gcc/tree-affine.c

   1 /* Operations with affine combinations of trees.
   2    Copyright (C) 2005, 2007, 2008, 2010 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
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 3, or (at your option) any
   9 later version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT
  12 ANY 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 "tree.h"
  24 #include "output.h"
  25 #include "diagnostic.h"
  26 #include "tree-pretty-print.h"
  27 #include "tree-dump.h"
  28 #include "pointer-set.h"
  29 #include "tree-affine.h"
  30 #include "gimple.h"
  31 #include "flags.h"
  32
  33 /* Extends CST as appropriate for the affine combinations COMB.  */
  34
  35 double_int
  36 double_int_ext_for_comb (double_int cst, aff_tree *comb)
  37 {
  38   return double_int_sext (cst, TYPE_PRECISION (comb->type));
  39 }
  40
  41 /* Initializes affine combination COMB so that its value is zero in TYPE.  */
  42
  43 static void
  44 aff_combination_zero (aff_tree *comb, tree type)
  45 {
  46   comb->type = type;
  47   comb->offset = double_int_zero;
  48   comb->n = 0;
  49   comb->rest = NULL_TREE;
  50 }
  51
  52 /* Sets COMB to CST.  */
  53
  54 void
  55 aff_combination_const (aff_tree *comb, tree type, double_int cst)
  56 {
  57   aff_combination_zero (comb, type);
  58   comb->offset = double_int_ext_for_comb (cst, comb);
  59 }
  60
  61 /* Sets COMB to single element ELT.  */
  62
  63 void
  64 aff_combination_elt (aff_tree *comb, tree type, tree elt)
  65 {
  66   aff_combination_zero (comb, type);
  67
  68   comb->n = 1;
  69   comb->elts[0].val = elt;
  70   comb->elts[0].coef = double_int_one;
  71 }
  72
  73 /* Scales COMB by SCALE.  */
  74
  75 void
  76 aff_combination_scale (aff_tree *comb, double_int scale)
  77 {
  78   unsigned i, j;
  79
  80   scale = double_int_ext_for_comb (scale, comb);
  81   if (double_int_one_p (scale))
  82     return;
  83
  84   if (double_int_zero_p (scale))
  85     {
  86       aff_combination_zero (comb, comb->type);
  87       return;
  88     }
  89
  90   comb->offset
  91     = double_int_ext_for_comb (double_int_mul (scale, comb->offset), comb);
  92   for (i = 0, j = 0; i < comb->n; i++)
  93     {
  94       double_int new_coef;
  95
  96       new_coef
  97         = double_int_ext_for_comb (double_int_mul (scale, comb->elts[i].coef),
  98                                    comb);
  99       /* A coefficient may become zero due to overflow.  Remove the zero
 100          elements.  */
 101       if (double_int_zero_p (new_coef))
 102         continue;
 103       comb->elts[j].coef = new_coef;
 104       comb->elts[j].val = comb->elts[i].val;
 105       j++;
 106     }
 107   comb->n = j;
 108
 109   if (comb->rest)
 110     {
 111       tree type = comb->type;
 112       if (POINTER_TYPE_P (type))
 113         type = sizetype;
 114       if (comb->n < MAX_AFF_ELTS)
 115         {
 116           comb->elts[comb->n].coef = scale;
 117           comb->elts[comb->n].val = comb->rest;
 118           comb->rest = NULL_TREE;
 119           comb->n++;
 120         }
 121       else
 122         comb->rest = fold_build2 (MULT_EXPR, type, comb->rest,
 123                                   double_int_to_tree (type, scale));
 124     }
 125 }
 126
 127 /* Adds ELT * SCALE to COMB.  */
 128
 129 void
 130 aff_combination_add_elt (aff_tree *comb, tree elt, double_int scale)
 131 {
 132   unsigned i;
 133   tree type;
 134
 135   scale = double_int_ext_for_comb (scale, comb);
 136   if (double_int_zero_p (scale))
 137     return;
 138
 139   for (i = 0; i < comb->n; i++)
 140     if (operand_equal_p (comb->elts[i].val, elt, 0))
 141       {
 142         double_int new_coef;
 143
