gcc/fortran/target-memory.c

   1 /* Simulate storage of variables into target memory.
   2    Copyright (C) 2007, 2008
   3    Free Software Foundation, Inc.
   4    Contributed by Paul Thomas and Brooks Moses
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "flags.h"
  25 #include "machmode.h"
  26 #include "tree.h"
  27 #include "gfortran.h"
  28 #include "arith.h"
  29 #include "trans.h"
  30 #include "trans-const.h"
  31 #include "trans-types.h"
  32 #include "target-memory.h"
  33
  34 /* --------------------------------------------------------------- */
  35 /* Calculate the size of an expression.  */
  36
  37 static size_t
  38 size_array (gfc_expr *e)
  39 {
  40   mpz_t array_size;
  41   size_t elt_size = gfc_target_expr_size (e->value.constructor->expr);
  42
  43   gfc_array_size (e, &array_size);
  44   return (size_t)mpz_get_ui (array_size) * elt_size;
  45 }
  46
  47 static size_t
  48 size_integer (int kind)
  49 {
  50   return GET_MODE_SIZE (TYPE_MODE (gfc_get_int_type (kind)));;
  51 }
  52
  53
  54 static size_t
  55 size_float (int kind)
  56 {
  57   return GET_MODE_SIZE (TYPE_MODE (gfc_get_real_type (kind)));;
  58 }
  59
  60
  61 static size_t
  62 size_complex (int kind)
  63 {
  64   return 2 * size_float (kind);
  65 }
  66
  67
  68 static size_t
  69 size_logical (int kind)
  70 {
  71   return GET_MODE_SIZE (TYPE_MODE (gfc_get_logical_type (kind)));;
  72 }
  73
  74
  75 static size_t
  76 size_character (int length, int kind)
  77 {
  78   int i = gfc_validate_kind (BT_CHARACTER, kind, false);
  79   return length * gfc_character_kinds[i].bit_size / 8;
  80 }
  81
  82
  83 size_t
  84 gfc_target_expr_size (gfc_expr *e)
  85 {
  86   tree type;
  87
  88   gcc_assert (e != NULL);
  89
  90   if (e->expr_type == EXPR_ARRAY)
  91     return size_array (e);
  92
  93   switch (e->ts.type)
  94     {
  95     case BT_INTEGER:
  96       return size_integer (e->ts.kind);
  97     case BT_REAL:
  98       return size_float (e->ts.kind);
  99     case BT_COMPLEX:
 100       return size_complex (e->ts.kind);
 101     case BT_LOGICAL:
 102       return size_logical (e->ts.kind);
 103     case BT_CHARACTER:
 104       if (e->expr_type == EXPR_SUBSTRING && e->ref)
 105         {
 106           int start, end;
 107
 108           gfc_extract_int (e->ref->u.ss.start, &start);
 109           gfc_extract_int (e->ref->u.ss.end, &end);
 110           return size_character (MAX(end - start + 1, 0), e->ts.kind);
 111         }
 112       else
 113         return size_character (e->value.character.length, e->ts.kind);
 114     case BT_HOLLERITH:
 115       return e->representation.length;
 116     case BT_DERIVED:
 117       type = gfc_typenode_for_spec (&e->ts);
 118       return int_size_in_bytes (type);
 119     default:
 120       gfc_internal_error ("Invalid expression in gfc_target_expr_size.");
 121       return 0;
 122     }
 123 }
 124
 125
 126 /* The encode_* functions export a value into a buffer, and
 127    return the number of bytes of the buffer that have been
 128    used.  */
 129
 130 static int
 131 encode_array (gfc_expr *expr, unsigned char *buffer, size_t buffer_size)
 132 {
 133   mpz_t array_size;
 134   int i;
 135   int ptr = 0;
 136
 137   gfc_array_size (expr, &array_size);
 138   for (i = 0; i < (int)mpz_get_ui (array_size); i++)
 139     {
 140       ptr += gfc_target_encode_expr (gfc_get_array_element (expr, i),
 141                                      &buffer[ptr], buffer_size - ptr);
 142     }
 143
 144   mpz_clear (array_size);
 145   return ptr;
 146 }
 147
 148
 149 static int
 150 encode_integer (int kind, mpz_t integer, unsigned char *buffer,
 151                 size_t buffer_size)
 152 {
 153   return native_encode_expr (gfc_conv_mpz_to_tree (integer, kind),
 154                              buffer, buffer_size);
