nsz Git - libfirm/blob - ir/be/ia32/ia32_address_mode.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  * @brief       This file contains functions for matching firm graphs for
  23  *              nodes that can be used as addressmode for x86 commands
  24  * @author      Matthias Braun
  25  * @version     $Id$
  26  */
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include "ia32_address_mode.h"
  32 #include "ia32_transform.h"
  33
  34 #include "irtypes.h"
  35 #include "irnode_t.h"
  36 #include "irprintf.h"
  37 #include "error.h"
  38 #include "iredges_t.h"
  39 #include "irgwalk.h"
  40
  41 #include "../benode_t.h"
  42
  43 #define AGGRESSIVE_AM
  44
  45 /* gas/ld don't support negative symconsts :-( */
  46 #undef SUPPORT_NEGATIVE_SYMCONSTS
  47
  48 static bitset_t *non_address_mode_nodes;
  49
  50 static int do_is_immediate(const ir_node *node, int *symconsts, int negate)
  51 {
  52         ir_node *left;
  53         ir_node *right;
  54
  55         switch(get_irn_opcode(node)) {
  56         case iro_Const:
  57                 if(!tarval_is_long(get_Const_tarval(node))) {
  58 #ifdef DEBUG_libfirm
  59                         ir_fprintf(stderr, "Optimisation warning tarval of %+F is not a "
  60                                    "long.");
  61 #endif
  62                         return 0;
  63                 }
  64                 return 1;
  65         case iro_SymConst:
  66 #ifndef SUPPORT_NEGATIVE_SYMCONSTS
  67                 /* unfortunately the assembler/linker doesn't support -symconst */
  68                 if(negate)
  69                         return 0;
  70 #endif
  71
  72                 if(get_SymConst_kind(node) != symconst_addr_ent)
  73                         return 0;
  74                 (*symconsts)++;
  75                 if(*symconsts > 1)
  76                         return 0;
  77
  78                 return 1;
  79         case iro_Add:
  80         case iro_Sub:
  81                 if(bitset_is_set(non_address_mode_nodes, get_irn_idx(node)))
  82                         return 0;
  83
  84                 left  = get_binop_left(node);
  85                 right = get_binop_right(node);
  86                 if(!do_is_immediate(left, symconsts, negate))
  87                         return 0;
  88                 if(!do_is_immediate(right, symconsts, is_Sub(node) ? !negate : negate))
  89                         return 0;
  90
  91                 return 1;
  92         default:
  93                 break;
  94         }
  95
  96         return 0;
  97 }
  98
  99 static int is_immediate_simple(const ir_node *node)
 100 {
 101         int symconsts = 0;
 102         return do_is_immediate(node, &symconsts, 0);
 103 }
 104
 105 static int is_immediate(ia32_address_t *addr, const ir_node *node, int negate)
 106 {
 107         int symconsts = 0;
 108         if(addr->symconst_ent != NULL)
 109                 symconsts = 1;
 110
 111         return do_is_immediate(node, &symconsts, negate);
 112 }
 113
 114 static void eat_immediate(ia32_address_t *addr, ir_node *node, int negate)
 115 {
 116         tarval  *tv;
 117         ir_node *left;
 118         ir_node *right;
 119
 120         switch(get_irn_opcode(node)) {
 121         case iro_Const:
 122                 tv = get_Const_tarval(node);
 123                 long val = get_tarval_long(tv);
 124                 if(negate) {
 125                         addr->offset -= val;
 126                 } else {
 127                         addr->offset += val;
 128                 }
 129                 break;
 130         case iro_SymConst:
 131                 if(addr->symconst_ent != NULL) {
 132                         panic("Internal error: more than 1 symconst in address "
 133                               "calculation");
 134                 }
 135                 addr->symconst_ent  = get_SymConst_entity(node);
 136 #ifndef SUPPORT_NEGATIVE_SYMCONSTS
 137                 assert(!negate);
 138 #endif
 139                 addr->symconst_sign = negate;
 140                 break;
 141         case iro_Add:
 142                 assert(!bitset_is_set(non_address_mode_nodes, get_irn_idx(node)));
 143                 left  = get_Add_left(node);
 144                 right = get_Add_right(node);
 145                 eat_immediate(addr, left, negate);
 146                 eat_immediate(addr, right, negate);
 147                 break;
 148         case iro_Sub:
 149                 assert(!bitset_is_set(non_address_mode_nodes, get_irn_idx(node)));
 150                 left  = get_Sub_left(node);
 151                 right = get_Sub_right(node);
 152                 eat_immediate(addr, left, negate);
