (i = irn_arity - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(n, i);
+ if (irn_not_visited(pred))
+ pdeq_putr(worklist, pred);
+ }
+ }
+ else if (is_Phi(n)) {
+ ir_node *pred;
+ ir_node *curr_block = get_irn_n(n, -1);
+ int in_dead_block = is_Block_unreachable(curr_block);
+
+ /*
+ * Phi nodes: move nodes from dead blocks into the effective use
+ * of the Phi-input if the Phi is not in a bad block.
+ */
+ pred = get_irn_n(n, -1);
+ if (irn_not_visited(pred))
+ pdeq_putr(worklist, pred);
+
+ for (i = irn_arity - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(n, i);
+
+ if (irn_not_visited(pred)) {
+ if (! in_dead_block &&
+ get_irn_pinned(pred) == op_pin_state_floats &&
+ is_Block_unreachable(get_irn_n(pred, -1))) {
+ set_nodes_block(pred, get_Block_cfgpred_block(curr_block, i));
+ }
+ pdeq_putr(worklist, pred);
+ }
+ }
+ }
+ else {
+ ir_node *pred;
+ ir_node *curr_block = get_irn_n(n, -1);
+ int in_dead_block = is_Block_unreachable(curr_block);
+
+ /*
+ * All other nodes: move nodes from dead blocks into the same block.
+ */
+ pred = get_irn_n(n, -1);
+ if (irn_not_visited(pred))
+ pdeq_putr(worklist, pred);
+
+ for (i = irn_arity - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(n, i);
+
+ if (irn_not_visited(pred)) {
+ if (! in_dead_block &&
+ get_irn_pinned(pred) == op_pin_state_floats &&
+ is_Block_unreachable(get_irn_n(pred, -1))) {
+ set_nodes_block(pred, curr_block);
+ }
+ pdeq_putr(worklist, pred);
+ }
}
}
}
place_floats_early(get_irg_end(current_ir_graph), worklist);
/* Work the content of the worklist. */
- while (!pdeq_empty (worklist)) {
- ir_node *n = pdeq_getl (worklist);
- if (irn_not_visited(n)) place_floats_early(n, worklist);
+ while (!pdeq_empty(worklist)) {
+ ir_node *n = pdeq_getl(worklist);
+ if (irn_not_visited(n))
+ place_floats_early(n, worklist);
}
set_irg_outs_inconsistent(current_ir_graph);
* A data flow edge points from producer to consumer.
*/
static ir_node *
-consumer_dom_dca (ir_node *dca, ir_node *consumer, ir_node *producer)
+consumer_dom_dca(ir_node *dca, ir_node *consumer, ir_node *producer)
{
ir_node *block = NULL;
if (! block)
block = get_irn_n(producer, -1);
-
- } else {
+ }
+ else {
assert(is_no_Block(consumer));
block = get_nodes_block(consumer);
}
place_floats_late(ir_node *n, pdeq *worklist)
{
int i;
- ir_node *early;
+ ir_node *early_blk;
- assert (irn_not_visited(n)); /* no multiple placement */
+ assert(irn_not_visited(n)); /* no multiple placement */
mark_irn_visited(n);
if ((get_irn_op(n) != op_Block) &&
(!is_cfop(n)) &&
(get_irn_mode(n) != mode_X)) {
- /* Remember the early placement of this block to move it
- out of loop no further than the early placement. */
- early = get_irn_n(n, -1);
+ /* Remember the early_blk placement of this block to move it
+ out of loop no further than the early_blk placement. */
+ early_blk = get_irn_n(n, -1);
/*
* BEWARE: Here we also get code, that is live, but
place_floats_late(succ, worklist);
}
- /* We have to determine the final block of this node... except for
- constants. */
- if ((get_irn_pinned(n) == op_pin_state_floats) &&
- (get_irn_op(n) != op_Const) &&
- (get_irn_op(n) != op_SymConst)) {
- ir_node *dca = NULL; /* deepest common ancestor in the
- dominator tree of all nodes'
- blocks depending on us; our final
- placement has to dominate DCA. */
- for (i = get_irn_n_outs(n) - 1; i >= 0; --i) {
- ir_node *out = get_irn_out(n, i);
- ir_node *outbl;
-
- if (get_irn_op(out) == op_End) {
- /*
- * This consumer is the End node, a keep alive edge.
- * This is not a real consumer, so we ignore it
- */
- continue;
- }
+ if (! is_Block_dead(early_blk)) {
+ /* do only move things that where not dead */
+
+ /* We have to determine the final block of this node... except for
+ constants. */
+ if ((get_irn_pinned(n) == op_pin_state_floats) &&
+ (get_irn_op(n) != op_Const) &&
+ (get_irn_op(n) != op_SymConst)) {
+ ir_node *dca = NULL; /* deepest common ancestor in the
+ dominator tree of all nodes'
+ blocks depending on us; our final
+ placement has to dominate DCA. */
+ for (i = get_irn_n_outs(n) - 1; i >= 0; --i) {
+ ir_node *succ = get_irn_out(n, i);
+ ir_node *succ_blk;
+
+ if (get_irn_op(succ) == op_End) {
+ /*
+ * This consumer is the End node, a keep alive edge.
+ * This is not a real consumer, so we ignore it
+ */
+ continue;
+ }
- /* ignore if out is in dead code */
- outbl = get_irn_n(out, -1);
- if (is_Block_unreachable(outbl))
- continue;
- dca = consumer_dom_dca(dca, out, n);
- }
- if (dca) {
- set_nodes_block(n, dca);
- move_out_of_loops (n, early);
+ /* ignore if succ is in dead code */
+ succ_blk = get_irn_n(succ, -1);
+ if (is_Block_unreachable(succ_blk))
+ continue;
+ dca = consumer_dom_dca(dca, succ, n);
+ }
+ if (dca) {
+ set_nodes_block(n, dca);
+ move_out_of_loops(n, early_blk);
+ }
}
- /* else all outs are in dead code */
}
}
for (i = 0; i < get_irn_n_outs(n); i++) {
ir_node *succ = get_irn_out(n, i);
if (irn_not_visited(get_irn_out(n, i))) {
- pdeq_putr (worklist, succ);
+ pdeq_putr(worklist, succ);
}
}
}
place_floats_late(get_irg_start_block(current_ir_graph), worklist);
/* And now empty the worklist again... */
- while (!pdeq_empty (worklist)) {
- ir_node *n = pdeq_getl (worklist);
- if (irn_not_visited(n)) place_floats_late(n, worklist);
+ while (!pdeq_empty(worklist)) {
+ ir_node *n = pdeq_getl(worklist);
+ if (irn_not_visited(n))
+ place_floats_late(n, worklist);
}
}
/* place_early() invalidates the outs, place_late needs them. */
compute_irg_outs(irg);
+
/* Now move the nodes down in the dominator tree. This reduces the
unnecessary executions of the node. */
place_late(worklist);
projects / libfirm / blobdiff