gcc/tree-ssa-scopedtables.c

   1 /* Header file for SSA dominator optimizations.
   2    Copyright (C) 2013-2017 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "function.h"
  24 #include "basic-block.h"
  25 #include "tree.h"
  26 #include "gimple.h"
  27 #include "tree-pass.h"
  28 #include "tree-pretty-print.h"
  29 #include "tree-ssa-scopedtables.h"
  30 #include "tree-ssa-threadedge.h"
  31 #include "stor-layout.h"
  32 #include "fold-const.h"
  33 #include "tree-eh.h"
  34 #include "internal-fn.h"
  35 #include "tree-dfa.h"
  36
  37 static bool hashable_expr_equal_p (const struct hashable_expr *,
  38                                    const struct hashable_expr *);
  39
  40 /* Initialize local stacks for this optimizer and record equivalences
  41    upon entry to BB.  Equivalences can come from the edge traversed to
  42    reach BB or they may come from PHI nodes at the start of BB.  */
  43
  44 /* Pop items off the unwinding stack, removing each from the hash table
  45    until a marker is encountered.  */
  46
  47 void
  48 avail_exprs_stack::pop_to_marker ()
  49 {
  50   /* Remove all the expressions made available in this block.  */
  51   while (m_stack.length () > 0)
  52     {
  53       std::pair<expr_hash_elt_t, expr_hash_elt_t> victim = m_stack.pop ();
  54       expr_hash_elt **slot;
  55
  56       if (victim.first == NULL)
  57         break;
  58
  59       /* This must precede the actual removal from the hash table,
  60          as ELEMENT and the table entry may share a call argument
  61          vector which will be freed during removal.  */
  62       if (dump_file && (dump_flags & TDF_DETAILS))
  63         {
  64           fprintf (dump_file, "<<<< ");
  65           victim.first->print (dump_file);
  66         }
  67
  68       slot = m_avail_exprs->find_slot (victim.first, NO_INSERT);
  69       gcc_assert (slot && *slot == victim.first);
  70       if (victim.second != NULL)
  71         {
  72           delete *slot;
  73           *slot = victim.second;
  74         }
  75       else
  76         m_avail_exprs->clear_slot (slot);
  77     }
  78 }
  79
  80 /* Add <ELT1,ELT2> to the unwinding stack so they can be later removed
  81    from the hash table.  */
  82
  83 void
  84 avail_exprs_stack::record_expr (class expr_hash_elt *elt1,
  85                                 class expr_hash_elt *elt2,
  86                                 char type)
  87 {
  88   if (elt1 && dump_file && (dump_flags & TDF_DETAILS))
  89     {
  90       fprintf (dump_file, "%c>>> ", type);
  91       elt1->print (dump_file);
  92     }
  93
  94   m_stack.safe_push (std::pair<expr_hash_elt_t, expr_hash_elt_t> (elt1, elt2));
  95 }
  96
  97 /* Generate a hash value for a pair of expressions.  This can be used
  98    iteratively by passing a previous result in HSTATE.
  99
 100    The same hash value is always returned for a given pair of expressions,
 101    regardless of the order in which they are presented.  This is useful in
 102    hashing the operands of commutative functions.  */
 103
 104 namespace inchash
 105 {
 106
 107 static void
 108 add_expr_commutative (const_tree t1, const_tree t2, hash &hstate)
 109 {
 110   hash one, two;
 111
 112   inchash::add_expr (t1, one);
 113   inchash::add_expr (t2, two);
 114   hstate.add_commutative (one, two);
 115 }
 116
 117 /* Compute a hash value for a hashable_expr value EXPR and a
 118    previously accumulated hash value VAL.  If two hashable_expr
 119    values compare equal with hashable_expr_equal_p, they must
 120    hash to the same value, given an identical value of VAL.
