+/**
+ * @file
+ * @brief
+ * This file contains the following IRG modifications for be routines:
+ * - backend dominance information
+ * - SSA construction for a set of nodes
+ * - insertion of Perm nodes
+ * - empty block elimination
+ * - a simple dead node elimination (set inputs of unreachable nodes to BAD)
+ *
+ * @author Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig
+ * @date 04.05.2005
+ * @version $Id$
+ * Copyright: (c) Universitaet Karlsruhe
+ * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ */
#ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
#endif
#include <stdlib.h>
#include "pmap.h"
#include "util.h"
#include "debug.h"
+#include "error.h"
#include "irflag_t.h"
#include "ircons_t.h"
#include "irmode_t.h"
#include "irdom_t.h"
#include "iredges_t.h"
+#include "irgraph_t.h"
#include "irgopt.h"
+#include "irprintf_t.h"
+#include "irgwalk.h"
#include "be_t.h"
+#include "bechordal_t.h"
#include "bearch.h"
#include "besched_t.h"
#include "belive_t.h"
#include "benode_t.h"
#include "beutil.h"
+#include "beinsn_t.h"
#include "beirgmod.h"
-#define DBG_MODULE "firm.be.irgmod"
-#define DBG_LEVEL SET_LEVEL_0
+DEBUG_ONLY(static firm_dbg_module_t *dbgssa = NULL;)
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
/*
- ____ _
- | _ \ ___ _ __ ___ (_)_ __ __ _ _ __ ___ ___
- | | | |/ _ \| '_ ` _ \| | '_ \ / _` | '_ \ / __/ _ \
- | |_| | (_) | | | | | | | | | | (_| | | | | (_| __/
- |____/ \___/|_| |_| |_|_|_| |_|\__,_|_| |_|\___\___|
- | ___| __ ___ _ __ | |_(_) ___ _ __ ___
- | |_ | '__/ _ \| '_ \| __| |/ _ \ '__/ __|
- | _|| | | (_) | | | | |_| | __/ | \__ \
- |_| |_| \___/|_| |_|\__|_|\___|_| |___/
+ ____ ____ _
+ / ___/ ___| / \
+ \___ \___ \ / _ \
+ ___) |__) / ___ \
+ |____/____/_/ \_\
+ ____ _ _ _
+ / ___|___ _ __ ___| |_ _ __ _ _ ___| |_(_) ___ _ __
+ | | / _ \| '_ \/ __| __| '__| | | |/ __| __| |/ _ \| '_ \
+ | |__| (_) | | | \__ \ |_| | | |_| | (__| |_| | (_) | | | |
+ \____\___/|_| |_|___/\__|_| \__,_|\___|\__|_|\___/|_| |_|
*/
-
-struct _dom_front_info_t {
- pmap *df_map;
-};
+/* 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.
+ * The we search for each use all 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 search do the same search for the
+ * phi arguments.
+ */
/**
- * A wrapper for get_Block_idom.
- * This function returns the block itself, if the block is the start
- * block. Returning NULL would make any != comparison true which
- * suggests, that the start block is dominated by some other node.
- * @param bl The block.
- * @return The immediate dominator of the block.
+ * 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 INLINE ir_node *get_idom(ir_node *bl)
+static
+void mark_iterated_dominance_frontiers(const be_dom_front_info_t *domfronts,
+ waitq *worklist)
{
- ir_node *idom = get_Block_idom(bl);
- return idom == NULL ? bl : idom;
+ DBG((dbgssa, LEVEL_3, "Dominance Frontier:"));
+ while(!pdeq_empty(worklist)) {
+ int i;
+ ir_node *block = waitq_get(worklist);
+ ir_node **domfront = be_get_dominance_frontier(domfronts, block);
+ int domfront_len = ARR_LEN(domfront);
+
+ for (i = 0; i < domfront_len; ++i) {
+ ir_node *y = domfront[i];
+ if(Block_block_visited(y))
+ continue;
+
+ if(!irn_visited(y)) {
+ set_irn_link(y, NULL);
+ waitq_put(worklist, y);
+ }
+ DBG((dbgssa, LEVEL_3, " %+F", y));
+ mark_Block_block_visited(y);
+ }
+ }
+ DBG((dbgssa, LEVEL_3, "\n"));
}
-static void compute_df(ir_node *n, pmap *df_map)
-{
- ir_node *c;
- const ir_edge_t *edge;
- pset *df = pset_new_ptr_default();
-
- /* Add local dominance frontiers */
- foreach_block_succ(n, edge) {
- ir_node *y = edge->src;
-
- if(get_idom(y) != n)
- pset_insert_ptr(df, y);
- }
-
- /*
- * Go recursively down the dominance tree and add all blocks
- * int the dominance frontiers of the children, which are not
- * dominated by the given block.
