/**
* @file
* @brief SSA construction for a set of nodes
- * @author Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig
+ * @author Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig,
+ * Sebastian Buchwald
* @date 04.05.2005
* @version $Id$
*
#include "pdeq.h"
#include "array.h"
#include "irdom.h"
+#include "irnodeset.h"
#include "ircons.h"
#include "iredges_t.h"
+#include "irphase_t.h"
DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+static ir_node *search_def_end_of_block(be_ssa_construction_env_t *env,
+ ir_node *block);
+
+struct constr_info {
+ bool is_definition;
+ bool is_use;
+ bool already_processed;
+ union {
+ /* Since we only consider scheduled nodes,
+ * this points to the real definition (e.g. a Proj). */
+ ir_node *definition;
+
+ /* Last definition of a block. */
+ ir_node *last_definition;
+ };
+};
+
+typedef struct constr_info constr_info;
+
+/**
+ * @return Whether the block contains a definition.
+ */
+static inline bool has_definition(be_ssa_construction_env_t *env, ir_node *block)
+{
+ (void)env;
+
+ return irn_visited(block);
+}
+
+/**
+ * @return Whether the block contains a use.
+ */
+static inline bool has_use(be_ssa_construction_env_t *env, ir_node *block)
+{
+ constr_info *info = phase_get_or_set_irn_data(env->phase, block);
+
+ return info->is_use;
+}
+
+/**
+ * @return Whether the node is a definition.
+ */
+static inline bool is_definition(be_ssa_construction_env_t *env, ir_node *node)
+{
+ constr_info *info = phase_get_irn_data(env->phase, node);
+
+ return info && info->is_definition;
+}
+
+/**
+ * @return Whether the node is a use.
+ */
+static inline bool is_use(const be_ssa_construction_env_t *env, ir_node *node)
+{
+ constr_info *info = phase_get_irn_data(env->phase, node);
+
+ return info && info->is_use;
+}
+
+/**
+ * Introduces a definition at the corresponding block.
+ */
+static void introduce_definition(be_ssa_construction_env_t *env, ir_node *def)
+{
+ ir_node *block = get_nodes_block(def);
+ ir_phase *phase = env->phase;
+ constr_info *def_info = phase_get_or_set_irn_data(phase, def);
+ ir_node *skip = skip_Proj(def);
+ constr_info *skip_info = phase_get_or_set_irn_data(phase, skip);
+ constr_info *block_info = phase_get_or_set_irn_data(phase, block);
+
+ DBG((dbg, LEVEL_2, "\tintroducing definition %+F in %+F\n", def, block));
+
+ def_info->is_definition = true;
+
+ skip_info->is_definition = true;
+ skip_info->definition = def;
+
+ // Set the last definition if we only introduce one definition for the block
+ if (has_definition(env, block)) {
+ assert(!block_info->already_processed);
+ block_info->last_definition = NULL;
+ }
+ else {
+ mark_irn_visited(block);
+ block_info->last_definition = def;
+ }
+}
+
+static void introduce_use(be_ssa_construction_env_t *env, ir_node *use)
+{
+ ir_node *block = get_nodes_block(use);
+ ir_phase *phase = env->phase;
+ constr_info *info = phase_get_or_set_irn_data(phase, use);
+ constr_info *block_info = phase_get_or_set_irn_data(phase, block);
+
+ DBG((dbg, LEVEL_2, "\tintroducing use %+F in %+F\n", use, block));
+
+ info->is_use = true;
+ block_info->is_use = true;
+
+ waitq_put(env->worklist, use);
+}
+
/**
* Calculates the iterated dominance frontier of a set of blocks. Marks the
* blocks as visited. Sets the link fields of the blocks in the dominance
DBG((dbg, LEVEL_3, "\n"));
}
-static ir_node *search_def_end_of_block(be_ssa_construction_env_t *env,
- ir_node *block);
-
-static ir_node *create_phi(be_ssa_construction_env_t *env, ir_node *block,
- ir_node *link_with)
+/**
+ * Inserts a new phi at the given block.
+ *
+ * The constructed phi has only Dummy operands,
+ * but can be used as definition for other nodes.