 121    The logic is intended to follow inchash::add_expr in tree.c.  */
 122
 123 static void
 124 add_hashable_expr (const struct hashable_expr *expr, hash &hstate)
 125 {
 126   switch (expr->kind)
 127     {
 128     case EXPR_SINGLE:
 129       inchash::add_expr (expr->ops.single.rhs, hstate);
 130       break;
 131
 132     case EXPR_UNARY:
 133       hstate.add_object (expr->ops.unary.op);
 134
 135       /* Make sure to include signedness in the hash computation.
 136          Don't hash the type, that can lead to having nodes which
 137          compare equal according to operand_equal_p, but which
 138          have different hash codes.  */
 139       if (CONVERT_EXPR_CODE_P (expr->ops.unary.op)
 140           || expr->ops.unary.op == NON_LVALUE_EXPR)
 141         hstate.add_int (TYPE_UNSIGNED (expr->type));
 142
 143       inchash::add_expr (expr->ops.unary.opnd, hstate);
 144       break;
 145
 146     case EXPR_BINARY:
 147       hstate.add_object (expr->ops.binary.op);
 148       if (commutative_tree_code (expr->ops.binary.op))
 149         inchash::add_expr_commutative (expr->ops.binary.opnd0,
 150                                           expr->ops.binary.opnd1, hstate);
 151       else
 152         {
 153           inchash::add_expr (expr->ops.binary.opnd0, hstate);
 154           inchash::add_expr (expr->ops.binary.opnd1, hstate);
 155         }
 156       break;
 157
 158     case EXPR_TERNARY:
 159       hstate.add_object (expr->ops.ternary.op);
 160       if (commutative_ternary_tree_code (expr->ops.ternary.op))
 161         inchash::add_expr_commutative (expr->ops.ternary.opnd0,
 162                                           expr->ops.ternary.opnd1, hstate);
 163       else
 164         {
 165           inchash::add_expr (expr->ops.ternary.opnd0, hstate);
 166           inchash::add_expr (expr->ops.ternary.opnd1, hstate);
 167         }
 168       inchash::add_expr (expr->ops.ternary.opnd2, hstate);
 169       break;
 170
 171     case EXPR_CALL:
 172       {
 173         size_t i;
 174         enum tree_code code = CALL_EXPR;
 175         gcall *fn_from;
 176
 177         hstate.add_object (code);
 178         fn_from = expr->ops.call.fn_from;
 179         if (gimple_call_internal_p (fn_from))
 180           hstate.merge_hash ((hashval_t) gimple_call_internal_fn (fn_from));
 181         else
 182           inchash::add_expr (gimple_call_fn (fn_from), hstate);
 183         for (i = 0; i < expr->ops.call.nargs; i++)
 184           inchash::add_expr (expr->ops.call.args[i], hstate);
 185       }
 186       break;
 187
 188     case EXPR_PHI:
 189       {
 190         size_t i;
 191
 192         for (i = 0; i < expr->ops.phi.nargs; i++)
 193           inchash::add_expr (expr->ops.phi.args[i], hstate);
 194       }
 195       break;
 196
 197     default:
 198       gcc_unreachable ();
 199     }
 200 }
 201
 202 }
 203
 204 /* Hashing and equality functions.  We compute a value number for expressions
 205    using the code of the expression and the SSA numbers of its operands.  */
 206
 207 static hashval_t
 208 avail_expr_hash (class expr_hash_elt *p)
 209 {
 210   const struct hashable_expr *expr = p->expr ();
 211   inchash::hash hstate;
 212
 213   if (expr->kind == EXPR_SINGLE)
 214     {
 215       /* T could potentially be a switch index or a goto dest.  */
 216       tree t = expr->ops.single.rhs;
 217       if (TREE_CODE (t) == MEM_REF || handled_component_p (t))
 218         {
 219           /* Make equivalent statements of both these kinds hash together.