- */
- for(c = get_Block_dominated_first(n); c; c = get_Block_dominated_next(c)) {
- pset *df_c;
- ir_node *w;
-
- compute_df(c, df_map);
- df_c = pmap_get(df_map, c);
-
- for(w = pset_first(df_c); w; w = pset_next(df_c)) {
- if(get_idom(w) != n)
- pset_insert_ptr(df, w);
- }
- }
-
- pmap_insert(df_map, n, df);
+typedef struct ssa_constr_env_t {
+ ir_node **new_phis; /**< ARR_F of newly created phis or NULL */
+ ir_mode *mode; /**< mode of the value */
+} ssa_constr_env_t;
-}
+static
+ir_node *search_def_end_of_block(ssa_constr_env_t *env, ir_node *block);
-dom_front_info_t *be_compute_dominance_frontiers(ir_graph *irg)
+static
+ir_node *create_phi(ssa_constr_env_t *env, ir_node *block, ir_node *link_with)
{
- dom_front_info_t *info = xmalloc(sizeof(*info));
+ int i, n_preds = get_Block_n_cfgpreds(block);
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *phi;
+ ir_node **ins = alloca(n_preds * sizeof(ins[0]));
- edges_assure(irg);
- info->df_map = pmap_create();
- compute_doms(irg);
- compute_df(get_irg_start_block(irg), info->df_map);
+ assert(n_preds > 1);
- return info;
-}
+ for(i = 0; i < n_preds; ++i) {
+ ins[i] = new_r_Unknown(irg, env->mode);
+ }
+ phi = new_r_Phi(irg, block, n_preds, ins, env->mode);
+ if(env->new_phis != NULL) {
+ ARR_APP1(ir_node*, env->new_phis, phi);
+ }
-void be_free_dominance_frontiers(dom_front_info_t *info)
-{
- pmap_entry *ent;
+ if(env->mode != mode_M) {
+ sched_add_after(block, phi);
+ }
- for(ent = pmap_first(info->df_map); ent; ent = pmap_next(info->df_map))
- del_pset(ent->value);
+ DBG((dbgssa, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, block));
+ set_irn_link(link_with, phi);
+ mark_irn_visited(block);
- pmap_destroy(info->df_map);
- free(info);
+ 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);
+ }
+
+ return phi;
}
-pset *be_get_dominance_frontier(dom_front_info_t *info, ir_node *block)
+static
+ir_node *get_def_at_idom(ssa_constr_env_t *env, ir_node *block)
{
- return pmap_get(info->df_map, block);
+ ir_node *dom = get_Block_idom(block);
+ ir_node *def = search_def_end_of_block(env, dom);
+
+ return def;
}
-static void determine_phi_blocks(pset *copies, pset *copy_blocks, pset *phi_blocks, dom_front_info_t *df_info)
+static
+ir_node *search_def_end_of_block(ssa_constr_env_t *env, ir_node *block)
{
- ir_node *bl;
- pdeq *worklist = new_pdeq();
- FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
+ 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);
+ } else {
+ ir_node *def = get_def_at_idom(env, block);
+#if 1
+ mark_irn_visited(block);
+ set_irn_link(block, def);
+#endif
- /*
- * Fill the worklist queue and the rest of the orig blocks array.
