-#ifdef HAVE_CONFIG_H
+/*
+ * 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.
+ */
+
+/**
+ * @file
+ * @brief Backend IRG modification routines.
+ * @author Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig
+ * @date 04.05.2005
+ *
+ * This file contains the following IRG modifications for be routines:
+ * - insertion of Perm nodes
+ * - empty block elimination
+ * - a simple dead node elimination (set inputs of unreachable nodes to BAD)
+ */
#include "config.h"
-#endif
#include <stdlib.h>
-#ifdef WIN32
-#include <malloc.h>
-#else
-#include <alloca.h>
-#endif
-
#include "hashptr.h"
#include "pdeq.h"
#include "pset.h"
#include "pmap.h"
#include "util.h"
#include "debug.h"
+#include "error.h"
+#include "xmalloc.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 "irgmod.h"
+#include "irprintf_t.h"
+#include "irgwalk.h"
#include "be_t.h"
+#include "bechordal_t.h"
#include "bearch.h"
-#include "besched_t.h"
+#include "besched.h"
#include "belive_t.h"
-#include "benode_t.h"
+#include "benode.h"
#include "beutil.h"
-
+#include "beinsn_t.h"
+#include "bessaconstr.h"
+#include "beirg.h"
#include "beirgmod.h"
+#include "bemodule.h"
-#define DBG_MODULE firm_dbg_register("firm.be.irgmod")
-#define DBG_LEVEL SET_LEVEL_0
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
-struct _dom_front_info_t {
- pmap *df_map;
-};
+/*
+ ___ _ ____
+ |_ _|_ __ ___ ___ _ __| |_ | _ \ ___ _ __ _ __ ___
+ | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ '__| '_ ` _ \
+ | || | | \__ \ __/ | | |_ | __/ __/ | | | | | | |
+ |___|_| |_|___/\___|_| \__| |_| \___|_| |_| |_| |_|
-/**
- * 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.
- */
-static INLINE ir_node *get_idom(ir_node *bl)
-{
- ir_node *idom = get_Block_idom(bl);
- return idom == NULL ? bl : idom;
-}
+*/
-static void compute_df(ir_node *n, pmap *df_map)
+ir_node *insert_Perm_after(ir_graph *irg, const arch_register_class_t *cls,
+ ir_node *pos)
{
- 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);
-
-}
+ be_lv_t *lv = be_get_irg_liveness(irg);
+ ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
+ ir_nodeset_t live;
+ ir_nodeset_iterator_t iter;
-dom_front_info_t *be_compute_dominance_frontiers(ir_graph *irg)
-{
- dom_front_info_t *info = malloc(sizeof(*info));
+ ir_node *irn, *perm, **nodes;
+ size_t i, n;
- edges_assure(irg);
- info->df_map = pmap_create();
- compute_df(get_irg_start_block(irg), info->df_map);
+ DBG((dbg, LEVEL_1, "Insert Perm after: %+F\n", pos));
- return info;
-}
+ ir_nodeset_init(&live);
+ be_liveness_nodes_live_at(lv, cls, pos, &live);
-void be_free_dominance_frontiers(dom_front_info_t *info)
-{
- pmap_entry *ent;
+ n = ir_nodeset_size(&live);
+ if (n == 0) {
+ ir_nodeset_destroy(&live);
+ return NULL;
+ }
- for(ent = pmap_first(info->df_map); ent; ent = pmap_next(info->df_map))
- del_pset(ent->value);
+ nodes = XMALLOCN(ir_node*, n);
- pmap_destroy(info->df_map);
- free(info);
-}
+ DBG((dbg, LEVEL_1, "live:\n"));
+ i = 0;
+ foreach_ir_nodeset(&live, irn, iter) {
+ DBG((dbg, LEVEL_1, "\t%+F\n", irn));
+ nodes[i] = irn;
+ i++;
+ }
+ ir_nodeset_destroy(&live);
+
+ perm = be_new_Perm(cls, bl, n, nodes);
+ sched_add_after(pos, perm);
+ free(nodes);
+
+ for (i = 0; i < n; ++i) {
+ ir_node *perm_op = get_irn_n(perm, i);
+ const arch_register_t *reg = arch_get_irn_register(perm_op);
+ be_ssa_construction_env_t senv;
+
+ ir_mode *mode = get_irn_mode(perm_op);
+ ir_node *proj = new_r_Proj(perm, mode, i);
+ arch_set_irn_register(proj, reg);
+
+ be_ssa_construction_init(&senv, irg);
+ be_ssa_construction_add_copy(&senv, perm_op);
+ be_ssa_construction_add_copy(&senv, proj);
+ be_ssa_construction_fix_users(&senv, perm_op);
+ be_ssa_construction_update_liveness_phis(&senv, lv);
+ be_liveness_update(lv, perm_op);
+ be_liveness_update(lv, proj);
+ be_ssa_construction_destroy(&senv);
+ }
-pset *be_get_dominance_frontier(dom_front_info_t *info, ir_node *block)
-{
- return pmap_get(info->df_map, block);
+ return perm;
}
-static void determine_phi_blocks(ir_node *orig, pset *copies,
- pset *copy_blocks, pset *phi_blocks, dom_front_info_t *df_info)
-{
- ir_node *bl;
- ir_node *orig_block = get_nodes_block(orig);
- pdeq *worklist = new_pdeq();
- firm_dbg_module_t *dbg = DBG_MODULE;
-
- /*
- * Fill the worklist queue and the rest of the orig blocks array.