 220              Dealing with both MEM_REF and ARRAY_REF allows us not to care
 221              about equivalence with other statements not considered here.  */
 222           bool reverse;
 223           HOST_WIDE_INT offset, size, max_size;
 224           tree base = get_ref_base_and_extent (t, &offset, &size, &max_size,
 225                                                &reverse);
 226           /* Strictly, we could try to normalize variable-sized accesses too,
 227             but here we just deal with the common case.  */
 228           if (size != -1
 229               && size == max_size)
 230             {
 231               enum tree_code code = MEM_REF;
 232               hstate.add_object (code);
 233               inchash::add_expr (base, hstate);
 234               hstate.add_object (offset);
 235               hstate.add_object (size);
 236               return hstate.end ();
 237             }
 238         }
 239     }
 240
 241   inchash::add_hashable_expr (expr, hstate);
 242
 243   return hstate.end ();
 244 }
 245
 246 /* Compares trees T0 and T1 to see if they are MEM_REF or ARRAY_REFs equivalent
 247    to each other.  (That is, they return the value of the same bit of memory.)
 248
 249    Return TRUE if the two are so equivalent; FALSE if not (which could still
 250    mean the two are equivalent by other means).  */
 251
 252 static bool
 253 equal_mem_array_ref_p (tree t0, tree t1)
 254 {
 255   if (TREE_CODE (t0) != MEM_REF && ! handled_component_p (t0))
 256     return false;
 257   if (TREE_CODE (t1) != MEM_REF && ! handled_component_p (t1))
 258     return false;
 259
 260   if (!types_compatible_p (TREE_TYPE (t0), TREE_TYPE (t1)))
 261     return false;
 262   bool rev0;
 263   HOST_WIDE_INT off0, sz0, max0;
 264   tree base0 = get_ref_base_and_extent (t0, &off0, &sz0, &max0, &rev0);
 265   if (sz0 == -1
 266       || sz0 != max0)
 267     return false;
 268
 269   bool rev1;
 270   HOST_WIDE_INT off1, sz1, max1;
 271   tree base1 = get_ref_base_and_extent (t1, &off1, &sz1, &max1, &rev1);
 272   if (sz1 == -1
 273       || sz1 != max1)
 274     return false;
 275
 276   if (rev0 != rev1)
 277     return false;
 278
 279   /* Types were compatible, so this is a sanity check.  */
 280   gcc_assert (sz0 == sz1);
 281
 282   return (off0 == off1) && operand_equal_p (base0, base1, 0);
 283 }
 284
 285 /* Compare two hashable_expr structures for equivalence.  They are
 286    considered equivalent when the expressions they denote must
 287    necessarily be equal.  The logic is intended to follow that of
 288    operand_equal_p in fold-const.c */
 289
 290 static bool
 291 hashable_expr_equal_p (const struct hashable_expr *expr0,
 292                        const struct hashable_expr *expr1)
 293 {
 294   tree type0 = expr0->type;
 295   tree type1 = expr1->type;
 296
 297   /* If either type is NULL, there is nothing to check.  */
 298   if ((type0 == NULL_TREE) ^ (type1 == NULL_TREE))
 299     return false;
 300
 301   /* If both types don't have the same signedness, precision, and mode,
 302      then we can't consider  them equal.  */
 303   if (type0 != type1
 304       && (TREE_CODE (type0) == ERROR_MARK
 305           || TREE_CODE (type1) == ERROR_MARK
 306           || TYPE_UNSIGNED (type0) != TYPE_UNSIGNED (type1)
 307           || TYPE_PRECISION (type0) != TYPE_PRECISION (type1)
 308           || TYPE_MODE (type0) != TYPE_MODE (type1)))
 309     return false;
 310
 311   if (expr0->kind != expr1->kind)
