/*
- * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
- *
* This file is part of libFirm.
- *
- * This file may be distributed and/or modified under the terms of the
- * GNU General Public License version 2 as published by the Free Software
- * Foundation and appearing in the file LICENSE.GPL included in the
- * packaging of this file.
- *
- * Licensees holding valid libFirm Professional Edition licenses may use
- * this file in accordance with the libFirm Commercial License.
- * Agreement provided with the Software.
- *
- * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
- * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE.
+ * Copyright (C) 2012 University of Karlsruhe.
*/
/**
* @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 $Id$
*
* The problem: Given a value and a set of "copies" that are known to
* represent the same abstract value, rewire all usages of the original value
* to their closest copy while introducing phis as necessary.
*
* Algorithm: Mark all blocks in the iterated dominance frontiers of the value
- * and it's copies. Link the copies ordered by dominance to the blocks. Then
+ * and its copies. Link the copies ordered by dominance to the blocks. Then
* we search for each use all definitions in the current block, if none is
* found, then we search one in the immediate dominator. If we are in a block
* of the dominance frontier, create a phi and do the same search for all
#include "pdeq.h"
#include "array.h"
#include "irdom.h"
+#include "irnodeset.h"
#include "ircons.h"
#include "iredges_t.h"
+#include "statev_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 : 1;
+ bool is_use : 1;
+ bool already_processed : 1;
+ 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;
+ } u;
+};
+
+typedef struct constr_info constr_info;
+
+/**
+ * @return Whether the block contains a definition.
+ */
+static bool has_definition(const ir_node *block)
+{
+ return irn_visited(block);
+}
+
+static constr_info *get_or_set_info(be_ssa_construction_env_t *env,
+ const ir_node *node)
+{
+ constr_info *info = ir_nodemap_get(constr_info, &env->infos, node);
+ if (info == NULL) {
+ info = OALLOCZ(&env->obst, constr_info);
+ ir_nodemap_insert(&env->infos, node, info);
+ }
+ return info;
+}
+
+static constr_info *get_info(const be_ssa_construction_env_t *env,
+ const ir_node *node)
+{
+ return ir_nodemap_get(constr_info, &env->infos, node);
+}
+
+/**
+ * @return Whether the block contains a use.
+ */
+static inline bool has_use(be_ssa_construction_env_t *env, ir_node *block)
+{
+ constr_info *info = get_or_set_info(env, block);
+ return info->is_use;
+}
+
+/**
+ * @return Whether the node is a definition.
+ */
+static bool is_definition(be_ssa_construction_env_t *env, ir_node *node)
+{
+ constr_info *info = get_info(env, node);
+ return info != NULL && info->is_definition;
+}
+
+/**
+ * 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);
+ constr_info *def_info = get_or_set_info(env, def);
+ ir_node *skip = skip_Proj(def);
+ constr_info *skip_info = get_or_set_info(env, skip);
+ constr_info *block_info = get_or_set_info(env, 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->u.definition = def;
+
+ // Set the last definition if we only introduce one definition for the block
+ if (has_definition(block)) {
+ assert(!block_info->already_processed);
+ block_info->u.last_definition = NULL;
+ } else {
+ mark_irn_visited(block);
+ block_info->u.last_definition = def;
+ }
+}
+
+static void introduce_use(be_ssa_construction_env_t *env, ir_node *use)
+{
+ ir_node *block = get_nodes_block(use);
+ constr_info *info = get_or_set_info(env, use);
+ constr_info *block_info = get_or_set_info(env, 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
* frontier to the block itself.