- */
- for(bl = pset_first(copy_blocks); bl; bl = pset_next(copy_blocks)) {
- pdeq_putr(worklist, bl);
+ return def;
}
+}
- while (!pdeq_empty(worklist)) {
- ir_node *bl = pdeq_getl(worklist);
- pset *df = be_get_dominance_frontier(df_info, bl);
-
- ir_node *y;
-
- DBG((dbg, LEVEL_3, "dom front of %+F\n", bl));
- DEBUG_ONLY(
- for (y = pset_first(df); y; y = pset_next(df))
- DBG((dbg, LEVEL_3, "\t%+F\n", y))
- );
-
- for(y = pset_first(df); y; y = pset_next(df)) {
- if(!pset_find_ptr(phi_blocks, y)) {
- pset_insert_ptr(phi_blocks, y);
+static
+ir_node *search_def(ssa_constr_env_t *env, ir_node *at)
+{
+ ir_node *block = get_nodes_block(at);
+ ir_node *node;
+ ir_node *def;
- /*
- * Clear the link field of a possible phi block, since
- * the possibly created phi will be stored there. See,
- * search_def()
- */
- set_irn_link(y, NULL);
+ DBG((dbgssa, LEVEL_3, "\t...searching def at %+F\n", at));
- if(!pset_find_ptr(copy_blocks, y))
- pdeq_putr(worklist, y);
+ /* no defs in the current block we can do the normal searching */
+ if(!irn_visited(block) && !Block_block_visited(block)) {
+ DBG((dbgssa, LEVEL_3, "\t...continue at idom\n"));
+ return get_def_at_idom(env, 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 0
+ assert(get_nodes_block(def) == block);
+ if(!value_dominates_intrablock(at, def)) {
+ DBG((dbgssa, LEVEL_3, "\t...found dominating def %+F\n", def));
+ return def;
+ }
+#else
+ if(!value_dominates(at, def)) {
+ DBG((dbgssa, LEVEL_3, "\t...found dominating def %+F\n", def));
+ return def;
}
+#endif
+ node = def;
+ def = get_irn_link(node);
}
- del_pdeq(worklist);
-}
+ /* block in dominance frontier? create a phi then */
+ if(Block_block_visited(block)) {
+ DBG((dbgssa, LEVEL_3, "\t...create phi at block %+F\n", block));
+ assert(!is_Phi(node));
+ return create_phi(env, block, node);
+ }
-/*
- ____ ____ _
- / ___/ ___| / \
- \___ \___ \ / _ \
- ___) |__) / ___ \
- |____/____/_/ \_\
- ____ _ _ _
- / ___|___ _ __ ___| |_ _ __ _ _ ___| |_(_) ___ _ __
- | | / _ \| '_ \/ __| __| '__| | | |/ __| __| |/ _ \| '_ \
- | |__| (_) | | | \__ \ |_| | | |_| | (__| |_| | (_) | | | |
- \____\___/|_| |_|___/\__|_| \__,_|\___|\__|_|\___/|_| |_|
-*/
+ DBG((dbgssa, LEVEL_3, "\t...continue at idom (after checking block)\n"));
+ return get_def_at_idom(env, block);
+}
/**
- * Find the copy of the given original node whose value is 'active'
- * at a usage.
- *
- * The usage is given as a node and a position. Initially, the given operand
- * points to a node for which copies were introduced. We have to find
- * the valid copy for this usage. This is done by traversing the
- * dominance tree upwards. If the usage is a phi function, we start
- * traversing from the predecessor block which corresponds to the phi
- * usage.
- *
- * @param usage The node which uses the original node.
- * @param pos The position of the argument which corresponds to the original node.
- * @param copies A set containing all node which are copies from the original node.
- * @param copy_blocks A set containing all basic block in which copies of the original node are located.
- * @param phis A set where all created phis are recorded.
- * @param phi_blocks A set of all blocks where Phis shall be inserted (iterated dominance frontier).
- * @param mode The mode for the Phi if one has to be created.
- * @return The valid copy for usage.
+ * 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.
*/
-static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blocks, pset *phis, pset *phi_blocks, ir_mode *mode)
+static
+void introduce_def_at_block(ir_node *block, ir_node *def)
{
- ir_node *curr_bl;
- ir_node *start_irn;
- FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
-
- curr_bl = get_nodes_block(usage);
-
- DBG((dbg, LEVEL_1, "Searching valid def for use %+F at pos %d\n", usage, pos));
- /*
- * If the usage is in a phi node, search the copy in the
- * predecessor denoted by pos.
- */
- if(is_Phi(usage)) {
- curr_bl = get_Block_cfgpred_block(curr_bl, pos);
- start_irn = sched_last(curr_bl);
- } else {
- start_irn = sched_prev(usage);
- }
-
- /*
- * Traverse the dominance tree upwards from the
- * predecessor block of the usage.
- */
- while(curr_bl != NULL) {
-
- /*
- * If this block contains a copy, search the block
- * instruction by instruction.
