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                 assert(get_irn_op(old)->opar != oparity_dynamic);
 100
 101                 hook_turn_into_id(old);
 102
 103                 block = old->in[0];
 104                 if (! block) {
 105                         block = is_Block(nw) ? nw : get_nodes_block(nw);
 106
 107                         if (! block) {
 108                                 panic("cannot find legal block for id");
 109                         }
 110                 }
 111
 112                 old->op    = op_Id;
 113                 old->in    = NEW_ARR_D (ir_node *, irg->obst, 2);
 114                 old->in[0] = block;
 115                 old->in[1] = nw;
 116         }
 117 }
 118
 119 /*--------------------------------------------------------------------*/
 120 /*  Functionality for collect_phis                                    */
 121 /*--------------------------------------------------------------------*/
 122
 123 /**
 124  * Walker: links all Phi nodes to their Blocks lists,
 125  *         all Proj nodes to there predecessors and all
 126  *         partBlocks to there MacroBlock header.
 127  */
 128 static void collect(ir_node *n, void *env) {
 129         ir_node *pred;
 130         (void) env;
 131
 132         if (is_Phi(n)) {
 133                 ir_node *block = get_nodes_block(n);
 134                 set_Phi_next(n, get_Block_phis(block));
 135                 set_Block_phis(block, n);
 136         } else if (is_Proj(n)) {
 137                 pred = n;
 138                 do {
 139                         pred = get_Proj_pred(pred);
 140                 } while (is_Proj(pred));
 141
 142                 set_irn_link(n, get_irn_link(pred));
 143                 set_irn_link(pred, n);
 144         } else if (is_Block(n)) {
 145                 ir_node *mbh = get_Block_MacroBlock(n);
 146
 147                 if (mbh != n) {
 148                         set_irn_link(n, get_irn_link(mbh));
 149                         set_irn_link(mbh, n);
 150                 }
 151         }
 152 }
 153
 154 /**
 155  * clear all links, including the Phi list of blocks and Phi nodes.
 156  */
 157 static void clear_links(ir_node *n, void *env) {
 158         (void) env;
 159
 160         set_irn_link(n, NULL);
 161         if (is_Block(n))
 162                 set_Block_phis(n, NULL);
 163         else if (is_Phi(n))
 164                 set_Phi_next(n, NULL);
 165 }
 166
 167 void collect_phiprojs(ir_graph *irg) {
 168         irg_walk_graph(irg, clear_links, collect, NULL);
 169 }
 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
 214         /* Turn off optimizations so that blocks are not merged again. */
 215         int rem_opt = get_opt_optimize();
 216         set_optimize(0);
 217
 218         /* Transform the control flow */
 219         old_block = get_nodes_block(node);
 220         mbh       = get_Block_MacroBlock(old_block);
 221         new_block = new_Block(get_Block_n_cfgpreds(old_block),
 222                               get_Block_cfgpred_arr(old_block));
 223         set_irn_n(new_block, -1, mbh);
 224         set_irg_current_block(current_ir_graph, new_block);
 225         {
 226                 ir_node *jmp = new_Jmp();
 227                 set_irn_in(old_block, 1, &jmp);
 228                 irn_vrfy_irg(old_block, current_ir_graph);
 229         }
 230
 231         /* move node and its predecessors to new_block */
 232         move(node, old_block, new_block);
 233
 234         /* move Phi nodes to new_block */
 235         phi = get_Block_phis(old_block);
 236         set_Block_phis(new_block, phi);
 237         set_Block_phis(old_block, NULL);
 238         while (phi) {
 239                 set_nodes_block(phi, new_block);
 240                 phi = get_Phi_next(phi);
 241         }
 242
 243         /* rewire partBlocks */
 244         if (mbh != old_block) {
 245                 ir_node *next, *block = get_irn_link(mbh);
 246
 247                 set_irn_link(mbh, NULL);
 248                 set_irn_link(old_block, NULL);
 249
 250                 /* note that we must splice the list of partBlock here */
 251                 for (; block != NULL; block = next) {
 252                         ir_node *curr = block;
 253                         assert(is_Block(curr));
 254
 255                         next = get_irn_link(block);
 256
 257                         for (;;) {
 258                                 if (curr == old_block) {
 259                                         /* old_block dominates the block, so old_block will be
 260                                            the new macro block header */
 261                                         set_irn_n(block, -1, old_block);
 262                                         set_irn_link(block, get_irn_link(old_block));
 263                                         set_irn_link(old_block, block);
 264                                         break;
 265                                 }
 266                                 if (curr == mbh) {
 267                                         /* leave it in the mbh */
 268                                         set_irn_link(block, get_irn_link(mbh));
 269                                         set_irn_link(mbh, block);
 270                                         break;
 271                                 }
 272
 273                                 assert(get_Block_n_cfgpreds(curr) == 1);
 274                                 curr = get_Block_cfgpred_block(curr, 0);
 275                         }
 276                 }
 277         }
 278
 279         set_optimize(rem_opt);
 280 }
 281
 282 /* kill a node by setting its predecessors to Bad and finally exchange the node by Bad itself. */
 283 void kill_node(ir_node *node) {
 284         ir_graph *irg = get_irn_irg(node);
 285         ir_node *bad = get_irg_bad(irg);
 286         int i;
 287
 288         for (i = get_irn_arity(node) - 1; i >= -1; --i) {
 289                 set_irn_n(node, i, bad);
 290         }
 291         exchange(node, bad);
 292 }