*/
static void mark_iterated_dominance_frontiers(
- const be_ssa_construction_env_t *env)
+ const be_ssa_construction_env_t *env)
{
stat_ev_cnt_decl(blocks);
DBG((dbg, LEVEL_3, "Dominance Frontier:"));
stat_ev_tim_push();
while (!waitq_empty(env->worklist)) {
int i;
- ir_node *block = waitq_get(env->worklist);
- ir_node **domfront = be_get_dominance_frontier(env->domfronts, block);
+ ir_node *block = (ir_node*)waitq_get(env->worklist);
+ ir_node **domfront = ir_get_dominance_frontier(block);
int domfront_len = ARR_LEN(domfront);
for (i = 0; i < domfront_len; ++i) {
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 **ins = ALLOCAN(ir_node*, n_preds);
+ 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);
for (i = 0; i < n_preds; ++i) {
- ins[i] = new_r_Unknown(irg, env->mode);
- }
- phi = be_new_Phi(block, n_preds, ins, env->mode, env->phi_cls);
- if (env->new_phis != NULL) {
- ARR_APP1(ir_node*, env->new_phis, phi);
- }
-
- if (env->mode != mode_M) {
- sched_add_after(block, phi);
+ ins[i] = dummy;
}
+ phi = be_new_Phi(block, n_preds, ins, env->mode, env->phi_req);
+ sched_add_after(block, phi);
+ ARR_APP1(ir_node*, env->new_phis, phi);
DBG((dbg, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, block));
- set_irn_link(link_with, phi);
- mark_irn_visited(block);
-
- 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);
+ introduce_definition(env, phi);
- 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)
+static ir_node *get_def_from_preds(be_ssa_construction_env_t *const env, ir_node *const block)
{
- if (irn_visited(block)) {
- assert(get_irn_link(block) != NULL);
- return get_irn_link(block);
- } else if (Block_block_visited(block)) {
- return create_phi(env, block, block);
+ /* Create a phi if the block is in the dominance frontier. */
+ if (Block_block_visited(block)) {
+ return insert_dummy_phi(env, block);
} else {
- ir_node *def = get_def_at_idom(env, block);
- mark_irn_visited(block);
- set_irn_link(block, def);
- return def;
+ return get_def_at_idom(env, 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, constr_info *const use_info)
+{
+ int arity = get_irn_arity(use);
+ for (int 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);
+ }
}
+
+ use_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 *def = NULL;
+ constr_info *block_info = get_or_set_info(env, block);
- DBG((dbg, LEVEL_3, "\t...searching def at %+F\n", at));
+ assert(has_definition(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 = 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) {
+ constr_info *const info = get_info(env, node);
+ if (!info)
+ continue;
- node = def;
- def = get_irn_link(node);
- }
+ if (info->is_use && !is_Phi(node)) {
+ DBG((dbg, LEVEL_3, "\t...found use %+F\n", node));
- /* 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);
+ if (def == NULL) {
+ /* Create a phi if the block is in the dominance frontier. */
+ def = get_def_from_preds(env, block);
+ }
+
+ set_operands(env, node, def, info);
+ }
+
+ if (info->is_definition) {
+ def = info->u.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->u.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 = get_irn_link(node);
- if (current_def == def) {
- /* already in block */
- return;
+ constr_info *block_info = get_or_set_info(env, block);
+ ir_node *last_definition = block_info->u.last_definition;
+
+ if (last_definition != NULL)
+ return last_definition;
+
+ if (has_definition(block)) {
+ if (has_use(env, block)) {
+ if (!block_info->already_processed) {
+ process_block(env, block);
+ }
+ }
+ else {
+ /* Search the last definition of the block. */
+ sched_foreach_reverse(block, def) {
+ constr_info const *const info = get_info(env, def);
+ if (info && info->is_definition) {
+ DBG((dbg, LEVEL_3, "\t...found definition %+F\n", info->u.definition));
+ block_info->u.last_definition = info->u.definition;
+ break;
+ }
}
- if (current_def == NULL)
- break;
- if (value_dominates(current_def, def))
- break;
- node = current_def;
+
+ assert(block_info->u.last_definition && "No definition found");
}
- set_irn_link(node, def);
- set_irn_link(def, current_def);
+ return block_info->u.last_definition;
} else {
- set_irn_link(block, def);
- set_irn_link(def, NULL);
+ ir_node *const def = get_def_from_preds(env, block);
+ block_info->u.last_definition = def;
+ return def;
}
}
-void be_ssa_construction_init(be_ssa_construction_env_t *env, be_irg_t *birg)
+/**
+ * Fixes all operands of the given use.