 312     return false;
 313
 314   switch (expr0->kind)
 315     {
 316     case EXPR_SINGLE:
 317       return equal_mem_array_ref_p (expr0->ops.single.rhs,
 318                                     expr1->ops.single.rhs)
 319              || operand_equal_p (expr0->ops.single.rhs,
 320                                  expr1->ops.single.rhs, 0);
 321     case EXPR_UNARY:
 322       if (expr0->ops.unary.op != expr1->ops.unary.op)
 323         return false;
 324
 325       if ((CONVERT_EXPR_CODE_P (expr0->ops.unary.op)
 326            || expr0->ops.unary.op == NON_LVALUE_EXPR)
 327           && TYPE_UNSIGNED (expr0->type) != TYPE_UNSIGNED (expr1->type))
 328         return false;
 329
 330       return operand_equal_p (expr0->ops.unary.opnd,
 331                               expr1->ops.unary.opnd, 0);
 332
 333     case EXPR_BINARY:
 334       if (expr0->ops.binary.op != expr1->ops.binary.op)
 335         return false;
 336
 337       if (operand_equal_p (expr0->ops.binary.opnd0,
 338                            expr1->ops.binary.opnd0, 0)
 339           && operand_equal_p (expr0->ops.binary.opnd1,
 340                               expr1->ops.binary.opnd1, 0))
 341         return true;
 342
 343       /* For commutative ops, allow the other order.  */
 344       return (commutative_tree_code (expr0->ops.binary.op)
 345               && operand_equal_p (expr0->ops.binary.opnd0,
 346                                   expr1->ops.binary.opnd1, 0)
 347               && operand_equal_p (expr0->ops.binary.opnd1,
 348                                   expr1->ops.binary.opnd0, 0));
 349
 350     case EXPR_TERNARY:
 351       if (expr0->ops.ternary.op != expr1->ops.ternary.op
 352           || !operand_equal_p (expr0->ops.ternary.opnd2,
 353                                expr1->ops.ternary.opnd2, 0))
 354         return false;
 355
 356       if (operand_equal_p (expr0->ops.ternary.opnd0,
 357                            expr1->ops.ternary.opnd0, 0)
 358           && operand_equal_p (expr0->ops.ternary.opnd1,
 359                               expr1->ops.ternary.opnd1, 0))
 360         return true;
 361
 362       /* For commutative ops, allow the other order.  */
 363       return (commutative_ternary_tree_code (expr0->ops.ternary.op)
 364               && operand_equal_p (expr0->ops.ternary.opnd0,
 365                                   expr1->ops.ternary.opnd1, 0)
 366               && operand_equal_p (expr0->ops.ternary.opnd1,
 367                                   expr1->ops.ternary.opnd0, 0));
 368
 369     case EXPR_CALL:
 370       {
 371         size_t i;
 372
 373         /* If the calls are to different functions, then they
 374            clearly cannot be equal.  */
 375         if (!gimple_call_same_target_p (expr0->ops.call.fn_from,
 376                                         expr1->ops.call.fn_from))
 377           return false;
 378
 379         if (! expr0->ops.call.pure)
 380           return false;
 381
 382         if (expr0->ops.call.nargs !=  expr1->ops.call.nargs)
 383           return false;
 384
 385         for (i = 0; i < expr0->ops.call.nargs; i++)
 386           if (! operand_equal_p (expr0->ops.call.args[i],
 387                                  expr1->ops.call.args[i], 0))
 388             return false;
 389
 390         if (stmt_could_throw_p (expr0->ops.call.fn_from))
 391           {
 392             int lp0 = lookup_stmt_eh_lp (expr0->ops.call.fn_from);