 144         new_coef = double_int_add (comb->elts[i].coef, scale);
 145         new_coef = double_int_ext_for_comb (new_coef, comb);
 146         if (!double_int_zero_p (new_coef))
 147           {
 148             comb->elts[i].coef = new_coef;
 149             return;
 150           }
 151
 152         comb->n--;
 153         comb->elts[i] = comb->elts[comb->n];
 154
 155         if (comb->rest)
 156           {
 157             gcc_assert (comb->n == MAX_AFF_ELTS - 1);
 158             comb->elts[comb->n].coef = double_int_one;
 159             comb->elts[comb->n].val = comb->rest;
 160             comb->rest = NULL_TREE;
 161             comb->n++;
 162           }
 163         return;
 164       }
 165   if (comb->n < MAX_AFF_ELTS)
 166     {
 167       comb->elts[comb->n].coef = scale;
 168       comb->elts[comb->n].val = elt;
 169       comb->n++;
 170       return;
 171     }
 172
 173   type = comb->type;
 174   if (POINTER_TYPE_P (type))
 175     type = sizetype;
 176
 177   if (double_int_one_p (scale))
 178     elt = fold_convert (type, elt);
 179   else
 180     elt = fold_build2 (MULT_EXPR, type,
 181                        fold_convert (type, elt),
 182                        double_int_to_tree (type, scale));
 183
 184   if (comb->rest)
 185     comb->rest = fold_build2 (PLUS_EXPR, type, comb->rest,
 186                               elt);
 187   else
 188     comb->rest = elt;
 189 }
 190
 191 /* Adds CST to C.  */
 192
 193 static void
 194 aff_combination_add_cst (aff_tree *c, double_int cst)
 195 {
 196   c->offset = double_int_ext_for_comb (double_int_add (c->offset, cst), c);
 197 }
 198
 199 /* Adds COMB2 to COMB1.  */
 200
 201 void
 202 aff_combination_add (aff_tree *comb1, aff_tree *comb2)
 203 {
 204   unsigned i;
 205
 206   aff_combination_add_cst (comb1, comb2->offset);
 207   for (i = 0; i < comb2->n; i++)
 208     aff_combination_add_elt (comb1, comb2->elts[i].val, comb2->elts[i].coef);
 209   if (comb2->rest)
 210     aff_combination_add_elt (comb1, comb2->rest, double_int_one);
 211 }
 212
 213 /* Converts affine combination COMB to TYPE.  */
 214
 215 void
 216 aff_combination_convert (aff_tree *comb, tree type)
 217 {
 218   unsigned i, j;
 219   tree comb_type = comb->type;
 220
 221   if  (TYPE_PRECISION (type) > TYPE_PRECISION (comb_type))
 222     {
 223       tree val = fold_convert (type, aff_combination_to_tree (comb));
 224       tree_to_aff_combination (val, type, comb);
 225       return;
 226     }
 227
 228   comb->type = type;
 229   if (comb->rest && !POINTER_TYPE_P (type))
 230     comb->rest = fold_convert (type, comb->rest);
 231
 232   if (TYPE_PRECISION (type) == TYPE_PRECISION (comb_type))
 233     return;
 234
 235   comb->offset = double_int_ext_for_comb (comb->offset, comb);
 236   for (i = j = 0; i < comb->n; i++)
 237     {
 238       double_int new_coef = double_int_ext_for_comb (comb->elts[i].coef, comb);
 239       if (double_int_zero_p (new_coef))
 240         continue;
 241       comb->elts[j].coef = new_coef;
 242       comb->elts[j].val = fold_convert (type, comb->elts[i].val);
 243       j++;
 244     }
 245
 246   comb->n = j;
 247   if (comb->n < MAX_AFF_ELTS && comb->rest)
 248     {
 249       comb->elts[comb->n].coef = double_int_one;
 250       comb->elts[comb->n].val = comb->rest;
 251       comb->rest = NULL_TREE;
 252       comb->n++;
 253     }
 254 }
 255
 256 /* Splits EXPR into an affine combination of parts.  */
 257
 258 void
 259 tree_to_aff_combination (tree expr, tree type, aff_tree *comb)
 260 {
 261   aff_tree tmp;
 262   enum tree_code code;
 263   tree cst, core, toffset;
 264   HOST_WIDE_INT bitpos, bitsize;
 265   enum machine_mode mode;
 266   int unsignedp, volatilep;