- */
- for(bl = pset_first(copy_blocks); bl; bl = pset_next(copy_blocks)) {
- assert(block_dominates(orig_block, bl)
- && "The block of the copy must be dominated by the block of the value");
-
- pdeq_putr(worklist, bl);
- }
-
- while(!pdeq_empty(worklist)) {
- ir_node *bl = pdeq_getl(worklist);
- ir_node *y;
- pset *df = be_get_dominance_frontier(df_info, bl);
-
- DBG((dbg, LEVEL_3, "dom front of %+F\n", bl));
- 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);
-
- /*
- * 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);
-
- if(!pset_find_ptr(copy_blocks, y))
- pdeq_putr(worklist, y);
-
- }
- }
- }
-
- del_pdeq(worklist);
-}
+static int blocks_removed;
/**
- * 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 travering 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 number of the argument which corresponds to the
- * original node.
- * @param copy_blocks A set containing all basic block in which copies
- * of the original node are located.
- * @param copies A set containing all node which are copies from the
- * original node.
- * @return The valid copy for usage.
+ * Post-block-walker: Find blocks containing only one jump and
+ * remove them.
*/
-static ir_node *search_def(ir_node *usage, int pos, pset *copies,
- pset *copy_blocks, pset *phi_blocks, ir_mode *mode)
+static void remove_empty_block(ir_node *block)
{
- ir_node *curr_bl;
- ir_node *start_irn;
- 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(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 = malloc(n_preds * sizeof(ins[0]));
-
- for(i = 0; i < n_preds; ++i)
- ins[i] = new_r_Unknown(irg, mode);
-
- 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, phi_blocks, mode);
- DBG((dbg, LEVEL_2, "\t\t%+F(%d) -> %+F\n", phi, i, arg));
- set_irn_n(phi, i, arg);
- }
- }
+ const ir_edge_t *edge, *next;
+ int i, arity;
+ ir_node *node;
+ ir_node *pred;
+ ir_node *succ_block;
+ ir_node *jump = NULL;
+ ir_graph *irg = get_irn_irg(block);
+
+ if (irn_visited_else_mark(block))
+ return;
+
+ if (get_Block_n_cfgpreds(block) != 1)
+ goto check_preds;
- return phi;
+ sched_foreach(block, node) {
+ if (! is_Jmp(node)
+ && !(arch_get_irn_flags(node) & arch_irn_flags_simple_jump))
+ goto check_preds;
+ if (jump != NULL) {
+ /* we should never have 2 jumps in a block */
+ panic("found 2 jumps in a block");
}
+ jump = node;
+ }
- /* 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);
- }
+ if (jump == NULL)
+ goto check_preds;
+
+ pred = get_Block_cfgpred(block, 0);
+ succ_block = NULL;
+ foreach_out_edge_safe(jump, edge, next) {
+ int pos = get_edge_src_pos(edge);
+
+ assert(succ_block == NULL);
+ succ_block = get_edge_src_irn(edge);
+ if (get_Block_entity(succ_block) != NULL
+ && get_Block_entity(block) != NULL) {
+ /*
+ * Currently we can add only one label for a block.
+ * Therefore we cannot combine them if both block already have one.
+ */
+ goto check_preds;
+ }
- return NULL;
-}
+ set_irn_n(succ_block, pos, pred);
+ }
-static void fix_usages(ir_node *orig, pset *copies, pset *copy_blocks,
- pset *phi_blocks, pset *ignore_uses)
-{
- int i = 0;
- int n_outs = 0;
- const ir_edge_t *edge;
- ir_mode *mode = get_irn_mode(orig);
-
- firm_dbg_module_t *dbg = DBG_MODULE;
-
- struct {
- ir_node *irn;
- int pos;
- } *outs;
-
- /* Count the number of outs. */
- foreach_out_edge(orig, edge)
- n_outs += !pset_find_ptr(ignore_uses, get_edge_src_irn(edge));
-
- /*
- * Put all outs into an array.
