gcc/graphite.h

   1 /* Graphite polyhedral representation.
   2    Copyright (C) 2009-2017 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.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 #include <isl/schedule_node.h>
  40
  41 typedef struct poly_dr *poly_dr_p;
  42
  43 typedef struct poly_bb *poly_bb_p;
  44
  45 typedef struct scop *scop_p;
  46
  47 typedef unsigned graphite_dim_t;
  48
  49 static inline graphite_dim_t scop_nb_params (scop_p);
  50
  51 /* A data reference can write or read some memory or we
  52    just know it may write some memory.  */
  53 enum poly_dr_type
  54 {
  55   PDR_READ,
  56   /* PDR_MAY_READs are represented using PDR_READS.  This does not
  57      limit the expressiveness.  */
  58   PDR_WRITE,
  59   PDR_MAY_WRITE
  60 };
  61
  62 struct poly_dr
  63 {
  64   /* An identifier for this PDR.  */
  65   int id;
  66
  67   /* The number of data refs identical to this one in the PBB.  */
  68   int nb_refs;
  69
  70   /* A pointer to the gimple stmt containing this reference.  */
  71   gimple *stmt;
  72
  73   /* A pointer to the PBB that contains this data reference.  */
  74   poly_bb_p pbb;
  75
  76   enum poly_dr_type type;
  77
  78   /* The access polyhedron contains the polyhedral space this data
  79      reference will access.
  80
  81      The polyhedron contains these dimensions:
  82
  83      - The alias set (a):
  84      Every memory access is classified in at least one alias set.
  85
  86      - The subscripts (s_0, ..., s_n):
  87      The memory is accessed using zero or more subscript dimensions.
  88
  89      - The iteration domain (variables and parameters)
  90
  91      Do not hardcode the dimensions.  Use the following accessor functions:
  92      - pdr_alias_set_dim
  93      - pdr_subscript_dim
  94      - pdr_iterator_dim
  95      - pdr_parameter_dim
  96
  97      Example:
  98
  99      | int A[1335][123];
 100      | int *p = malloc ();
 101      |
 102      | k = ...
 103      | for i
 104      |   {
 105      |     if (unknown_function ())
 106      |       p = A;
 107      |       ... = p[?][?];
 108      |     for j
 109      |       A[i][j+k] = m;
 110      |   }
 111
 112      The data access A[i][j+k] in alias set "5" is described like this:
 113
 114      | i   j   k   a  s0  s1   1
 115      | 0   0   0   1   0   0  -5     =  0
 116      |-1   0   0   0   1   0   0     =  0
 117      | 0  -1  -1   0   0   1   0     =  0
 118      | 0   0   0   0   1   0   0     >= 0  # The last four lines describe the
 119      | 0   0   0   0   0   1   0     >= 0  # array size.
 120      | 0   0   0   0  -1   0 1335    >= 0
 121      | 0   0   0   0   0  -1 123     >= 0
 122
 123      The pointer "*p" in alias set "5" and "7" is described as a union of
 124      polyhedron:
 125
 126
 127      | i   k   a  s0   1
 128      | 0   0   1   0  -5   =  0
 129      | 0   0   0   1   0   >= 0
 130
 131      "or"
 132
 133      | i   k   a  s0   1
 134      | 0   0   1   0  -7   =  0
 135      | 0   0   0   1   0   >= 0
 136
 137      "*p" accesses all of the object allocated with 'malloc'.
 138
 139      The scalar data access "m" is represented as an array with zero subscript
 140      dimensions.
 141
 142      | i   j   k   a   1
 143      | 0   0   0  -1   15  = 0
 144
 145      The difference between the graphite internal format for access data and
 146      the OpenSop format is in the order of columns.
 147      Instead of having:
 148
 149      | i   j   k   a  s0  s1   1
 150      | 0   0   0   1   0   0  -5     =  0
 151      |-1   0   0   0   1   0   0     =  0
 152      | 0  -1  -1   0   0   1   0     =  0
 153      | 0   0   0   0   1   0   0     >= 0  # The last four lines describe the
 154      | 0   0   0   0   0   1   0     >= 0  # array size.
