gcc/graphite-poly.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
  27 #ifndef HAVE_ISL_OPTIONS_SET_SCHEDULE_SERIALIZE_SCCS
  28 # define isl_stat int
  29 # define isl_stat_ok 0
  30 #endif
  31
  32 typedef struct poly_dr *poly_dr_p;
  33
  34 typedef struct poly_bb *poly_bb_p;
  35
  36 typedef struct scop *scop_p;
  37
  38 typedef unsigned graphite_dim_t;
  39
  40 static inline graphite_dim_t scop_nb_params (scop_p);
  41
  42 /* A data reference can write or read some memory or we
  43    just know it may write some memory.  */
  44 enum poly_dr_type
  45 {
  46   PDR_READ,
  47   /* PDR_MAY_READs are represented using PDR_READS.  This does not
  48      limit the expressiveness.  */
  49   PDR_WRITE,
  50   PDR_MAY_WRITE
  51 };
  52
  53 struct poly_dr
  54 {
  55   /* An identifier for this PDR.  */
  56   int id;
  57
  58   /* The number of data refs identical to this one in the PBB.  */
  59   int nb_refs;
  60
  61   /* A pointer to compiler's data reference description.  */
  62   data_reference_p compiler_dr;
  63
  64   /* A pointer to the PBB that contains this data reference.  */
  65   poly_bb_p pbb;
  66
  67   enum poly_dr_type type;
  68
  69   /* The access polyhedron contains the polyhedral space this data
  70      reference will access.
  71
  72      The polyhedron contains these dimensions:
  73
  74      - The alias set (a):
  75      Every memory access is classified in at least one alias set.
  76
  77      - The subscripts (s_0, ..., s_n):
  78      The memory is accessed using zero or more subscript dimensions.
  79
  80      - The iteration domain (variables and parameters)
  81
  82      Do not hardcode the dimensions.  Use the following accessor functions:
  83      - pdr_alias_set_dim
  84      - pdr_subscript_dim
  85      - pdr_iterator_dim
  86      - pdr_parameter_dim
  87
  88      Example:
  89
  90      | int A[1335][123];
  91      | int *p = malloc ();
  92      |
  93      | k = ...
  94      | for i
  95      |   {
  96      |     if (unknown_function ())
  97      |       p = A;
  98      |       ... = p[?][?];
  99      |     for j
 100      |       A[i][j+k] = m;
 101      |   }
 102
 103      The data access A[i][j+k] in alias set "5" is described like this:
 104
 105      | i   j   k   a  s0  s1   1
 106      | 0   0   0   1   0   0  -5     =  0
 107      |-1   0   0   0   1   0   0     =  0
 108      | 0  -1  -1   0   0   1   0     =  0
 109      | 0   0   0   0   1   0   0     >= 0  # The last four lines describe the
 110      | 0   0   0   0   0   1   0     >= 0  # array size.
 111      | 0   0   0   0  -1   0 1335    >= 0
 112      | 0   0   0   0   0  -1 123     >= 0
 113
 114      The pointer "*p" in alias set "5" and "7" is described as a union of
 115      polyhedron:
 116
 117
 118      | i   k   a  s0   1
 119      | 0   0   1   0  -5   =  0
 120      | 0   0   0   1   0   >= 0
 121
 122      "or"
 123
 124      | i   k   a  s0   1
 125      | 0   0   1   0  -7   =  0
 126      | 0   0   0   1   0   >= 0
 127
 128      "*p" accesses all of the object allocated with 'malloc'.
 129
 130      The scalar data access "m" is represented as an array with zero subscript
 131      dimensions.
 132
 133      | i   j   k   a   1
 134      | 0   0   0  -1   15  = 0
 135
 136      The difference between the graphite internal format for access data and
 137      the OpenSop format is in the order of columns.
 138      Instead of having:
 139
 140      | i   j   k   a  s0  s1   1
 141      | 0   0   0   1   0   0  -5     =  0
 142      |-1   0   0   0   1   0   0     =  0
 143      | 0  -1  -1   0   0   1   0     =  0
 144      | 0   0   0   0   1   0   0     >= 0  # The last four lines describe the
 145      | 0   0   0   0   0   1   0     >= 0  # array size.
 146      | 0   0   0   0  -1   0 1335    >= 0
 147      | 0   0   0   0   0  -1 123     >= 0
 148
 149      In OpenScop we have:
 150
 151      | a  s0  s1   i   j   k   1
 152      | 1   0   0   0   0   0  -5     =  0
 153      | 0   1   0  -1   0   0   0     =  0
 154      | 0   0   1   0  -1  -1   0     =  0
 155      | 0   1   0   0   0   0   0     >= 0  # The last four lines describe the
 156      | 0   0   1   0   0   0   0     >= 0  # array size.
 157      | 0  -1   0   0   0   0 1335    >= 0
 158      | 0   0  -1   0   0   0 123     >= 0
 159
 160      The OpenScop access function is printed as follows:
 161
 162      | 1  # The number of disjunct components in a union of access functions.