- * This is neccessary, since the outs would be modified while
- * interating on them what could bring the outs module in trouble.
- */
- outs = malloc(n_outs * sizeof(outs[0]));
- foreach_out_edge(orig, edge) {
- if(!pset_find_ptr(ignore_uses, get_edge_src_irn(edge))) {
- outs[i].irn = get_edge_src_irn(edge);
- outs[i].pos = get_edge_src_pos(edge);
- i += 1;
- }
- }
+ if (get_Block_entity(block) != NULL) {
+ /* move the label to the successor block */
+ ir_entity *entity = get_Block_entity(block);
+ set_Block_entity(succ_block, entity);
+ }
- /*
- * Search the valid def for each out and set it.
- */
- for(i = 0; i < n_outs; ++i) {
- ir_node *def;
- ir_node *irn = outs[i].irn;
- int pos = outs[i].pos;
+ /* there can be some non-scheduled Pin nodes left in the block, move them
+ * to the succ block (Pin) or pred block (Sync) */
+ foreach_out_edge_safe(block, edge, next) {
+ node = get_edge_src_irn(edge);
+
+ if (node == jump)
+ continue;
+ /* we simply kill Pins, because there are some strange interactions
+ * between jump threading, which produce PhiMs with Pins, we simply
+ * kill the pins here, everything is scheduled anyway */
+ if (is_Pin(node)) {
+ exchange(node, get_Pin_op(node));
+ continue;
+ }
+ if (is_Sync(node)) {
+ set_nodes_block(node, get_nodes_block(pred));
+ continue;
+ }
+ if (is_End(node)) { /* End-keep, reroute it to the successor */
+ int pos = get_edge_src_pos(edge);
+ set_irn_n(node, pos, succ_block);
+ continue;
+ }
+ panic("Unexpected node %+F in block %+F with empty schedule", node, block);
+ }
- def = search_def(irn, pos, copies, copy_blocks, phi_blocks, mode);
- DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", irn, pos, def));
+ set_Block_cfgpred(block, 0, new_r_Bad(irg, mode_X));
+ kill_node(jump);
+ blocks_removed = 1;
- if(def != NULL)
- set_irn_n(irn, pos, def);
- }
+ /* check predecessor */
+ remove_empty_block(get_nodes_block(pred));
+ return;
- free(outs);
+check_preds:
+ arity = get_Block_n_cfgpreds(block);
+ for (i = 0; i < arity; ++i) {
+ ir_node *pred = get_Block_cfgpred_block(block, i);
+ remove_empty_block(pred);
+ }
}
-/**
- * Remove phis which are not neccesary.
- * 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)
+/* removes basic blocks that just contain a jump instruction */
+int be_remove_empty_blocks(ir_graph *irg)
{
- ir_node *irn;
+ ir_node *end;
+ int i, arity;
+
+ blocks_removed = 0;
+
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
+ inc_irg_visited(irg);
+ remove_empty_block(get_irg_end_block(irg));
+ end = get_irg_end(irg);
+ arity = get_irn_arity(end);
+ for (i = 0; i < arity; ++i) {
+ ir_node *pred = get_irn_n(end, i);
+ if (!is_Block(pred))
+ continue;
+ remove_empty_block(pred);
+ }
+ ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
- for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
- if(is_Phi(irn)) {
- int i, n;
- int illegal = 0;
+ if (blocks_removed) {
+ /* invalidate analysis info */
+ clear_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_DOMINANCE
+ | IR_GRAPH_STATE_VALID_EXTENDED_BLOCKS);
+ }
+ return blocks_removed;
+}
- 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;
+//---------------------------------------------------------------------------
- if(illegal)
- sched_remove(irn);
- }
- }
+typedef struct remove_dead_nodes_env_t_ {
+ bitset_t *reachable;
+ ir_graph *irg;
+ be_lv_t *lv;
+} remove_dead_nodes_env_t;
- for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
- sched_remove(irn);
- }
+/**
+ * Post-walker: remember all visited nodes in a bitset.
+ */
+static void mark_dead_nodes_walker(ir_node *node, void *data)
+{
+ remove_dead_nodes_env_t *env = (remove_dead_nodes_env_t*) data;
+ bitset_set(env->reachable, get_irn_idx(node));
}
-void be_introduce_copies_ignore(dom_front_info_t *info, ir_node *orig,
- int n, ir_node *copy_nodes[], pset *ignore_uses)
+/**
+ * Post-block-walker:
+ * Walk through the schedule of every block and remove all dead nodes from it.