 155 }
 156
 157
 158 static int
 159 encode_float (int kind, mpfr_t real, unsigned char *buffer, size_t buffer_size)
 160 {
 161   return native_encode_expr (gfc_conv_mpfr_to_tree (real, kind), buffer,
 162                              buffer_size);
 163 }
 164
 165
 166 static int
 167 encode_complex (int kind, mpfr_t real, mpfr_t imaginary, unsigned char *buffer,
 168                 size_t buffer_size)
 169 {
 170   int size;
 171   size = encode_float (kind, real, &buffer[0], buffer_size);
 172   size += encode_float (kind, imaginary, &buffer[size], buffer_size - size);
 173   return size;
 174 }
 175
 176
 177 static int
 178 encode_logical (int kind, int logical, unsigned char *buffer, size_t buffer_size)
 179 {
 180   return native_encode_expr (build_int_cst (gfc_get_logical_type (kind),
 181                                             logical),
 182                              buffer, buffer_size);
 183 }
 184
 185
 186 int
 187 gfc_encode_character (int kind, int length, const gfc_char_t *string,
 188                       unsigned char *buffer, size_t buffer_size)
 189 {
 190   size_t elsize = size_character (1, kind);
 191   tree type = gfc_get_char_type (kind);
 192   int i;
 193
 194   gcc_assert (buffer_size >= size_character (length, kind));
 195
 196   for (i = 0; i < length; i++)
 197     native_encode_expr (build_int_cst (type, string[i]), &buffer[i*elsize],
 198                         elsize);
 199
 200   return length;
 201 }
 202
 203
 204 static int
 205 encode_derived (gfc_expr *source, unsigned char *buffer, size_t buffer_size)
 206 {
 207   gfc_constructor *ctr;
 208   gfc_component *cmp;
 209   int ptr;
 210   tree type;
 211
 212   type = gfc_typenode_for_spec (&source->ts);
 213
 214   ctr = source->value.constructor;
 215   cmp = source->ts.derived->components;
 216   for (;ctr; ctr = ctr->next, cmp = cmp->next)
 217     {
 218       gcc_assert (cmp);
 219       if (!ctr->expr)
 220         continue;
 221       ptr = TREE_INT_CST_LOW(DECL_FIELD_OFFSET(cmp->backend_decl))
 222             + TREE_INT_CST_LOW(DECL_FIELD_BIT_OFFSET(cmp->backend_decl))/8;
 223       gfc_target_encode_expr (ctr->expr, &buffer[ptr],
 224                               buffer_size - ptr);
 225     }
 226
 227   return int_size_in_bytes (type);
 228 }
 229
 230
 231 /* Write a constant expression in binary form to a buffer.  */
 232 int
 233 gfc_target_encode_expr (gfc_expr *source, unsigned char *buffer,
 234                         size_t buffer_size)
 235 {
 236   if (source == NULL)
 237     return 0;
 238
 239   if (source->expr_type == EXPR_ARRAY)
 240     return encode_array (source, buffer, buffer_size);
 241
 242   gcc_assert (source->expr_type == EXPR_CONSTANT
 243               || source->expr_type == EXPR_STRUCTURE
 244               || source->expr_type == EXPR_SUBSTRING);
 245
 246   /* If we already have a target-memory representation, we use that rather
 247      than recreating one.  */
 248   if (source->representation.string)
 249     {
 250       memcpy (buffer, source->representation.string,
 251               source->representation.length);
 252       return source->representation.length;
 253     }
 254
 255   switch (source->ts.type)
 256     {
 257     case BT_INTEGER:
 258       return encode_integer (source->ts.kind, source->value.integer, buffer,
 259                              buffer_size);
 260     case BT_REAL:
 261       return encode_float (source->ts.kind, source->value.real, buffer,
 262                            buffer_size);
 263     case BT_COMPLEX:
 264       return encode_complex (source->ts.kind, source->value.complex.r,
 265                              source->value.complex.i, buffer, buffer_size);
 266     case BT_LOGICAL:
 267       return encode_logical (source->ts.kind, source->value.logical, buffer,