- */
- if(pset_find_ptr(copy_blocks, curr_bl)) {
- ir_node *irn;
-
- /* Look at each instruction from last to first. */
- sched_foreach_reverse_from(start_irn, irn) {
-
- /* Take the first copy we find. */
- if(pset_find_ptr(copies, irn))
- return irn;
+ if(irn_visited(block)) {
+ ir_node *node = block;
+ ir_node *current_def;
+
+ while(1) {
+ current_def = get_irn_link(node);
+ if(current_def == def) {
+ /* already in block */
+ return;
}
+ if(current_def == NULL)
+ break;
+ if(value_dominates(current_def, def))
+ break;
+ node = current_def;
}
- if(pset_find_ptr(phi_blocks, curr_bl)) {
- ir_node *phi = get_irn_link(curr_bl);
-
- if(!phi) {
- int i, n_preds = get_irn_arity(curr_bl);
- ir_graph *irg = get_irn_irg(curr_bl);
- ir_node **ins = xmalloc(n_preds * sizeof(ins[0]));
-
- for(i = 0; i < n_preds; ++i)
- ins[i] = new_r_Bad(irg);
-
- phi = new_r_Phi(irg, curr_bl, n_preds, ins, mode);
- DBG((dbg, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, curr_bl));
-
- set_irn_link(curr_bl, phi);
- sched_add_after(curr_bl, phi);
- free(ins);
-
- for(i = 0; i < n_preds; ++i) {
- ir_node *arg = search_def(phi, i, copies, copy_blocks, phis, phi_blocks, mode);
- DBG((dbg, LEVEL_2, "\t\t%+F(%d) -> %+F\n", phi, i, arg));
- set_irn_n(phi, i, arg);
- }
-
- if(phis)
- pset_insert_ptr(phis, phi);
- }
-
- return phi;
- }
-
- /* If were not done yet, look in the immediate dominator */
- curr_bl = get_Block_idom(curr_bl);
- if(curr_bl)
- start_irn = sched_last(curr_bl);
+ set_irn_link(node, def);
+ set_irn_link(def, current_def);
+ } else {
+ set_irn_link(block, def);
+ set_irn_link(def, NULL);
+ mark_irn_visited(block);
}
-
- return NULL;
}
-static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *phis, pset *ignore_uses)
+ir_node **be_ssa_construction(const be_dom_front_info_t *domfronts, be_lv_t *lv,
+ ir_node *value, int copies_len, ir_node **copies,
+ const ir_nodeset_t *ignore_uses, int need_new_phis)
{
- int n_outs = 0;
- struct obstack obst;
- ir_node *irn;
+ ir_graph *irg = get_irn_irg(value);
+ const ir_edge_t *edge, *next;
int i;
- struct out {
- ir_node *irn;
- int pos;
- } *outs;
-
- FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
-
- obstack_init(&obst);
+ ir_node *block;
+ waitq *worklist;
+ ssa_constr_env_t env;
- /*
- * Put all outs into an array.
- * This is necessary, since the outs would be modified while
- * iterating on them what could bring the outs module in trouble.
- */
- for (irn = pset_first(copies); irn; irn = pset_next(copies)) {
- const ir_edge_t *edge;
- foreach_out_edge(irn, edge) {
- if (!pset_find_ptr(ignore_uses, get_edge_src_irn(edge))) {
- struct out tmp;
- tmp.irn = get_edge_src_irn(edge);
- tmp.pos = get_edge_src_pos(edge);
- obstack_grow(&obst, &tmp, sizeof(tmp));
- n_outs++;
- }
+ /* We need to collect the phi functions to compute their liveness. */
+ if(lv != NULL || need_new_phis) {
+ env.new_phis = NEW_ARR_F(ir_node*, 0);
+ } else {
+ env.new_phis = NULL;
+ }
+ env.mode = get_irn_mode(value);
+
+ set_using_visited(irg);
+ set_using_block_visited(irg);
+ set_using_irn_link(irg);
+
+ /* we use the visited flag to indicate blocks in the dominance frontier
+ * and blocks that already have the relevant value at the end calculated */
+ inc_irg_visited(irg);
+ /* We use the block visited flag to indicate blocks in the dominance
+ * froniter of some values (and this potentially needing phis) */
+ inc_irg_block_visited(irg);
+
+ DBG((dbgssa, LEVEL_1, "Introducing following copies for: %+F\n", value));
+ /* compute iterated dominance frontiers and create lists in the block link
+ * fields that sort usages by dominance. Blocks in the dominance frontier
+ * are marked by links back to the block. */
+ worklist = new_waitq();
+
+ block = get_nodes_block(value);
+ introduce_def_at_block(block, value);
+ waitq_put(worklist, block);
+
+ for(i = 0; i < copies_len; ++i) {
+ ir_node *copy = copies[i];
+ block = get_nodes_block(copy);
+
+ if(!irn_visited(block)) {
+ waitq_put(worklist, block);
}
+ introduce_def_at_block(block, copy);
+ DBG((dbgssa, LEVEL_1, "\t%+F in %+F\n", copy, block));
}
- outs = obstack_finish(&obst);
+ mark_iterated_dominance_frontiers(domfronts, worklist);
+ del_waitq(worklist);
+
+ DBG((dbgssa, LEVEL_2, "New Definitions:\n"));
/*
- * Search the valid def for each out and set it.
