nsz Git - libfirm/blob - ir/lower/lower_mode_b.c

   1 /*
   2  * Copyright (C) 1995-2007 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  * @author      Matthias Braun, Christoph Mallon
  23  * @version     $Id$
  24  */
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28
  29 #include <stdlib.h>
  30
  31 #include "irnode_t.h"
  32 #include "ircons_t.h"
  33 #include "irgwalk.h"
  34 #include "irtools.h"
  35 #include "iredges.h"
  36 #include "tv.h"
  37 #include "error.h"
  38 #include "lowering.h"
  39 #include "pdeq.h"
  40
  41 static ir_mode *lowered_mode     = NULL;
  42 static int      lower_direct_cmp = 0;
  43 static ir_type *lowered_type     = NULL;
  44 static pdeq    *lowered_nodes    = NULL;
  45
  46 /**
  47  * Removes a node if its out-edge count has reached 0.
  48  * temporary hack until we have proper automatic dead code elimination.
  49  */
  50 static void maybe_kill_node(ir_node *node)
  51 {
  52         ir_graph *irg;
  53         int       i, arity;
  54
  55         if(get_irn_n_edges(node) != 0)
  56                 return;
  57
  58         irg = get_irn_irg(node);
  59
  60         assert(!is_Bad(node));
  61
  62         arity = get_irn_arity(node);
  63         for (i = 0; i < arity; ++i) {
  64                 set_irn_n(node, i, new_Bad());
  65         }
  66         set_nodes_block(node, new_Bad());
  67
  68         edges_node_deleted(node, irg);
  69 }
  70
  71 static ir_node *create_not(dbg_info *dbgi, ir_node *node)
  72 {
  73         ir_graph *irg    = current_ir_graph;
  74         ir_node  *block  = get_nodes_block(node);
  75         tarval   *tv_one = get_tarval_one(lowered_mode);
  76         ir_node  *one    = new_d_Const(dbgi, lowered_mode, tv_one);
  77
  78         return new_rd_Eor(dbgi, irg, block, node, one, lowered_mode);
  79 }
  80
  81 static ir_node *create_convb(ir_node *node)
  82 {
  83         ir_graph *irg   = current_ir_graph;
  84         ir_node  *block = get_nodes_block(node);
  85         ir_node  *conv  = new_rd_Conv(NULL, irg, block, node, mode_b);
  86
  87         return conv;
  88 }
  89
  90 static ir_type *create_lowered_type(void)
  91 {
  92         if(lowered_type == NULL) {
  93                 lowered_type = new_type_primitive(new_id_from_str("__lowered_mode_b"),
  94                                                   lowered_mode);
  95         }
  96         return lowered_type;
  97 }
  98
  99 static void adjust_method_type(ir_type *method_type)
 100 {
 101         int i;
 102         int n_params;
 103         int n_res;
 104
 105         n_params = get_method_n_params(method_type);
 106         for(i = 0; i < n_params; ++i) {
 107                 ir_type *param = get_method_param_type(method_type, i);
 108                 if(get_type_mode(param) == mode_b) {
 109                         set_method_param_type(method_type, i, create_lowered_type());
 110                 }
 111         }
 112
 113         n_res = get_method_n_ress(method_type);
 114         for(i = 0; i < n_res; ++i) {
 115                 ir_type *res_type = get_method_res_type(method_type, i);
 116                 if(get_type_mode(res_type) == mode_b) {
 117                         set_method_res_type(method_type, i, create_lowered_type());
 118                 }
 119         }
 120 }
 121
 122 static ir_node *lower_node(ir_node *node)
 123 {
 124         ir_graph *irg   = current_ir_graph;
 125         dbg_info *dbgi  = get_irn_dbg_info(node);
 126         ir_op    *op    = get_irn_op(node);
 127         ir_node  *block = get_nodes_block(node);
 128         ir_node  *res;
 129
 130         assert(get_irn_mode(node) == mode_b);
 131
 132         res = get_irn_link(node);
 133         if(res != NULL)
 134                 return res;
 135
 136         /* TODO: be robust against phi-loops... */
 137         if(op == op_Phi) {
 138                 int       i, arity;
 139                 ir_node **in;
 140                 ir_node  *unknown, *new_phi;
 141
 142                 arity = get_irn_arity(node);
 143                 in    = alloca(arity * sizeof(in[0]));
 144                 unknown = new_Unknown(lowered_mode);
 145                 for(i = 0; i < arity; ++i) {
 146                         in[i] = unknown;