 163      | R C O I L P  # Described bellow.
 164      | a  s0  s1   i   j   k   1
 165      | 1   0   0   0   0   0  -5     =  0
 166      | 0   1   0  -1   0   0   0     =  0
 167      | 0   0   1   0  -1  -1   0     =  0
 168      | 0   1   0   0   0   0   0     >= 0  # The last four lines describe the
 169      | 0   0   1   0   0   0   0     >= 0  # array size.
 170      | 0  -1   0   0   0   0 1335    >= 0
 171      | 0   0  -1   0   0   0 123     >= 0
 172
 173      Where:
 174      - R: Number of rows.
 175      - C: Number of columns.
 176      - O: Number of output dimensions = alias set + number of subscripts.
 177      - I: Number of input dimensions (iterators).
 178      - L: Number of local (existentially quantified) dimensions.
 179      - P: Number of parameters.
 180
 181      In the example, the vector "R C O I L P" is "7 7 3 2 0 1".  */
 182   isl_map *accesses;
 183   isl_set *subscript_sizes;
 184
 185   /* The number of subscripts.  */
 186   graphite_dim_t nb_subscripts;
 187 };
 188
 189 #define PDR_ID(PDR) (PDR->id)
 190 #define PDR_NB_REFS(PDR) (PDR->nb_refs)
 191 #define PDR_CDR(PDR) (PDR->compiler_dr)
 192 #define PDR_PBB(PDR) (PDR->pbb)
 193 #define PDR_TYPE(PDR) (PDR->type)
 194 #define PDR_ACCESSES(PDR) (NULL)
 195 #define PDR_NB_SUBSCRIPTS(PDR) (PDR->nb_subscripts)
 196
 197 void new_poly_dr (poly_bb_p, enum poly_dr_type, data_reference_p,
 198                   graphite_dim_t, isl_map *, isl_set *);
 199 void free_poly_dr (poly_dr_p);
 200 void debug_pdr (poly_dr_p);
 201 void print_pdr (FILE *, poly_dr_p);
 202
 203 static inline bool
 204 pdr_read_p (poly_dr_p pdr)
 205 {
 206   return PDR_TYPE (pdr) == PDR_READ;
 207 }
 208
 209 /* Returns true when PDR is a "write".  */
 210
 211 static inline bool
 212 pdr_write_p (poly_dr_p pdr)
 213 {
 214   return PDR_TYPE (pdr) == PDR_WRITE;
 215 }
 216
 217 /* Returns true when PDR is a "may write".  */
 218
 219 static inline bool
 220 pdr_may_write_p (poly_dr_p pdr)
 221 {
 222   return PDR_TYPE (pdr) == PDR_MAY_WRITE;
 223 }
 224
 225 /* POLY_BB represents a blackbox in the polyhedral model.  */
 226
 227 struct poly_bb
 228 {
 229   /* Pointer to a basic block or a statement in the compiler.  */
 230   gimple_poly_bb_p black_box;
 231
 232   /* Pointer to the SCOP containing this PBB.  */
 233   scop_p scop;
 234
 235   /* The iteration domain of this bb.  The layout of this polyhedron
 236      is I|G with I the iteration domain, G the context parameters.
 237
 238      Example:
 239
 240      for (i = a - 7*b + 8; i <= 3*a + 13*b + 20; i++)
 241        for (j = 2; j <= 2*i + 5; j++)
 242          for (k = 0; k <= 5; k++)
 243            S (i,j,k)
 244
 245      Loop iterators: i, j, k
 246      Parameters: a, b
 247
 248      | i >=  a -  7b +  8
 249      | i <= 3a + 13b + 20
 250      | j >= 2
 251      | j <= 2i + 5
 252      | k >= 0
 253      | k <= 5
 254
 255      The number of variables in the DOMAIN may change and is not
 256      related to the number of loops in the original code.  */
 257   isl_set *domain;
 258
 259   /* The data references we access.  */
 260   vec<poly_dr_p> drs;
 261
 262   /* The original scattering.  */
 263   isl_map *schedule;
 264
 265   /* The transformed scattering.  */
 266   isl_map *transformed;
 267
 268   /* A copy of the transformed scattering.  */
 269   isl_map *saved;
 270
 271   /* True when this PBB contains only a reduction statement.  */
 272   bool is_reduction;
 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 /* Returns a gimple_bb from BB.  */
 318
 319 static inline gimple_poly_bb_p
 320 gbb_from_bb (basic_block bb)
 321 {
 322   return (gimple_poly_bb_p) bb->aux;
 323 }
 324
 325 /* The poly_bb of the BB.  */
 326
 327 static inline poly_bb_p
 328 pbb_from_bb (basic_block bb)
 329 {
 330   return GBB_PBB (gbb_from_bb (bb));
 331 }
 332
 333 /* The basic block of the PBB.  */
 334
 335 static inline basic_block
 336 pbb_bb (poly_bb_p pbb)
 337 {
 338   return GBB_BB (PBB_BLACK_BOX (pbb));
 339 }
 340
 341 static inline int
 342 pbb_index (poly_bb_p pbb)
 343 {
 344   return pbb_bb (pbb)->index;
 345 }
 346
 347 /* The loop of the PBB.  */
 348
 349 static inline loop_p
 350 pbb_loop (poly_bb_p pbb)
 351 {
 352   return gbb_loop (PBB_BLACK_BOX (pbb));
 353 }
 354
 355 /* The scop that contains the PDR.  */
 356
 357 static inline scop_p
 358 pdr_scop (poly_dr_p pdr)
 359 {
 360   return PBB_SCOP (PDR_PBB (pdr));
 361 }
 362
 363 /* Set black box of PBB to BLACKBOX.  */
 364
 365 static inline void
 366 pbb_set_black_box (poly_bb_p pbb, gimple_poly_bb_p black_box)
 367 {
 368   pbb->black_box = black_box;
 369 }
 370
 371 /* A helper structure to keep track of data references, polyhedral BBs, and
 372    alias sets.  */
 373
 374 struct dr_info
 375 {
 376   enum {
 377     invalid_alias_set = -1
 378   };
 379   /* The data reference.  */
 380   data_reference_p dr;
 381
 382   /* The polyhedral BB containing this DR.  */
 383   poly_bb_p pbb;
 384
 385   /* ALIAS_SET is the SCC number assigned by a graph_dfs of the alias graph.
