gcc/graphite.h

   1 /* Graphite polyhedral representation.
   2    Copyright (C) 2009-2016 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/options.h>
  27 #include <isl/ctx.h>
  28 #include <isl/val_gmp.h>
  29 #include <isl/set.h>
  30 #include <isl/union_set.h>
  31 #include <isl/map.h>
  32 #include <isl/union_map.h>
  33 #include <isl/aff.h>
  34 #include <isl/constraint.h>
  35 #include <isl/flow.h>
  36 #include <isl/ilp.h>
  37 #include <isl/schedule.h>
  38 #include <isl/ast_build.h>
  39
  40 #ifdef HAVE_ISL_OPTIONS_SET_SCHEDULE_SERIALIZE_SCCS
  41 /* isl 0.15 or later.  */
  42 #include <isl/schedule_node.h>
  43
  44 #else
  45 /* isl 0.14 or 0.13.  */
  46 # define isl_stat int
  47 # define isl_stat_ok 0
  48 #endif
  49
  50 typedef struct poly_dr *poly_dr_p;
  51
  52 typedef struct poly_bb *poly_bb_p;
  53
  54 typedef struct scop *scop_p;
  55
  56 typedef unsigned graphite_dim_t;
  57
  58 static inline graphite_dim_t scop_nb_params (scop_p);
  59
  60 /* A data reference can write or read some memory or we
  61    just know it may write some memory.  */
  62 enum poly_dr_type
  63 {
  64   PDR_READ,
  65   /* PDR_MAY_READs are represented using PDR_READS.  This does not
  66      limit the expressiveness.  */
  67   PDR_WRITE,
  68   PDR_MAY_WRITE
  69 };
  70
  71 struct poly_dr
  72 {
  73   /* An identifier for this PDR.  */
  74   int id;
  75
  76   /* The number of data refs identical to this one in the PBB.  */
  77   int nb_refs;
  78
  79   /* A pointer to the gimple stmt containing this reference.  */
  80   gimple *stmt;
  81
  82   /* A pointer to the PBB that contains this data reference.  */
  83   poly_bb_p pbb;
  84
  85   enum poly_dr_type type;
  86
  87   /* The access polyhedron contains the polyhedral space this data
  88      reference will access.
  89
  90      The polyhedron contains these dimensions:
  91
  92      - The alias set (a):
  93      Every memory access is classified in at least one alias set.
  94
  95      - The subscripts (s_0, ..., s_n):
  96      The memory is accessed using zero or more subscript dimensions.
  97
  98      - The iteration domain (variables and parameters)
  99
 100      Do not hardcode the dimensions.  Use the following accessor functions:
 101      - pdr_alias_set_dim
 102      - pdr_subscript_dim
 103      - pdr_iterator_dim
 104      - pdr_parameter_dim
 105
 106      Example:
 107
 108      | int A[1335][123];
 109      | int *p = malloc ();
 110      |
 111      | k = ...
 112      | for i
 113      |   {
 114      |     if (unknown_function ())
 115      |       p = A;
 116      |       ... = p[?][?];
 117      |     for j
 118      |       A[i][j+k] = m;
 119      |   }
 120
 121      The data access A[i][j+k] in alias set "5" is described like this:
 122
 123      | i   j   k   a  s0  s1   1
 124      | 0   0   0   1   0   0  -5     =  0
 125      |-1   0   0   0   1   0   0     =  0
 126      | 0  -1  -1   0   0   1   0     =  0
 127      | 0   0   0   0   1   0   0     >= 0  # The last four lines describe the
 128      | 0   0   0   0   0   1   0     >= 0  # array size.
 129      | 0   0   0   0  -1   0 1335    >= 0
 130      | 0   0   0   0   0  -1 123     >= 0
 131
 132      The pointer "*p" in alias set "5" and "7" is described as a union of
 133      polyhedron:
 134
 135
 136      | i   k   a  s0   1
 137      | 0   0   1   0  -5   =  0
 138      | 0   0   0   1   0   >= 0
 139
 140      "or"
 141
 142      | i   k   a  s0   1
 143      | 0   0   1   0  -7   =  0
 144      | 0   0   0   1   0   >= 0
 145
 146      "*p" accesses all of the object allocated with 'malloc'.
 147
 148      The scalar data access "m" is represented as an array with zero subscript
 149      dimensions.
 150
 151      | i   j   k   a   1
 152      | 0   0   0  -1   15  = 0
 153
 154      The difference between the graphite internal format for access data and
 155      the OpenSop format is in the order of columns.
 156      Instead of having:
 157
 158      | i   j   k   a  s0  s1   1
 159      | 0   0   0   1   0   0  -5     =  0
 160      |-1   0   0   0   1   0   0     =  0
 161      | 0  -1  -1   0   0   1   0     =  0
 162      | 0   0   0   0   1   0   0     >= 0  # The last four lines describe the
 163      | 0   0   0   0   0   1   0     >= 0  # array size.