 267
 268   STRIP_NOPS (expr);
 269
 270   code = TREE_CODE (expr);
 271   switch (code)
 272     {
 273     case INTEGER_CST:
 274       aff_combination_const (comb, type, tree_to_double_int (expr));
 275       return;
 276
 277     case POINTER_PLUS_EXPR:
 278       tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
 279       tree_to_aff_combination (TREE_OPERAND (expr, 1), sizetype, &tmp);
 280       aff_combination_add (comb, &tmp);
 281       return;
 282
 283     case PLUS_EXPR:
 284     case MINUS_EXPR:
 285       tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
 286       tree_to_aff_combination (TREE_OPERAND (expr, 1), type, &tmp);
 287       if (code == MINUS_EXPR)
 288         aff_combination_scale (&tmp, double_int_minus_one);
 289       aff_combination_add (comb, &tmp);
 290       return;
 291
 292     case MULT_EXPR:
 293       cst = TREE_OPERAND (expr, 1);
 294       if (TREE_CODE (cst) != INTEGER_CST)
 295         break;
 296       tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
 297       aff_combination_scale (comb, tree_to_double_int (cst));
 298       return;
 299
 300     case NEGATE_EXPR:
 301       tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
 302       aff_combination_scale (comb, double_int_minus_one);
 303       return;
 304
 305     case BIT_NOT_EXPR:
 306       /* ~x = -x - 1 */
 307       tree_to_aff_combination (TREE_OPERAND (expr, 0), type, comb);
 308       aff_combination_scale (comb, double_int_minus_one);
 309       aff_combination_add_cst (comb, double_int_minus_one);
 310       return;
 311
 312     case ADDR_EXPR:
 313       core = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize, &bitpos,
 314                                   &toffset, &mode, &unsignedp, &volatilep,
 315                                   false);
 316       if (bitpos % BITS_PER_UNIT != 0)
 317         break;
 318       aff_combination_const (comb, type,
 319                              uhwi_to_double_int (bitpos / BITS_PER_UNIT));
 320       core = build_fold_addr_expr (core);
 321       if (TREE_CODE (core) == ADDR_EXPR)
 322         aff_combination_add_elt (comb, core, double_int_one);
 323       else
 324         {
 325           tree_to_aff_combination (core, type, &tmp);
 326           aff_combination_add (comb, &tmp);
 327         }
 328       if (toffset)
 329         {
 330           tree_to_aff_combination (toffset, type, &tmp);
 331           aff_combination_add (comb, &tmp);
 332         }
 333       return;
 334
 335     default:
 336       break;
 337     }
 338
 339   aff_combination_elt (comb, type, expr);
 340 }
 341
 342 /* Creates EXPR + ELT * SCALE in TYPE.  EXPR is taken from affine
 343    combination COMB.  */
 344
 345 static tree
 346 add_elt_to_tree (tree expr, tree type, tree elt, double_int scale,
 347                  aff_tree *comb)
 348 {
 349   enum tree_code code;
 350   tree type1 = type;
 351   if (POINTER_TYPE_P (type))
 352     type1 = sizetype;
 353
 354   scale = double_int_ext_for_comb (scale, comb);
 355   elt = fold_convert (type1, elt);
 356
 357   if (double_int_one_p (scale))
 358     {
 359       if (!expr)
 360         return fold_convert (type, elt);
 361
 362       if (POINTER_TYPE_P (type))
 363         return fold_build2 (POINTER_PLUS_EXPR, type, expr, elt);
 364       return fold_build2 (PLUS_EXPR, type, expr, elt);
 365     }
 366
 367   if (double_int_minus_one_p (scale))
 368     {
 369       if (!expr)
 370         return fold_convert (type, fold_build1 (NEGATE_EXPR, type1, elt));
 371
 372       if (POINTER_TYPE_P (type))
 373         {
 374           elt = fold_build1 (NEGATE_EXPR, type1, elt);
 375           return fold_build2 (POINTER_PLUS_EXPR, type, expr, elt);