 268                              buffer_size);
 269     case BT_CHARACTER:
 270       if (source->expr_type == EXPR_CONSTANT || source->ref == NULL)
 271         return gfc_encode_character (source->ts.kind,
 272                                      source->value.character.length,
 273                                      source->value.character.string,
 274                                      buffer, buffer_size);
 275       else
 276         {
 277           int start, end;
 278
 279           gcc_assert (source->expr_type == EXPR_SUBSTRING);
 280           gfc_extract_int (source->ref->u.ss.start, &start);
 281           gfc_extract_int (source->ref->u.ss.end, &end);
 282           return gfc_encode_character (source->ts.kind, MAX(end - start + 1, 0),
 283                                        &source->value.character.string[start-1],
 284                                        buffer, buffer_size);
 285         }
 286
 287     case BT_DERIVED:
 288       return encode_derived (source, buffer, buffer_size);
 289     default:
 290       gfc_internal_error ("Invalid expression in gfc_target_encode_expr.");
 291       return 0;
 292     }
 293 }
 294
 295
 296 static int
 297 interpret_array (unsigned char *buffer, size_t buffer_size, gfc_expr *result)
 298 {
 299   int array_size = 1;
 300   int i;
 301   int ptr = 0;
 302   gfc_constructor *head = NULL, *tail = NULL;
 303
 304   /* Calculate array size from its shape and rank.  */
 305   gcc_assert (result->rank > 0 && result->shape);
 306
 307   for (i = 0; i < result->rank; i++)
 308     array_size *= (int)mpz_get_ui (result->shape[i]);
 309
 310   /* Iterate over array elements, producing constructors.  */
 311   for (i = 0; i < array_size; i++)
 312     {
 313       if (head == NULL)
 314         head = tail = gfc_get_constructor ();
 315       else
 316         {
 317           tail->next = gfc_get_constructor ();
 318           tail = tail->next;
 319         }
 320
 321       tail->where = result->where;
 322       tail->expr = gfc_constant_result (result->ts.type,
 323                                           result->ts.kind, &result->where);
 324       tail->expr->ts = result->ts;
 325
 326       if (tail->expr->ts.type == BT_CHARACTER)
 327         tail->expr->value.character.length = result->value.character.length;
 328
 329       ptr += gfc_target_interpret_expr (&buffer[ptr], buffer_size - ptr,
 330                                         tail->expr);
 331     }
 332   result->value.constructor = head;
 333
 334   return ptr;
 335 }
 336
 337
 338 int
 339 gfc_interpret_integer (int kind, unsigned char *buffer, size_t buffer_size,
 340                    mpz_t integer)
 341 {
 342   mpz_init (integer);
 343   gfc_conv_tree_to_mpz (integer,
 344                         native_interpret_expr (gfc_get_int_type (kind),
 345                                                buffer, buffer_size));
 346   return size_integer (kind);
 347 }
 348
 349
 350 int
 351 gfc_interpret_float (int kind, unsigned char *buffer, size_t buffer_size,
 352                  mpfr_t real)
 353 {
 354   mpfr_init (real);
 355   gfc_conv_tree_to_mpfr (real,
 356                          native_interpret_expr (gfc_get_real_type (kind),
 357                                                 buffer, buffer_size));
 358
 359   return size_float (kind);
 360 }
 361
 362
 363 int
 364 gfc_interpret_complex (int kind, unsigned char *buffer, size_t buffer_size,
 365                    mpfr_t real, mpfr_t imaginary)
 366 {
 367   int size;
 368   size = gfc_interpret_float (kind, &buffer[0], buffer_size, real);
 369   size += gfc_interpret_float (kind, &buffer[size], buffer_size - size,
 370                                imaginary);
 371   return size;
 372 }
 373
 374
 375 int