+ * Search the valid def for each use and set it.
*/
- for(i = 0; i < n_outs; ++i) {
- ir_node *irn = outs[i].irn;
- int pos = outs[i].pos;
- ir_mode *mode = get_irn_mode(get_irn_n(irn, pos));
+ 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);
+
+ if(ignore_uses != NULL && ir_nodeset_contains(ignore_uses, 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);
+ }
- ir_node *def;
+ ir_node *def = search_def(&env, at);
- def = search_def(irn, pos, copies, copy_blocks, phis, phi_blocks, mode);
- DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", irn, pos, def));
+ if(def == NULL) {
+ panic("no definition found for %+F at position %d\n", use, pos);
+ }
- if(def != NULL)
- set_irn_n(irn, pos, def);
+ DBG((dbgssa, LEVEL_2, "\t%+F(%d) -> %+F\n", use, pos, def));
+ set_irn_n(use, pos, def);
}
- obstack_free(&obst, NULL);
-}
-
-/**
- * Remove phis which are not necessary.
- * During place_phi_functions() phi functions are put on the dominance
- * frontiers blindly. However some of them will never be used (these
- * have at least one predecessor which is NULL, see search_def() for
- * this case). Since place_phi_functions() enters them into the
- * schedule, we have to remove them from there.
- *
- * @param copies The set of all copies made (including the phi functions).
- */
-static void remove_odd_phis(pset *copies, pset *unused_copies)
-{
- ir_node *irn;
+ /* Recompute the liveness of the original nodes, the copies and the
+ * inserted phis. */
+ if(lv != NULL) {
+ int n;
- for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
- if(is_Phi(irn)) {
- int i, n;
- int illegal = 0;
+ be_liveness_update(lv, value);
+ for(i = 0; i < copies_len; ++i) {
+ ir_node *copy = copies[i];
+ be_liveness_update(lv, copy);
+ }
- assert(sched_is_scheduled(irn) && "phi must be scheduled");
- for(i = 0, n = get_irn_arity(irn); i < n && !illegal; ++i)
- illegal = get_irn_n(irn, i) == NULL;
+ n = ARR_LEN(env.new_phis);
+ for(i = 0; i < n; ++i) {
+ ir_node *phi = env.new_phis[i];
+ be_liveness_introduce(lv, phi);
+ }
+ }
- if(illegal)
- sched_remove(irn);
- }
- }
+ clear_using_visited(irg);
+ clear_using_block_visited(irg);
+ clear_using_irn_link(irg);
- for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
- sched_remove(irn);
+ if(!need_new_phis && env.new_phis != NULL) {
+ DEL_ARR_F(env.new_phis);
+ return NULL;
}
+ return env.new_phis;
}
-void be_ssa_constr_phis_ignore(dom_front_info_t *info, int n, ir_node *nodes[], pset *phis, pset *ignore_uses)
+void be_ssa_constr_set_ignore(const be_dom_front_info_t *domfronts, be_lv_t *lv,
+ pset *nodes, pset *ignores)
{
- pset *irns = pset_new_ptr(n);
+ ir_graph *irg;
+ const ir_edge_t *edge, *next;
int i;
+ ir_node *block;