 376         }
 377       return fold_build2 (MINUS_EXPR, type, expr, elt);
 378     }
 379
 380   if (!expr)
 381     return fold_convert (type,
 382                          fold_build2 (MULT_EXPR, type1, elt,
 383                                       double_int_to_tree (type1, scale)));
 384
 385   if (double_int_negative_p (scale))
 386     {
 387       code = MINUS_EXPR;
 388       scale = double_int_neg (scale);
 389     }
 390   else
 391     code = PLUS_EXPR;
 392
 393   elt = fold_build2 (MULT_EXPR, type1, elt,
 394                      double_int_to_tree (type1, scale));
 395   if (POINTER_TYPE_P (type))
 396     {
 397       if (code == MINUS_EXPR)
 398         elt = fold_build1 (NEGATE_EXPR, type1, elt);
 399       return fold_build2 (POINTER_PLUS_EXPR, type, expr, elt);
 400     }
 401   return fold_build2 (code, type, expr, elt);
 402 }
 403
 404 /* Makes tree from the affine combination COMB.  */
 405
 406 tree
 407 aff_combination_to_tree (aff_tree *comb)
 408 {
 409   tree type = comb->type;
 410   tree expr = comb->rest;
 411   unsigned i;
 412   double_int off, sgn;
 413   tree type1 = type;
 414   if (POINTER_TYPE_P (type))
 415     type1 = sizetype;
 416
 417   gcc_assert (comb->n == MAX_AFF_ELTS || comb->rest == NULL_TREE);
 418
 419   for (i = 0; i < comb->n; i++)
 420     expr = add_elt_to_tree (expr, type, comb->elts[i].val, comb->elts[i].coef,
 421                             comb);
 422
 423   /* Ensure that we get x - 1, not x + (-1) or x + 0xff..f if x is
 424      unsigned.  */
 425   if (double_int_negative_p (comb->offset))
 426     {
 427       off = double_int_neg (comb->offset);
 428       sgn = double_int_minus_one;
 429     }
 430   else
 431     {
 432       off = comb->offset;
 433       sgn = double_int_one;
 434     }
 435   return add_elt_to_tree (expr, type, double_int_to_tree (type1, off), sgn,
 436                           comb);
 437 }
 438
 439 /* Copies the tree elements of COMB to ensure that they are not shared.  */
 440
 441 void
 442 unshare_aff_combination (aff_tree *comb)
 443 {
 444   unsigned i;
 445
 446   for (i = 0; i < comb->n; i++)
 447     comb->elts[i].val = unshare_expr (comb->elts[i].val);
 448   if (comb->rest)
 449     comb->rest = unshare_expr (comb->rest);
 450 }
 451
 452 /* Remove M-th element from COMB.  */
 453
 454 void
 455 aff_combination_remove_elt (aff_tree *comb, unsigned m)
 456 {
 457   comb->n--;
 458   if (m <= comb->n)
 459     comb->elts[m] = comb->elts[comb->n];
 460   if (comb->rest)
 461     {
 462       comb->elts[comb->n].coef = double_int_one;
 463       comb->elts[comb->n].val = comb->rest;
 464       comb->rest = NULL_TREE;
 465       comb->n++;
 466     }
 467 }
 468
 469 /* Adds C * COEF * VAL to R.  VAL may be NULL, in that case only
 470    C * COEF is added to R.  */
 471
 472
 473 static void
 474 aff_combination_add_product (aff_tree *c, double_int coef, tree val,
 475                              aff_tree *r)
 476 {
 477   unsigned i;
 478   tree aval, type;
 479
 480   for (i = 0; i < c->n; i++)
 481     {
 482       aval = c->elts[i].val;
 483       if (val)
 484         {
 485           type = TREE_TYPE (aval);
 486           aval = fold_build2 (MULT_EXPR, type, aval,
 487                               fold_convert (type, val));
 488         }
 489
 490       aff_combination_add_elt (r, aval,
 491                                double_int_mul (coef, c->elts[i].coef));
 492     }
 493
 494   if (c->rest)
 495     {
 496       aval = c->rest;
 497       if (val)
 498         {
 499           type = TREE_TYPE (aval);
 500           aval = fold_build2 (MULT_EXPR, type, aval,
 501                               fold_convert (type, val));
 502         }
 503