 376 gfc_interpret_logical (int kind, unsigned char *buffer, size_t buffer_size,
 377                    int *logical)
 378 {
 379   tree t = native_interpret_expr (gfc_get_logical_type (kind), buffer,
 380                                   buffer_size);
 381   *logical = double_int_zero_p (tree_to_double_int (t))
 382              ? 0 : 1;
 383   return size_logical (kind);
 384 }
 385
 386
 387 int
 388 gfc_interpret_character (unsigned char *buffer, size_t buffer_size,
 389                          gfc_expr *result)
 390 {
 391   int i;
 392
 393   if (result->ts.cl && result->ts.cl->length)
 394     result->value.character.length =
 395       (int) mpz_get_ui (result->ts.cl->length->value.integer);
 396
 397   gcc_assert (buffer_size >= size_character (result->value.character.length,
 398                                              result->ts.kind));
 399   result->value.character.string =
 400     gfc_get_wide_string (result->value.character.length + 1);
 401
 402   gcc_assert (result->ts.kind == gfc_default_character_kind);
 403   for (i = 0; i < result->value.character.length; i++)
 404     result->value.character.string[i] = (gfc_char_t) buffer[i];
 405   result->value.character.string[result->value.character.length] = '\0';
 406
 407   return result->value.character.length;
 408 }
 409
 410
 411 int
 412 gfc_interpret_derived (unsigned char *buffer, size_t buffer_size, gfc_expr *result)
 413 {
 414   gfc_component *cmp;
 415   gfc_constructor *head = NULL, *tail = NULL;
 416   int ptr;
 417   tree type;
 418
 419   /* The attributes of the derived type need to be bolted to the floor.  */
 420   result->expr_type = EXPR_STRUCTURE;
 421
 422   type = gfc_typenode_for_spec (&result->ts);
 423   cmp = result->ts.derived->components;
 424
 425   /* Run through the derived type components.  */
 426   for (;cmp; cmp = cmp->next)
 427     {
 428       if (head == NULL)
 429         head = tail = gfc_get_constructor ();
 430       else
 431         {
 432           tail->next = gfc_get_constructor ();
 433           tail = tail->next;
 434         }
 435
 436       /* The constructor points to the component.  */
 437       tail->n.component = cmp;
 438
 439       tail->expr = gfc_constant_result (cmp->ts.type, cmp->ts.kind,
 440                                         &result->where);
 441       tail->expr->ts = cmp->ts;
 442
 443       /* Copy shape, if needed.  */
 444       if (cmp->as && cmp->as->rank)
 445         {
 446           int n;
 447
 448           tail->expr->expr_type = EXPR_ARRAY;
 449           tail->expr->rank = cmp->as->rank;
 450
 451           tail->expr->shape = gfc_get_shape (tail->expr->rank);
 452           for (n = 0; n < tail->expr->rank; n++)
 453              {
 454                mpz_init_set_ui (tail->expr->shape[n], 1);
 455                mpz_add (tail->expr->shape[n], tail->expr->shape[n],
 456                         cmp->as->upper[n]->value.integer);
 457                mpz_sub (tail->expr->shape[n], tail->expr->shape[n],
 458                         cmp->as->lower[n]->value.integer);
 459              }
 460         }
 461
 462       ptr = TREE_INT_CST_LOW (DECL_FIELD_OFFSET (cmp->backend_decl));
 463       gfc_target_interpret_expr (&buffer[ptr], buffer_size - ptr,
 464                                  tail->expr);
 465
 466       result->value.constructor = head;
 467     }
 468
 469   return int_size_in_bytes (type);
 470 }
 471
 472
 473 /* Read a binary buffer to a constant expression.  */
 474 int
 475 gfc_target_interpret_expr (unsigned char *buffer, size_t buffer_size,
 476                            gfc_expr *result)
 477 {
 478   if (result->expr_type == EXPR_ARRAY)
 479     return interpret_array (buffer, buffer_size, result);
 480
 481   switch (result->ts.type)
 482     {
 483     case BT_INTEGER:
 484       result->representation.length =