 393             int lp1 = lookup_stmt_eh_lp (expr1->ops.call.fn_from);
 394             if ((lp0 > 0 || lp1 > 0) && lp0 != lp1)
 395               return false;
 396           }
 397
 398         return true;
 399       }
 400
 401     case EXPR_PHI:
 402       {
 403         size_t i;
 404
 405         if (expr0->ops.phi.nargs !=  expr1->ops.phi.nargs)
 406           return false;
 407
 408         for (i = 0; i < expr0->ops.phi.nargs; i++)
 409           if (! operand_equal_p (expr0->ops.phi.args[i],
 410                                  expr1->ops.phi.args[i], 0))
 411             return false;
 412
 413         return true;
 414       }
 415
 416     default:
 417       gcc_unreachable ();
 418     }
 419 }
 420
 421 /* Given a statement STMT, construct a hash table element.  */
 422
 423 expr_hash_elt::expr_hash_elt (gimple *stmt, tree orig_lhs)
 424 {
 425   enum gimple_code code = gimple_code (stmt);
 426   struct hashable_expr *expr = this->expr ();
 427
 428   if (code == GIMPLE_ASSIGN)
 429     {
 430       enum tree_code subcode = gimple_assign_rhs_code (stmt);
 431
 432       switch (get_gimple_rhs_class (subcode))
 433         {
 434         case GIMPLE_SINGLE_RHS:
 435           expr->kind = EXPR_SINGLE;
 436           expr->type = TREE_TYPE (gimple_assign_rhs1 (stmt));
 437           expr->ops.single.rhs = gimple_assign_rhs1 (stmt);
 438           break;
 439         case GIMPLE_UNARY_RHS:
 440           expr->kind = EXPR_UNARY;
 441           expr->type = TREE_TYPE (gimple_assign_lhs (stmt));
 442           if (CONVERT_EXPR_CODE_P (subcode))
 443             subcode = NOP_EXPR;
 444           expr->ops.unary.op = subcode;
 445           expr->ops.unary.opnd = gimple_assign_rhs1 (stmt);
 446           break;
 447         case GIMPLE_BINARY_RHS:
 448           expr->kind = EXPR_BINARY;
 449           expr->type = TREE_TYPE (gimple_assign_lhs (stmt));
 450           expr->ops.binary.op = subcode;
 451           expr->ops.binary.opnd0 = gimple_assign_rhs1 (stmt);
 452           expr->ops.binary.opnd1 = gimple_assign_rhs2 (stmt);
 453           break;
 454         case GIMPLE_TERNARY_RHS:
 455           expr->kind = EXPR_TERNARY;
 456           expr->type = TREE_TYPE (gimple_assign_lhs (stmt));
 457           expr->ops.ternary.op = subcode;
 458           expr->ops.ternary.opnd0 = gimple_assign_rhs1 (stmt);
 459           expr->ops.ternary.opnd1 = gimple_assign_rhs2 (stmt);
 460           expr->ops.ternary.opnd2 = gimple_assign_rhs3 (stmt);
 461           break;
 462         default:
 463           gcc_unreachable ();
 464         }
 465     }
 466   else if (code == GIMPLE_COND)
 467     {
 468       expr->type = boolean_type_node;
 469       expr->kind = EXPR_BINARY;
 470       expr->ops.binary.op = gimple_cond_code (stmt);
 471       expr->ops.binary.opnd0 = gimple_cond_lhs (stmt);
 472       expr->ops.binary.opnd1 = gimple_cond_rhs (stmt);
 473     }
 474   else if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
 475     {
 476       size_t nargs = gimple_call_num_args (call_stmt);
 477       size_t i;
 478
 479       gcc_assert (gimple_call_lhs (call_stmt));
 480
 481       expr->type = TREE_TYPE (gimple_call_lhs (call_stmt));
 482       expr->kind = EXPR_CALL;
 483       expr->ops.call.fn_from = call_stmt;
 484
 485       if (gimple_call_flags (call_stmt) & (ECF_CONST | ECF_PURE))
 486         expr->ops.call.pure = true;
 487       else
 488         expr->ops.call.pure = false;
 489
 490       expr->ops.call.nargs = nargs;