 147                 }
 148                 new_phi = new_rd_Phi(dbgi, irg, block, arity, in,
 149                                               lowered_mode);
 150                 set_irn_link(node, new_phi);
 151                 pdeq_putr(lowered_nodes, node);
 152
 153                 for(i = 0; i < arity; ++i) {
 154                         ir_node *in     = get_irn_n(node, i);
 155                         ir_node *low_in = lower_node(in);
 156
 157                         set_irn_n(new_phi, i, low_in);
 158                 }
 159
 160                 return new_phi;
 161         }
 162
 163         if(op == op_And || op == op_Or || op == op_Eor) {
 164                 int i, arity;
 165                 ir_node *copy = exact_copy(node);
 166
 167                 arity = get_irn_arity(node);
 168                 for(i = 0; i < arity; ++i) {
 169                         ir_node *in     = get_irn_n(node, i);
 170                         ir_node *low_in = lower_node(in);
 171
 172                         set_irn_n(copy, i, low_in);
 173                 }
 174                 set_irn_mode(copy, lowered_mode);
 175
 176                 set_irn_link(node, copy);
 177                 pdeq_putr(lowered_nodes, node);
 178                 return copy;
 179         }
 180         if(op == op_Not) {
 181                 ir_node *op     = get_Not_op(node);
 182                 ir_node *low_op = lower_node(op);
 183
 184                 res = create_not(dbgi, low_op);
 185                 set_irn_link(node, res);
 186                 pdeq_putr(lowered_nodes, node);
 187                 return res;
 188         }
 189         if(op == op_Psi) {
 190                 ir_node *cond        = get_Psi_cond(node, 0);
 191                 ir_node *low_cond    = lower_node(cond);
 192                 ir_node *v_true      = get_Psi_val(node, 0);
 193                 ir_node *low_v_true  = lower_node(v_true);
 194                 ir_node *v_false     = get_Psi_default(node);
 195                 ir_node *low_v_false = lower_node(v_false);
 196
 197                 ir_node *and0     = new_rd_And(dbgi, irg, block, low_cond, low_v_true,
 198                                                lowered_mode);
 199
 200                 ir_node *not_cond = create_not(dbgi, low_cond);
 201
 202                 ir_node *and1     = new_rd_And(dbgi, irg, block, not_cond, low_v_false,
 203                                                lowered_mode);
 204
 205                 ir_node *or       = new_rd_Or(dbgi, irg, block, and0, and1,
 206                                               lowered_mode);
 207
 208                 set_irn_link(node, or);
 209                 pdeq_putr(lowered_nodes, node);
 210                 return or;
 211         }
 212         if(op == op_Conv) {
 213                 tarval  *tv_one   = get_tarval_one(lowered_mode);
 214                 ir_node *one      = new_d_Const(dbgi, lowered_mode, tv_one);
 215                 tarval  *tv_zero  = get_tarval_null(lowered_mode);
 216                 ir_node *zero     = new_d_Const(dbgi, lowered_mode, tv_zero);
 217                 ir_node *pred     = get_Conv_op(node);
 218                 ir_mode *mode     = get_irn_mode(pred);
 219                 tarval  *tv_zeroc = get_tarval_null(mode);
 220                 ir_node *zero_cmp = new_d_Const(dbgi, mode, tv_zeroc);
 221
 222                 ir_node *cmp      = new_rd_Cmp(dbgi, irg, block, pred, zero_cmp);
 223                 ir_node *proj     = new_rd_Proj(dbgi, irg, block, cmp, mode_b,
 224                                                 pn_Cmp_Lg);
 225                 ir_node *vals[2]  = { one, zero };
 226                 ir_node *psi      = new_rd_Psi(dbgi, irg, block, 1, &proj, vals,
 227                                                lowered_mode);
 228
 229                 set_irn_link(node, psi);
 230                 pdeq_putr(lowered_nodes, node);
 231                 return psi;
 232         }
 233         if(op == op_Proj) {
 234                 ir_node *pred = get_Proj_pred(node);
 235
 236                 if(is_Cmp(pred)) {
 237                         ir_node *left  = get_Cmp_left(pred);
 238                         ir_node *right = get_Cmp_right(pred);
