src/vm/jit/optimizing/graph.c

   1 /* src/vm/jit/optimizing/graph.c - CFG
   2
   3    Copyright (C) 2005, 2006 R. Grafl, A. Krall, C. Kruegel, C. Oates,
   4    R. Obermaisser, M. Platter, M. Probst, S. Ring, E. Steiner,
   5    C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich, J. Wenninger,
   6    Institut f. Computersprachen - TU Wien
   7
   8    This file is part of CACAO.
   9
  10    This program is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU General Public License as
  12    published by the Free Software Foundation; either version 2, or (at
  13    your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful, but
  16    WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  23    02111-1307, USA.
  24
  25    Contact: cacao@complang.tuwien.ac.at
  26
  27    Authors: Christian Ullrich
  28
  29    $Id: graph.c$
  30
  31 */
  32
  33 #include <stdlib.h>
  34
  35 #include "config.h"
  36
  37 #include "mm/memory.h"
  38
  39 #include "toolbox/bitvector.h"
  40
  41 #include "vm/jit/jit.h"
  42
  43 #include "vm/jit/optimizing/lsra.h"
  44 #include "vm/jit/optimizing/ssa.h"
  45 #include "vm/jit/optimizing/graph.h"
  46
  47 #ifdef GRAPH_DEBUG_VERBOSE
  48 #include "vmcore/options.h"
  49 #endif
  50
  51 /* Helpers for graph_make_cfg */
  52 void graph_add_cfg( jitdata *jd, graphdata *gd, basicblock *, basicblock *);
  53 void graph_add_exceptions(jitdata *jd, graphdata *gd);
  54 void graph_add_edge( graphdata *gd, int from, int to );
  55
  56 /* Helper for graph_get_first_* */
  57 int graph_get_first_(graph_element *ge, graphiterator *i);
  58 void transform_CFG(jitdata *, graphdata *);
  59
  60 #ifdef GRAPH_DEBUG_VERBOSE
  61 void graph_print(lsradata *ls, graphdata *gd);
  62 #endif
  63
  64
  65 graphdata *graph_init(int basicblockcount) {
  66         graphdata *gd;
  67         int i;
  68
  69         gd = NEW(graphdata);
  70 #ifdef GRAPH_DEBUG_CHECK
  71         /* Remember basicblockcount, so Array Bound checks can be made */
  72         gd->basicblockcount = basicblockcount;
  73 #endif
  74
  75         gd->num_succ = DMNEW(int, basicblockcount);
  76         gd->successor = DMNEW(graph_element *, basicblockcount);
  77
  78         gd->num_pred = DMNEW(int, basicblockcount);
  79         gd->predecessor = DMNEW(graph_element *, basicblockcount);
  80
  81         for(i = 0; i < basicblockcount; i++) {
  82                 gd->num_succ[i] = gd->num_pred[i] = 0;
  83                 gd->successor[i] = NULL;
  84                 gd->predecessor[i] = NULL;
  85         }
  86         return gd;
  87 }
  88
  89 int graph_get_num_predecessor(graphdata *gd, int b_index) {
  90         _GRAPH_CHECK_BOUNDS(b_index, 0, gd->basicblockcount);
  91         return gd->num_pred[b_index];
  92 }
  93
  94 int graph_get_num_successor(graphdata *gd, int b_index) {
  95         _GRAPH_CHECK_BOUNDS(b_index, 0, gd->basicblockcount);
  96         return gd->num_succ[b_index];
  97 }
  98
  99 int graph_get_first_successor(graphdata *gd, int b_index, graphiterator *i) {
 100         _GRAPH_CHECK_BOUNDS(b_index, 0, gd->basicblockcount);
 101         return graph_get_first_(gd->successor[b_index], i);
 102 }
 103
 104 int graph_get_first_predecessor(graphdata *gd, int b_index, graphiterator *i) {
 105         _GRAPH_CHECK_BOUNDS(b_index, 0, gd->basicblockcount);
 106         return graph_get_first_(gd->predecessor[b_index], i);
 107 }
 108
 109 int graph_get_next(graphiterator *i) {
 110         if ((*i) == NULL)
 111                 return -1;
 112         (*i) = (*i)->next;
 113         if ( (*i) == NULL )
 114                 return -1;
 115         else
 116                 return (*i)->value;
 117 }
 118
 119 int graph_get_first_(graph_element *ge, graphiterator *i) {
 120         if ( ((*i) = ge) == NULL)
 121                 return -1;
 122         else
 123                 return (*i)->value;
 124 }
 125
 126 bool graph_has_multiple_predecessors( graphdata *gd, int b_index) {
 127         _GRAPH_CHECK_BOUNDS(b_index, 0, gd->basicblockcount);
 128         return (gd->num_pred[b_index] > 1);
 129 }
 130
 131 bool graph_has_multiple_successors( graphdata *gd, int b_index) {
 132         _GRAPH_CHECK_BOUNDS(b_index, 0, gd->basicblockcount);
 133         return (gd->num_succ[b_index] > 1);
 134 }
 135
 136 void graph_add_edge( graphdata *gd, int from, int to ) {
 137         graphiterator i;
 138         graph_element *n;
 139         int b;
 140
 141         /* prevent multiple similar edges from TABLESWITCH and */
 142         /* LOOKUPSWITCH */
 143         b = graph_get_first_successor(gd, from, &i);
 144         for( ; (b != -1) && ( b != to); b = graph_get_next(&i));
 145         if (b != -1) /* edge from->to already existing */
 146                 return;
 147
 148         /* We need two new graph_elements. One for successors and one for */
 149         /* predecessors */
 150         n = DMNEW(graph_element, 2);
 151
 152         n->value=to;
 153         n->next=gd->successor[from];
 154         gd->successor[from]=n;
 155         gd->num_succ[from]++;
 156