 491       expr->ops.call.args = XCNEWVEC (tree, nargs);
 492       for (i = 0; i < nargs; i++)
 493         expr->ops.call.args[i] = gimple_call_arg (call_stmt, i);
 494     }
 495   else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt))
 496     {
 497       expr->type = TREE_TYPE (gimple_switch_index (swtch_stmt));
 498       expr->kind = EXPR_SINGLE;
 499       expr->ops.single.rhs = gimple_switch_index (swtch_stmt);
 500     }
 501   else if (code == GIMPLE_GOTO)
 502     {
 503       expr->type = TREE_TYPE (gimple_goto_dest (stmt));
 504       expr->kind = EXPR_SINGLE;
 505       expr->ops.single.rhs = gimple_goto_dest (stmt);
 506     }
 507   else if (code == GIMPLE_PHI)
 508     {
 509       size_t nargs = gimple_phi_num_args (stmt);
 510       size_t i;
 511
 512       expr->type = TREE_TYPE (gimple_phi_result (stmt));
 513       expr->kind = EXPR_PHI;
 514       expr->ops.phi.nargs = nargs;
 515       expr->ops.phi.args = XCNEWVEC (tree, nargs);
 516       for (i = 0; i < nargs; i++)
 517         expr->ops.phi.args[i] = gimple_phi_arg_def (stmt, i);
 518     }
 519   else
 520     gcc_unreachable ();
 521
 522   m_lhs = orig_lhs;
 523   m_vop = gimple_vuse (stmt);
 524   m_hash = avail_expr_hash (this);
 525   m_stamp = this;
 526 }
 527
 528 /* Given a hashable_expr expression ORIG and an ORIG_LHS,
 529    construct a hash table element.  */
 530
 531 expr_hash_elt::expr_hash_elt (struct hashable_expr *orig, tree orig_lhs)
 532 {
 533   m_expr = *orig;
 534   m_lhs = orig_lhs;
 535   m_vop = NULL_TREE;
 536   m_hash = avail_expr_hash (this);
 537   m_stamp = this;
 538 }
 539
 540 /* Copy constructor for a hash table element.  */
 541
 542 expr_hash_elt::expr_hash_elt (class expr_hash_elt &old_elt)
 543 {
 544   m_expr = old_elt.m_expr;
 545   m_lhs = old_elt.m_lhs;
 546   m_vop = old_elt.m_vop;
 547   m_hash = old_elt.m_hash;
 548   m_stamp = this;
 549
 550   /* Now deep copy the malloc'd space for CALL and PHI args.  */
 551   if (old_elt.m_expr.kind == EXPR_CALL)
 552     {
 553       size_t nargs = old_elt.m_expr.ops.call.nargs;
 554       size_t i;
 555
 556       m_expr.ops.call.args = XCNEWVEC (tree, nargs);
 557       for (i = 0; i < nargs; i++)
 558         m_expr.ops.call.args[i] = old_elt.m_expr.ops.call.args[i];
 559     }
 560   else if (old_elt.m_expr.kind == EXPR_PHI)
 561     {
 562       size_t nargs = old_elt.m_expr.ops.phi.nargs;
 563       size_t i;
 564
 565       m_expr.ops.phi.args = XCNEWVEC (tree, nargs);
 566       for (i = 0; i < nargs; i++)
 567         m_expr.ops.phi.args[i] = old_elt.m_expr.ops.phi.args[i];
 568     }
 569 }
 570
 571 /* Calls and PHIs have a variable number of arguments that are allocated
 572    on the heap.  Thus we have to have a special dtor to release them.  */
 573
 574 expr_hash_elt::~expr_hash_elt ()
 575 {
 576   if (m_expr.kind == EXPR_CALL)
 577     free (m_expr.ops.call.args);
 578   else if (m_expr.kind == EXPR_PHI)
 579     free (m_expr.ops.phi.args);
 580 }
 581
 582 /* Print a diagnostic dump of an expression hash table entry.  */
 583
 584 void
 585 expr_hash_elt::print (FILE *stream)
 586 {
 587   fprintf (stream, "STMT ");
 588
 589   if (m_lhs)
 590     {
 591       print_generic_expr (stream, m_lhs, 0);
 592       fprintf (stream, " = ");
 593     }
 594
 595   switch (m_expr.kind)
 596     {
 597       case EXPR_SINGLE:
 598         print_generic_expr (stream, m_expr.ops.single.rhs, 0);
 599         break;
 600
 601       case EXPR_UNARY:
 602         fprintf (stream, "%s ", get_tree_code_name (m_expr.ops.unary.op));
 603         print_generic_expr (stream, m_expr.ops.unary.opnd, 0);
 604         break;
 605
 606       case EXPR_BINARY:
 607         print_generic_expr (stream, m_expr.ops.binary.opnd0, 0);
 608         fprintf (stream, " %s ", get_tree_code_name (m_expr.ops.binary.op));
 609         print_generic_expr (stream, m_expr.ops.binary.opnd1, 0);
 610         break;
 611
 612       case EXPR_TERNARY:
 613         fprintf (stream, " %s <", get_tree_code_name (m_expr.ops.ternary.op));
 614         print_generic_expr (stream, m_expr.ops.ternary.opnd0, 0);
 615         fputs (", ", stream);
 616         print_generic_expr (stream, m_expr.ops.ternary.opnd1, 0);
 617         fputs (", ", stream);
 618         print_generic_expr (stream, m_expr.ops.ternary.opnd2, 0);
 619         fputs (">", stream);
 620         break;
 621
 622       case EXPR_CALL:
 623         {
 624           size_t i;
 625           size_t nargs = m_expr.ops.call.nargs;
 626           gcall *fn_from;
 627
 628           fn_from = m_expr.ops.call.fn_from;
 629           if (gimple_call_internal_p (fn_from))
 630             fputs (internal_fn_name (gimple_call_internal_fn (fn_from)),
 631                    stream);
 632           else
 633             print_generic_expr (stream, gimple_call_fn (fn_from), 0);
 634           fprintf (stream, " (");
 635           for (i = 0; i < nargs; i++)
 636             {
 637               print_generic_expr (stream, m_expr.ops.call.args[i], 0);
 638               if (i + 1 < nargs)
 639                 fprintf (stream, ", ");
 640             }
 641           fprintf (stream, ")");
 642         }
 643         break;
 644
 645       case EXPR_PHI:
 646         {
 647           size_t i;
 648           size_t nargs = m_expr.ops.phi.nargs;
 649
 650           fprintf (stream, "PHI <");
 651           for (i = 0; i < nargs; i++)
 652             {
 653               print_generic_expr (stream, m_expr.ops.phi.args[i], 0);
 654               if (i + 1 < nargs)
 655                 fprintf (stream, ", ");
 656             }
 657           fprintf (stream, ">");
 658         }
 659         break;
 660     }
 661
 662   if (m_vop)
 663     {
 664       fprintf (stream, " with ");
 665       print_generic_expr (stream, m_vop, 0);
 666     }
 667
 668   fprintf (stream, "\n");
 669 }
 670
 671 /* Pop entries off the stack until we hit the NULL marker.
 672    For each entry popped, use the SRC/DEST pair to restore
 673    SRC to its prior value.  */
 674
 675 void
 676 const_and_copies::pop_to_marker (void)
 677 {
 678   while (m_stack.length () > 0)
 679     {
 680       tree prev_value, dest;
 681
 682       dest = m_stack.pop ();
 683
 684       /* A NULL value indicates we should stop unwinding, otherwise
 685          pop off the next entry as they're recorded in pairs.  */
 686       if (dest == NULL)
 687         break;
 688
 689       if (dump_file && (dump_flags & TDF_DETAILS))
 690         {
 691           fprintf (dump_file, "<<<< COPY ");
 692           print_generic_expr (dump_file, dest, 0);
 693           fprintf (dump_file, " = ");
 694           print_generic_expr (dump_file, SSA_NAME_VALUE (dest), 0);
 695           fprintf (dump_file, "\n");
 696         }
 697
 698       prev_value = m_stack.pop ();
 699       set_ssa_name_value (dest, prev_value);
 700     }
 701 }
 702
 703 /* Record that X has the value Y and that X's previous value is PREV_X.