 485         gfc_interpret_integer (result->ts.kind, buffer, buffer_size,
 486                                result->value.integer);
 487       break;
 488
 489     case BT_REAL:
 490       result->representation.length =
 491         gfc_interpret_float (result->ts.kind, buffer, buffer_size,
 492                              result->value.real);
 493       break;
 494
 495     case BT_COMPLEX:
 496       result->representation.length =
 497         gfc_interpret_complex (result->ts.kind, buffer, buffer_size,
 498                                result->value.complex.r,
 499                                result->value.complex.i);
 500       break;
 501
 502     case BT_LOGICAL:
 503       result->representation.length =
 504         gfc_interpret_logical (result->ts.kind, buffer, buffer_size,
 505                                &result->value.logical);
 506       break;
 507
 508     case BT_CHARACTER:
 509       result->representation.length =
 510         gfc_interpret_character (buffer, buffer_size, result);
 511       break;
 512
 513     case BT_DERIVED:
 514       result->representation.length =
 515         gfc_interpret_derived (buffer, buffer_size, result);
 516       break;
 517
 518     default:
 519       gfc_internal_error ("Invalid expression in gfc_target_interpret_expr.");
 520       break;
 521     }
 522
 523   if (result->ts.type == BT_CHARACTER)
 524     result->representation.string
 525       = gfc_widechar_to_char (result->value.character.string,
 526                               result->value.character.length);
 527   else
 528     {
 529       result->representation.string =
 530         gfc_getmem (result->representation.length + 1);
 531       memcpy (result->representation.string, buffer,
 532               result->representation.length);
 533       result->representation.string[result->representation.length] = '\0';
 534     }
 535
 536   return result->representation.length;
 537 }
 538
 539
 540 /* --------------------------------------------------------------- */
 541 /* Two functions used by trans-common.c to write overlapping
 542    equivalence initializers to a buffer.  This is added to the union
 543    and the original initializers freed.  */
 544
 545
 546 /* Writes the values of a constant expression to a char buffer. If another
 547    unequal initializer has already been written to the buffer, this is an
 548    error.  */
 549
 550 static size_t
 551 expr_to_char (gfc_expr *e, unsigned char *data, unsigned char *chk, size_t len)
 552 {
 553   int i;
 554   int ptr;
 555   gfc_constructor *ctr;
 556   gfc_component *cmp;
 557   unsigned char *buffer;
 558
 559   if (e == NULL)
 560     return 0;
 561
 562   /* Take a derived type, one component at a time, using the offsets from the backend
 563      declaration.  */
 564   if (e->ts.type == BT_DERIVED)
 565     {
 566       ctr = e->value.constructor;
 567       cmp = e->ts.derived->components;
 568       for (;ctr; ctr = ctr->next, cmp = cmp->next)
 569         {
 570           gcc_assert (cmp && cmp->backend_decl);
 571           if (!ctr->expr)
 572             continue;
 573             ptr = TREE_INT_CST_LOW(DECL_FIELD_OFFSET(cmp->backend_decl))
 574                         + TREE_INT_CST_LOW(DECL_FIELD_BIT_OFFSET(cmp->backend_decl))/8;
 575           expr_to_char (ctr->expr, &data[ptr], &chk[ptr], len);
 576         }
 577       return len;
 578     }
 579
 580   /* Otherwise, use the target-memory machinery to write a bitwise image, appropriate
 581      to the target, in a buffer and check off the initialized part of the buffer.  */
 582   len = gfc_target_expr_size (e);
 583   buffer = (unsigned char*)alloca (len);
 584   len = gfc_target_encode_expr (e, buffer, len);
 585
 586     for (i = 0; i < (int)len; i++)
 587     {
 588       if (chk[i] && (buffer[i] != data[i]))