 157         n++; /* take next allocated graph_element */
 158         n->value=from;
 159         n->next=gd->predecessor[to];
 160         gd->predecessor[to]=n;
 161         gd->num_pred[to]++;
 162 }
 163
 164 /* split the edge from BB from shown by iterator i with new_block */
 165 void graph_split_edge(graphdata *gd, int from, graphiterator *i, int new_block) {
 166         graphiterator i_pred;
 167         graph_element *n;
 168         int l, succ;
 169
 170         /* i->value is the BB index of the "old" successor */
 171
 172         succ = (*i)->value;
 173
 174         /* search for iterator showing predecessor edge from BB succ back to */
 175         /* from */
 176
 177         l = graph_get_first_predecessor(gd, succ, &i_pred);
 178         for(; (l != -1) && (l != from); l = graph_get_next(&i_pred));
 179         _GRAPH_ASSERT(l == from);
 180
 181         /* change CFG entries */
 182
 183         (*i)->value = new_block;
 184         i_pred->value = new_block;
 185
 186         /* and insert the CFG successor and predecesser entries for new_block */
 187         /* 2 entries needed */
 188
 189         n = DMNEW(graph_element, 2);
 190
 191         /* make the successor entry for new_block */
 192
 193         n->value = succ;
 194         n->next = gd->successor[new_block];
 195         gd->successor[new_block] = n;
 196         gd->num_succ[new_block]++;
 197
 198         /* make the predecessor entry for new_block */
 199
 200         n++;
 201         n->value = from;
 202         n->next = gd->predecessor[new_block];
 203         gd->predecessor[new_block] = n;
 204         gd->num_pred[new_block]++;
 205 }
 206
 207 /***********************************************
 208 Generate the Control Flow Graph
 209 ( pred,succ,num_pred of lsradata structure)
 210 ************************************************/
 211 void graph_make_cfg(jitdata *jd,graphdata *gd) {
 212         instruction *iptr;
 213         lookup_target_t *lookup;
 214         branch_target_t *table;
 215         int len, i, l;
 216         methodinfo *m;
 217         codegendata *cd;
 218         registerdata *rd;
 219         lsradata *ls;
 220         basicblock *bptr;
 221
 222         m = jd->m;
 223         cd = jd->cd;
 224         rd = jd->rd;
 225         ls = jd->ls;
 226
 227         /* Add edge from new Basic Block 0 (parameter initialization) */
 228         graph_add_edge(gd, 0, 1);
 229
 230         for (bptr = jd->basicblocks; bptr != NULL; bptr = bptr->next) {
 231                 if (bptr->flags >= BBREACHED) {
 232                         if ((len = bptr->icount)) {
 233                                 /* set iptr to last non NOP instruction */
 234                                 iptr = bptr->iinstr + bptr->icount -1;
 235                                 while ((len>0) && (iptr->opc == ICMD_NOP)) {
 236                                         len--;
 237                                         iptr--;
 238                                 }
 239                                 /* block contains instructions  */
 240                                 switch (iptr->opc) {            /* check type of last instruction */
 241                                 case ICMD_RETURN:
 242                                 case ICMD_IRETURN:
 243                                 case ICMD_LRETURN:
 244                                 case ICMD_FRETURN:
 245                                 case ICMD_DRETURN:
 246                                 case ICMD_ARETURN:
 247                                 case ICMD_ATHROW:
 248                                         break;                            /* function returns -> end of graph */
 249
 250                                 case ICMD_IFNULL:
 251                                 case ICMD_IFNONNULL:
 252                                 case ICMD_IFEQ:
 253                                 case ICMD_IFNE:
 254                                 case ICMD_IFLT:
 255                                 case ICMD_IFGE:
 256                                 case ICMD_IFGT:
 257                                 case ICMD_IFLE:
 258                                 case ICMD_IF_LEQ:
 259                                 case ICMD_IF_LNE:
 260                                 case ICMD_IF_LLT:
 261                                 case ICMD_IF_LGE:
 262                                 case ICMD_IF_LGT:
 263                                 case ICMD_IF_LLE:
 264                                 case ICMD_IF_ICMPEQ:
 265                                 case ICMD_IF_ICMPNE:
 266                                 case ICMD_IF_ICMPLT:
 267                                 case ICMD_IF_ICMPGE:
 268                                 case ICMD_IF_ICMPGT:
 269                                 case ICMD_IF_ICMPLE:
 270                                 case ICMD_IF_LCMPEQ:
 271                                 case ICMD_IF_LCMPNE:
 272                                 case ICMD_IF_LCMPLT:
 273                                 case ICMD_IF_LCMPGE:
 274                                 case ICMD_IF_LCMPGT:
 275                                 case ICMD_IF_LCMPLE:
 276                                 case ICMD_IF_ACMPEQ:
 277                                 case ICMD_IF_ACMPNE:                /* branch -> add next block */
 278                                         /* Add branch target */
 279                                         graph_add_cfg(jd, gd, bptr, iptr->dst.block);
 280                                         /* Add fall through path */
 281                                         graph_add_cfg(jd, gd, bptr, bptr->next);
 282                                         break;
 283
 284
 285                                 case ICMD_GOTO:
 286                                         graph_add_cfg(jd, gd, bptr,  iptr->dst.block);
 287                                         break;                                  /* visit branch (goto) target   */
 288
 289                                 case ICMD_TABLESWITCH:          /* switch statement                             */
 290                                         table = iptr->dst.table;
 291                                         l = iptr->sx.s23.s2.tablelow;
 292                                         i = iptr->sx.s23.s3.tablehigh;
 293                                         i = i - l + 1;
 294
 295                                         /* Add default target */
 296
 297                                         graph_add_cfg(jd, gd, bptr,  table[0].block);
 298                                         table += i;
 299
 300                                         while (--i >= 0) {
 301                                                 graph_add_cfg(jd, gd, bptr,  table->block);
 302                                                 --table;
 303                                         }
 304                                         break;
 305
 306                                 case ICMD_LOOKUPSWITCH:         /* switch statement                             */
 307                                         lookup = iptr->dst.lookup;
 308                                         i = iptr->sx.s23.s2.lookupcount;
 309
 310                                         while (--i >= 0) {
 311                                                 graph_add_cfg(jd, gd, bptr, lookup->target.block);
 312                                                 lookup++;
 313                                         }
 314
 315                                         graph_add_cfg(jd, gd, bptr, iptr->sx.s23.s3.lookupdefault.block);
 316                                         break;
 317
 318                                 case ICMD_RET:
 319                                 case ICMD_JSR:
 320                                         assert(0);
 321                                         break;
 322
 323                                 case ICMD_NOP:
 324                                         assert(0);
 325
 326                                 default:
 327                                         graph_add_cfg(jd, gd, bptr, bptr + 1 );
 328                                         break;
 329                             } /* switch (iptr->opc)*/
 330                     }     /* if (bptr->icount) */
 331             }         /* if (bptr->flags >= BBREACHED) */
 332         }             /* for (bptr = ...; bptr != NULL; bptr = bptr->next) */
 333
 334         graph_add_exceptions(jd, gd);
 335         transform_CFG(jd, gd);
 336
 337 #ifdef GRAPH_DEBUG_VERBOSE
 338         if (compileverbose)
 339                 graph_print(ls, gd);
 340 #endif
 341 }
 342
 343 /*****************************************************************
 344 add Edges from guarded Areas to Exception handlers in the CFG
 345 *****************************************************************/
 346 void graph_add_exceptions(jitdata *jd, graphdata *gd) {
 347 #if 0
 348         basicblock *bptr;
 349         raw_exception_entry *ex;
 350         codegendata *cd;
 351
 352         cd = jd->cd;
 353
 354         /* add cfg edges from all bb of a try block to the start of the according */
 355         /* exception handler to ensure the right order after depthfirst search    */
 356
 357         ex=jd->exceptiontable;
 358
 359 #ifdef GRAPH_DEBUG_VERBOSE
 360         if (compileverbose)
 361                 printf("ExTable(%i): ", jd->exceptiontablelength);
 362 #endif
 363
 364         for (; ex != NULL; ex = ex->down) {
 365
 366 #ifdef GRAPH_DEBUG_VERBOSE
 367                 if (compileverbose)
 368                         printf("[%i-%i]->%i ",ex->start->nr, ex->end->nr,
 369                                    ex->handler->nr);
 370 #endif
 371
 372                 _GRAPH_ASSERT(ex->handler->nr < jd->new_basicblockcount);
 373                 _GRAPH_ASSERT(ex->handler->flags >= BBREACHED);
 374                 _GRAPH_ASSERT(ex->start->nr <= ex->end->nr);
 375
 376                 /* loop all valid Basic Blocks of the guarded area and add CFG edges  */
 377                 /* to the appropriate handler */
 378                 for (bptr = ex->start; (bptr != NULL) && (bptr != ex->end); bptr = bptr->next)
 379                         if (bptr->flags >= BBREACHED)