 164      | 0   0   0   0  -1   0 1335    >= 0
 165      | 0   0   0   0   0  -1 123     >= 0
 166
 167      In OpenScop we have:
 168
 169      | a  s0  s1   i   j   k   1
 170      | 1   0   0   0   0   0  -5     =  0
 171      | 0   1   0  -1   0   0   0     =  0
 172      | 0   0   1   0  -1  -1   0     =  0
 173      | 0   1   0   0   0   0   0     >= 0  # The last four lines describe the
 174      | 0   0   1   0   0   0   0     >= 0  # array size.
 175      | 0  -1   0   0   0   0 1335    >= 0
 176      | 0   0  -1   0   0   0 123     >= 0
 177
 178      The OpenScop access function is printed as follows:
 179
 180      | 1  # The number of disjunct components in a union of access functions.
 181      | R C O I L P  # Described bellow.
 182      | a  s0  s1   i   j   k   1
 183      | 1   0   0   0   0   0  -5     =  0
 184      | 0   1   0  -1   0   0   0     =  0
 185      | 0   0   1   0  -1  -1   0     =  0
 186      | 0   1   0   0   0   0   0     >= 0  # The last four lines describe the
 187      | 0   0   1   0   0   0   0     >= 0  # array size.
 188      | 0  -1   0   0   0   0 1335    >= 0
 189      | 0   0  -1   0   0   0 123     >= 0
 190
 191      Where:
 192      - R: Number of rows.
 193      - C: Number of columns.
 194      - O: Number of output dimensions = alias set + number of subscripts.
 195      - I: Number of input dimensions (iterators).
 196      - L: Number of local (existentially quantified) dimensions.
 197      - P: Number of parameters.
 198
 199      In the example, the vector "R C O I L P" is "7 7 3 2 0 1".  */
 200   isl_map *accesses;
 201   isl_set *subscript_sizes;
 202 };
 203
 204 #define PDR_ID(PDR) (PDR->id)
 205 #define PDR_NB_REFS(PDR) (PDR->nb_refs)
 206 #define PDR_PBB(PDR) (PDR->pbb)
 207 #define PDR_TYPE(PDR) (PDR->type)
 208 #define PDR_ACCESSES(PDR) (NULL)
 209
 210 void new_poly_dr (poly_bb_p, gimple *, enum poly_dr_type,
 211                   isl_map *, isl_set *);
 212 void free_poly_dr (poly_dr_p);
 213 void debug_pdr (poly_dr_p);
 214 void print_pdr (FILE *, poly_dr_p);
 215
 216 static inline bool
 217 pdr_read_p (poly_dr_p pdr)
 218 {
 219   return PDR_TYPE (pdr) == PDR_READ;
 220 }
 221
 222 /* Returns true when PDR is a "write".  */
 223
 224 static inline bool
 225 pdr_write_p (poly_dr_p pdr)
 226 {
 227   return PDR_TYPE (pdr) == PDR_WRITE;
 228 }
 229
 230 /* Returns true when PDR is a "may write".  */
 231
 232 static inline bool
 233 pdr_may_write_p (poly_dr_p pdr)
 234 {
 235   return PDR_TYPE (pdr) == PDR_MAY_WRITE;
 236 }
 237
 238 /* POLY_BB represents a blackbox in the polyhedral model.  */
 239
 240 struct poly_bb
 241 {
 242   /* Pointer to a basic block or a statement in the compiler.  */
 243   gimple_poly_bb_p black_box;
 244
 245   /* Pointer to the SCOP containing this PBB.  */
 246   scop_p scop;
 247
 248   /* The iteration domain of this bb.  The layout of this polyhedron
 249      is I|G with I the iteration domain, G the context parameters.