 589         {
 590           gfc_error ("Overlapping unequal initializers in EQUIVALENCE "
 591                      "at %L", &e->where);
 592           return 0;
 593         }
 594       chk[i] = 0xFF;
 595     }
 596
 597   memcpy (data, buffer, len);
 598   return len;
 599 }
 600
 601
 602 /* Writes the values from the equivalence initializers to a char* array
 603    that will be written to the constructor to make the initializer for
 604    the union declaration.  */
 605
 606 size_t
 607 gfc_merge_initializers (gfc_typespec ts, gfc_expr *e, unsigned char *data,
 608                         unsigned char *chk, size_t length)
 609 {
 610   size_t len = 0;
 611   gfc_constructor * c;
 612
 613   switch (e->expr_type)
 614     {
 615     case EXPR_CONSTANT:
 616     case EXPR_STRUCTURE:
 617       len = expr_to_char (e, &data[0], &chk[0], length);
 618
 619       break;
 620
 621     case EXPR_ARRAY:
 622       for (c = e->value.constructor; c; c = c->next)
 623         {
 624           size_t elt_size = gfc_target_expr_size (c->expr);
 625
 626           if (c->n.offset)
 627             len = elt_size * (size_t)mpz_get_si (c->n.offset);
 628
 629           len = len + gfc_merge_initializers (ts, c->expr, &data[len],
 630                                               &chk[len], length - len);
 631         }
 632       break;
 633
 634     default:
 635       return 0;
 636     }
 637
 638   return len;
 639 }
 640
 641
 642 /* Transfer the bitpattern of a (integer) BOZ to real or complex variables.
 643    When successful, no BOZ or nothing to do, true is returned.  */
 644
 645 bool
 646 gfc_convert_boz (gfc_expr *expr, gfc_typespec *ts)
 647 {
 648   size_t buffer_size, boz_bit_size, ts_bit_size;
 649   int index;
 650   unsigned char *buffer;
 651
 652   if (!expr->is_boz)
 653     return true;
 654
 655   gcc_assert (expr->expr_type == EXPR_CONSTANT
 656               && expr->ts.type == BT_INTEGER);
 657
 658   /* Don't convert BOZ to logical, character, derived etc.  */
 659   if (ts->type == BT_REAL)
 660     {
 661       buffer_size = size_float (ts->kind);
 662       ts_bit_size = buffer_size * 8;
 663     }
 664   else if (ts->type == BT_COMPLEX)
 665     {
 666       buffer_size = size_complex (ts->kind);
 667       ts_bit_size = buffer_size * 8 / 2;
 668     }
 669   else
 670     return true;
 671
 672   /* Convert BOZ to the smallest possible integer kind.  */
 673   boz_bit_size = mpz_sizeinbase (expr->value.integer, 2);
 674
 675   if (boz_bit_size > ts_bit_size)
 676     {
 677       gfc_error_now ("BOZ constant at %L is too large (%ld vs %ld bits)",
 678                      &expr->where, (long) boz_bit_size, (long) ts_bit_size);
 679       return false;
 680     }
 681
 682   for (index = 0; gfc_integer_kinds[index].kind != 0; ++index)
 683     {
 684         if ((unsigned) gfc_integer_kinds[index].bit_size >= ts_bit_size)
 685           break;
 686     }
 687
 688   expr->ts.kind = gfc_integer_kinds[index].kind;
 689   buffer_size = MAX (buffer_size, size_integer (expr->ts.kind));
 690
 691   buffer = (unsigned char*)alloca (buffer_size);
 692   encode_integer (expr->ts.kind, expr->value.integer, buffer, buffer_size);
 693   mpz_clear (expr->value.integer);
 694
 695   if (ts->type == BT_REAL)
 696     {
 697       mpfr_init (expr->value.real);
 698       gfc_interpret_float (ts->kind, buffer, buffer_size, expr->value.real);
 699     }
 700   else
 701     {
 702       mpfr_init (expr->value.complex.r);
 703       mpfr_init (expr->value.complex.i);
 704       gfc_interpret_complex (ts->kind, buffer, buffer_size,
 705                              expr->value.complex.r, expr->value.complex.i);
 706     }
 707   expr->is_boz = 0;
 708   expr->ts.type = ts->type;
 709   expr->ts.kind = ts->kind;
 710
 711   return true;
 712 }