 380                                 graph_add_cfg(jd, gd, bptr, ex->handler);
 381
 382                 _GRAPH_ASSERT((bptr != NULL)
 383                                           && ((bptr->flags >=BBREACHED) || (bptr == ex->end)));
 384         }
 385 #ifdef GRAPH_DEBUG_VERBOSE
 386         if (compileverbose)
 387                 printf("\n");
 388 #endif
 389 #endif
 390 }
 391
 392
 393 /******************************************************************
 394 Add the CFG Edge into next und succ
 395 ******************************************************************/
 396 void graph_add_cfg( jitdata *jd, graphdata *gd, basicblock *from,
 397                                         basicblock *to) {
 398
 399         /* ignore Empty, Deleted,... Basic Blocks as target */
 400         /* TODO: Setup BasicBlock array before to avoid this */
 401         /*       best together with using the basicblock list, so lsra works */
 402         /*       with opt_loops, too */
 403
 404         for (; (to != NULL) && (to->flags < BBREACHED); to = to->next);
 405
 406         _GRAPH_ASSERT(to != NULL);
 407
 408
 409         /* add one to from and to, so the to be inserted Basic Block 0 is */
 410         /* already regarded */
 411         graph_add_edge( gd, from->nr + 1, to->nr + 1);
 412 }
 413
 414
 415 /*****************************************************************
 416 Sort Basic Blocks using Depth First search in reverse post order
 417 In: ls->basicblockcount, ls->basicblocks[], gd->
 418 Out: ls->sorted, ls->sorted_rev
 419 *****************************************************************/
 420
 421 void graph_DFS(lsradata *ls, graphdata *gd) {
 422         int *stack;
 423         int *visited;
 424         int stack_top;
 425         bool not_finished;
 426         int i,p,s, num_pred;
 427         graphiterator iter;
 428
 429         ls->sorted = DMNEW(int, ls->basicblockcount);
 430         ls->sorted_rev = DMNEW(int, ls->basicblockcount);
 431
 432         stack = DMNEW( int, ls->basicblockcount);
 433         visited = (int *)DMNEW( bool, ls->basicblockcount);
 434         for (i = 0; i < ls->basicblockcount; i++) {
 435                 visited[i] = 0;
 436                 ls->sorted[i]=-1;
 437                 ls->sorted_rev[i]=-1;
 438         }
 439
 440     stack[0] = 0; /* start with Block 0 */
 441         stack_top = 1;
 442         /* Start Block is handled right and can be put in sorted */
 443         visited[0] = graph_get_num_predecessor(gd , 0);
 444         p = 0;
 445         not_finished = true;
 446         while (not_finished) {
 447                 while (stack_top != 0) {
 448                         stack_top--;
 449                         i = stack[stack_top];
 450                         ls->sorted[p]=i;
 451                         p++;
 452                         s = graph_get_first_successor(gd, i, &iter);
 453                         for (; s != -1; s = graph_get_next(&iter)) {
 454                                 visited[s]++;
 455                                 if (visited[s] ==  graph_get_num_predecessor(gd, s)) {
 456                                         /* push the node on the stack, only if all ancestors have */
 457                                         /* been visited */
 458                                         stack[stack_top] = s;
 459                                         stack_top++;
 460                                 }
 461                         }
 462                 }
 463                 not_finished = false;
 464                 for (i=1; i < ls->basicblockcount; i++) {
 465                         /* search for visited blocks, which have not reached the num_pre */
 466                         /* and put them on the stack -> happens with backedges */
 467                         num_pred = graph_get_num_predecessor(gd, i);
 468                         if ((visited[i] != 0) && (visited[i] < num_pred)) {
 469                                 stack[stack_top] = i;
 470                                 stack_top++;
 471                                 visited[i] = num_pred;
 472                                 not_finished=true;
 473                                 break;
 474                         }
 475                 }
 476         }
 477
 478         for(i = 0; i < ls->basicblockcount; i++)
 479                 if (ls->sorted[i] != -1)
 480                          ls->sorted_rev[ls->sorted[i]] = i;
 481 }
 482
 483
 484 void graph_init_basicblock(jitdata *jd, basicblock *bptr, int b_index) {
 485                 bptr->nr = b_index;
 486                 bptr->icount = 0;
 487                 bptr->iinstr = NULL;
 488                 bptr->type = BBTYPE_STD;
 489                 bptr->flags = BBFINISHED;
 490                 bptr->invars = NULL;
 491                 bptr->outvars = NULL;
 492                 bptr->indepth = 0;
 493                 bptr->outdepth = 0;
 494                 bptr->branchrefs = NULL;
 495                 bptr->mpc = -1;
 496                 bptr->next = NULL;
 497                 bptr->method = jd->m;
