+/*
+ * 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
+ * @version $Id$
+ *
+ * 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)
+ */
#ifdef HAVE_CONFIG_H
#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 "bearch.h"
+#include "bechordal_t.h"
+#include "bearch_t.h"
#include "besched_t.h"
#include "belive_t.h"
#include "benode_t.h"
#include "beutil.h"
-
+#include "beinsn_t.h"
+#include "bessaconstr.h"
+#include "beirg_t.h"
#include "beirgmod.h"
+#include "bemodule.h"
-#define DBG_MODULE firm_dbg_register("firm.be.irgmod")
-#define DBG_LEVEL SET_LEVEL_0
-
-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 *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);
-
-}
-
-dom_front_info_t *be_compute_dominance_frontiers(ir_graph *irg)
-{
- dom_front_info_t *info = malloc(sizeof(*info));
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
- edges_assure(irg);
- info->df_map = pmap_create();
- compute_doms(irg);
- compute_df(get_irg_start_block(irg), info->df_map);
+/*
+ ___ _ ____
+ |_ _|_ __ ___ ___ _ __| |_ | _ \ ___ _ __ _ __ ___
+ | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ '__| '_ ` _ \
+ | || | | \__ \ __/ | | |_ | __/ __/ | | | | | | |
+ |___|_| |_|___/\___|_| \__| |_| \___|_| |_| |_| |_|
- return info;
-}
+*/
-void be_free_dominance_frontiers(dom_front_info_t *info)
+ir_node *insert_Perm_after(be_irg_t *birg,
+ const arch_register_class_t *cls,
+ ir_node *pos)
{
- pmap_entry *ent;
+ be_lv_t *lv = birg->lv;
+ ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
+ ir_graph *irg = get_irn_irg(bl);
+ ir_nodeset_t live;
+ ir_nodeset_iterator_t iter;
- for(ent = pmap_first(info->df_map); ent; ent = pmap_next(info->df_map))
- del_pset(ent->value);
+ ir_node *curr, *irn, *perm, **nodes;
+ size_t i, n;
- pmap_destroy(info->df_map);
- free(info);
-}
+ DBG((dbg, LEVEL_1, "Insert Perm after: %+F\n", pos));
-pset *be_get_dominance_frontier(dom_front_info_t *info, ir_node *block)
-{
- return pmap_get(info->df_map, block);
-}
+ ir_nodeset_init(&live);
+ be_liveness_nodes_live_at(lv, cls, pos, &live);
-static void determine_phi_blocks(pset *copies, pset* copy_blocks, pset *phi_blocks, dom_front_info_t *df_info)
-{
- ir_node *bl;
- 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)) {
- pdeq_putr(worklist, bl);
+ n = ir_nodeset_size(&live);
+ if(n == 0) {
+ ir_nodeset_destroy(&live);
+ return NULL;
}
- 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));
- 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);
+ nodes = XMALLOCN(ir_node*, n);
- if(!pset_find_ptr(copy_blocks, y))
- pdeq_putr(worklist, y);
-
- }
- }
+ 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, irg, bl, n, nodes);
+ sched_add_after(pos, perm);
+ free(nodes);
+
+ curr = perm;
+ 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(irg, bl, perm, mode, i);
+ arch_set_irn_register(proj, reg);
+
+ curr = proj;
+
+ be_ssa_construction_init(&senv, birg);
+ 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);
}
- del_pdeq(worklist);
+ return perm;
}
+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 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.
