nsz Git - libfirm/blob - ir/lower/lower_mode_b.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  * @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 "iropt_t.h"
  37 #include "tv.h"
  38 #include "error.h"
  39 #include "lowering.h"
  40 #include "pdeq.h"
  41
  42 static lower_mode_b_config_t  config;
  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         ir_mode  *mode   = config.lowered_mode;
  76         tarval   *tv_one = get_tarval_one(mode);
  77         ir_node  *one    = new_d_Const(dbgi, mode, tv_one);
  78
  79         return new_rd_Eor(dbgi, irg, block, node, one, mode);
  80 }
  81
  82 static ir_node *create_convb(ir_node *node)
  83 {
  84         ir_graph *irg   = current_ir_graph;
  85         ir_node  *block = get_nodes_block(node);
  86         ir_node  *conv  = new_rd_Conv(NULL, irg, block, node, mode_b);
  87
  88         return conv;
  89 }
  90
  91 static ir_type *create_lowered_type(void)
  92 {
  93         if(lowered_type == NULL) {
  94                 lowered_type = new_type_primitive(new_id_from_str("__lowered_mode_b"),
  95                                                   config.lowered_mode);
  96         }
  97         return lowered_type;
  98 }
  99
 100 /**
 101  * creates a "set" node that produces a 0 or 1 based on a Cmp result
 102  */
 103 static ir_node *create_set(ir_node *node)
 104 {
 105         ir_graph *irg     = current_ir_graph;
 106         dbg_info *dbgi    = get_irn_dbg_info(node);
 107         ir_mode  *mode    = config.lowered_set_mode;
 108         tarval   *tv_one  = get_tarval_one(mode);
 109         ir_node  *one     = new_d_Const(dbgi, mode, tv_one);
 110         ir_node  *block   = get_nodes_block(node);
 111         tarval   *tv_zero = get_tarval_null(mode);
 112         ir_node  *zero    = new_d_Const(dbgi, mode, tv_zero);
 113
 114         ir_node *vals[2]  = { one, zero };
 115         ir_node *set      = new_rd_Psi(dbgi, irg, block, 1, &node, vals, mode);
 116
 117         if(mode != config.lowered_mode) {
 118                 set = new_r_Conv(irg, block, set, config.lowered_mode);
 119         }
 120
 121         return set;
 122 }
 123
 124 static void adjust_method_type(ir_type *method_type)
 125 {
 126         int i;
 127         int n_params;
 128         int n_res;
 129
 130         n_params = get_method_n_params(method_type);
 131         for(i = 0; i < n_params; ++i) {
 132                 ir_type *param = get_method_param_type(method_type, i);
 133                 if(get_type_mode(param) == mode_b) {
 134                         set_method_param_type(method_type, i, create_lowered_type());
 135                 }
 136         }
 137
 138         n_res = get_method_n_ress(method_type);
 139         for(i = 0; i < n_res; ++i) {
 140                 ir_type *res_type = get_method_res_type(method_type, i);
 141                 if(get_type_mode(res_type) == mode_b) {
 142                         set_method_res_type(method_type, i, create_lowered_type());
 143                 }
 144         }
 145 }
 146
 147 static ir_node *lower_node(ir_node *node)
 148 {
 149         ir_graph *irg   = current_ir_graph;
 150         dbg_info *dbgi  = get_irn_dbg_info(node);
 151         ir_op    *op    = get_irn_op(node);
 152         ir_node  *block = get_nodes_block(node);
 153         ir_mode *mode   = config.lowered_mode;
 154         ir_node  *res;
 155
 156         assert(get_irn_mode(node) == mode_b);
 157
 158         res = get_irn_link(node);
 159         if(res != NULL)
 160                 return res;
 161
 162         /* TODO: be robust against phi-loops... */
 163         if(op == op_Phi) {
 164                 int       i, arity;
 165                 ir_node **in;
 166                 ir_node  *unknown, *new_phi;
 167
 168                 arity = get_irn_arity(node);
 169                 in    = alloca(arity * sizeof(in[0]));
 170                 unknown = new_Unknown(config.lowered_mode);
 171                 for(i = 0; i < arity; ++i) {
 172                         in[i] = unknown;
 173                 }
 174                 new_phi = new_r_Phi(irg, block, arity, in, config.lowered_mode);
 175                 set_irn_link(node, new_phi);
 176                 pdeq_putr(lowered_nodes, node);
 177
 178                 for(i = 0; i < arity; ++i) {
 179                         ir_node *in     = get_irn_n(node, i);
 180                         ir_node *low_in = lower_node(in);
 181
 182                         set_irn_n(new_phi, i, low_in);
 183                 }
 184
 185                 return new_phi;
 186         }
 187
 188         if(op == op_And || op == op_Or || op == op_Eor) {
 189                 int i, arity;
 190                 ir_node *copy = exact_copy(node);
 191
 192                 arity = get_irn_arity(node);
 193                 for(i = 0; i < arity; ++i) {
 194                         ir_node *in     = get_irn_n(node, i);
 195                         ir_node *low_in = lower_node(in);
 196
 197                         set_irn_n(copy, i, low_in);
 198                 }
 199                 set_irn_mode(copy, config.lowered_mode);
 200
 201                 set_irn_link(node, copy);
 202                 pdeq_putr(lowered_nodes, node);
