gcc/graphite.h

   1 /* Graphite polyhedral representation.
   2    Copyright (C) 2009-2015 Free Software Foundation, Inc.
   3    Contributed by Sebastian Pop <sebastian.pop@amd.com> and
   4    Tobias Grosser <grosser@fim.uni-passau.de>.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License 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 #ifndef GCC_GRAPHITE_POLY_H
  23 #define GCC_GRAPHITE_POLY_H
  24
  25 #include "sese.h"
  26 #include <isl/schedule.h>
  27
  28 #ifndef HAVE_ISL_OPTIONS_SET_SCHEDULE_SERIALIZE_SCCS
  29   /* isl 0.14.  */
  30 # define isl_stat int
  31 # define isl_stat_ok 0
  32 #endif
  33
  34 typedef struct poly_dr *poly_dr_p;
  35
  36 typedef struct poly_bb *poly_bb_p;
  37
  38 typedef struct scop *scop_p;
  39
  40 typedef unsigned graphite_dim_t;
  41
  42 static inline graphite_dim_t scop_nb_params (scop_p);
  43
  44 /* A data reference can write or read some memory or we
  45    just know it may write some memory.  */
  46 enum poly_dr_type
  47 {
  48   PDR_READ,
  49   /* PDR_MAY_READs are represented using PDR_READS.  This does not
  50      limit the expressiveness.  */
  51   PDR_WRITE,
  52   PDR_MAY_WRITE
  53 };
  54
  55 struct poly_dr
  56 {
  57   /* An identifier for this PDR.  */
  58   int id;
  59
  60   /* The number of data refs identical to this one in the PBB.  */
  61   int nb_refs;
  62
  63   /* A pointer to the gimple stmt containing this reference.  */
  64   gimple *stmt;
  65
  66   /* A pointer to the PBB that contains this data reference.  */
  67   poly_bb_p pbb;
  68
  69   enum poly_dr_type type;
  70
  71   /* The access polyhedron contains the polyhedral space this data
  72      reference will access.
  73
  74      The polyhedron contains these dimensions:
  75
  76      - The alias set (a):
  77      Every memory access is classified in at least one alias set.
  78
  79      - The subscripts (s_0, ..., s_n):
  80      The memory is accessed using zero or more subscript dimensions.
  81
  82      - The iteration domain (variables and parameters)
  83
  84      Do not hardcode the dimensions.  Use the following accessor functions:
  85      - pdr_alias_set_dim
  86      - pdr_subscript_dim
  87      - pdr_iterator_dim
  88      - pdr_parameter_dim
  89
  90      Example:
  91
  92      | int A[1335][123];
  93      | int *p = malloc ();
  94      |
  95      | k = ...
  96      | for i
  97      |   {
  98      |     if (unknown_function ())
  99      |       p = A;
 100      |       ... = p[?][?];
 101      |     for j
 102      |       A[i][j+k] = m;
 103      |   }
 104
 105      The data access A[i][j+k] in alias set "5" is described like this:
 106
 107      | i   j   k   a  s0  s1   1
 108      | 0   0   0   1   0   0  -5     =  0
 109      |-1   0   0   0   1   0   0     =  0
 110      | 0  -1  -1   0   0   1   0     =  0
 111      | 0   0   0   0   1   0   0     >= 0  # The last four lines describe the
 112      | 0   0   0   0   0   1   0     >= 0  # array size.
 113      | 0   0   0   0  -1   0 1335    >= 0
 114      | 0   0   0   0   0  -1 123     >= 0
 115
 116      The pointer "*p" in alias set "5" and "7" is described as a union of
 117      polyhedron:
 118
 119
 120      | i   k   a  s0   1
 121      | 0   0   1   0  -5   =  0
 122      | 0   0   0   1   0   >= 0
 123
 124      "or"
 125
 126      | i   k   a  s0   1
 127      | 0   0   1   0  -7   =  0
 128      | 0   0   0   1   0   >= 0
 129
 130      "*p" accesses all of the object allocated with 'malloc'.
 131
 132      The scalar data access "m" is represented as an array with zero subscript
 133      dimensions.
 134
 135      | i   j   k   a   1
 136      | 0   0   0  -1   15  = 0
 137
 138      The difference between the graphite internal format for access data and
 139      the OpenSop format is in the order of columns.
