nsz Git - libfirm/blob - ir/ir/irgmod.c

   1 /*
   2  * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief    Support for ir graph modification.
  23  * @author   Martin Trapp, Christian Schaefer, Goetz Lindenmaier
  24  * @version  $Id$
  25  */
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include "irvrfy.h"
  31 #include "irflag_t.h"
  32 #include "irgwalk.h"
  33 #include "irnode_t.h"
  34 #include "irgraph_t.h"
  35 #include "irgmod.h"
  36 #include "array.h"
  37 #include "ircons.h"
  38 #include "irhooks.h"
  39 #include "iredges_t.h"
  40 #include "irtools.h"
  41 #include "error.h"
  42
  43 /**
  44  * Turns a node into a "useless" Tuple.  The Tuple just forms a tuple
  45  * from several inputs.
  46  * This is useful if a node returning a tuple is removed, but the Projs
  47  * extracting values from the tuple are not available.
  48  */
  49 void turn_into_tuple(ir_node *node, int arity) {
  50         assert(node);
  51         set_irn_op(node, op_Tuple);
  52         if (get_irn_arity(node) == arity) {
  53                 /* keep old array */
  54         } else {
  55                 ir_graph *irg = get_irn_irg(node);
  56                 ir_node *block = get_nodes_block(node);
  57                 edges_node_deleted(node, irg);
  58                 /* Allocate new array, don't free old in_array, it's on the obstack. */
  59                 node->in = NEW_ARR_D(ir_node *, irg->obst, arity+1);
  60                 /* clear the new in array, else edge_notify tries to delete garbage */
  61                 memset(node->in, 0, (arity+1) * sizeof(node->in[0]));
  62                 /* set the block back */
  63                 set_nodes_block(node, block);
  64         }
  65 }
  66
  67 /**
  68  * Insert irnode `new' in place of irnode `old'
  69  * Since `new' may be bigger than `old' replace `old'
  70  * by an op_Id which is smaller than everything.
  71  */
  72 void exchange(ir_node *old, ir_node *nw) {
  73         ir_graph *irg;
  74
  75         assert(old && nw);
  76         assert(old != nw && "Exchanging node with itself is not allowed");
  77
  78         irg = get_irn_irg(old);
  79         assert(irg == get_irn_irg(nw) && "New node must be in same irg as old node");
  80
  81         hook_replace(old, nw);
  82
  83         /*
  84          * If new outs are on, we can skip the id node creation and reroute
  85          * the edges from the old node to the new directly.
  86          */
  87         if (edges_activated(irg)) {
  88                 /* copy all dependencies from old to new */
  89                 add_irn_deps(nw, old);
  90
  91                 edges_reroute(old, nw, irg);
  92                 edges_reroute_kind(old, nw, EDGE_KIND_DEP, irg);
  93                 edges_node_deleted(old, irg);
  94                 old->op = op_Bad;
  95         } else {
  96                 /* Else, do it the old-fashioned way. */
  97                 ir_node *block;
  98
  99                 hook_turn_into_id(old);
 100
 101                 block = old->in[0];
 102                 if (! block) {
 103                         block = is_Block(nw) ? nw : get_nodes_block(nw);
 104
 105                         if (! block) {
 106                                 panic("cannot find legal block for id");
 107                         }
 108                 }
 109
 110                 if (get_irn_op(old)->opar == oparity_dynamic) {
 111                         DEL_ARR_F(get_irn_in(old));
 112                 }
 113
 114                 old->op    = op_Id;
 115                 old->in    = NEW_ARR_D (ir_node *, irg->obst, 2);
 116                 old->in[0] = block;
 117                 old->in[1] = nw;
 118         }
 119 }
 120
 121 /*--------------------------------------------------------------------*/
 122 /*  Functionality for collect_phis                                    */
 123 /*--------------------------------------------------------------------*/
 124
 125 /**
 126  * Walker: links all Phi nodes to their Blocks lists,
 127  *         all Proj nodes to there predecessors and all
 128  *         partBlocks to there MacroBlock header.
 129  */
 130 static void collect_phiprojs_walker(ir_node *n, void *env) {
 131         ir_node *pred;
 132         (void) env;
 133
 134         if (is_Phi(n)) {
 135                 ir_node *block = get_nodes_block(n);
 136                 add_Block_phi(block, n);
 137         } else if (is_Proj(n)) {
 138                 pred = n;
 139                 do {
 140                         pred = get_Proj_pred(pred);
 141                 } while (is_Proj(pred));
 142
 143                 set_irn_link(n, get_irn_link(pred));
 144                 set_irn_link(pred, n);
 145         } else if (is_Block(n)) {
 146                 ir_node *mbh = get_Block_MacroBlock(n);
 147
 148                 if (mbh != n) {
 149                         set_irn_link(n, get_irn_link(mbh));
 150                         set_irn_link(mbh, n);
 151                 }
 152         }
 153 }
 154
 155 /**
 156  * clear all links, including the Phi list of blocks and Phi nodes.
 157  */
 158 static void clear_node_and_phis_links(ir_node *n, void *env) {
 159         (void) env;
 160
 161         set_irn_link(n, NULL);
 162         if (is_Block(n))
 163                 set_Block_phis(n, NULL);
 164         else if (is_Phi(n))
 165                 set_Phi_next(n, NULL);
 166 }
 167
 168 void collect_phiprojs(ir_graph *irg) {
 169         irg_walk_graph(irg, clear_node_and_phis_links, collect_phiprojs_walker, NULL);
 170 }
 171
 172 /*--------------------------------------------------------------------*/
 173 /*  Functionality for part_block                                      */
 174 /*--------------------------------------------------------------------*/
 175
 176 /**
 177  * Moves node and all predecessors of node from from_bl to to_bl.