 250
 251      Example:
 252
 253      for (i = a - 7*b + 8; i <= 3*a + 13*b + 20; i++)
 254        for (j = 2; j <= 2*i + 5; j++)
 255          for (k = 0; k <= 5; k++)
 256            S (i,j,k)
 257
 258      Loop iterators: i, j, k
 259      Parameters: a, b
 260
 261      | i >=  a -  7b +  8
 262      | i <= 3a + 13b + 20
 263      | j >= 2
 264      | j <= 2i + 5
 265      | k >= 0
 266      | k <= 5
 267
 268      The number of variables in the DOMAIN may change and is not
 269      related to the number of loops in the original code.  */
 270   isl_set *domain;
 271
 272   /* The data references we access.  */
 273   vec<poly_dr_p> drs;
 274
 275   /* The original scattering.  */
 276   isl_map *schedule;
 277
 278   /* The transformed scattering.  */
 279   isl_map *transformed;
 280
 281   /* A copy of the transformed scattering.  */
 282   isl_map *saved;
 283
 284   /* True when this PBB contains only a reduction statement.  */
 285   bool is_reduction;
 286
 287   /* The last basic block generated for this pbb.  */
 288   basic_block new_bb;
 289 };
 290
 291 #define PBB_BLACK_BOX(PBB) ((gimple_poly_bb_p) PBB->black_box)
 292 #define PBB_SCOP(PBB) (PBB->scop)
 293 #define PBB_DRS(PBB) (PBB->drs)
 294 #define PBB_IS_REDUCTION(PBB) (PBB->is_reduction)
 295
 296 extern poly_bb_p new_poly_bb (scop_p, gimple_poly_bb_p);
 297 extern void free_poly_bb (poly_bb_p);
 298 extern void debug_loop_vec (poly_bb_p);
 299 extern void print_pbb_domain (FILE *, poly_bb_p);
 300 extern void print_pbb (FILE *, poly_bb_p);
 301 extern void print_scop_context (FILE *, scop_p);
 302 extern void print_scop (FILE *, scop_p);
 303 extern void debug_pbb_domain (poly_bb_p);
 304 extern void debug_pbb (poly_bb_p);
 305 extern void print_pdrs (FILE *, poly_bb_p);
 306 extern void debug_pdrs (poly_bb_p);
 307 extern void debug_scop_context (scop_p);
 308 extern void debug_scop (scop_p);
 309 extern void print_scop_params (FILE *, scop_p);
 310 extern void debug_scop_params (scop_p);
 311 extern void print_iteration_domain (FILE *, poly_bb_p);
 312 extern void print_iteration_domains (FILE *, scop_p);
 313 extern void debug_iteration_domain (poly_bb_p);
 314 extern void debug_iteration_domains (scop_p);
 315 extern void print_isl_set (FILE *, isl_set *);
 316 extern void print_isl_map (FILE *, isl_map *);
 317 extern void print_isl_union_map (FILE *, isl_union_map *);
 318 extern void print_isl_aff (FILE *, isl_aff *);
 319 extern void print_isl_constraint (FILE *, isl_constraint *);
 320 extern void debug_isl_set (isl_set *);
 321 extern void debug_isl_map (isl_map *);
 322 extern void debug_isl_union_map (isl_union_map *);
 323 extern void debug_isl_aff (isl_aff *);
 324 extern void debug_isl_constraint (isl_constraint *);
 325 extern int scop_do_interchange (scop_p);
 326 extern int scop_do_strip_mine (scop_p, int);
 327 extern bool scop_do_block (scop_p);
 328 extern bool flatten_all_loops (scop_p);
 329 extern bool optimize_isl (scop_p);
 330 extern void pbb_number_of_iterations_at_time (poly_bb_p, graphite_dim_t, mpz_t);
 331 extern void debug_gmp_value (mpz_t);
 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   /* SCoP final schedule.  */
 432   isl_schedule *schedule;
 433
 434   /* The data dependence relation among the data references in this scop.  */
 435   isl_union_map *dependence;
 436 };
 437
 438 extern scop_p new_scop (edge, edge);
 439 extern void free_scop (scop_p);
 440 extern gimple_poly_bb_p new_gimple_poly_bb (basic_block, vec<data_reference_p>,
 441                                             vec<scalar_use>, vec<tree>);
 442 extern void free_gimple_poly_bb (gimple_poly_bb_p);
 443 extern void print_generated_program (FILE *, scop_p);
 444 extern void debug_generated_program (scop_p);
 445 extern int unify_scattering_dimensions (scop_p);
 446 extern bool apply_poly_transforms (scop_p);
 447
 448 /* Set the region of SCOP to REGION.  */
 449
 450 static inline void
 451 scop_set_region (scop_p scop, sese_info_p region)
 452 {
 453   scop->scop_info = region;
 454 }
 455
 456 /* Returns the number of parameters for SCOP.  */
 457
 458 static inline graphite_dim_t
 459 scop_nb_params (scop_p scop)
 460 {
 461   return scop->nb_params;
 462 }
 463
 464 /* Set the number of params of SCOP to NB_PARAMS.  */
 465
 466 static inline void
 467 scop_set_nb_params (scop_p scop, graphite_dim_t nb_params)
 468 {
 469   scop->nb_params = nb_params;
 470 }
 471
 472 isl_union_map *
 473 scop_get_dependences (scop_p scop);
 474
 475 bool
 476 carries_deps (__isl_keep isl_union_map *schedule,
 477               __isl_keep isl_union_map *deps,
 478               int depth);
 479
 480 extern bool build_poly_scop (scop_p);
 481 extern bool graphite_regenerate_ast_isl (scop_p);
 482
 483 extern void build_scops (vec<scop_p> *);
 484 extern void dot_all_sese (FILE *, vec<sese_l> &);
 485 extern void dot_sese (sese_l &);
 486 extern void dot_cfg ();
 487 #endif