 140      Instead of having:
 141
 142      | i   j   k   a  s0  s1   1
 143      | 0   0   0   1   0   0  -5     =  0
 144      |-1   0   0   0   1   0   0     =  0
 145      | 0  -1  -1   0   0   1   0     =  0
 146      | 0   0   0   0   1   0   0     >= 0  # The last four lines describe the
 147      | 0   0   0   0   0   1   0     >= 0  # array size.
 148      | 0   0   0   0  -1   0 1335    >= 0
 149      | 0   0   0   0   0  -1 123     >= 0
 150
 151      In OpenScop we have:
 152
 153      | a  s0  s1   i   j   k   1
 154      | 1   0   0   0   0   0  -5     =  0
 155      | 0   1   0  -1   0   0   0     =  0
 156      | 0   0   1   0  -1  -1   0     =  0
 157      | 0   1   0   0   0   0   0     >= 0  # The last four lines describe the
 158      | 0   0   1   0   0   0   0     >= 0  # array size.
 159      | 0  -1   0   0   0   0 1335    >= 0
 160      | 0   0  -1   0   0   0 123     >= 0
 161
 162      The OpenScop access function is printed as follows:
 163
 164      | 1  # The number of disjunct components in a union of access functions.
 165      | R C O I L P  # Described bellow.
 166      | a  s0  s1   i   j   k   1
 167      | 1   0   0   0   0   0  -5     =  0
 168      | 0   1   0  -1   0   0   0     =  0
 169      | 0   0   1   0  -1  -1   0     =  0
 170      | 0   1   0   0   0   0   0     >= 0  # The last four lines describe the
 171      | 0   0   1   0   0   0   0     >= 0  # array size.
 172      | 0  -1   0   0   0   0 1335    >= 0
 173      | 0   0  -1   0   0   0 123     >= 0
 174
 175      Where:
 176      - R: Number of rows.
 177      - C: Number of columns.
 178      - O: Number of output dimensions = alias set + number of subscripts.
 179      - I: Number of input dimensions (iterators).
 180      - L: Number of local (existentially quantified) dimensions.
 181      - P: Number of parameters.
 182
 183      In the example, the vector "R C O I L P" is "7 7 3 2 0 1".  */
 184   isl_map *accesses;
 185   isl_set *subscript_sizes;
 186 };
 187
 188 #define PDR_ID(PDR) (PDR->id)
 189 #define PDR_NB_REFS(PDR) (PDR->nb_refs)
 190 #define PDR_PBB(PDR) (PDR->pbb)
 191 #define PDR_TYPE(PDR) (PDR->type)
 192 #define PDR_ACCESSES(PDR) (NULL)
 193
 194 void new_poly_dr (poly_bb_p, gimple *, enum poly_dr_type,
 195                   isl_map *, isl_set *);
 196 void free_poly_dr (poly_dr_p);
 197 void debug_pdr (poly_dr_p);
 198 void print_pdr (FILE *, poly_dr_p);
 199
 200 static inline bool
 201 pdr_read_p (poly_dr_p pdr)
 202 {
 203   return PDR_TYPE (pdr) == PDR_READ;
 204 }
 205
 206 /* Returns true when PDR is a "write".  */
 207
 208 static inline bool
 209 pdr_write_p (poly_dr_p pdr)
 210 {
 211   return PDR_TYPE (pdr) == PDR_WRITE;
 212 }
 213
 214 /* Returns true when PDR is a "may write".  */
 215
 216 static inline bool
 217 pdr_may_write_p (poly_dr_p pdr)
 218 {
 219   return PDR_TYPE (pdr) == PDR_MAY_WRITE;
 220 }
 221
 222 /* POLY_BB represents a blackbox in the polyhedral model.  */
 223
 224 struct poly_bb
 225 {
 226   /* Pointer to a basic block or a statement in the compiler.  */
 227   gimple_poly_bb_p black_box;
 228
 229   /* Pointer to the SCOP containing this PBB.  */
 230   scop_p scop;
 231
 232   /* The iteration domain of this bb.  The layout of this polyhedron
 233      is I|G with I the iteration domain, G the context parameters.