 178  * Does not move predecessors of Phi nodes (or block nodes).
 179  */
 180 static void move(ir_node *node, ir_node *from_bl, ir_node *to_bl) {
 181         int i, arity;
 182
 183         /* move this node */
 184         set_nodes_block(node, to_bl);
 185
 186         /* move its Projs */
 187         if (get_irn_mode(node) == mode_T) {
 188                 ir_node *proj = get_irn_link(node);
 189                 while (proj) {
 190                         if (get_nodes_block(proj) == from_bl)
 191                                 set_nodes_block(proj, to_bl);
 192                         proj = get_irn_link(proj);
 193                 }
 194         }
 195
 196         /* recursion ... */
 197         if (is_Phi(node))
 198                 return;
 199
 200         arity = get_irn_arity(node);
 201         for (i = 0; i < arity; i++) {
 202                 ir_node *pred = get_irn_n(node, i);
 203                 if (get_nodes_block(pred) == from_bl)
 204                         move(pred, from_bl, to_bl);
 205         }
 206 }
 207
 208 void part_block(ir_node *node) {
 209         ir_node *new_block;
 210         ir_node *old_block;
 211         ir_node *phi;
 212         ir_node *mbh;
 213         ir_node *next, *block;
 214
 215         /* Turn off optimizations so that blocks are not merged again. */
 216         int rem_opt = get_opt_optimize();
 217         set_optimize(0);
 218
 219         /* Transform the control flow */
 220         old_block = get_nodes_block(node);
 221         mbh       = get_Block_MacroBlock(old_block);
 222         new_block = new_Block(get_Block_n_cfgpreds(old_block),
 223                               get_Block_cfgpred_arr(old_block));
 224
 225         if (mbh != old_block) {
 226                 /* we splitting a partBlock */
 227                 set_Block_MacroBlock(new_block, mbh);
 228         } else {
 229                 /* we are splitting a header: this creates a new header */
 230                 set_Block_MacroBlock(new_block, new_block);
 231         }
 232         set_irg_current_block(current_ir_graph, new_block);
 233         {
 234                 ir_node *jmp = new_Jmp();
 235                 set_irn_in(old_block, 1, &jmp);
 236                 irn_vrfy_irg(old_block, current_ir_graph);
 237         }
 238
 239         /* move node and its predecessors to new_block */
 240         move(node, old_block, new_block);
 241
 242         /* move Phi nodes to new_block */
 243         phi = get_Block_phis(old_block);
 244         set_Block_phis(new_block, phi);
 245         set_Block_phis(old_block, NULL);
 246         while (phi) {
 247                 set_nodes_block(phi, new_block);
 248                 phi = get_Phi_next(phi);
 249         }
 250
 251         /* rewire partBlocks */
 252         if (mbh != old_block) {
 253                 ir_node *list = NULL;
 254
 255                 /* move blocks from mbh to old_block if old_block dominates them */
 256                 block = get_irn_link(mbh);
 257
 258                 set_irn_link(mbh, NULL);
 259                 set_Block_MacroBlock(old_block, old_block);
 260
 261                 /* note that we must splice the list of partBlock here */
 262                 for (; block != NULL; block = next) {
 263                         ir_node *curr = block;
 264                         assert(is_Block(curr));
 265
 266                         next = get_irn_link(block);
 267
 268                         if (block == old_block)
 269                                 continue;
 270
 271                         assert(get_Block_MacroBlock(curr) == mbh);
 272
 273                         for (;;) {
 274                                 if (curr == old_block) {
 275                                         /* old_block dominates the block, so old_block will be
 276                                            the new macro block header */
 277                                         set_Block_MacroBlock(block, old_block);
 278                                         set_irn_link(block, list);
 279                                         list = block;
 280                                         break;
 281                                 }
 282                                 if (curr == mbh) {
 283                                         /* leave it in the mbh */
 284                                         set_irn_link(block, get_irn_link(mbh));
 285                                         set_irn_link(mbh, block);
 286                                         break;
 287                                 }
 288
 289                                 assert(get_Block_n_cfgpreds(curr) == 1);
 290                                 curr = get_Block_cfgpred_block(curr, 0);
 291                         }
 292                 }
 293                 /* beware: do NOT directly manipulate old_block's list, as old_block is
 294                    in mbh's list and this would destroy the list! */
 295                 set_irn_link(old_block, list);
 296
 297                 /* finally add new_block to mbh's list */
 298                 set_irn_link(new_block, get_irn_link(mbh));
 299                 set_irn_link(mbh, new_block);
 300         } else {
 301                 /* move blocks from mbh to new_block */
 302                 block = get_irn_link(mbh);
 303
 304                 set_irn_link(mbh, NULL);
 305                 set_irn_link(new_block, NULL);
 306
 307                 for (; block != NULL; block = next) {
 308                         next = get_irn_link(block);
 309
 310                         set_Block_MacroBlock(block, new_block);
 311                         set_irn_link(block, get_irn_link(new_block));
 312                         set_irn_link(new_block, block);
 313                 }
 314         }
 315
 316         set_optimize(rem_opt);
 317 }
 318
 319 /* kill a node by setting its predecessors to Bad and finally exchange the node by Bad itself. */
 320 void kill_node(ir_node *node) {
 321         ir_graph *irg = get_irn_irg(node);
 322         ir_node *bad = get_irg_bad(irg);
 323         int i;
 324
 325         for (i = get_irn_arity(node) - 1; i >= -1; --i) {
 326                 set_irn_n(node, i, bad);
 327         }
 328         exchange(node, bad);
 329 }