+ waitq *worklist;
+ ir_node *value;
+ ssa_constr_env_t env;
+
+ foreach_pset(nodes, value) {
+ pset_break(nodes);
+ break;
+ }
+ irg = get_irn_irg(value);
- for(i = 0; i < n; ++i)
- pset_insert_ptr(irns, nodes[i]);
- be_ssa_constr_set_phis_ignore(info, irns, phis, ignore_uses);
- del_pset(irns);
-}
+ /* We need to collect the phi functions to compute their liveness. */
+ if(lv != NULL) {
+ env.new_phis = NEW_ARR_F(ir_node*, 0);
+ }
-void be_ssa_constr_ignore(dom_front_info_t *info, int n, ir_node *nodes[], pset *ignore_uses)
-{
- be_ssa_constr_phis_ignore(info, n, nodes, NULL, ignore_uses);
-}
+ set_using_visited(irg);
+ set_using_block_visited(irg);
+ set_using_irn_link(irg);
-void be_ssa_constr(dom_front_info_t *info, int n, ir_node *nodes[])
-{
- pset *empty_set = be_empty_set();
- be_ssa_constr_ignore(info, n, nodes, empty_set);
-}
+ /* we use the visited flag to indicate blocks in the dominance frontier
+ * and blocks that already have the relevant value at the end calculated */
+ inc_irg_visited(irg);
+ /* We use the block visited flag to indicate blocks in the dominance
+ * froniter of some values (and this potentially needing phis) */
+ inc_irg_block_visited(irg);
-void be_ssa_constr_set_phis_ignore(dom_front_info_t *df, pset *nodes, pset *phis, pset *ignore_uses)
-{
- int n = pset_count(nodes);
- pset *blocks = pset_new_ptr(n);
- pset *phi_blocks = pset_new_ptr(n);
- int save_optimize = get_optimize();
- int save_normalize = get_opt_normalize();
- FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
-
- ir_node *irn;
-
- DBG((dbg, LEVEL_1, "Introducing following copies for:\n"));
-
- /* Fill the sets. */
- for(irn = pset_first(nodes); irn; irn = pset_next(nodes)) {
- ir_node *bl = get_nodes_block(irn);
- pset_insert_ptr(blocks, bl);
- DBG((dbg, LEVEL_1, "\t%+F in %+F\n", irn, bl));
+ DBG((dbgssa, LEVEL_1, "Introducing following copies for:\n"));
+
+ /* compute iterated dominance frontiers and create lists in the block link
+ * fields that sort usages by dominance. Blocks in the dominance frontier
+ * are marked by links back to the block. */
+ worklist = new_waitq();
+
+ foreach_pset(nodes, value) {
+ block = get_nodes_block(value);
+ env.mode = get_irn_mode(value);
+
+ if(!irn_visited(block)) {
+ waitq_put(worklist, block);
+ }
+ introduce_def_at_block(block, value);
+ DBG((dbgssa, LEVEL_1, "\t%+F in %+F\n", value, block));
}
- /*
- * Disable optimization so that the phi functions do not
- * disappear.
- */
- set_optimize(0);
- set_opt_normalize(0);
+ mark_iterated_dominance_frontiers(domfronts, worklist);
+ del_waitq(worklist);
/*
- * Place the phi functions and reroute the usages.
+ * Search the valid def for each use and set it.
