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 #include "config.h"
  27
  28 #include "irvrfy.h"
  29 #include "irflag_t.h"
  30 #include "irgwalk.h"
  31 #include "irnode_t.h"
  32 #include "irgraph_t.h"
  33 #include "irgmod.h"
  34 #include "array.h"
  35 #include "ircons.h"
  36 #include "irhooks.h"
  37 #include "iredges_t.h"
  38 #include "irtools.h"
  39 #include "error.h"
  40
  41 /**
  42  * Turns a node into a "useless" Tuple.  The Tuple just forms a tuple
  43  * from several inputs.
  44  * This is useful if a node returning a tuple is removed, but the Projs
  45  * extracting values from the tuple are not available.
  46  */
  47 void turn_into_tuple(ir_node *node, int arity)
  48 {
  49         assert(node);
  50         set_irn_op(node, op_Tuple);
  51         if (get_irn_arity(node) == arity) {
  52                 /* keep old array */
  53         } else {
  54                 ir_graph *irg = get_irn_irg(node);
  55                 ir_node *block = get_nodes_block(node);
  56                 edges_node_deleted(node, irg);
  57                 /* Allocate new array, don't free old in_array, it's on the obstack. */
  58                 node->in = NEW_ARR_D(ir_node *, irg->obst, arity+1);
  59                 /* clear the new in array, else edge_notify tries to delete garbage */
  60                 memset(node->in, 0, (arity+1) * sizeof(node->in[0]));
  61                 /* set the block back */
  62                 set_nodes_block(node, block);
  63         }
  64 }
  65
  66 /**
  67  * Insert irnode `new' in place of irnode `old'
  68  * Since `new' may be bigger than `old' replace `old'
  69  * by an op_Id which is smaller than everything.
  70  */
  71 void exchange(ir_node *old, ir_node *nw)
  72 {
  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 {
 132         ir_node *pred;
 133         (void) env;
 134
 135         if (is_Phi(n)) {
 136                 ir_node *block = get_nodes_block(n);
 137                 add_Block_phi(block, n);
 138         } else if (is_Proj(n)) {
 139                 pred = n;
 140                 do {
 141                         pred = get_Proj_pred(pred);
 142                 } while (is_Proj(pred));
 143
 144                 set_irn_link(n, get_irn_link(pred));
 145                 set_irn_link(pred, n);
 146         } else if (is_Block(n)) {
 147                 ir_node *mbh = get_Block_MacroBlock(n);
 148
 149                 if (mbh != n) {
 150                         set_irn_link(n, get_irn_link(mbh));
 151                         set_irn_link(mbh, n);
 152                 }
 153         }
 154 }
 155
 156 void collect_phiprojs(ir_graph *irg)
 157 {
 158         assert((ir_resources_reserved(irg) & (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST)) ==
 159                 (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST));
 160         irg_walk_graph(irg, firm_clear_node_and_phi_links, collect_phiprojs_walker, NULL);
 161 }
 162
 163 /*--------------------------------------------------------------------*/
 164 /*  Functionality for part_block                                      */
 165 /*--------------------------------------------------------------------*/
 166
 167 /**
 168  * Moves node and all predecessors of node from from_bl to to_bl.
 169  * Does not move predecessors of Phi nodes (or block nodes).