 498 }
 499
 500 /*********************************************************************+
 501 After the "original" CFG has been created, it has to be adopted for
 502 SSA. (inluding insertion of new Basic Blocks)
 503
 504 TODO: Do not insert blocks right now - just adopt the call graph!
 505       After the phi moves are determined create only the needed Blocks
 506 **********************************************************************/
 507 void transform_CFG(jitdata *jd, graphdata *gd) {
 508         int i, j, k, n, num_new_blocks;
 509         int **var_def;
 510         basicblock *tmp, *bptr;
 511         s4 *in, *out, *new_in_stack, *new_out_stack;
 512         graphiterator iter;
 513         int *num_succ;
 514         struct graph_element **successor;
 515         int *num_pred;
 516         struct graph_element **predecessor;
 517         methodinfo *m;
 518         codegendata *cd;
 519         registerdata *rd;
 520         lsradata *ls;
 521
 522         m = jd->m;
 523         cd = jd->cd;
 524         rd = jd->rd;
 525         ls = jd->ls;
 526
 527         /* with SSA a new Basic Block 0 is inserted for parameter initialisation  */
 528         /* & look for nodes with multiple successors leading to nodes with        */
 529         /* multiple predecessor -> if found insert a new block between to split   */
 530         /* this edge. As first step count how many blocks have to be inserted.    */
 531
 532         num_new_blocks = 1;
 533         for(i = 0; i< jd->basicblockcount + 1; i++) {
 534                 if (graph_has_multiple_successors(gd, i)) {
 535                         k = graph_get_first_successor(gd, i, &iter);
 536                         for(; k != -1; k = graph_get_next(&iter)) {
 537                                 /* check for successor blocks with more than one       */
 538                                 /* predecessor. For each found incremet num_new_blocks */
 539                                 if (graph_has_multiple_predecessors(gd, k))
 540                                         num_new_blocks++;
 541                         }
 542                 }
 543         }
 544
 545         /* increase now basicblockcount accordingly. */
 546         ls->basicblockcount = jd->basicblockcount + num_new_blocks;
 547
 548         ls->basicblocks = DMNEW(basicblock *, ls->basicblockcount);
 549         for(i = 0; i< ls->basicblockcount; i++)
 550                 ls->basicblocks[i] = NULL;
 551
 552         /* copy Basic Block References to ls->basicblocks */
 553
 554         for (bptr = jd->basicblocks; bptr != NULL; bptr = bptr->next) {
 555 /*              if (bptr->flags >= BBREACHED) { */
 556                         _GRAPH_ASSERT(bptr->nr < jd->basicblockcount);
 557                         ls->basicblocks[bptr->nr + 1] = bptr;
 558                         bptr->nr = bptr->nr+1;
 559 /*              } */
 560         }
 561
 562         /* Create new Basic Blocks:
 563            0, [jd->new_basicblockcount..ls->basicblockcount[ */
 564         /* num_new_blocks have to be inserted*/
 565
 566         tmp = DMNEW( basicblock, num_new_blocks);
 567         ls->basicblocks[0] = tmp;
 568         graph_init_basicblock( jd, tmp, 0);
 569         tmp++;
 570         ls->basicblocks[0]->next = ls->basicblocks[1];
 571
 572         if (ls->basicblockcount > jd->basicblockcount + 1) {
 573                 /* new Blocks have to be inserted                   */
 574                 num_succ = DMNEW(int, ls->basicblockcount);
 575                 successor = DMNEW(graph_element *, ls->basicblockcount);
 576
 577                 num_pred = DMNEW(int, ls->basicblockcount);
 578                 predecessor = DMNEW(graph_element *, ls->basicblockcount);
 579
 580                 /* regard the + 1 for the already inserted new BB 0 */
 581                 /* So recreate ls->var_def                          */
 582                 var_def = DMNEW(int *, ls->basicblockcount);
 583                 for(i = 0; i < jd->basicblockcount + 1; i++) {
 584                         var_def[i] = ls->var_def[i];
 585                         num_succ[i] = gd->num_succ[i];
 586                         num_pred[i] = gd->num_pred[i];
 587                         successor[i] = gd->successor[i];
 588                         predecessor[i] = gd->predecessor[i];
 589                 }
 590                 for(i = jd->basicblockcount + 1; i < ls->basicblockcount; i++) {
 591                         var_def[i] = bv_new(jd->varcount);
 592                         graph_init_basicblock( jd, tmp, i);
 593                         ls->basicblocks[i] = tmp;
 594                         tmp++;
 595
 596                         num_succ[i] = 0;
 597                         num_pred[i] = 0;
 598                         successor[i] = NULL;
 599                         predecessor[i] = NULL;
 600                 }
 601                 ls->var_def = var_def;
 602                 gd->num_succ = num_succ;
 603                 gd->num_pred = num_pred;
 604                 gd->successor = successor;
 605                 gd->predecessor = predecessor;
 606 #ifdef GRAPH_DEBUG_CHECK
 607                 /* Remember basicblockcount, so Array Bound checks can be made */
 608                 gd->basicblockcount = ls->basicblockcount;