+ * 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 *phis, 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;
- }
+ const ir_edge_t *edge, *next;
+ int i, arity;
+ ir_node *node;
+ ir_node *pred;
+ ir_node *succ_block;
+ ir_node *jump = NULL;
+
+ if (irn_visited_else_mark(block))
+ return;
+
+ if (get_Block_n_cfgpreds(block) != 1)
+ goto check_preds;
+
+ sched_foreach(block, node) {
+ if (! is_Jmp(node))
+ 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(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_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, phis, phi_blocks, mode);
- DBG((dbg, LEVEL_2, "\t\t%+F(%d) -> %+F\n", phi, i, arg));
- set_irn_n(phi, i, arg);
- }
+ if (jump == NULL)
+ goto check_preds;
- if(phis)
- pset_insert_ptr(phis, phi);
- }
+ pred = get_Block_cfgpred(block, 0);
+ succ_block = NULL;
+ foreach_out_edge_safe(jump, edge, next) {
+ int pos = get_edge_src_pos(edge);
- return phi;
- }
+ assert(succ_block == NULL);
+ succ_block = get_edge_src_irn(edge);
- /* 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_n(succ_block, pos, pred);
}
- return NULL;
-}
-
-static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *phis, pset *ignore_uses)
-{
- firm_dbg_module_t *dbg = DBG_MODULE;
- int n_outs = 0;
-
- struct obstack obst;
- ir_node *irn;
- int i;
-
- struct out {
- ir_node *irn;
- int pos;
- } *outs;
-
- obstack_init(&obst);
-
- /*
- * 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++;
- }
+ /* 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;
+ if (is_Block(node)) {
+ /* a Block->Block edge: This should be the MacroBlock
+ edge, ignore it. */
+ assert(get_Block_MacroBlock(node) == block && "Wrong Block->Block edge");
+ continue;
+ }
+ if (is_Pin(node)) {
+ set_nodes_block(node, succ_block);
+ 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);
}
- outs = obstack_finish(&obst);
-
- /*
- * Search the valid def for each out 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));
- ir_node *def;
+ set_Block_cfgpred(block, 0, new_Bad());
+ kill_node(jump);
+ blocks_removed = 1;
- def = search_def(irn, pos, copies, copy_blocks, phis, phi_blocks, mode);
- DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", irn, pos, def));
+ /* check predecessor */
+ remove_empty_block(get_nodes_block(pred));
+ return;
- if(def != NULL)
- set_irn_n(irn, pos, def);
+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);
}
-
- 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)
+/* removes basic blocks that just contain a jump instruction */
+int be_remove_empty_blocks(ir_graph *irg)
{
- ir_node *irn;
-
- for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
- if(is_Phi(irn)) {
- int i, n;
- int illegal = 0;
-
- 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);
- }
- }
-
- for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
- sched_remove(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);
}
-}
-
-void be_ssa_constr_phis_ignore(dom_front_info_t *info, int n, ir_node *nodes[], pset *phis, pset *ignore_uses)
-{
- pset *irns = pset_new_ptr(n);
- int i;
-
- 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);
-}
-
-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);
-}
-
-void be_ssa_constr(dom_front_info_t *info, int n, ir_node *nodes[])
-{
- pset *empty_set = be_empty_set();
- assert(pset_count(empty_set) == 0);
- be_ssa_constr_ignore(info, n, nodes, empty_set);
-}
-
-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_module_t *dbg = DBG_MODULE;
-
- ir_node *irn;
-
- firm_dbg_set_mask(dbg, DBG_LEVEL);
- 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));
+ ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
+
+ if (blocks_removed) {
+ /* invalidate analysis info */
+ set_irg_doms_inconsistent(irg);
+ set_irg_extblk_inconsistent(irg);
+ set_irg_outs_inconsistent(irg);
+ set_irg_loopinfo_inconsistent(irg);
}
-
- /*
- * 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(nodes, blocks, phi_blocks, df);
- fix_usages(nodes, blocks, phi_blocks, phis, ignore_uses);
-
- /* reset the optimizations */
- set_optimize(save_optimize);
- set_opt_normalize(save_normalize);
-
- del_pset(phi_blocks);
- del_pset(blocks);
-
-}
-
-void be_ssa_constr_set_phis(dom_front_info_t *df, pset *nodes, pset *phis)
-{
- pset *empty_set = be_empty_set();
- assert(pset_count(empty_set) == 0);
-
- be_ssa_constr_set_phis_ignore(df, nodes,phis, empty_set);
+ return blocks_removed;
}
-void be_ssa_constr_set_ignore(dom_front_info_t *df, pset *nodes, pset *ignore_uses)
+void be_init_irgmod(void)
{
- be_ssa_constr_set_phis_ignore(df, nodes, NULL, ignore_uses);
+ FIRM_DBG_REGISTER(dbg, "firm.be.irgmod");
}
-void be_ssa_constr_set(dom_front_info_t *info, pset *nodes)
-{
- pset *empty_set = be_empty_set();
- assert(pset_count(empty_set) == 0);
- be_ssa_constr_set_ignore(info, nodes, empty_set);
-}
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_irgmod);
projects / libfirm / blobdiff