 155      | 0   0   0   0  -1   0 1335    >= 0
 156      | 0   0   0   0   0  -1 123     >= 0
 157
 158      In OpenScop we have:
 159
 160      | a  s0  s1   i   j   k   1
 161      | 1   0   0   0   0   0  -5     =  0
 162      | 0   1   0  -1   0   0   0     =  0
 163      | 0   0   1   0  -1  -1   0     =  0
 164      | 0   1   0   0   0   0   0     >= 0  # The last four lines describe the
 165      | 0   0   1   0   0   0   0     >= 0  # array size.
 166      | 0  -1   0   0   0   0 1335    >= 0
 167      | 0   0  -1   0   0   0 123     >= 0
 168
 169      The OpenScop access function is printed as follows:
 170
 171      | 1  # The number of disjunct components in a union of access functions.
 172      | R C O I L P  # Described bellow.
 173      | a  s0  s1   i   j   k   1
 174      | 1   0   0   0   0   0  -5     =  0
 175      | 0   1   0  -1   0   0   0     =  0
 176      | 0   0   1   0  -1  -1   0     =  0
 177      | 0   1   0   0   0   0   0     >= 0  # The last four lines describe the
 178      | 0   0   1   0   0   0   0     >= 0  # array size.
 179      | 0  -1   0   0   0   0 1335    >= 0
 180      | 0   0  -1   0   0   0 123     >= 0
 181
 182      Where:
 183      - R: Number of rows.
 184      - C: Number of columns.
 185      - O: Number of output dimensions = alias set + number of subscripts.
 186      - I: Number of input dimensions (iterators).
 187      - L: Number of local (existentially quantified) dimensions.
 188      - P: Number of parameters.
 189
 190      In the example, the vector "R C O I L P" is "7 7 3 2 0 1".  */
 191   isl_map *accesses;
 192   isl_set *subscript_sizes;
 193 };
 194
 195 #define PDR_ID(PDR) (PDR->id)
 196 #define PDR_NB_REFS(PDR) (PDR->nb_refs)
 197 #define PDR_PBB(PDR) (PDR->pbb)
 198 #define PDR_TYPE(PDR) (PDR->type)
 199 #define PDR_ACCESSES(PDR) (NULL)
 200
 201 void new_poly_dr (poly_bb_p, gimple *, enum poly_dr_type,
 202                   isl_map *, isl_set *);
 203 void debug_pdr (poly_dr_p);
 204 void print_pdr (FILE *, poly_dr_p);
 205
 206 static inline bool
 207 pdr_read_p (poly_dr_p pdr)
 208 {
 209   return PDR_TYPE (pdr) == PDR_READ;
 210 }
 211
 212 /* Returns true when PDR is a "write".  */
 213
 214 static inline bool
 215 pdr_write_p (poly_dr_p pdr)
 216 {
 217   return PDR_TYPE (pdr) == PDR_WRITE;
 218 }
 219
 220 /* Returns true when PDR is a "may write".  */
 221
 222 static inline bool
 223 pdr_may_write_p (poly_dr_p pdr)
 224 {
 225   return PDR_TYPE (pdr) == PDR_MAY_WRITE;
 226 }
 227
 228 /* POLY_BB represents a blackbox in the polyhedral model.  */
 229
 230 struct poly_bb
 231 {
 232   /* Pointer to a basic block or a statement in the compiler.  */
 233   gimple_poly_bb_p black_box;
 234
 235   /* Pointer to the SCOP containing this PBB.  */
 236   scop_p scop;
 237
 238   /* The iteration domain of this bb.  The layout of this polyhedron
 239      is I|G with I the iteration domain, G the context parameters.