+ *
+ * @see fix_phi_arguments
+ */
+static ir_node *insert_dummy_phi(be_ssa_construction_env_t *env, ir_node *block)
{
int i, n_preds = get_Block_n_cfgpreds(block);
ir_graph *irg = get_Block_irg(block);
ir_node *dummy;
ir_node *phi;
+ DBG((dbg, LEVEL_3, "\t...create phi at block %+F\n", block));
+
assert(n_preds > 1);
dummy = new_r_Dummy(irg, env->mode);
}
DBG((dbg, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, block));
- set_irn_link(link_with, phi);
- mark_irn_visited(block);
+ introduce_definition(env, phi);
- for (i = 0; i < n_preds; ++i) {
- ir_node *pred_block = get_Block_cfgpred_block(block, i);
- ir_node *pred_def = search_def_end_of_block(env, pred_block);
-
- set_irn_n(phi, i, pred_def);
- }
+ waitq_put(env->worklist, phi);
return phi;
}
+/**
+ * @return Last definition of the immediate dominator.
+ */
static ir_node *get_def_at_idom(be_ssa_construction_env_t *env, ir_node *block)
{
ir_node *dom = get_Block_idom(block);
assert(dom != NULL);
+ DBG((dbg, LEVEL_3, "\t...continue at idom %+F\n", dom));
return search_def_end_of_block(env, dom);
}
-static ir_node *search_def_end_of_block(be_ssa_construction_env_t *env,
- ir_node *block)
+/**
+ * Fixes all operands of a use.
+ *
+ * If an operand of the use is a (original) definition,
+ * it will be replaced by the given definition.
+ */
+static void set_operands(be_ssa_construction_env_t *env, ir_node *use, ir_node *def)
{
- if (irn_visited(block)) {
- assert(get_irn_link(block) != NULL);
- return (ir_node*)get_irn_link(block);
- } else if (Block_block_visited(block)) {
- return create_phi(env, block, block);
- } else {
- ir_node *def = get_def_at_idom(env, block);
- mark_irn_visited(block);
- set_irn_link(block, def);
- return def;
+ constr_info *info = phase_get_irn_data(env->phase, use);
+ int arity = get_irn_arity(use);
+ int i;
+
+ for (i = 0; i < arity; ++i) {
+ ir_node *op = get_irn_n(use, i);
+
+ if (is_definition(env, op)) {
+ DBG((dbg, LEVEL_1, "\t...%+F(%d) -> %+F\n", use, i, def));
+ set_irn_n(use, i, def);
+ }
}
+
+ info->already_processed = true;
}
-static ir_node *search_def(be_ssa_construction_env_t *env, ir_node *at)
+/**
+ * Fixes all uses of the given block.
+ */
+static void process_block(be_ssa_construction_env_t *env, ir_node *block)
{
- ir_node *block = get_nodes_block(at);
- ir_node *node;
- ir_node *def;
+ ir_node *node;
+ ir_node *def = NULL;
+ constr_info *block_info = phase_get_or_set_irn_data(env->phase, block);
- DBG((dbg, LEVEL_3, "\t...searching def at %+F\n", at));
+ assert(has_definition(env, block));
+ assert(!block_info->already_processed && "Block already processed");
- /* no defs in the current block we can do the normal searching */
- if (!irn_visited(block) && !Block_block_visited(block)) {
- DBG((dbg, LEVEL_3, "\t...continue at idom\n"));
- return get_def_at_idom(env, block);
- }
+ DBG((dbg, LEVEL_3, "\tprocessing block %+F\n", block));
- /* there are defs in the current block, walk the linked list to find
- the one immediately dominating us
- */
- node = block;
- def = (ir_node*)get_irn_link(node);
- while (def != NULL) {
- if (!value_dominates(at, def)) {
- DBG((dbg, LEVEL_3, "\t...found dominating def %+F\n", def));
- return def;
- }
+ sched_foreach(block, node) {
+ if (is_use(env, node) && !is_Phi(node)) {
+ DBG((dbg, LEVEL_3, "\t...found use %+F\n", node));
- node = def;
- def = (ir_node*)get_irn_link(node);
- }
+ if (def == NULL) {
+ /* Create a phi if the block is in the dominance frontier. */
+ if (Block_block_visited(block)) {
+ def = insert_dummy_phi(env, block);
+ }
+ else {
+ def = get_def_at_idom(env, block);
+ }
+ }
- /* block in dominance frontier? create a phi then */
- if (Block_block_visited(block)) {
- DBG((dbg, LEVEL_3, "\t...create phi at block %+F\n", block));
- assert(!is_Phi(node));
- return create_phi(env, block, node);
+ set_operands(env, node, def);
+ }
+
+ if (is_definition(env, node)) {
+ constr_info *info = phase_get_irn_data(env->phase, node);
+ def = info->definition;
+ DBG((dbg, LEVEL_3, "\t...found definition %+F\n", def));
+ }
}
- DBG((dbg, LEVEL_3, "\t...continue at idom (after checking block)\n"));
- return get_def_at_idom(env, block);
+ block_info->already_processed = true;
+ block_info->last_definition = def;
}
/**
- * Adds a definition into the link field of the block. The definitions are
- * sorted by dominance. A non-visited block means no definition has been
- * inserted yet.