 153                 eat_immediate(addr, right, !negate);
 154                 break;
 155         default:
 156                 panic("Internal error in immediate address calculation");
 157         }
 158 }
 159
 160 static ir_node *eat_immediates(ia32_address_t *addr, ir_node *node, int force)
 161 {
 162         if(!force && bitset_is_set(non_address_mode_nodes, get_irn_idx(node)))
 163                 return node;
 164
 165         if(is_Add(node)) {
 166                 ir_node *left  = get_Add_left(node);
 167                 ir_node *right = get_Add_right(node);
 168
 169                 if(is_immediate(addr, left, 0)) {
 170                         eat_immediate(addr, left, 0);
 171                         return eat_immediates(addr, right, 0);
 172                 }
 173                 if(is_immediate(addr, right, 0)) {
 174                         eat_immediate(addr, right, 0);
 175                         return eat_immediates(addr, left, 0);
 176                 }
 177         } else if(is_Sub(node)) {
 178                 ir_node *left  = get_Sub_left(node);
 179                 ir_node *right = get_Sub_right(node);
 180
 181                 if(is_immediate(addr, right, 1)) {
 182                         eat_immediate(addr, right, 1);
 183                         return eat_immediates(addr, left, 0);
 184                 }
 185         }
 186
 187         return node;
 188 }
 189
 190 static int eat_shl(ia32_address_t *addr, ir_node *node)
 191 {
 192         ir_node *right = get_Shl_right(node);
 193         tarval  *tv;
 194         long     val;
 195
 196         /* we can only eat a shl if we don't have a scale or index set */
 197         if(addr->scale != 0 || addr->index != NULL)
 198                 return 0;
 199
 200         /* we can use shl with 1, 2 or 3 shift */
 201         if(!is_Const(right))
 202                 return 0;
 203         tv = get_Const_tarval(right);
 204         if(!tarval_is_long(tv))
 205                 return 0;
 206         val = get_tarval_long(tv);
 207         if(val < 0 || val > 3)
 208                 return 0;
 209         if(val == 0) {
 210                 ir_fprintf(stderr, "Optimisation warning: unoptimized Shl(,0) found\n");
 211         }
 212         if(bitset_is_set(non_address_mode_nodes, get_irn_idx(node)))
 213                 return 0;
 214
 215 #ifndef AGGRESSIVE_AM
 216         if(get_irn_n_edges(node) > 1)
 217                 return 0;
 218 #endif
 219
 220         addr->scale = val;
 221         addr->index = eat_immediates(addr, get_Shl_left(node), 0);
 222         return 1;
 223 }
 224
 225 void ia32_create_address_mode(ia32_address_t *addr, ir_node *node, int force)
 226 {
 227         int      res = 0;
 228         ir_node *eat_imms;
 229
 230         if(is_immediate(addr, node, 0)) {
 231                 eat_immediate(addr, node, 0);
 232                 return;
 233         }
 234
 235 #ifndef AGGRESSIVE_AM
 236         if(!force && get_irn_n_edges(node) > 1) {
 237                 addr->base = node;
 238                 return;
 239         }
 240 #endif
 241
 242         if(!force && bitset_is_set(non_address_mode_nodes, get_irn_idx(node))) {
 243                 addr->base = node;
 244                 return;
 245         }
 246
 247         eat_imms = eat_immediates(addr, node, force);
 248         if(eat_imms != node) {
 249                 res  = 1;
 250                 node = eat_imms;
 251 #ifndef AGGRESSIVE_AM
 252                 if(get_irn_n_edges(node) > 1) {
 253                         addr->base = node;
 254                         return;
 255                 }
 256 #endif
 257                 if(bitset_is_set(non_address_mode_nodes, get_irn_idx(node))) {
 258                         addr->base = node;
 259                         return;
 260                 }
 261         }
 262
 263         /* starting point Add, Sub or Shl, FrameAddr */
 264         if(is_Shl(node)) {
 265                 if(eat_shl(addr, node))
 266                         return;
 267         } else if(is_immediate(addr, node, 0)) {
 268                 eat_immediate(addr, node, 0);
 269                 return;
 270         } else if(be_is_FrameAddr(node)) {
 271                 assert(addr->base == NULL);
 272                 assert(addr->frame_entity == NULL);
 273                 addr->base         = be_get_FrameAddr_frame(node);
 274                 addr->use_frame    = 1;
 275                 addr->frame_entity = be_get_FrameAddr_entity(node);
 276                 return;
 277         } else if(is_Add(node)) {
 278                 ir_node *left  = get_Add_left(node);
 279                 ir_node *right = get_Add_right(node);
 280                 assert(force || !is_immediate(addr, left, 0));