 240
 241      Example:
 242
 243      for (i = a - 7*b + 8; i <= 3*a + 13*b + 20; i++)
 244        for (j = 2; j <= 2*i + 5; j++)
 245          for (k = 0; k <= 5; k++)
 246            S (i,j,k)
 247
 248      Loop iterators: i, j, k
 249      Parameters: a, b
 250
 251      | i >=  a -  7b +  8
 252      | i <= 3a + 13b + 20
 253      | j >= 2
 254      | j <= 2i + 5
 255      | k >= 0
 256      | k <= 5
 257
 258      The number of variables in the DOMAIN may change and is not
 259      related to the number of loops in the original code.  */
 260   isl_set *domain;
 261   isl_set *iterators;
 262
 263   /* The data references we access.  */
 264   vec<poly_dr_p> drs;
 265
 266   /* The last basic block generated for this pbb.  */
 267   basic_block new_bb;
 268 };
 269
 270 #define PBB_BLACK_BOX(PBB) ((gimple_poly_bb_p) PBB->black_box)
 271 #define PBB_SCOP(PBB) (PBB->scop)
 272 #define PBB_DRS(PBB) (PBB->drs)
 273
 274 extern poly_bb_p new_poly_bb (scop_p, gimple_poly_bb_p);
 275 extern void print_pbb_domain (FILE *, poly_bb_p);
 276 extern void print_pbb (FILE *, poly_bb_p);
 277 extern void print_scop_context (FILE *, scop_p);
 278 extern void print_scop (FILE *, scop_p);
 279 extern void debug_pbb_domain (poly_bb_p);
 280 extern void debug_pbb (poly_bb_p);
 281 extern void print_pdrs (FILE *, poly_bb_p);
 282 extern void debug_pdrs (poly_bb_p);
 283 extern void debug_scop_context (scop_p);
 284 extern void debug_scop (scop_p);
 285 extern void print_scop_params (FILE *, scop_p);
 286 extern void debug_scop_params (scop_p);
 287 extern void print_iteration_domain (FILE *, poly_bb_p);
 288 extern void print_iteration_domains (FILE *, scop_p);
 289 extern void debug_iteration_domain (poly_bb_p);
 290 extern void debug_iteration_domains (scop_p);
 291 extern void print_isl_set (FILE *, isl_set *);
 292 extern void print_isl_map (FILE *, isl_map *);
 293 extern void print_isl_union_map (FILE *, isl_union_map *);
 294 extern void print_isl_aff (FILE *, isl_aff *);
 295 extern void print_isl_constraint (FILE *, isl_constraint *);
 296 extern void print_isl_schedule (FILE *, isl_schedule *);
 297 extern void debug_isl_schedule (isl_schedule *);
 298 extern void print_isl_ast (FILE *, isl_ast_node *);
 299 extern void debug_isl_ast (isl_ast_node *);
 300 extern void debug_isl_set (isl_set *);
 301 extern void debug_isl_map (isl_map *);
 302 extern void debug_isl_union_map (isl_union_map *);
 303 extern void debug_isl_aff (isl_aff *);
 304 extern void debug_isl_constraint (isl_constraint *);
 305 extern void debug_gmp_value (mpz_t);
 306 extern void debug_scop_pbb (scop_p scop, int i);
 307 extern void print_schedule_ast (FILE *, __isl_keep isl_schedule *, scop_p);
 308 extern void debug_schedule_ast (__isl_keep isl_schedule *, scop_p);
 309
 310 /* The basic block of the PBB.  */
 311
 312 static inline basic_block
 313 pbb_bb (poly_bb_p pbb)
 314 {
 315   return GBB_BB (PBB_BLACK_BOX (pbb));
 316 }
 317
 318 static inline int
 319 pbb_index (poly_bb_p pbb)
 320 {
 321   return pbb_bb (pbb)->index;
 322 }
 323
 324 /* The loop of the PBB.  */
 325
 326 static inline loop_p
 327 pbb_loop (poly_bb_p pbb)
 328 {
 329   return gbb_loop (PBB_BLACK_BOX (pbb));
 330 }
 331
 332 /* The scop that contains the PDR.  */
 333
 334 static inline scop_p
 335 pdr_scop (poly_dr_p pdr)
 336 {
 337   return PBB_SCOP (PDR_PBB (pdr));
 338 }
 339
 340 /* Set black box of PBB to BLACKBOX.  */
 341
 342 static inline void
 343 pbb_set_black_box (poly_bb_p pbb, gimple_poly_bb_p black_box)
 344 {
 345   pbb->black_box = black_box;
 346 }
 347
 348 /* A helper structure to keep track of data references, polyhedral BBs, and
 349    alias sets.  */
 350
 351 struct dr_info
 352 {
 353   enum {
 354     invalid_alias_set = -1
 355   };
 356   /* The data reference.  */
 357   data_reference_p dr;
 358
 359   /* The polyhedral BB containing this DR.  */
 360   poly_bb_p pbb;
 361
 362   /* ALIAS_SET is the SCC number assigned by a graph_dfs of the alias graph.