 234
 235      Example:
 236
 237      for (i = a - 7*b + 8; i <= 3*a + 13*b + 20; i++)
 238        for (j = 2; j <= 2*i + 5; j++)
 239          for (k = 0; k <= 5; k++)
 240            S (i,j,k)
 241
 242      Loop iterators: i, j, k
 243      Parameters: a, b
 244
 245      | i >=  a -  7b +  8
 246      | i <= 3a + 13b + 20
 247      | j >= 2
 248      | j <= 2i + 5
 249      | k >= 0
 250      | k <= 5
 251
 252      The number of variables in the DOMAIN may change and is not
 253      related to the number of loops in the original code.  */
 254   isl_set *domain;
 255
 256   /* The data references we access.  */
 257   vec<poly_dr_p> drs;
 258
 259   /* The original scattering.  */
 260   isl_map *schedule;
 261
 262   /* The transformed scattering.  */
 263   isl_map *transformed;
 264
 265   /* A copy of the transformed scattering.  */
 266   isl_map *saved;
 267
 268   /* True when this PBB contains only a reduction statement.  */
 269   bool is_reduction;
 270
 271   /* The last basic block generated for this pbb.  */
 272   basic_block new_bb;
 273 };
 274
 275 #define PBB_BLACK_BOX(PBB) ((gimple_poly_bb_p) PBB->black_box)
 276 #define PBB_SCOP(PBB) (PBB->scop)
 277 #define PBB_DRS(PBB) (PBB->drs)
 278 #define PBB_IS_REDUCTION(PBB) (PBB->is_reduction)
 279
 280 extern poly_bb_p new_poly_bb (scop_p, gimple_poly_bb_p);
 281 extern void free_poly_bb (poly_bb_p);
 282 extern void debug_loop_vec (poly_bb_p);
 283 extern void print_pbb_domain (FILE *, poly_bb_p);
 284 extern void print_pbb (FILE *, poly_bb_p);
 285 extern void print_scop_context (FILE *, scop_p);
 286 extern void print_scop (FILE *, scop_p);
 287 extern void debug_pbb_domain (poly_bb_p);
 288 extern void debug_pbb (poly_bb_p);
 289 extern void print_pdrs (FILE *, poly_bb_p);
 290 extern void debug_pdrs (poly_bb_p);
 291 extern void debug_scop_context (scop_p);
 292 extern void debug_scop (scop_p);
 293 extern void print_scop_params (FILE *, scop_p);
 294 extern void debug_scop_params (scop_p);
 295 extern void print_iteration_domain (FILE *, poly_bb_p);
 296 extern void print_iteration_domains (FILE *, scop_p);
 297 extern void debug_iteration_domain (poly_bb_p);
 298 extern void debug_iteration_domains (scop_p);
 299 extern void print_isl_set (FILE *, isl_set *);
 300 extern void print_isl_map (FILE *, isl_map *);
 301 extern void print_isl_union_map (FILE *, isl_union_map *);
 302 extern void print_isl_aff (FILE *, isl_aff *);
 303 extern void print_isl_constraint (FILE *, isl_constraint *);
 304 extern void debug_isl_set (isl_set *);
 305 extern void debug_isl_map (isl_map *);
 306 extern void debug_isl_union_map (isl_union_map *);
 307 extern void debug_isl_aff (isl_aff *);
 308 extern void debug_isl_constraint (isl_constraint *);
 309 extern int scop_do_interchange (scop_p);
 310 extern int scop_do_strip_mine (scop_p, int);
 311 extern bool scop_do_block (scop_p);
 312 extern bool flatten_all_loops (scop_p);
 313 extern bool optimize_isl (scop_p);
 314 extern void pbb_number_of_iterations_at_time (poly_bb_p, graphite_dim_t, mpz_t);
 315 extern void debug_gmp_value (mpz_t);
 316
 317 /* The basic block of the PBB.  */
 318
 319 static inline basic_block
 320 pbb_bb (poly_bb_p pbb)
 321 {
 322   return GBB_BB (PBB_BLACK_BOX (pbb));
 323 }
 324
 325 static inline int
 326 pbb_index (poly_bb_p pbb)
 327 {
 328   return pbb_bb (pbb)->index;
 329 }
 330
 331 /* The loop of the PBB.  */
 332
 333 static inline loop_p
 334 pbb_loop (poly_bb_p pbb)
 335 {
 336   return gbb_loop (PBB_BLACK_BOX (pbb));
 337 }
 338
 339 /* The scop that contains the PDR.  */
 340
 341 static inline scop_p
 342 pdr_scop (poly_dr_p pdr)
 343 {
 344   return PBB_SCOP (PDR_PBB (pdr));
 345 }
 346
 347 /* Set black box of PBB to BLACKBOX.  */
 348
 349 static inline void
 350 pbb_set_black_box (poly_bb_p pbb, gimple_poly_bb_p black_box)
 351 {
 352   pbb->black_box = black_box;
 353 }
 354
 355 /* A helper structure to keep track of data references, polyhedral BBs, and
 356    alias sets.  */
 357
 358 struct dr_info
 359 {
 360   enum {
 361     invalid_alias_set = -1
 362   };
 363   /* The data reference.  */
 364   data_reference_p dr;
 365
 366   /* The polyhedral BB containing this DR.  */
 367   poly_bb_p pbb;
 368
 369   /* ALIAS_SET is the SCC number assigned by a graph_dfs of the alias graph.