 504       aff_combination_add_elt (r, aval, coef);
 505     }
 506
 507   if (val)
 508     aff_combination_add_elt (r, val,
 509                              double_int_mul (coef, c->offset));
 510   else
 511     aff_combination_add_cst (r, double_int_mul (coef, c->offset));
 512 }
 513
 514 /* Multiplies C1 by C2, storing the result to R  */
 515
 516 void
 517 aff_combination_mult (aff_tree *c1, aff_tree *c2, aff_tree *r)
 518 {
 519   unsigned i;
 520   gcc_assert (TYPE_PRECISION (c1->type) == TYPE_PRECISION (c2->type));
 521
 522   aff_combination_zero (r, c1->type);
 523
 524   for (i = 0; i < c2->n; i++)
 525     aff_combination_add_product (c1, c2->elts[i].coef, c2->elts[i].val, r);
 526   if (c2->rest)
 527     aff_combination_add_product (c1, double_int_one, c2->rest, r);
 528   aff_combination_add_product (c1, c2->offset, NULL, r);
 529 }
 530
 531 /* Returns the element of COMB whose value is VAL, or NULL if no such
 532    element exists.  If IDX is not NULL, it is set to the index of VAL in
 533    COMB.  */
 534
 535 static struct aff_comb_elt *
 536 aff_combination_find_elt (aff_tree *comb, tree val, unsigned *idx)
 537 {
 538   unsigned i;
 539
 540   for (i = 0; i < comb->n; i++)
 541     if (operand_equal_p (comb->elts[i].val, val, 0))
 542       {
 543         if (idx)
 544           *idx = i;
 545
 546         return &comb->elts[i];
 547       }
 548
 549   return NULL;
 550 }
 551
 552 /* Element of the cache that maps ssa name NAME to its expanded form
 553    as an affine expression EXPANSION.  */
 554
 555 struct name_expansion
 556 {
 557   aff_tree expansion;
 558
 559   /* True if the expansion for the name is just being generated.  */
 560   unsigned in_progress : 1;
 561 };
 562
 563 /* Expands SSA names in COMB recursively.  CACHE is used to cache the
 564    results.  */
 565
 566 void
 567 aff_combination_expand (aff_tree *comb ATTRIBUTE_UNUSED,
 568                         struct pointer_map_t **cache ATTRIBUTE_UNUSED)
 569 {
 570   unsigned i;
 571   aff_tree to_add, current, curre;
 572   tree e, rhs;
 573   gimple def;
 574   double_int scale;
 575   void **slot;
 576   struct name_expansion *exp;
 577
 578   aff_combination_zero (&to_add, comb->type);
 579   for (i = 0; i < comb->n; i++)
 580     {
 581       tree type, name;
 582       enum tree_code code;
 583
 584       e = comb->elts[i].val;
 585       type = TREE_TYPE (e);
 586       name = e;
 587       /* Look through some conversions.  */
 588       if (TREE_CODE (e) == NOP_EXPR
 589           && (TYPE_PRECISION (type)
 590               >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (e, 0)))))
 591         name = TREE_OPERAND (e, 0);
 592       if (TREE_CODE (name) != SSA_NAME)
 593         continue;
 594       def = SSA_NAME_DEF_STMT (name);
 595       if (!is_gimple_assign (def) || gimple_assign_lhs (def) != name)
 596         continue;
 597
 598       code = gimple_assign_rhs_code (def);
 599       if (code != SSA_NAME
 600           && !IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
 601           && (get_gimple_rhs_class (code) != GIMPLE_SINGLE_RHS
 602               || !is_gimple_min_invariant (gimple_assign_rhs1 (def))))
 603         continue;
 604
 605       /* We do not know whether the reference retains its value at the
 606          place where the expansion is used.  */
 607       if (TREE_CODE_CLASS (code) == tcc_reference)
 608         continue;
 609
 610       if (!*cache)
 611         *cache = pointer_map_create ();
 612       slot = pointer_map_insert (*cache, e);
 613       exp = (struct name_expansion *) *slot;
 614
 615       if (!exp)
 616         {
 617           exp = XNEW (struct name_expansion);
 618           exp->in_progress = 1;