 203                 return copy;
 204         }
 205         if(op == op_Not) {
 206                 ir_node *op     = get_Not_op(node);
 207                 ir_node *low_op = lower_node(op);
 208
 209                 res = create_not(dbgi, low_op);
 210                 set_irn_link(node, res);
 211                 pdeq_putr(lowered_nodes, node);
 212                 return res;
 213         }
 214         if(op == op_Psi) {
 215                 ir_node *cond        = get_Psi_cond(node, 0);
 216                 ir_node *low_cond    = lower_node(cond);
 217                 ir_node *v_true      = get_Psi_val(node, 0);
 218                 ir_node *low_v_true  = lower_node(v_true);
 219                 ir_node *v_false     = get_Psi_default(node);
 220                 ir_node *low_v_false = lower_node(v_false);
 221
 222                 ir_node *and0     = new_rd_And(dbgi, irg, block, low_cond, low_v_true,
 223                                                mode);
 224
 225                 ir_node *not_cond = create_not(dbgi, low_cond);
 226
 227                 ir_node *and1     = new_rd_And(dbgi, irg, block, not_cond, low_v_false,
 228                                                mode);
 229
 230                 ir_node *or       = new_rd_Or(dbgi, irg, block, and0, and1,
 231                                               mode);
 232
 233                 set_irn_link(node, or);
 234                 pdeq_putr(lowered_nodes, node);
 235                 return or;
 236         }
 237         if(op == op_Conv) {
 238                 ir_node *pred     = get_Conv_op(node);
 239                 ir_mode *mode     = get_irn_mode(pred);
 240                 tarval  *tv_zeroc = get_tarval_null(mode);
 241                 ir_node *zero_cmp = new_d_Const(dbgi, mode, tv_zeroc);
 242                 ir_node *set;
 243
 244                 ir_node *cmp      = new_rd_Cmp(dbgi, irg, block, pred, zero_cmp);
 245                 ir_node *proj     = new_rd_Proj(dbgi, irg, block, cmp, mode_b,
 246                                                 pn_Cmp_Lg);
 247                 set = create_set(proj);
 248
 249                 set_irn_link(node, set);
 250                 pdeq_putr(lowered_nodes, node);
 251                 return set;
 252         }
 253         if(op == op_Proj) {
 254                 ir_node *pred = get_Proj_pred(node);
 255
 256                 if(is_Cmp(pred)) {
 257                         ir_node *left  = get_Cmp_left(pred);
 258                         ir_node *right = get_Cmp_right(pred);
 259                         ir_mode *cmp_mode  = get_irn_mode(left);
 260                         ir_node *set;
 261
 262                         if ((mode_is_int(cmp_mode) || mode_is_reference(cmp_mode)) && (
 263                                                 get_mode_size_bits(cmp_mode) < get_mode_size_bits(mode) ||
 264                                                 (mode_is_signed(cmp_mode) && is_Const(right) && is_Const_null(right))
 265                                         )) {
 266                                 int      pnc      = get_Proj_proj(node);
 267                                 int      need_not = 0;
 268                                 ir_node *a        = NULL;
 269                                 ir_node *b        = NULL;
 270
 271                                 if(pnc == pn_Cmp_Lt) {
 272                                         /* a < b  ->  (a - b) >> 31 */
 273                                         a = left;
 274                                         b = right;
 275                                 } else if(pnc == pn_Cmp_Le) {
 276                                         /* a <= b  -> ~(a - b) >> 31 */
 277                                         a        = right;
 278                                         b        = left;
 279                                         need_not = 1;
 280                                 } else if(pnc == pn_Cmp_Gt) {
 281                                         /* a > b   -> (b - a) >> 31 */
 282                                         a = right;
 283                                         b = left;
 284                                 } else if(pnc == pn_Cmp_Ge) {
 285                                         /* a >= b   -> ~(a - b) >> 31 */
 286                                         a        = left;
 287                                         b        = right;
 288                                         need_not = 1;
 289                                 }
 290
 291                                 if(a != NULL) {
 292                                         int      bits      = get_mode_size_bits(mode);
 293                                         tarval  *tv        = new_tarval_from_long(bits-1, mode_Iu);
 294                                         ir_node *shift_cnt = new_d_Const(dbgi, mode_Iu, tv);
 295
 296                                         if(cmp_mode != mode) {
 297                                                 a = new_rd_Conv(dbgi, irg, block, a, mode);
 298                                                 b = new_rd_Conv(dbgi, irg, block, b, mode);
 299                                         }
 300
 301                                         res = new_rd_Sub(dbgi, irg, block, a, b, mode);