+ */
+static void search_def_at_block(be_ssa_construction_env_t *const env, ir_node *const use, constr_info *const info)
{
- ir_graph *irg = be_get_birg_irg(birg);
- ir_node *sb = get_irg_start_block(irg);
- int n_blocks = get_Block_dom_max_subtree_pre_num(sb);
+ ir_node *block = get_nodes_block(use);
+ constr_info *block_info = get_or_set_info(env, block);
+
+ if (block_info->already_processed)
+ return;
+
+ if (has_definition(block)) {
+ process_block(env, block);
+ } else {
+ ir_node *const def = get_def_from_preds(env, block);
+ set_operands(env, use, def, info);
+ }
+}
- stat_ev_ctx_push_fobj("bessaconstr", irg);
+void be_ssa_construction_init(be_ssa_construction_env_t *env, ir_graph *irg)
+{
+ stat_ev_ctx_push_fmt("bessaconstr", "%+F", irg);
stat_ev_tim_push();
- (void) n_blocks;
- stat_ev_dbl("bessaconstr_n_blocks", n_blocks);
+ stat_ev_dbl("bessaconstr_n_blocks", get_Block_dom_max_subtree_pre_num(get_irg_start_block(irg)));
memset(env, 0, sizeof(env[0]));
- be_assure_dom_front(birg);
env->irg = irg;
- env->domfronts = be_get_birg_dom_front(birg);
env->new_phis = NEW_ARR_F(ir_node*, 0);
env->worklist = new_waitq();
+ ir_nodemap_init(&env->infos, irg);
+ obstack_init(&env->obst);
+
+ assure_irg_properties(env->irg,
+ IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE_FRONTIERS);
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));
+ obstack_free(&env->obst, NULL);
+ ir_nodemap_destroy(&env->infos);
del_waitq(env->worklist);
DEL_ARR_F(env->new_phis);
stat_ev_ctx_pop("bessaconstr");
}
+static void determine_phi_req(be_ssa_construction_env_t *env, ir_node *value)
+{
+ const arch_register_req_t *req = arch_get_irn_register_req(value);
+ env->mode = get_irn_mode(value);
+ if (req->width == 1) {
+ env->phi_req = req->cls->class_req;
+ } else {
+ /* construct a new register req... */
+ ir_graph *irg = get_irn_irg(value);
+ struct obstack *obst = be_get_be_obst(irg);
+ arch_register_req_t *new_req = OALLOCZ(obst, arch_register_req_t);
+ new_req->cls = req->cls;
+ new_req->type = req->type & arch_register_req_type_aligned;
+ new_req->width = req->width;
+ env->phi_req = new_req;
+ }
+}
+
void be_ssa_construction_add_copy(be_ssa_construction_env_t *env,
ir_node *copy)
{
assert(env->iterated_domfront_calculated == 0);
if (env->mode == NULL) {
- env->mode = get_irn_mode(copy);
- env->phi_cls = arch_get_irn_reg_class_out(copy);
+ determine_phi_req(env, copy);
} else {
assert(env->mode == get_irn_mode(copy));
}
block = get_nodes_block(copy);
- if (!irn_visited(block)) {
+ if (!has_definition(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,
assert(env->iterated_domfront_calculated == 0);
if (env->mode == NULL) {
- env->mode = get_irn_mode(copies[0]);
- env->phi_cls = arch_get_irn_reg_class_out(copies[0]);
+ determine_phi_req(env, copies[0]);
}
for (i = 0; i < copies_len; ++i) {
ir_node *block = get_nodes_block(copy);
assert(env->mode == get_irn_mode(copy));
- if (!irn_visited(block)) {
+ if (!has_definition(block)) {
waitq_put(env->worklist, block);
}
- introduce_def_at_block(block, copy);
+ introduce_definition(env, copy);
}
}
-void be_ssa_construction_set_ignore_uses(be_ssa_construction_env_t *env,
- const ir_nodeset_t *ignore_uses)
+ir_node **be_ssa_construction_get_new_phis(be_ssa_construction_env_t *env)
{
- env->ignore_uses = ignore_uses;
+ return env->new_phis;
}
-ir_node **be_ssa_construction_get_new_phis(be_ssa_construction_env_t *env)
+/**
+ * Fixes all arguments of a newly constructed phi.
+ *
+ * @see insert_dummy_phi
+ */
+static void fix_phi_arguments(be_ssa_construction_env_t *const env, ir_node *const phi, constr_info *const info)
{
- return env->new_phis;
+ ir_node *block = get_nodes_block(phi);
+ int n_preds = get_Block_n_cfgpreds(block);
+
+ DBG((dbg, LEVEL_3, "\tfixing phi arguments %+F\n", phi));
+
+ for (int 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) {
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;
-
- if (env->ignore_uses != NULL &&
- ir_nodeset_contains(env->ignore_uses, use))
- continue;
+ foreach_out_edge_safe(value, edge) {
+ ir_node *const use = get_edge_src_irn(edge);
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 = get_info(env, use);
+
+ if (info->already_processed)
+ continue;
- DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", use, pos, def));
- set_irn_n(use, pos, def);
- stat_ev_cnt_inc(uses);
+ if (is_Phi(use)) {
+ fix_phi_arguments(env, use, info);
}
+ else {
+ DBG((dbg, LEVEL_3, "\tsearching def for %+F at %+F\n", use, get_nodes_block(use)));
+ search_def_at_block(env, use, info);
+ }
+
+ stat_ev_cnt_inc(uses);
}
+
be_timer_pop(T_SSA_CONSTR);
stat_ev_tim_pop("bessaconstr_fix_time");
be_timer_pop(T_SSA_CONSTR);
}
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_ssaconstr)
void be_init_ssaconstr(void)
{
FIRM_DBG_REGISTER(dbg, "firm.be.ssaconstr");
}
-
-BE_REGISTER_MODULE_CONSTRUCTOR(be_init_ssaconstr);
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