 370      -1 is an invalid alias set.  */
 371   int alias_set;
 372
 373   /* Construct a DR_INFO from a data reference DR, an ALIAS_SET, and a PBB.  */
 374   dr_info (data_reference_p dr, poly_bb_p pbb,
 375            int alias_set = invalid_alias_set)
 376     : dr (dr), pbb (pbb), alias_set (alias_set) {}
 377 };
 378
 379 /* A SCOP is a Static Control Part of the program, simple enough to be
 380    represented in polyhedral form.  */
 381 struct scop
 382 {
 383   /* A SCOP is defined as a SESE region.  */
 384   sese_info_p scop_info;
 385
 386   /* Number of parameters in SCoP.  */
 387   graphite_dim_t nb_params;
 388
 389   /* All the basic blocks in this scop that contain memory references
 390      and that will be represented as statements in the polyhedral
 391      representation.  */
 392   vec<poly_bb_p> pbbs;
 393
 394   /* All the data references in this scop.  */
 395   vec<dr_info> drs;
 396
 397   /* The context describes known restrictions concerning the parameters
 398      and relations in between the parameters.
 399
 400   void f (int8_t a, uint_16_t b) {
 401     c = 2 a + b;
 402     ...
 403   }
 404
 405   Here we can add these restrictions to the context:
 406
 407   -128 >= a >= 127
 408      0 >= b >= 65,535
 409      c = 2a + b  */
 410   isl_set *param_context;
 411
 412   /* The context used internally by ISL.  */
 413   isl_ctx *isl_context;
 414
 415   /* SCoP final schedule.  */
 416   isl_schedule *schedule;
 417
 418   /* The data dependence relation among the data references in this scop.  */
 419   isl_union_map *dependence;
 420 };
 421
 422 extern scop_p new_scop (edge, edge);
 423 extern void free_scop (scop_p);
 424 extern gimple_poly_bb_p new_gimple_poly_bb (basic_block, vec<data_reference_p>,
 425                                             vec<scalar_use>, vec<tree>);
 426 extern void free_gimple_poly_bb (gimple_poly_bb_p);
 427 extern void print_generated_program (FILE *, scop_p);
 428 extern void debug_generated_program (scop_p);
 429 extern int unify_scattering_dimensions (scop_p);
 430 extern bool apply_poly_transforms (scop_p);
 431
 432 /* Set the region of SCOP to REGION.  */
 433
 434 static inline void
 435 scop_set_region (scop_p scop, sese_info_p region)
 436 {
 437   scop->scop_info = region;
 438 }
 439
 440 /* Returns the number of parameters for SCOP.  */
 441
 442 static inline graphite_dim_t
 443 scop_nb_params (scop_p scop)
 444 {
 445   return scop->nb_params;
 446 }
 447
 448 /* Set the number of params of SCOP to NB_PARAMS.  */
 449
 450 static inline void
 451 scop_set_nb_params (scop_p scop, graphite_dim_t nb_params)
 452 {
 453   scop->nb_params = nb_params;
 454 }
 455
 456 isl_union_map *
 457 scop_get_dependences (scop_p scop);
 458
 459 bool
 460 carries_deps (__isl_keep isl_union_map *schedule,
 461               __isl_keep isl_union_map *deps,
 462               int depth);
 463
 464 extern bool build_poly_scop (scop_p);
 465 extern bool graphite_regenerate_ast_isl (scop_p);
 466
 467 extern void build_scops (vec<scop_p> *);
 468 extern void dot_all_sese (FILE *, vec<sese_l> &);
 469 extern void dot_sese (sese_l &);
 470 extern void dot_cfg ();
 471 #endif