 302                                         if(need_not) {
 303                                                 res = new_rd_Not(dbgi, irg, block, res, mode);
 304                                         }
 305                                         res = new_rd_Shr(dbgi, irg, block, res, shift_cnt, mode);
 306
 307                                         set_irn_link(node, res);
 308                                         pdeq_putr(lowered_nodes, node);
 309                                         return res;
 310                                 }
 311                         }
 312
 313                         /* synthesize the 0/1 value */
 314                         set = create_set(node);
 315                         set_irn_link(node, set);
 316                         pdeq_putr(lowered_nodes, node);
 317                         return set;
 318                 } else if(is_Proj(pred) && is_Call(get_Proj_pred(pred))) {
 319                         ir_type   *type   = get_Call_type(get_Proj_pred(pred));
 320                         adjust_method_type(type);
 321                         set_irn_mode(node, mode);
 322                         return node;
 323                 } else if(is_Proj(pred) && is_Start(get_Proj_pred(pred))) {
 324                         ir_entity *entity = get_irg_entity(irg);
 325                         ir_type   *type   = get_entity_type(entity);
 326                         adjust_method_type(type);
 327                         set_irn_mode(node, mode);
 328                         return node;
 329                 }
 330
 331                 panic("unexpected projb: %+F (pred: %+F)", node, pred);
 332         }
 333         if(op == op_Const) {
 334                 tarval *tv = get_Const_tarval(node);
 335                 if(tv == get_tarval_b_true()) {
 336                         tarval  *tv_one  = get_tarval_one(mode);
 337                         res              = new_d_Const(dbgi, mode, tv_one);
 338                 } else if(tv == get_tarval_b_false()) {
 339                         tarval  *tv_zero = get_tarval_null(mode);
 340                         res              = new_d_Const(dbgi, mode, tv_zero);
 341                 } else {
 342                         panic("invalid boolean const %+F", node);
 343                 }
 344                 set_irn_link(node, res);
 345                 pdeq_putr(lowered_nodes, node);
 346                 return res;
 347         }
 348         if (op == op_Unknown) {
 349                 return new_Unknown(config.lowered_mode);
 350         }
 351
 352         panic("didn't expect %+F to have mode_b", node);
 353 }
 354
 355 static void lower_mode_b_walker(ir_node *node, void *env)
 356 {
 357         int i, arity;
 358         int changed = 0;
 359         (void) env;
 360
 361         arity = get_irn_arity(node);
 362         for(i = 0; i < arity; ++i) {
 363                 ir_node *lowered_in;
 364                 ir_node *in = get_irn_n(node, i);
 365                 if(get_irn_mode(in) != mode_b)
 366                         continue;
 367
 368                 if(! config.lower_direct_cmp) {
 369                         if(is_Cond(node)
 370                                         || (is_Psi(node) && get_irn_mode(node) != mode_b)) {
 371                                 if(is_Proj(in)) {
 372                                         ir_node *pred = get_Proj_pred(in);
 373                                         if(is_Cmp(pred))
 374                                                 continue;
 375                                 }
 376                         }
 377                 }
 378
 379                 lowered_in = lower_node(in);
 380
 381                 if(is_Return(node)) {
 382                         ir_entity *entity = get_irg_entity(current_ir_graph);
 383                         ir_type   *type   = get_entity_type(entity);
 384                         adjust_method_type(type);
 385                 } else if(is_Call(node)) {
 386                         ir_type *type = get_Call_type(node);
 387                         adjust_method_type(type);
 388                 } else {
 389                         lowered_in = create_convb(lowered_in);
 390                 }
 391                 set_irn_n(node, i, lowered_in);
 392                 changed = 1;
 393         }
 394         if(changed) {
 395                 add_identities(current_ir_graph->value_table, node);
 396         }
 397 }
 398
 399 static void clear_links(ir_node *node, void *env)
 400 {
 401         (void) env;
 402         set_irn_link(node, NULL);
 403 }
 404
 405 void ir_lower_mode_b(ir_graph *irg, const lower_mode_b_config_t *nconfig)
 406 {
 407         config        = *nconfig;
 408         lowered_nodes = new_pdeq();
 409         set_using_irn_link(irg);
 410
 411         irg_walk_graph(irg, clear_links, NULL, NULL);
 412         irg_walk_graph(irg, lower_mode_b_walker, NULL, NULL);
 413
 414         while(!pdeq_empty(lowered_nodes)) {
 415                 ir_node *node = (ir_node*) pdeq_getr(lowered_nodes);
 416                 maybe_kill_node(node);
 417         }
 418         del_pdeq(lowered_nodes);
 419
 420         clear_using_irn_link(irg);
 421 }