 281                 assert(force || !is_immediate(addr, right, 0));
 282
 283                 if(is_Shl(left) && eat_shl(addr, left)) {
 284                         left = NULL;
 285                 } else if(is_Shl(right) && eat_shl(addr, right)) {
 286                         right = NULL;
 287                 }
 288                 if(left != NULL && be_is_FrameAddr(left)
 289                                 && !bitset_is_set(non_address_mode_nodes, get_irn_idx(left))) {
 290                         assert(addr->base == NULL);
 291                         assert(addr->frame_entity == NULL);
 292                         addr->base         = be_get_FrameAddr_frame(left);
 293                         addr->use_frame    = 1;
 294                         addr->frame_entity = be_get_FrameAddr_entity(left);
 295                         left               = NULL;
 296                 } else if(right != NULL && be_is_FrameAddr(right)
 297                                 && !bitset_is_set(non_address_mode_nodes, get_irn_idx(right))) {
 298                         assert(addr->base == NULL);
 299                         assert(addr->frame_entity == NULL);
 300                         addr->base         = be_get_FrameAddr_frame(right);
 301                         addr->use_frame    = 1;
 302                         addr->frame_entity = be_get_FrameAddr_entity(right);
 303                         right              = NULL;
 304                 }
 305
 306                 if(left != NULL) {
 307                         if(addr->base != NULL) {
 308                                 assert(addr->index == NULL && addr->scale == 0);
 309                                 assert(right == NULL);
 310                                 addr->index = left;
 311                         } else {
 312                                 addr->base = left;
 313                         }
 314                 }
 315                 if(right != NULL) {
 316                         if(addr->base == NULL) {
 317                                 addr->base = right;
 318                         } else {
 319                                 assert(addr->index == NULL && addr->scale == 0);
 320                                 addr->index = right;
 321                         }
 322                 }
 323                 return;
 324         }
 325
 326         addr->base = node;
 327 }
 328
 329
 330
 331 static void mark_non_address_nodes(ir_node *node, void *env)
 332 {
 333         int i, arity;
 334         ir_node *ptr;
 335         ir_node *mem;
 336         ir_node *val;
 337         ir_node *left;
 338         ir_node *right;
 339         (void) env;
 340
 341         switch(get_irn_opcode(node)) {
 342         case iro_Load:
 343                 ptr = get_Load_ptr(node);
 344                 mem = get_Load_mem(node);
 345
 346                 bitset_set(non_address_mode_nodes, get_irn_idx(mem));
 347                 break;
 348
 349         case iro_Store:
 350                 val = get_Store_value(node);
 351                 ptr = get_Store_ptr(node);
 352                 mem = get_Store_mem(node);
 353
 354                 bitset_set(non_address_mode_nodes, get_irn_idx(val));
 355                 bitset_set(non_address_mode_nodes, get_irn_idx(mem));
 356                 break;
 357
 358         case iro_Add:
 359                 left  = get_Add_left(node);
 360                 right = get_Add_right(node);
 361                 /* if we can do source address mode then we will never fold the add
 362                  * into address mode */
 363                 if(is_immediate_simple(right) ||
 364                          (!use_source_address_mode(get_nodes_block(node), left, right)
 365                      && !use_source_address_mode(get_nodes_block(node), right, left))) {
 366                     break;
 367                 }
 368                 bitset_set(non_address_mode_nodes, get_irn_idx(node));
 369                 /* fallthrough */
 370
 371         default:
 372                 arity = get_irn_arity(node);
 373
 374                 for(i = 0; i < arity; ++i) {
 375                         ir_node *in = get_irn_n(node, i);
 376                         bitset_set(non_address_mode_nodes, get_irn_idx(in));
 377                 }
 378                 break;
 379         }
 380 }
 381
 382 void calculate_non_address_mode_nodes(ir_graph *irg)
 383 {
 384         non_address_mode_nodes = bitset_malloc(get_irg_last_idx(irg));
 385
 386         irg_walk_graph(irg, NULL, mark_non_address_nodes, NULL);
 387 }
 388
 389 void free_non_address_mode_nodes(void)
 390 {
 391         bitset_free(non_address_mode_nodes);
 392 }