 363      -1 is an invalid alias set.  */
 364   int alias_set;
 365
 366   /* Construct a DR_INFO from a data reference DR, an ALIAS_SET, and a PBB.  */
 367   dr_info (data_reference_p dr, poly_bb_p pbb,
 368            int alias_set = invalid_alias_set)
 369     : dr (dr), pbb (pbb), alias_set (alias_set) {}
 370 };
 371
 372 /* A SCOP is a Static Control Part of the program, simple enough to be
 373    represented in polyhedral form.  */
 374 struct scop
 375 {
 376   /* A SCOP is defined as a SESE region.  */
 377   sese_info_p scop_info;
 378
 379   /* Number of parameters in SCoP.  */
 380   graphite_dim_t nb_params;
 381
 382   /* All the basic blocks in this scop that contain memory references
 383      and that will be represented as statements in the polyhedral
 384      representation.  */
 385   vec<poly_bb_p> pbbs;
 386
 387   /* All the data references in this scop.  */
 388   vec<dr_info> drs;
 389
 390   /* The context describes known restrictions concerning the parameters
 391      and relations in between the parameters.
 392
 393   void f (int8_t a, uint_16_t b) {
 394     c = 2 a + b;
 395     ...
 396   }
 397
 398   Here we can add these restrictions to the context:
 399
 400   -128 >= a >= 127
 401      0 >= b >= 65,535
 402      c = 2a + b  */
 403   isl_set *param_context;
 404
 405   /* The context used internally by isl.  */
 406   isl_ctx *isl_context;
 407
 408   /* SCoP original schedule.  */
 409   isl_schedule *original_schedule;
 410
 411   /* SCoP transformed schedule.  */
 412   isl_schedule *transformed_schedule;
 413
 414   /* The data dependence relation among the data references in this scop.  */
 415   isl_union_map *dependence;
 416 };
 417
 418 extern scop_p new_scop (edge, edge);
 419 extern void free_scop (scop_p);
 420 extern gimple_poly_bb_p new_gimple_poly_bb (basic_block, vec<data_reference_p>,
 421                                             vec<scalar_use>, vec<tree>);
 422 extern bool apply_poly_transforms (scop_p);
 423
 424 /* Set the region of SCOP to REGION.  */
 425
 426 static inline void
 427 scop_set_region (scop_p scop, sese_info_p region)
 428 {
 429   scop->scop_info = region;
 430 }
 431
 432 /* Returns the number of parameters for SCOP.  */
 433
 434 static inline graphite_dim_t
 435 scop_nb_params (scop_p scop)
 436 {
 437   return scop->nb_params;
 438 }
 439
 440 /* Set the number of params of SCOP to NB_PARAMS.  */
 441
 442 static inline void
 443 scop_set_nb_params (scop_p scop, graphite_dim_t nb_params)
 444 {
 445   scop->nb_params = nb_params;
 446 }
 447
 448 extern void scop_get_dependences (scop_p scop);
 449
 450 bool
 451 carries_deps (__isl_keep isl_union_map *schedule,
 452               __isl_keep isl_union_map *deps,
 453               int depth);
 454
 455 extern bool build_poly_scop (scop_p);
 456 extern bool graphite_regenerate_ast_isl (scop_p);
 457 extern void build_scops (vec<scop_p> *);
 458 extern void dot_all_sese (FILE *, vec<sese_l> &);
 459 extern void dot_sese (sese_l &);
 460 extern void dot_cfg ();
 461
 462 #endif