+ * @return Last definition of the given block.
*/
-static void introduce_def_at_block(ir_node *block, ir_node *def)
+static ir_node *search_def_end_of_block(be_ssa_construction_env_t *env,
+ ir_node *block)
{
- if (irn_visited_else_mark(block)) {
- ir_node *node = block;
- ir_node *current_def;
-
- for (;;) {
- current_def = (ir_node*)get_irn_link(node);
- if (current_def == def) {
- /* already in block */
- return;
+ constr_info *block_info = phase_get_or_set_irn_data(env->phase, block);
+ ir_node *last_definition = block_info->last_definition;
+
+ if (last_definition != NULL)
+ return last_definition;
+
+ if (has_definition(env, block)) {
+ if (has_use(env, block)) {
+ if (!block_info->already_processed) {
+ process_block(env, block);
}
- if (current_def == NULL)
- break;
- if (value_dominates(current_def, def))
- break;
- node = current_def;
}
+ else {
+ ir_node *def = NULL;
+
+ /* Search the last definition of the block. */
+ sched_foreach_reverse(block, def) {
+ if (is_definition(env, def)) {
+ constr_info *info = phase_get_irn_data(env->phase, def);
+ def = info->definition;
+ DBG((dbg, LEVEL_3, "\t...found definition %+F\n", def));
+
+ break;
+ }
+ }
- set_irn_link(node, def);
- set_irn_link(def, current_def);
+ assert(def && "No definition found");
+
+ block_info->last_definition = def;
+ }
+
+ return block_info->last_definition;
+ } else if (Block_block_visited(block)) {
+ ir_node *phi = insert_dummy_phi(env, block);
+
+ block_info->last_definition = phi;
+
+ return phi;
} else {
- set_irn_link(block, def);
- set_irn_link(def, NULL);
+ ir_node *def = get_def_at_idom(env, block);
+
+ block_info->last_definition = def;
+
+ return def;
}
}
+/**
+ * Fixes all operands of the given use.
+ */
+static void search_def_at_block(be_ssa_construction_env_t *env, ir_node *use)
+{
+ ir_node *block = get_nodes_block(use);
+ constr_info *block_info = phase_get_or_set_irn_data(env->phase, block);
+
+ if (block_info->already_processed)
+ return;
+
+ if (has_definition(env, block)) {
+ process_block(env, block);
+ } else if (Block_block_visited(block)) {
+ ir_node *phi = insert_dummy_phi(env, block);
+
+ set_operands(env, use, phi);
+ } else {
+ ir_node *def = get_def_at_idom(env, block);
+
+ set_operands(env, use, def);
+ }
+}
+
+static void *init_constr_info(ir_phase *phase, const ir_node *node)
+{
+ constr_info *info = phase_alloc(phase, sizeof(constr_info));
+ (void)node;
+
+ info->is_definition = false;
+ info->is_use = false;
+ info->already_processed = false;
+ info->definition = NULL;
+
+ return info;
+}
+
void be_ssa_construction_init(be_ssa_construction_env_t *env, ir_graph *irg)
{
ir_node *sb = get_irg_start_block(irg);
env->domfronts = be_get_irg_dom_front(irg);
env->new_phis = NEW_ARR_F(ir_node*, 0);
env->worklist = new_waitq();
+ env->phase = new_phase(irg, init_constr_info);
ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED
| IR_RESOURCE_BLOCK_VISITED | IR_RESOURCE_IRN_LINK);
void be_ssa_construction_destroy(be_ssa_construction_env_t *env)
{
stat_ev_int("bessaconstr_phis", ARR_LEN(env->new_phis));
+ phase_free(env->phase);
del_waitq(env->worklist);
DEL_ARR_F(env->new_phis);
block = get_nodes_block(copy);
- if (!irn_visited(block)) {
+ if (!has_definition(env, block)) {
waitq_put(env->worklist, block);
}
- introduce_def_at_block(block, copy);
+ introduce_definition(env, copy);
}
void be_ssa_construction_add_copies(be_ssa_construction_env_t *env,
ir_node *block = get_nodes_block(copy);
assert(env->mode == get_irn_mode(copy));
- if (!irn_visited(block)) {
+ if (!has_definition(env, block)) {
waitq_put(env->worklist, block);
}
- introduce_def_at_block(block, copy);
+ introduce_definition(env, copy);
}
}
return env->new_phis;
}
+/**
+ * Fixes all arguments of a newly constructed phi.