 239                         ir_mode *mode  = get_irn_mode(left);
 240
 241                         if ((mode_is_int(mode) || mode_is_reference(mode)) && (
 242                                                 get_mode_size_bits(mode) < get_mode_size_bits(lowered_mode) ||
 243                                                 (mode_is_signed(mode) && is_Const(right) && is_Const_null(right))
 244                                         )) {
 245                                 int      pnc      = get_Proj_proj(node);
 246                                 int      need_not = 0;
 247                                 ir_node *a        = NULL;
 248                                 ir_node *b        = NULL;
 249
 250                                 if(pnc == pn_Cmp_Lt) {
 251                                         /* a < b  ->  (a - b) >> 31 */
 252                                         a = left;
 253                                         b = right;
 254                                 } else if(pnc == pn_Cmp_Le) {
 255                                         /* a <= b  -> ~(a - b) >> 31 */
 256                                         a        = right;
 257                                         b        = left;
 258                                         need_not = 1;
 259                                 } else if(pnc == pn_Cmp_Gt) {
 260                                         /* a > b   -> (b - a) >> 31 */
 261                                         a = right;
 262                                         b = left;
 263                                 } else if(pnc == pn_Cmp_Ge) {
 264                                         /* a >= b   -> ~(a - b) >> 31 */
 265                                         a        = left;
 266                                         b        = right;
 267                                         need_not = 1;
 268                                 }
 269
 270                                 if(a != NULL) {
 271                                         tarval  *tv        = new_tarval_from_long(get_mode_size_bits(lowered_mode) - 1, mode_Iu);
 272                                         ir_node *shift_cnt = new_d_Const(dbgi, mode_Iu, tv);
 273
 274                                         if(mode != lowered_mode) {
 275                                                 a = new_rd_Conv(dbgi, irg, block, a, lowered_mode);
 276                                                 b = new_rd_Conv(dbgi, irg, block, b, lowered_mode);
 277                                         }
 278
 279                                         res = new_rd_Sub(dbgi, irg, block, a, b, lowered_mode);
 280                                         if(need_not) {
 281                                                 res = new_rd_Not(dbgi, irg, block, res, lowered_mode);
 282                                         }
 283                                         res = new_rd_Shr(dbgi, irg, block, res, shift_cnt,
 284                                                          lowered_mode);
 285
 286                                         set_irn_link(node, res);
 287                                         pdeq_putr(lowered_nodes, node);
 288                                         return res;
 289                                 }
 290                         }
 291
 292                         {
 293                         /* synthesize the 0/1 value */
 294                         tarval  *tv_one  = get_tarval_one(lowered_mode);
 295                         ir_node *one     = new_d_Const(dbgi, lowered_mode, tv_one);
 296                         tarval  *tv_zero = get_tarval_null(lowered_mode);
 297                         ir_node *zero    = new_d_Const(dbgi, lowered_mode, tv_zero);
 298
 299                         ir_node *vals[2] = { one, zero };
 300                         ir_node *psi     = new_rd_Psi(dbgi, irg, block, 1, &node, vals,
 301                                                       lowered_mode);
 302
 303                         set_irn_link(node, psi);
 304                         pdeq_putr(lowered_nodes, node);
 305                         return psi;
 306                         }
 307                 } else if(is_Proj(pred) && is_Call(get_Proj_pred(pred))) {