 619           *slot = exp;
 620           /* In principle this is a generally valid folding, but
 621              it is not unconditionally an optimization, so do it
 622              here and not in fold_unary.  */
 623           /* Convert (T1)(X *+- CST) into (T1)X *+- (T1)CST if T1 is wider
 624              than the type of X and overflow for the type of X is
 625              undefined.  */
 626           if (e != name
 627               && INTEGRAL_TYPE_P (type)
 628               && INTEGRAL_TYPE_P (TREE_TYPE (name))
 629               && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (name))
 630               && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (name))
 631               && (code == PLUS_EXPR || code == MINUS_EXPR || code == MULT_EXPR)
 632               && TREE_CODE (gimple_assign_rhs2 (def)) == INTEGER_CST)
 633             rhs = fold_build2 (code, type,
 634                                fold_convert (type, gimple_assign_rhs1 (def)),
 635                                fold_convert (type, gimple_assign_rhs2 (def)));
 636           else
 637             {
 638               rhs = gimple_assign_rhs_to_tree (def);
 639               if (e != name)
 640                 rhs = fold_convert (type, rhs);
 641             }
 642           tree_to_aff_combination_expand (rhs, comb->type, &current, cache);
 643           exp->expansion = current;
 644           exp->in_progress = 0;
 645         }
 646       else
 647         {
 648           /* Since we follow the definitions in the SSA form, we should not
 649              enter a cycle unless we pass through a phi node.  */
 650           gcc_assert (!exp->in_progress);
 651           current = exp->expansion;
 652         }
 653
 654       /* Accumulate the new terms to TO_ADD, so that we do not modify
 655          COMB while traversing it; include the term -coef * E, to remove
 656          it from COMB.  */
 657       scale = comb->elts[i].coef;
 658       aff_combination_zero (&curre, comb->type);
 659       aff_combination_add_elt (&curre, e, double_int_neg (scale));
 660       aff_combination_scale (&current, scale);
 661       aff_combination_add (&to_add, &current);
 662       aff_combination_add (&to_add, &curre);
 663     }
 664   aff_combination_add (comb, &to_add);
 665 }
 666
 667 /* Similar to tree_to_aff_combination, but follows SSA name definitions
 668    and expands them recursively.  CACHE is used to cache the expansions
 669    of the ssa names, to avoid exponential time complexity for cases
 670    like
 671
 672    a1 = a0 + a0;
 673    a2 = a1 + a1;
 674    a3 = a2 + a2;
 675    ...  */
 676
 677 void
 678 tree_to_aff_combination_expand (tree expr, tree type, aff_tree *comb,
 679                                 struct pointer_map_t **cache)
 680 {
 681   tree_to_aff_combination (expr, type, comb);
 682   aff_combination_expand (comb, cache);
 683 }
 684
 685 /* Frees memory occupied by struct name_expansion in *VALUE.  Callback for
 686    pointer_map_traverse.  */
 687
 688 static bool
 689 free_name_expansion (const void *key ATTRIBUTE_UNUSED, void **value,
 690                      void *data ATTRIBUTE_UNUSED)
 691 {
 692   struct name_expansion *const exp = (struct name_expansion *) *value;
 693
 694   free (exp);
 695   return true;
 696 }
 697
 698 /* Frees memory allocated for the CACHE used by
 699    tree_to_aff_combination_expand.  */
 700
 701 void
 702 free_affine_expand_cache (struct pointer_map_t **cache)
 703 {
 704   if (!*cache)
 705     return;
 706
 707   pointer_map_traverse (*cache, free_name_expansion, NULL);
 708   pointer_map_destroy (*cache);
 709   *cache = NULL;
 710 }
 711
 712 /* If VAL != CST * DIV for any constant CST, returns false.