 609 #endif
 610         }
 611
 612         /* Now Split the edges */
 613         num_new_blocks = jd->basicblockcount + 1; /* first free new block index */
 614         for(i = 0; i < jd->basicblockcount + 1; i++) {
 615                 if (graph_has_multiple_successors(gd, i)) {/* more than one successor */
 616                         j = graph_get_first_successor( gd, i, &iter);
 617                         for(; j != -1; j = graph_get_next(&iter)) {
 618                                 if (graph_has_multiple_predecessors(gd, j)) {
 619                                         /* and more than one predecessor -> split edge */
 620                                         _GRAPH_ASSERT(num_new_blocks < ls->basicblockcount);
 621
 622                                         /* insert new Block num_new_blocks */
 623
 624                                         /* splite the edge from BB i to j with the new BB */
 625                                         /* num_new_blocks ( i->j --> i->nnb->j)*/
 626                                         /* iter_succ shows the edge from i to j */
 627                                         graph_split_edge(gd, i, &iter, num_new_blocks);
 628
 629                                         ls->basicblocks[num_new_blocks]->indepth =
 630                                                 ls->basicblocks[i]->outdepth;
 631                                         out = ls->basicblocks[i]->outvars;
 632                                         ls->basicblocks[num_new_blocks]->invars = in = NULL;
 633
 634                                         if (ls->basicblocks[num_new_blocks]->indepth > 0)
 635                                                 new_in_stack = DMNEW( s4,
 636                                                                           ls->basicblocks[num_new_blocks]->indepth);
 637                                                 new_out_stack = DMNEW( s4,
 638                                                                           ls->basicblocks[num_new_blocks]->indepth);
 639
 640                                         for(n=0; n<ls->basicblocks[num_new_blocks]->indepth; n++) {
 641                                                 new_in_stack[n] = out[n];
 642                                                 new_out_stack[n] = out[n];
 643                                         }
 644                                         ls->basicblocks[num_new_blocks]->invars = new_in_stack;
 645
 646                                         /* Create Outstack */
 647                                         ls->basicblocks[num_new_blocks]->outvars =
 648                                                 new_out_stack;
 649                                         ls->basicblocks[num_new_blocks]->outdepth =
 650                                                 ls->basicblocks[num_new_blocks]->indepth;
 651
 652                                         _GRAPH_ASSERT(ls->basicblocks[num_new_blocks]->outdepth ==
 653                                                                   ls->basicblocks[j]->indepth );
 654
 655 #if 0
 656                                         /* !!!! There can't be inoutvar definitions in one of these */
 657                                         /* newly inserted basicblocks !!!! */
 658
 659                                         /* Add Definition */
 660                                         /* decrease nr temporarly, because ssa_set_interface*/
 661                                         /* adds 1 since it is called from stack.c, where there is */
 662                                         /* no new BB 0 inserted like now */
 663
 664                                         ls->basicblocks[num_new_blocks]->nr--;
 665                                         ssa_set_interface(jd, ls->basicblocks[num_new_blocks]);
 666                                         ls->basicblocks[num_new_blocks]->nr++;
 667 #endif
 668                                         num_new_blocks++;
 669                                 }
 670                         }
 671                 }
 672         }
 673 }
 674
 675 void transform_BB(jitdata *jd, graphdata *gd) {
 676         int n, len;
 677         int pred, succ;
 678         basicblock *last_block;
 679         instruction *iptr;
 680         graphiterator iter;
 681         methodinfo *m;
 682         lsradata *ls;
 683
 684         m = jd->m;
 685         ls = jd->ls;
 686
 687         /* the "real" last Block is always an empty block        */
 688         /* so take the one before, to insert new blocks after it */
 689         last_block = &(jd->basicblocks[jd->basicblockcount - 1]);
 690         _GRAPH_ASSERT(last_block->next->next == NULL);
 691         _GRAPH_ASSERT(last_block->next->flags <= BBREACHED);
 692         last_block->next->nr = ls->basicblockcount;
 693
 694         /* look through new blocks */
 695         for(n = jd->basicblockcount + 1; n < ls->basicblockcount ; n++) {
 696                 /* if a phi move happens at this block, we need this block */
 697                 /* if not, remove him from the CFG */
 698                 if (ls->num_phi_moves[n] > 0) {
 699                         /* i can only have one predecessor and one successor! */
 700                         _GRAPH_ASSERT( graph_has_multiple_predecessors(gd, n) == false);