 308                         ir_type   *type   = get_Call_type(get_Proj_pred(pred));
 309                         adjust_method_type(type);
 310                         set_irn_mode(node, lowered_mode);
 311                         return node;
 312                 } else if(is_Proj(pred) && is_Start(get_Proj_pred(pred))) {
 313                         ir_entity *entity = get_irg_entity(irg);
 314                         ir_type   *type   = get_entity_type(entity);
 315                         adjust_method_type(type);
 316                         set_irn_mode(node, lowered_mode);
 317                         return node;
 318                 }
 319
 320                 panic("unexpected projb: %+F (pred: %+F)", node, pred);
 321         }
 322         if(op == op_Const) {
 323                 tarval *tv = get_Const_tarval(node);
 324                 if(tv == get_tarval_b_true()) {
 325                         tarval  *tv_one  = get_tarval_one(lowered_mode);
 326                         res              = new_d_Const(dbgi, lowered_mode, tv_one);
 327                 } else if(tv == get_tarval_b_false()) {
 328                         tarval  *tv_zero = get_tarval_null(lowered_mode);
 329                         res              = new_d_Const(dbgi, lowered_mode, tv_zero);
 330                 } else {
 331                         panic("invalid boolean const %+F", node);
 332                 }
 333                 set_irn_link(node, res);
 334                 pdeq_putr(lowered_nodes, node);
 335                 return res;
 336         }
 337
 338         panic("didn't expect %+F to have mode_b", node);
 339 }
 340
 341 static void lower_mode_b_walker(ir_node *node, void *env)
 342 {
 343         int i, arity;
 344         int changed = 0;
 345         (void) env;
 346
 347         arity = get_irn_arity(node);
 348         for(i = 0; i < arity; ++i) {
 349                 ir_node *lowered_in;
 350                 ir_node *in = get_irn_n(node, i);
 351                 if(get_irn_mode(in) != mode_b)
 352                         continue;
 353
 354                 if(! lower_direct_cmp) {
 355                         if(is_Cond(node)
 356                                         || (is_Psi(node) && get_irn_mode(node) != mode_b)) {
 357                                 if(is_Proj(in)) {
 358                                         ir_node *pred = get_Proj_pred(in);
 359                                         if(is_Cmp(pred))
 360                                                 continue;
 361                                 }
 362                         }
 363                 }
 364
 365                 lowered_in = lower_node(in);
 366
 367                 if(is_Return(node)) {
 368                         ir_entity *entity = get_irg_entity(current_ir_graph);
 369                         ir_type   *type   = get_entity_type(entity);
 370                         adjust_method_type(type);
 371                 } else if(is_Call(node)) {
 372                         ir_type *type = get_Call_type(node);
 373                         adjust_method_type(type);
 374                 } else {
 375                         lowered_in = create_convb(lowered_in);
 376                 }
 377                 set_irn_n(node, i, lowered_in);
 378                 changed = 1;
 379         }
 380         if(changed) {
 381                 add_identities(current_ir_graph->value_table, node);
 382         }
 383 }
 384
 385 static void clear_links(ir_node *node, void *env)
 386 {
 387         (void) env;
 388         set_irn_link(node, NULL);
 389 }
 390
 391 void ir_lower_mode_b(ir_graph *irg, ir_mode *mode, int do_lower_direct_cmp)
 392 {
 393         lowered_mode     = mode;
 394         lower_direct_cmp = do_lower_direct_cmp;
 395         lowered_nodes    = new_pdeq();
 396         set_using_irn_link(irg);
 397
 398         irg_walk_graph(irg, clear_links, NULL, NULL);
 399         irg_walk_graph(irg, lower_mode_b_walker, NULL, NULL);
 400
 401         while(!pdeq_empty(lowered_nodes)) {
 402                 ir_node *node = (ir_node*) pdeq_getr(lowered_nodes);
 403                 maybe_kill_node(node);
 404         }
 405         del_pdeq(lowered_nodes);
 406
 407         clear_using_irn_link(irg);
 408 }