--- /dev/null
+/* A scheduling optimizer for Graphite
+ Copyright (C) 2012 Free Software Foundation, Inc.
+ Contributed by Tobias Grosser <tobias@grosser.es>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+
+#ifdef HAVE_cloog
+#include <isl/set.h>
+#include <isl/map.h>
+#include <isl/union_map.h>
+#include <isl/schedule.h>
+#include <isl/band.h>
+#include <isl/aff.h>
+#include <isl/options.h>
+
+#include "system.h"
+#include "coretypes.h"
+#include "tree-flow.h"
+#include "tree-dump.h"
+#include "cfgloop.h"
+#include "tree-chrec.h"
+#include "tree-data-ref.h"
+#include "tree-scalar-evolution.h"
+#include "sese.h"
+
+#include "graphite-poly.h"
+
+static isl_union_set *
+scop_get_domains (scop_p scop ATTRIBUTE_UNUSED)
+{
+ int i;
+ poly_bb_p pbb;
+ isl_space *space = isl_set_get_space (scop->context);
+ isl_union_set *res = isl_union_set_empty (space);
+
+ FOR_EACH_VEC_ELT (poly_bb_p, scop->bbs, i, pbb)
+ res = isl_union_set_add_set (res, isl_set_copy (pbb->domain));
+
+ return res;
+}
+
+static isl_union_map *
+scop_get_dependences (scop_p scop)
+{
+ isl_union_map *dependences;
+
+ if (!scop->must_raw)
+ compute_deps (scop, SCOP_BBS (scop),
+ &scop->must_raw, &scop->may_raw,
+ &scop->must_raw_no_source, &scop->may_raw_no_source,
+ &scop->must_war, &scop->may_war,
+ &scop->must_war_no_source, &scop->may_war_no_source,
+ &scop->must_waw, &scop->may_waw,
+ &scop->must_waw_no_source, &scop->may_waw_no_source);
+
+ dependences = isl_union_map_copy (scop->must_raw);
+ dependences = isl_union_map_union (dependences,
+ isl_union_map_copy (scop->must_war));
+ dependences = isl_union_map_union (dependences,
+ isl_union_map_copy (scop->must_waw));
+ dependences = isl_union_map_union (dependences,
+ isl_union_map_copy (scop->may_raw));
+ dependences = isl_union_map_union (dependences,
+ isl_union_map_copy (scop->may_war));
+ dependences = isl_union_map_union (dependences,
+ isl_union_map_copy (scop->may_waw));
+
+ return dependences;
+}
+
+/* getTileMap - Create a map that describes a n-dimensonal tiling.
+
+ getTileMap creates a map from a n-dimensional scattering space into an
+ 2*n-dimensional scattering space. The map describes a rectangular tiling.
+
+ Example:
+ scheduleDimensions = 2, parameterDimensions = 1, tileSize = 32
+
+ tileMap := [p0] -> {[s0, s1] -> [t0, t1, s0, s1]:
+ t0 % 32 = 0 and t0 <= s0 < t0 + 32 and
+ t1 % 32 = 0 and t1 <= s1 < t1 + 32}
+
+ Before tiling:
+
+ for (i = 0; i < N; i++)
+ for (j = 0; j < M; j++)
+ S(i,j)
+
+ After tiling:
+
+ for (t_i = 0; t_i < N; i+=32)
+ for (t_j = 0; t_j < M; j+=32)
+ for (i = t_i; i < min(t_i + 32, N); i++) | Unknown that N % 32 = 0
+ for (j = t_j; j < t_j + 32; j++) | Known that M % 32 = 0
+ S(i,j)
+ */
+
+static isl_basic_map *
+getTileMap(isl_ctx *ctx, int scheduleDimensions, int tileSize)
+{
+ int x;
+ /* We construct
+
+ tileMap := [p0] -> {[s0, s1] -> [t0, t1, p0, p1, a0, a1]:
+ s0 = a0 * 32 and s0 = p0 and t0 <= p0 < t0 + 32 and
+ s1 = a1 * 32 and s1 = p1 and t1 <= p1 < t1 + 32}
+
+ and project out the auxilary dimensions a0 and a1. */
+ isl_space *Space = isl_space_alloc(ctx, 0, scheduleDimensions,
+ scheduleDimensions * 3);
+ isl_basic_map *tileMap = isl_basic_map_universe(isl_space_copy(Space));
+
+ isl_local_space *LocalSpace = isl_local_space_from_space(Space);
+
+ for (x = 0; x < scheduleDimensions; x++)
+ {
+ int sX = x;
+ int tX = x;
+ int pX = scheduleDimensions + x;
+ int aX = 2 * scheduleDimensions + x;
+
+ isl_constraint *c;
+
+ /* sX = aX * tileSize; */
+ c = isl_equality_alloc(isl_local_space_copy(LocalSpace));