 386      -1 is an invalid alias set.  */
 387   int alias_set;
 388
 389   /* Construct a DR_INFO from a data reference DR, an ALIAS_SET, and a PBB.  */
 390   dr_info (data_reference_p dr, poly_bb_p pbb,
 391            int alias_set = invalid_alias_set)
 392     : dr (dr), pbb (pbb), alias_set (alias_set) {}
 393 };
 394
 395 /* A SCOP is a Static Control Part of the program, simple enough to be
 396    represented in polyhedral form.  */
 397 struct scop
 398 {
 399   /* A SCOP is defined as a SESE region.  */
 400   sese_info_p scop_info;
 401
 402   /* Number of parameters in SCoP.  */
 403   graphite_dim_t nb_params;
 404
 405   /* All the basic blocks in this scop that contain memory references
 406      and that will be represented as statements in the polyhedral
 407      representation.  */
 408   vec<poly_bb_p> pbbs;
 409
 410   /* All the data references in this scop.  */
 411   vec<dr_info> drs;
 412
 413   /* The context describes known restrictions concerning the parameters
 414      and relations in between the parameters.
 415
 416   void f (int8_t a, uint_16_t b) {
 417     c = 2 a + b;
 418     ...
 419   }
 420
 421   Here we can add these restrictions to the context:
 422
 423   -128 >= a >= 127
 424      0 >= b >= 65,535
 425      c = 2a + b  */
 426   isl_set *param_context;
 427
 428   /* The context used internally by ISL.  */
 429   isl_ctx *isl_context;
 430
 431   /* The original dependence relations:
 432      RAW are read after write dependences,
 433      WAR are write after read dependences,
 434      WAW are write after write dependences.  */
 435   isl_union_map *must_raw, *may_raw, *must_raw_no_source, *may_raw_no_source,
 436     *must_war, *may_war, *must_war_no_source, *may_war_no_source,
 437     *must_waw, *may_waw, *must_waw_no_source, *may_waw_no_source;
 438
 439   /* True when the scop has been converted to its polyhedral
 440      representation.  */
 441   bool poly_scop_p;
 442 };
 443
 444 extern scop_p new_scop (edge, edge);
 445 extern void free_scop (scop_p);
 446 extern gimple_poly_bb_p new_gimple_poly_bb (basic_block, vec<data_reference_p>);
 447 extern void free_gimple_poly_bb (gimple_poly_bb_p);
 448 extern void print_generated_program (FILE *, scop_p);
 449 extern void debug_generated_program (scop_p);
 450 extern int unify_scattering_dimensions (scop_p);
 451 extern bool apply_poly_transforms (scop_p);
 452
 453 /* Set the region of SCOP to REGION.  */
 454
 455 static inline void
 456 scop_set_region (scop_p scop, sese_info_p region)
 457 {
 458   scop->scop_info = region;
 459 }
 460
 461 /* Returns the number of parameters for SCOP.  */
 462
 463 static inline graphite_dim_t
 464 scop_nb_params (scop_p scop)
 465 {
 466   return scop->nb_params;
 467 }
 468
 469 /* Set the number of params of SCOP to NB_PARAMS.  */
 470
 471 static inline void
 472 scop_set_nb_params (scop_p scop, graphite_dim_t nb_params)
 473 {
 474   scop->nb_params = nb_params;
 475 }
 476
 477 isl_union_map *
 478 scop_get_dependences (scop_p scop);
 479
 480 bool
 481 carries_deps (__isl_keep isl_union_map *schedule,
 482               __isl_keep isl_union_map *deps,
 483               int depth);
 484
 485 #endif