 704
 705    This variant does not follow the value chain for Y.  */
 706
 707 void
 708 const_and_copies::record_const_or_copy_raw (tree x, tree y, tree prev_x)
 709 {
 710   if (dump_file && (dump_flags & TDF_DETAILS))
 711     {
 712       fprintf (dump_file, "0>>> COPY ");
 713       print_generic_expr (dump_file, x, 0);
 714       fprintf (dump_file, " = ");
 715       print_generic_expr (dump_file, y, 0);
 716       fprintf (dump_file, "\n");
 717     }
 718
 719   set_ssa_name_value (x, y);
 720   m_stack.reserve (2);
 721   m_stack.quick_push (prev_x);
 722   m_stack.quick_push (x);
 723 }
 724
 725 /* Record that X has the value Y.  */
 726
 727 void
 728 const_and_copies::record_const_or_copy (tree x, tree y)
 729 {
 730   record_const_or_copy (x, y, SSA_NAME_VALUE (x));
 731 }
 732
 733 /* Record that X has the value Y and that X's previous value is PREV_X.
 734
 735    This variant follow's Y value chain.  */
 736
 737 void
 738 const_and_copies::record_const_or_copy (tree x, tree y, tree prev_x)
 739 {
 740   /* Y may be NULL if we are invalidating entries in the table.  */
 741   if (y && TREE_CODE (y) == SSA_NAME)
 742     {
 743       tree tmp = SSA_NAME_VALUE (y);
 744       y = tmp ? tmp : y;
 745     }
 746
 747   record_const_or_copy_raw (x, y, prev_x);
 748 }
 749
 750 bool
 751 expr_elt_hasher::equal (const value_type &p1, const compare_type &p2)
 752 {
 753   const struct hashable_expr *expr1 = p1->expr ();
 754   const struct expr_hash_elt *stamp1 = p1->stamp ();
 755   const struct hashable_expr *expr2 = p2->expr ();
 756   const struct expr_hash_elt *stamp2 = p2->stamp ();
 757
 758   /* This case should apply only when removing entries from the table.  */
 759   if (stamp1 == stamp2)
 760     return true;
 761
 762   if (p1->hash () != p2->hash ())
 763     return false;
 764
 765   /* In case of a collision, both RHS have to be identical and have the
 766      same VUSE operands.  */
 767   if (hashable_expr_equal_p (expr1, expr2)
 768       && types_compatible_p (expr1->type, expr2->type))
 769     return true;
 770
 771   return false;
 772 }
 773
 774 /* Given a conditional expression COND as a tree, initialize
 775    a hashable_expr expression EXPR.  The conditional must be a
 776    comparison or logical negation.  A constant or a variable is
 777    not permitted.  */
 778
 779 void
 780 initialize_expr_from_cond (tree cond, struct hashable_expr *expr)
 781 {
 782   expr->type = boolean_type_node;
 783
 784   if (COMPARISON_CLASS_P (cond))
 785     {
 786       expr->kind = EXPR_BINARY;
 787       expr->ops.binary.op = TREE_CODE (cond);
 788       expr->ops.binary.opnd0 = TREE_OPERAND (cond, 0);
 789       expr->ops.binary.opnd1 = TREE_OPERAND (cond, 1);
 790     }
 791   else if (TREE_CODE (cond) == TRUTH_NOT_EXPR)
 792     {
 793       expr->kind = EXPR_UNARY;
 794       expr->ops.unary.op = TRUTH_NOT_EXPR;
 795       expr->ops.unary.opnd = TREE_OPERAND (cond, 0);
 796     }
 797   else
 798     gcc_unreachable ();
 799 }
 800