+ isl_constraint_set_coefficient_si(c, isl_dim_out, sX, 1);
+ isl_constraint_set_coefficient_si(c, isl_dim_out, aX, -tileSize);
+ tileMap = isl_basic_map_add_constraint(tileMap, c);
+
+ /* pX = sX; */
+ c = isl_equality_alloc(isl_local_space_copy(LocalSpace));
+ isl_constraint_set_coefficient_si(c, isl_dim_out, pX, 1);
+ isl_constraint_set_coefficient_si(c, isl_dim_in, sX, -1);
+ tileMap = isl_basic_map_add_constraint(tileMap, c);
+
+ /* tX <= pX */
+ c = isl_inequality_alloc(isl_local_space_copy(LocalSpace));
+ isl_constraint_set_coefficient_si(c, isl_dim_out, pX, 1);
+ isl_constraint_set_coefficient_si(c, isl_dim_out, tX, -1);
+ tileMap = isl_basic_map_add_constraint(tileMap, c);
+
+ /* pX <= tX + (tileSize - 1) */
+ c = isl_inequality_alloc(isl_local_space_copy(LocalSpace));
+ isl_constraint_set_coefficient_si(c, isl_dim_out, tX, 1);
+ isl_constraint_set_coefficient_si(c, isl_dim_out, pX, -1);
+ isl_constraint_set_constant_si(c, tileSize - 1);
+ tileMap = isl_basic_map_add_constraint(tileMap, c);
+ }
+
+ /* Project out auxilary dimensions.
+
+ The auxilary dimensions are transformed into existentially quantified ones.
+ This reduces the number of visible scattering dimensions and allows Cloog
+ to produces better code. */
+ tileMap = isl_basic_map_project_out(tileMap, isl_dim_out,
+ 2 * scheduleDimensions,
+ scheduleDimensions);
+ isl_local_space_free(LocalSpace);
+ return tileMap;
+}
+
+/* getScheduleForBand - Get the schedule for this band.
+
+ Polly applies transformations like tiling on top of the isl calculated value.
+ This can influence the number of scheduling dimension. The number of
+ schedule dimensions is returned in the parameter 'Dimension'. */
+static bool DisableTiling = false;
+
+static isl_union_map *
+getScheduleForBand(isl_band *Band, int *Dimensions)
+{
+ isl_union_map *PartialSchedule;
+ isl_ctx *ctx;
+ isl_space *Space;
+ isl_basic_map *TileMap;
+ isl_union_map *TileUMap;
+
+ PartialSchedule = isl_band_get_partial_schedule(Band);
+ *Dimensions = isl_band_n_member(Band);
+
+ if (DisableTiling)
+ return PartialSchedule;
+
+ /* It does not make any sense to tile a band with just one dimension. */
+ if (*Dimensions == 1)
+ return PartialSchedule;
+
+ ctx = isl_union_map_get_ctx(PartialSchedule);
+ Space = isl_union_map_get_space(PartialSchedule);
+
+ TileMap = getTileMap(ctx, *Dimensions, 32);
+ TileUMap = isl_union_map_from_map(isl_map_from_basic_map(TileMap));
+ TileUMap = isl_union_map_align_params(TileUMap, Space);
+ *Dimensions = 2 * *Dimensions;
+
+ return isl_union_map_apply_range(PartialSchedule, TileUMap);
+}
+
+/* Create a map that pre-vectorizes one scheduling dimension.
+
+ getPrevectorMap creates a map that maps each input dimension to the same
+ output dimension, except for the dimension DimToVectorize. DimToVectorize is
+ strip mined by 'VectorWidth' and the newly created point loop of
+ DimToVectorize is moved to the innermost level.
+
+ Example (DimToVectorize=0, ScheduleDimensions=2, VectorWidth=4):
+
+ | Before transformation
+ |
+ | A[i,j] -> [i,j]
+ |
+ | for (i = 0; i < 128; i++)
+ | for (j = 0; j < 128; j++)
+ | A(i,j);
+
+ Prevector map:
+ [i,j] -> [it,j,ip] : it % 4 = 0 and it <= ip <= it + 3 and i = ip
+
+ | After transformation:
+ |
+ | A[i,j] -> [it,j,ip] : it % 4 = 0 and it <= ip <= it + 3 and i = ip
+ |
+ | for (it = 0; it < 128; it+=4)
+ | for (j = 0; j < 128; j++)
+ | for (ip = max(0,it); ip < min(128, it + 3); ip++)
+ | A(ip,j);
+
+ The goal of this transformation is to create a trivially vectorizable loop.