 701                         _GRAPH_ASSERT( graph_has_multiple_successors(gd, n) == false);
 702
 703                         succ = graph_get_first_successor(gd, n, &iter);
 704                         pred = graph_get_first_predecessor(gd, n, &iter);
 705
 706                         /* set iptr to last instruction                       */
 707                         len = ls->basicblocks[pred]->icount;
 708                         iptr = ls->basicblocks[pred]->iinstr + len - 1;
 709                         while ((len>0) && (iptr->opc == ICMD_NOP)) {
 710                                 len--;
 711                                 iptr--;
 712                         }
 713
 714
 715                         /* with JSR there can not be multiple successors  */
 716                         _GRAPH_ASSERT(iptr->opc != ICMD_JSR);
 717                         /* If the return Statment has more successors and  */
 718                         /* one of these has more predecessor, we are in    */
 719                         /* troubles - one would have to insert a new Block */
 720                         /* after the one which executes the ICMD_JSR       */
 721                         /* !!TODO!! if subroutines will not be inlined     */
 722                         _GRAPH_ASSERT(iptr->opc != ICMD_RET);
 723
 724                         /* link new block into basicblocks list */
 725                         /* if edge to split is the "fallthrough" path of the */
 726                         /* conditional, then link the new block inbetween    */
 727                         /* and generate no ICMD */
 728                         /* else if edge to split is the branch, generate a   */
 729                         /* ICMD_GOTO and add new BB at the end of the BB List*/
 730                         if ((ls->basicblocks[pred]->next == ls->basicblocks[succ])
 731                                 && (iptr->opc != ICMD_LOOKUPSWITCH)
 732                                 && (iptr->opc != ICMD_TABLESWITCH)
 733                                 && (iptr->opc != ICMD_GOTO)) {
 734                                 /* GOTO, *SWITCH have no fallthrough path */
 735
 736                                 /* link into fallthrough path */
 737
 738
 739                                 ls->basicblocks[n]->next =
 740                                         ls->basicblocks[pred]->next;
 741                                 ls->basicblocks[pred]->next =
 742                                         ls->basicblocks[n];
 743                                 /* generate no instructions */
 744                                 ls->basicblocks[n]->icount = 1;
 745                                 ls->basicblocks[n]->iinstr = NEW(instruction);
 746                                 ls->basicblocks[n]->iinstr[0].opc =     ICMD_NOP;
 747                         } else {
 748                                 /* Block n is in the Branch path */
 749                                 /* link Block at the end */
 750                                 ls->basicblocks[n]->next =last_block->next;
 751                                 last_block->next = ls->basicblocks[n];
 752                                 last_block = ls->basicblocks[n];
 753
 754                                 /* change the Branch Target to BB i */
 755
 756
 757
 758                                 switch(iptr->opc) {
 759                                 case ICMD_LOOKUPSWITCH:
 760                                         {
 761                                                 s4 i;
 762                                                 lookup_target_t *lookup;
 763
 764                                                 lookup = iptr->dst.lookup;
 765
 766                                                 i = iptr->sx.s23.s2.lookupcount;
 767
 768                                                 while (--i >= 0) {
 769                                                         if (lookup->target.block == ls->basicblocks[succ])
 770                                                                 /* target found -> change */
 771                                                                 lookup->target.block = ls->basicblocks[n];
 772                                                         lookup++;
 773                                                 }
 774
 775                                                 if (iptr->sx.s23.s3.lookupdefault.block == ls->basicblocks[succ])
 776                                                         /* target found -> change */
 777                                                         iptr->sx.s23.s3.lookupdefault.block = ls->basicblocks[n];
 778                                         }
 779                                         break;
 780                                 case ICMD_TABLESWITCH:
 781                                         {
 782                                                 s4 i, l;
 783                                                 branch_target_t *table;
 784
 785                                                 table = iptr->dst.table;
 786
 787                                                 l = iptr->sx.s23.s2.tablelow;
 788                                                 i = iptr->sx.s23.s3.tablehigh;