+ *
+ * @see insert_dummy_phi
+ */
+static void fix_phi_arguments(be_ssa_construction_env_t *env, ir_node *phi)
+{
+ constr_info *info = phase_get_irn_data(env->phase, phi);
+ ir_node *block = get_nodes_block(phi);
+ int i;
+ int n_preds = get_Block_n_cfgpreds(block);
+
+ DBG((dbg, LEVEL_3, "\tfixing phi arguments %+F\n", phi));
+
+ for (i = 0; i < n_preds; ++i) {
+ ir_node *op = get_irn_n(phi, i);
+
+ if (is_definition(env, op) || is_Dummy(op)) {
+ ir_node *pred_block = get_Block_cfgpred_block(block, i);
+ ir_node *pred_def = search_def_end_of_block(env, pred_block);
+
+ DBG((dbg, LEVEL_1, "\t...%+F(%d) -> %+F\n", phi, i, pred_def));
+ set_irn_n(phi, i, pred_def);
+ }
+ }
+
+ info->already_processed = true;
+}
+
void be_ssa_construction_fix_users_array(be_ssa_construction_env_t *env,
ir_node **nodes, size_t nodes_len)
{
- const ir_edge_t *edge, *next;
size_t i;
stat_ev_cnt_decl(uses);
env->iterated_domfront_calculated = 1;
}
+ DBG((dbg, LEVEL_1, "\tfixing users array\n"));
+
+ assert(waitq_empty(env->worklist));
+
stat_ev_tim_push();
+
for (i = 0; i < nodes_len; ++i) {
+ const ir_edge_t *edge, *next;
ir_node *value = nodes[i];
+ DBG((dbg, LEVEL_3, "\tfixing users of %+F\n", value));
+ introduce_definition(env, value);
- /*
- * Search the valid def for each use and set it.
- */
foreach_out_edge_safe(value, edge, next) {
- ir_node *use = get_edge_src_irn(edge);
- ir_node *at = use;
- int pos = get_edge_src_pos(edge);
- ir_node *def;
+ ir_node *use = get_edge_src_irn(edge);
if (env->ignore_uses != NULL &&
- ir_nodeset_contains(env->ignore_uses, use))
+ ir_nodeset_contains(env->ignore_uses, use))
continue;
+
if (is_Anchor(use) || is_End(use))
continue;
- if (is_Phi(use)) {
- ir_node *block = get_nodes_block(use);
- ir_node *predblock = get_Block_cfgpred_block(block, pos);
- at = sched_last(predblock);
- }
+ introduce_use(env, use);
+ }
+ }
- def = search_def(env, at);
+ assert(!waitq_empty(env->worklist));
- if (def == NULL) {
- panic("no definition found for %+F at position %d", use, pos);
- }
+ while (!waitq_empty(env->worklist)) {
+ ir_node *use = (ir_node *)waitq_get(env->worklist);
+ constr_info *info = phase_get_irn_data(env->phase, use);
- DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", use, pos, def));
- set_irn_n(use, pos, def);
- stat_ev_cnt_inc(uses);
+ if (info->already_processed)
+ continue;
+
+ if (is_Phi(use)) {
+ fix_phi_arguments(env, use);
+ }
+ else {
+ DBG((dbg, LEVEL_3, "\tsearching def for %+F at %+F\n", use, get_nodes_block(use)));
+ search_def_at_block(env, use);
}
+
+ stat_ev_cnt_inc(uses);
}
+
be_timer_pop(T_SSA_CONSTR);
stat_ev_tim_pop("bessaconstr_fix_time");
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