+ This means a parallel loop at the innermost level that has a constant number
+ of iterations corresponding to the target vector width.
+
+ This transformation creates a loop at the innermost level. The loop has a
+ constant number of iterations, if the number of loop iterations at
+ DimToVectorize can be devided by VectorWidth. The default VectorWidth is
+ currently constant and not yet target specific. This function does not reason
+ about parallelism. */
+static isl_map *
+getPrevectorMap(isl_ctx *ctx, int DimToVectorize,
+ int ScheduleDimensions,
+ int VectorWidth)
+{
+ isl_space *Space;
+ isl_local_space *LocalSpace, *LocalSpaceRange;
+ isl_set *Modulo;
+ isl_map *TilingMap;
+ isl_constraint *c;
+ isl_aff *Aff;
+ int PointDimension; /* ip */
+ int TileDimension; /* it */
+ isl_int VectorWidthMP;
+ int i;
+
+ /* assert (0 <= DimToVectorize && DimToVectorize < ScheduleDimensions);*/
+
+ Space = isl_space_alloc(ctx, 0, ScheduleDimensions, ScheduleDimensions + 1);
+ TilingMap = isl_map_universe(isl_space_copy(Space));
+ LocalSpace = isl_local_space_from_space(Space);
+ PointDimension = ScheduleDimensions;
+ TileDimension = DimToVectorize;
+
+ /* Create an identity map for everything except DimToVectorize and map
+ DimToVectorize to the point loop at the innermost dimension. */
+ for (i = 0; i < ScheduleDimensions; i++)
+ {
+ c = isl_equality_alloc(isl_local_space_copy(LocalSpace));
+ isl_constraint_set_coefficient_si(c, isl_dim_in, i, -1);
+
+ if (i == DimToVectorize)
+ isl_constraint_set_coefficient_si(c, isl_dim_out, PointDimension, 1);
+ else
+ isl_constraint_set_coefficient_si(c, isl_dim_out, i, 1);
+
+ TilingMap = isl_map_add_constraint(TilingMap, c);
+ }
+
+ /* it % 'VectorWidth' = 0 */
+ LocalSpaceRange = isl_local_space_range(isl_local_space_copy(LocalSpace));
+ Aff = isl_aff_zero_on_domain(LocalSpaceRange);
+ Aff = isl_aff_set_constant_si(Aff, VectorWidth);
+ Aff = isl_aff_set_coefficient_si(Aff, isl_dim_in, TileDimension, 1);
+ isl_int_init(VectorWidthMP);
+ isl_int_set_si(VectorWidthMP, VectorWidth);
+ Aff = isl_aff_mod(Aff, VectorWidthMP);
+ isl_int_clear(VectorWidthMP);
+ Modulo = isl_pw_aff_zero_set(isl_pw_aff_from_aff(Aff));
+ TilingMap = isl_map_intersect_range(TilingMap, Modulo);
+
+ /* it <= ip */
+ c = isl_inequality_alloc(isl_local_space_copy(LocalSpace));
+ isl_constraint_set_coefficient_si(c, isl_dim_out, TileDimension, -1);
+ isl_constraint_set_coefficient_si(c, isl_dim_out, PointDimension, 1);
+ TilingMap = isl_map_add_constraint(TilingMap, c);
+
+ /* ip <= it + ('VectorWidth' - 1) */
+ c = isl_inequality_alloc(LocalSpace);
+ isl_constraint_set_coefficient_si(c, isl_dim_out, TileDimension, 1);
+ isl_constraint_set_coefficient_si(c, isl_dim_out, PointDimension, -1);
+ isl_constraint_set_constant_si(c, VectorWidth - 1);
+ TilingMap = isl_map_add_constraint(TilingMap, c);
+
+ isl_map_dump(TilingMap);
+
+ return TilingMap;
+}
+
+static bool EnablePollyVector = false;
+
+/* getScheduleForBandList - Get the scheduling map for a list of bands.