 170  */
 171 static void move(ir_node *node, ir_node *from_bl, ir_node *to_bl)
 172 {
 173         int i, arity;
 174
 175         /* move this node */
 176         set_nodes_block(node, to_bl);
 177
 178         /* move its Projs */
 179         if (get_irn_mode(node) == mode_T) {
 180                 ir_node *proj = get_irn_link(node);
 181                 while (proj) {
 182                         if (get_nodes_block(proj) == from_bl)
 183                                 set_nodes_block(proj, to_bl);
 184                         proj = get_irn_link(proj);
 185                 }
 186         }
 187
 188         /* recursion ... */
 189         if (is_Phi(node))
 190                 return;
 191
 192         arity = get_irn_arity(node);
 193         for (i = 0; i < arity; i++) {
 194                 ir_node *pred = get_irn_n(node, i);
 195                 if (get_nodes_block(pred) == from_bl)
 196                         move(pred, from_bl, to_bl);
 197         }
 198 }
 199
 200 void part_block(ir_node *node)
 201 {
 202         ir_node *new_block, *old_block, *mbh;
 203         ir_node *phi, *jmp, *next, *block;
 204         ir_graph *rem = current_ir_graph;
 205
 206         /* Turn off optimizations so that blocks are not merged again. */
 207         int rem_opt = get_opt_optimize();
 208         set_optimize(0);
 209
 210         current_ir_graph = get_irn_irg(node);
 211
 212         /* Transform the control flow */
 213         old_block = get_nodes_block(node);
 214         mbh       = get_Block_MacroBlock(old_block);
 215         new_block = new_Block(get_Block_n_cfgpreds(old_block),
 216                               get_Block_cfgpred_arr(old_block));
 217
 218         if (mbh != old_block) {
 219                 /* we splitting a partBlock */
 220                 set_Block_MacroBlock(new_block, mbh);
 221         } else {
 222                 /* we are splitting a header: this creates a new header */
 223                 set_Block_MacroBlock(new_block, new_block);
 224         }
 225
 226         /* create a jump from new_block to old_block, which is now the lower one */
 227         jmp = new_r_Jmp(new_block);
 228         set_irn_in(old_block, 1, &jmp);
 229
 230         /* move node and its predecessors to new_block */
 231         move(node, old_block, new_block);
 232
 233         /* move Phi nodes to new_block */
 234         phi = get_Block_phis(old_block);
 235         set_Block_phis(new_block, phi);
 236         set_Block_phis(old_block, NULL);
 237         while (phi) {
 238                 set_nodes_block(phi, new_block);
 239                 phi = get_Phi_next(phi);
 240         }
 241
 242         /* rewire partBlocks: This is necessary, because old_block is a new MacroBlock
 243            header now */
 244         if (mbh != old_block) {
 245                 ir_node *list = NULL;
 246
 247                 /* move blocks from mbh to old_block if old_block dominates them */
 248                 block = get_irn_link(mbh);
 249
 250                 /* mbh's list will be rebuild */
 251                 set_irn_link(mbh, NULL);
 252                 /* old_block is a new mbh */
 253                 set_Block_MacroBlock(old_block, old_block);
 254
 255                 /* note that we must splice the list of partBlock here */
 256                 for (; block != NULL; block = next) {
 257                         ir_node *curr = block;
 258                         assert(is_Block(curr));
 259
 260                         next = get_irn_link(block);
 261
 262                         if (block == old_block) {
 263                                 /* this effectively removed old_block from mbh's list */
 264                                 continue;
 265                         }
 266
 267                         assert(get_Block_MacroBlock(curr) == mbh);
 268
 269                         for (;;) {
 270                                 if (curr == old_block) {
 271                                         /* old_block dominates the block, so old_block will be
 272                                            the new macro block header */
 273                                         set_Block_MacroBlock(block, old_block);
 274                                         set_irn_link(block, list);
 275                                         list = block;
 276                                         break;
 277                                 }
 278                                 if (curr == mbh) {
 279                                         /* leave it in the mbh */
 280                                         set_irn_link(block, get_irn_link(mbh));
 281                                         set_irn_link(mbh, block);
 282                                         break;
 283                                 }
 284
 285                                 assert(get_Block_n_cfgpreds(curr) == 1);
 286                                 curr = get_Block_cfgpred_block(curr, 0);
 287                         }
 288                 }
 289                 /* beware: do NOT directly manipulate old_block's list, as old_block is
 290                    in mbh's list and this would destroy the list! */
 291                 set_irn_link(old_block, list);
 292
 293                 /* finally add new_block to mbh's list */
 294                 set_irn_link(new_block, get_irn_link(mbh));
 295                 set_irn_link(mbh, new_block);
 296         } else {
 297                 /* old_block is the mbh, as well as new_block */
 298                 set_Block_MacroBlock(new_block, new_block);
 299         }
 300
 301         set_optimize(rem_opt);
 302         current_ir_graph = rem;
 303 }
 304
 305 /* kill a node by setting its predecessors to Bad and finally exchange the node by Bad itself. */
 306 void kill_node(ir_node *node)
 307 {
 308         ir_graph *irg = get_irn_irg(node);
 309         ir_node *bad = get_irg_bad(irg);
 310         int i;
 311
 312         for (i = get_irn_arity(node) - 1; i >= -1; --i) {
 313                 set_irn_n(node, i, bad);
 314         }
 315         exchange(node, bad);
 316 }