*/
- determine_phi_blocks(nodes, blocks, phi_blocks, df);
- fix_usages(nodes, blocks, phi_blocks, phis, ignore_uses);
+ foreach_pset(nodes, value) {
+ 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);
+
+ if(ignores != NULL && pset_find_ptr(ignores, 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);
+ }
- /* reset the optimizations */
- set_optimize(save_optimize);
- set_opt_normalize(save_normalize);
+ ir_node *def = search_def(&env, at);
- del_pset(phi_blocks);
- del_pset(blocks);
+ if(def == NULL) {
+ panic("no definition found for %+F input %d\n", use, pos);
+ }
-}
+ DBG((dbgssa, LEVEL_2, "\t%+F(%d) -> %+F\n", use, pos, def));
+ set_irn_n(use, pos, def);
+ }
+ }
-void be_ssa_constr_set_phis(dom_front_info_t *df, pset *nodes, pset *phis)
-{
- pset *empty_set = be_empty_set();
- be_ssa_constr_set_phis_ignore(df, nodes, phis, empty_set);
-}
+ /* Recompute the liveness of the original nodes, the copies and the
+ * inserted phis. */
+ if(lv != NULL) {
+ int n;
-void be_ssa_constr_set_ignore(dom_front_info_t *df, pset *nodes, pset *ignore_uses)
-{
- be_ssa_constr_set_phis_ignore(df, nodes, NULL, ignore_uses);
-}
+ foreach_pset(nodes, value) {
+ be_liveness_update(lv, value);
+ }
-void be_ssa_constr_set(dom_front_info_t *info, pset *nodes)
-{
- pset *empty_set = be_empty_set();
- be_ssa_constr_set_ignore(info, nodes, empty_set);
+ n = ARR_LEN(env.new_phis);
+ for(i = 0; i < n; ++i) {
+ ir_node *phi = env.new_phis[i];
+ be_liveness_introduce(lv, phi);
+ }
+ DEL_ARR_F(env.new_phis);
+ }
+
+ clear_using_visited(irg);
+ clear_using_block_visited(irg);
+ clear_using_irn_link(irg);
}
/*
*/
ir_node *insert_Perm_after(const arch_env_t *arch_env,
+ be_lv_t *lv,
const arch_register_class_t *cls,
- dom_front_info_t *dom_front,
+ be_dom_front_info_t *dom_front,
ir_node *pos)
{
- ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
- ir_graph *irg = get_irn_irg(bl);
- pset *live = pset_new_ptr_default();
- FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, "be.node");
+ ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
+ ir_graph *irg = get_irn_irg(bl);
+ pset *live = pset_new_ptr_default();
ir_node *curr, *irn, *perm, **nodes;
int i, n;
DBG((dbg, LEVEL_1, "Insert Perm after: %+F\n", pos));
- if(!be_liveness_nodes_live_at(arch_env, cls, pos, live));
+ be_liveness_nodes_live_at(lv, arch_env, cls, pos, live);
n = pset_count(live);
free(nodes);
curr = perm;
- for(i = 0; i < n; ++i) {
- ir_node *copies[2];
+ for (i = 0; i < n; ++i) {
+ ir_node *copies[1];
ir_node *perm_op = get_irn_n(perm, i);
const arch_register_t *reg = arch_get_irn_register(arch_env, perm_op);
sched_add_after(curr, proj);
curr = proj;
- copies[0] = perm_op;
- copies[1] = proj;
- be_ssa_constr(dom_front, 2, copies);
+ copies[0] = proj;
+
+ be_ssa_construction(dom_front, lv, perm_op, 1, copies, NULL, 0);
}
+
return perm;
}
+
+/**
+ * Post-block-walker: Find blocks containing only one jump and
+ * remove them.
+ */
+static void remove_empty_block(ir_node *block, void *data) {
+ const ir_edge_t *edge, *next;
+ ir_node *node;
+ int *changed = data;
+ ir_node *jump = NULL;
+
+ assert(is_Block(block));
+
+ if (get_Block_n_cfgpreds(block) != 1)
+ return;
+
+ sched_foreach(block, node) {
+ if (! is_Jmp(node))
+ return;
+ if (jump != NULL) {
+ /* we should never have 2 jumps in a block */
+ panic("We should never have 2 jumps in a block");
+ }
+ jump = node;
+ }
+
+ if (jump == NULL)
+ return;
+
+ node = get_Block_cfgpred(block, 0);
+ foreach_out_edge_safe(jump, edge, next) {
+ ir_node *block = get_edge_src_irn(edge);
+ int pos = get_edge_src_pos(edge);
+
+ set_irn_n(block, pos, node);
+ }
+
+ set_Block_cfgpred(block, 0, new_Bad());
+ be_kill_node(jump);
+ *changed = 1;
+}
+
+/* removes basic blocks that just contain a jump instruction */
+int be_remove_empty_blocks(ir_graph *irg) {
+ int changed = 0;
+
+ irg_block_walk_graph(irg, remove_empty_block, NULL, &changed);
+ if (changed) {
+ /* invalidate analysis info */
+ set_irg_doms_inconsistent(irg);
+ set_irg_extblk_inconsistent(irg);
+ set_irg_outs_inconsistent(irg);
+ }
+ return changed;
+}
+
+void be_init_irgmod(void)
+{
+ FIRM_DBG_REGISTER(dbgssa, "firm.be.ssaconstr");
+ FIRM_DBG_REGISTER(dbg, "firm.be.irgmod");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_irgmod);
projects / libfirm / blobdiff