+ */
+static void remove_dead_nodes_walker(ir_node *block, void *data)
{
- pset *copies = pset_new_ptr(2 * n);
- pset *copy_blocks = pset_new_ptr(2 * n);
- pset *phi_blocks = pset_new_ptr(2 * n);
- int save_optimize = get_optimize();
- int save_normalize = get_opt_normalize();
- firm_dbg_module_t *dbg = DBG_MODULE;
- int i;
-
-#if 0
- {
- static int ser = 0;
- char buf[128];
-
- snprintf(buf, sizeof(buf), "-post-%d", ser++);
- dump_ir_block_graph_sched(get_irn_irg(orig), buf);
+ remove_dead_nodes_env_t *env = (remove_dead_nodes_env_t*) data;
+ ir_node *node, *next;
+
+ for (node = sched_first(block); ! sched_is_end(node); node = next) {
+ /* get next node now, as after calling sched_remove it will be invalid */
+ next = sched_next(node);
+
+ if (bitset_is_set(env->reachable, get_irn_idx(node)))
+ continue;
+
+ if (env->lv != NULL)
+ be_liveness_remove(env->lv, node);
+ sched_remove(node);
+
+ /* kill projs */
+ if (get_irn_mode(node) == mode_T) {
+ const ir_edge_t *edge;
+ const ir_edge_t *next_edge;
+ foreach_out_edge_safe(node, edge, next_edge) {
+ ir_node *proj = get_edge_src_irn(edge);
+ if (!is_Proj(proj))
+ continue;
+ if (env->lv != NULL)
+ be_liveness_remove(env->lv, proj);
+ kill_node(proj);
+ }
+ }
+ kill_node(node);
}
-#endif
-
- firm_dbg_set_mask(dbg, DBG_LEVEL);
- DBG((dbg, LEVEL_1, "Introducing following copies of %+F\n", orig));
-
- /* Fill the sets. */
- pset_insert_ptr(copies, orig);
- pset_insert_ptr(copy_blocks, get_nodes_block(orig));
-
- /*
- * All phis using the original value are also copies of it
- * and must be present in the copies set.
- */
- for(i = 0; i < n; ++i) {
- DBG((dbg, LEVEL_1,
- " %+F in block %+F\n", copy_nodes[i], get_nodes_block(copy_nodes[i])));
- pset_insert_ptr(copies, copy_nodes[i]);
- pset_insert_ptr(copy_blocks, get_nodes_block(copy_nodes[i]));
- }
-
- /*
- * Disable optimization so that the phi functions do not
- * disappear.
- */
- set_optimize(0);
- set_opt_normalize(0);
-
- /*
- * Place the phi functions and reroute the usages.
- */
- determine_phi_blocks(orig, copies, copy_blocks, phi_blocks, info);
- fix_usages(orig, copies, copy_blocks, phi_blocks, ignore_uses);
-
- /* reset the optimizations */
- set_optimize(save_optimize);
- set_opt_normalize(save_normalize);
-
- del_pset(copies);
- del_pset(phi_blocks);
- del_pset(copy_blocks);
-
-
}
-void be_introduce_copies(dom_front_info_t *info, ir_node *orig, int n, ir_node *copy_nodes[])
+void be_remove_dead_nodes_from_schedule(ir_graph *irg)
{
- static pset *empty_set = NULL;
+ remove_dead_nodes_env_t env;
+ env.reachable = bitset_alloca(get_irg_last_idx(irg));
+ env.lv = be_get_irg_liveness(irg);
+ env.irg = irg;
- if(!empty_set)
- empty_set = pset_new_ptr_default();
+ // mark all reachable nodes
+ irg_walk_graph(irg, mark_dead_nodes_walker, NULL, &env);
- be_introduce_copies_ignore(info, orig, n, copy_nodes, empty_set);
+ // walk schedule and remove non-marked nodes
+ irg_block_walk_graph(irg, remove_dead_nodes_walker, NULL, &env);
}
-void be_introduce_copies_pset(dom_front_info_t *info, pset *nodes) {
- int i, n = pset_count(nodes);
- ir_node *orig, *irn, **copy_nodes;
- static pset *empty_set = NULL;
-
- if (n<2)
- return;
-
- copy_nodes = alloca((n-1)*sizeof(*copy_nodes));
- irn = pset_first(nodes);
- orig = irn;
- for (i=0, irn = pset_next(nodes); irn; irn=pset_next(nodes))
- copy_nodes[i++] = irn;
-
-
- if(!empty_set)
- empty_set = pset_new_ptr_default();
-
- be_introduce_copies_ignore(info, orig, n-1, copy_nodes, empty_set);
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_irgmod)
+void be_init_irgmod(void)
+{
+ FIRM_DBG_REGISTER(dbg, "firm.be.irgmod");
}
projects / libfirm / blobdiff