 713    Otherwise, if VAL != 0 (and hence CST != 0), and *MULT_SET is true,
 714    additionally compares CST and MULT, and if they are different,
 715    returns false.  Finally, if neither of these two cases occur,
 716    true is returned, and if CST != 0, CST is stored to MULT and
 717    MULT_SET is set to true.  */
 718
 719 static bool
 720 double_int_constant_multiple_p (double_int val, double_int div,
 721                                 bool *mult_set, double_int *mult)
 722 {
 723   double_int rem, cst;
 724
 725   if (double_int_zero_p (val))
 726     return true;
 727
 728   if (double_int_zero_p (div))
 729     return false;
 730
 731   cst = double_int_sdivmod (val, div, FLOOR_DIV_EXPR, &rem);
 732   if (!double_int_zero_p (rem))
 733     return false;
 734
 735   if (*mult_set && !double_int_equal_p (*mult, cst))
 736     return false;
 737
 738   *mult_set = true;
 739   *mult = cst;
 740   return true;
 741 }
 742
 743 /* Returns true if VAL = X * DIV for some constant X.  If this is the case,
 744    X is stored to MULT.  */
 745
 746 bool
 747 aff_combination_constant_multiple_p (aff_tree *val, aff_tree *div,
 748                                      double_int *mult)
 749 {
 750   bool mult_set = false;
 751   unsigned i;
 752
 753   if (val->n == 0 && double_int_zero_p (val->offset))
 754     {
 755       *mult = double_int_zero;
 756       return true;
 757     }
 758   if (val->n != div->n)
 759     return false;
 760
 761   if (val->rest || div->rest)
 762     return false;
 763
 764   if (!double_int_constant_multiple_p (val->offset, div->offset,
 765                                        &mult_set, mult))
 766     return false;
 767
 768   for (i = 0; i < div->n; i++)
 769     {
 770       struct aff_comb_elt *elt
 771               = aff_combination_find_elt (val, div->elts[i].val, NULL);
 772       if (!elt)
 773         return false;
 774       if (!double_int_constant_multiple_p (elt->coef, div->elts[i].coef,
 775                                            &mult_set, mult))
 776         return false;
 777     }
 778
 779   gcc_assert (mult_set);
 780   return true;
 781 }
 782
 783 /* Prints the affine VAL to the FILE. */
 784
 785 void
 786 print_aff (FILE *file, aff_tree *val)
 787 {
 788   unsigned i;
 789   bool uns = TYPE_UNSIGNED (val->type);
 790   if (POINTER_TYPE_P (val->type))
 791     uns = false;
 792   fprintf (file, "{\n  type = ");
 793   print_generic_expr (file, val->type, TDF_VOPS|TDF_MEMSYMS);
 794   fprintf (file, "\n  offset = ");
 795   dump_double_int (file, val->offset, uns);
 796   if (val->n > 0)
 797     {
 798       fprintf (file, "\n  elements = {\n");
 799       for (i = 0; i < val->n; i++)
 800         {
 801           fprintf (file, "    [%d] = ", i);
 802           print_generic_expr (file, val->elts[i].val, TDF_VOPS|TDF_MEMSYMS);
 803
 804           fprintf (file, " * ");
 805           dump_double_int (file, val->elts[i].coef, uns);
 806           if (i != val->n - 1)
 807             fprintf (file, ", \n");
 808         }
 809       fprintf (file, "\n  }");
 810   }
 811   if (val->rest)
 812     {
 813       fprintf (file, "\n  rest = ");
 814       print_generic_expr (file, val->rest, TDF_VOPS|TDF_MEMSYMS);
 815     }
 816   fprintf (file, "\n}");
 817 }
 818
 819 /* Prints the affine VAL to the standard error, used for debugging.  */
 820
 821 void
 822 debug_aff (aff_tree *val)
 823 {
 824   print_aff (stderr, val);
 825   fprintf (stderr, "\n");
 826 }
 827
 828 /* Returns address of the reference REF in ADDR.  The size of the accessed
 829    location is stored to SIZE.  */
 830
 831 void
 832 get_inner_reference_aff (tree ref, aff_tree *addr, double_int *size)
 833 {
 834   HOST_WIDE_INT bitsize, bitpos;
 835   tree toff;
 836   enum machine_mode mode;
 837   int uns, vol;
 838   aff_tree tmp;
 839   tree base = get_inner_reference (ref, &bitsize, &bitpos, &toff, &mode,
 840                                    &uns, &vol, false);
 841   tree base_addr = build_fold_addr_expr (base);
 842
 843   /* ADDR = &BASE + TOFF + BITPOS / BITS_PER_UNIT.  */
 844
 845   tree_to_aff_combination (base_addr, sizetype, addr);
 846
 847   if (toff)
 848     {
 849       tree_to_aff_combination (toff, sizetype, &tmp);
 850       aff_combination_add (addr, &tmp);
 851     }
 852
 853   aff_combination_const (&tmp, sizetype,
 854                          shwi_to_double_int (bitpos / BITS_PER_UNIT));
 855   aff_combination_add (addr, &tmp);
 856
 857   *size = shwi_to_double_int ((bitsize + BITS_PER_UNIT - 1) / BITS_PER_UNIT);
 858 }
 859