 789
 790                                                 i = i - l + 1;
 791
 792                                                 if (table[0].block ==  ls->basicblocks[succ]) /* default target */
 793                                                         /* target found -> change*/
 794                                                         table[0].block = ls->basicblocks[n];
 795
 796                                                 table += i;
 797
 798                                                 while (--i >= 0) {
 799                                                         if (table->block == ls->basicblocks[succ])
 800                                                                 /* target found -> change */
 801                                                                 table->block = ls->basicblocks[n];
 802                                                         --table;
 803                                                 }
 804                                         }
 805                                         break;
 806                                 case ICMD_IFNULL:
 807                                 case ICMD_IFNONNULL:
 808                                 case ICMD_IFEQ:
 809                                 case ICMD_IFNE:
 810                                 case ICMD_IFLT:
 811                                 case ICMD_IFGE:
 812                                 case ICMD_IFGT:
 813                                 case ICMD_IFLE:
 814                                 case ICMD_IF_LEQ:
 815                                 case ICMD_IF_LNE:
 816                                 case ICMD_IF_LLT:
 817                                 case ICMD_IF_LGE:
 818                                 case ICMD_IF_LGT:
 819                                 case ICMD_IF_LLE:
 820                                 case ICMD_IF_ICMPEQ:
 821                                 case ICMD_IF_ICMPNE:
 822                                 case ICMD_IF_ICMPLT:
 823                                 case ICMD_IF_ICMPGE:
 824                                 case ICMD_IF_ICMPGT:
 825                                 case ICMD_IF_ICMPLE:
 826                                 case ICMD_IF_LCMPEQ:
 827                                 case ICMD_IF_LCMPNE:
 828                                 case ICMD_IF_LCMPLT:
 829                                 case ICMD_IF_LCMPGE:
 830                                 case ICMD_IF_LCMPGT:
 831                                 case ICMD_IF_LCMPLE:
 832                                 case ICMD_IF_ACMPEQ:
 833                                 case ICMD_IF_ACMPNE:
 834                                 case ICMD_GOTO:
 835                                         _GRAPH_ASSERT(iptr->dst.block == ls->basicblocks[succ]);
 836                                         iptr->dst.block = ls->basicblocks[n];
 837                                         break;
 838                                 default:
 839                                         /* Exception Edge to split */
 840                                         /* not handled by now -> fallback to regalloc */
 841                                         exit(1);
 842                                 }
 843
 844                                 /* Generate the ICMD_GOTO */
 845                                 ls->basicblocks[n]->icount = 1;
 846                                 ls->basicblocks[n]->iinstr =
 847                                         DNEW(instruction);
 848                                 ls->basicblocks[n]->iinstr->opc =
 849                                         ICMD_GOTO;
 850                                 ls->basicblocks[n]->iinstr->dst.block =
 851                                         ls->basicblocks[succ];
 852                         }
 853                 }
 854         }
 855 }
 856
 857 #ifdef GRAPH_DEBUG_VERBOSE
 858 void graph_print(lsradata *ls, graphdata *gd) {
 859         int i,j;
 860         graphiterator iter;
 861         printf("graph_print: basicblockcount %3i\n", ls->basicblockcount);
 862
 863         printf("CFG: \n");
 864         for(i = 0; i < ls->basicblockcount; i++) {
 865                 printf("%3i: ",i);
 866                 j = graph_get_first_successor(gd, i, &iter);
 867                 for(; j != -1; j = graph_get_next(&iter)) {
 868                         printf("%3i ",j);
 869                 }
 870                 printf("\n");
 871         }
 872         printf("Pred: \n");
 873         for(i = 0; i < ls->basicblockcount; i++) {
 874                 printf("%3i: ",i);
 875                 j = graph_get_first_predecessor(gd, i, &iter);
 876                 for(; j != -1; j = graph_get_next(&iter)) {
 877                         printf("%3i ", j);
 878                 }
 879                 printf("\n");
 880         }
 881 }
 882 #endif
 883
 884
 885
 886 /*
 887  * These are local overrides for various environment variables in Emacs.
 888  * Please do not remove this and leave it at the end of the file, where
 889  * Emacs will automagically detect them.
 890  * ---------------------------------------------------------------------
 891  * Local variables:
 892  * mode: c
 893  * indent-tabs-mode: t
 894  * c-basic-offset: 4
 895  * tab-width: 4
 896  * End:
 897  */