+
+ We walk recursively the forest of bands to combine the schedules of the
+ individual bands to the overall schedule. In case tiling is requested,
+ the individual bands are tiled. */
+static isl_union_map *
+getScheduleForBandList(isl_band_list *BandList)
+{
+ int NumBands, i;
+ isl_union_map *Schedule;
+ isl_ctx *ctx;
+
+ ctx = isl_band_list_get_ctx(BandList);
+ NumBands = isl_band_list_n_band(BandList);
+ Schedule = isl_union_map_empty(isl_space_params_alloc(ctx, 0));
+
+ for (i = 0; i < NumBands; i++)
+ {
+ isl_band *Band;
+ isl_union_map *PartialSchedule;
+ int ScheduleDimensions;
+ isl_space *Space;
+
+ Band = isl_band_list_get_band(BandList, i);
+ PartialSchedule = getScheduleForBand(Band, &ScheduleDimensions);
+ Space = isl_union_map_get_space(PartialSchedule);
+
+ if (isl_band_has_children(Band))
+ {
+ isl_band_list *Children;
+ isl_union_map *SuffixSchedule;
+
+ Children = isl_band_get_children(Band);
+ SuffixSchedule = getScheduleForBandList(Children);
+ PartialSchedule = isl_union_map_flat_range_product(PartialSchedule,
+ SuffixSchedule);
+ isl_band_list_free(Children);
+ }
+ else if (EnablePollyVector)
+ {
+ for (i = ScheduleDimensions - 1 ; i >= 0 ; i--)
+ {
+ if (isl_band_member_is_zero_distance(Band, i))
+ {
+ isl_map *TileMap;
+ isl_union_map *TileUMap;
+
+ TileMap = getPrevectorMap(ctx, i, ScheduleDimensions, 4);
+ TileUMap = isl_union_map_from_map(TileMap);
+ TileUMap = isl_union_map_align_params(TileUMap,
+ isl_space_copy(Space));
+ PartialSchedule = isl_union_map_apply_range(PartialSchedule,
+ TileUMap);
+ break;
+ }
+ }
+ }
+
+ Schedule = isl_union_map_union(Schedule, PartialSchedule);
+
+ isl_band_free(Band);
+ isl_space_free(Space);
+ }
+
+ return Schedule;
+}
+
+static isl_union_map *
+getScheduleMap(isl_schedule *Schedule)
+{
+ isl_band_list *BandList = isl_schedule_get_band_forest(Schedule);
+ isl_union_map *ScheduleMap = getScheduleForBandList(BandList);
+ isl_band_list_free(BandList);
+ return ScheduleMap;
+}
+
+static int
+getSingleMap(__isl_take isl_map *map, void *user)
+{
+ isl_map **singleMap = (isl_map **) user;
+ *singleMap = map;
+
+ return 0;
+}
+
+static void
+apply_schedule_map_to_scop (scop_p scop, isl_union_map *schedule_map)
+{
+ int i;
+ poly_bb_p pbb;
+
+ FOR_EACH_VEC_ELT (poly_bb_p, scop->bbs, i, pbb)
+ {
+ isl_set *domain = isl_set_copy (pbb->domain);
+ isl_union_map *stmtBand;
+ isl_map *stmtSchedule;
+
+ stmtBand = isl_union_map_intersect_domain(isl_union_map_copy(schedule_map),
+ isl_union_set_from_set(domain));
+ isl_union_map_foreach_map(stmtBand, getSingleMap, &stmtSchedule);
+ isl_map_free(pbb->transformed);
+ pbb->transformed = stmtSchedule;
+ isl_union_map_free(stmtBand);
+ }
+}
+
+static const int CONSTANT_BOUND = 20;
+
+bool
+optimize_isl (scop_p scop)
+{
+
+ isl_schedule *schedule;
+ isl_union_set *domain;
+ isl_union_map *validity, *proximity, *dependences;
+ isl_union_map *schedule_map;
+
+ domain = scop_get_domains (scop);
+ dependences = scop_get_dependences (scop);
+ dependences = isl_union_map_gist_domain(dependences,
+ isl_union_set_copy(domain));
+ dependences = isl_union_map_gist_range(dependences,
+ isl_union_set_copy(domain));
+ validity = dependences;
+
+ proximity = isl_union_map_copy (validity);
+
+ isl_options_set_schedule_max_constant_term(scop->ctx, CONSTANT_BOUND);
+ isl_options_set_schedule_maximize_band_depth(scop->ctx, 1);
+ isl_options_set_schedule_fuse(scop->ctx, ISL_SCHEDULE_FUSE_MIN);
+ isl_options_set_on_error(scop->ctx, ISL_ON_ERROR_CONTINUE);
+ schedule = isl_union_set_compute_schedule (domain, validity, proximity);
+ isl_options_set_on_error(scop->ctx, ISL_ON_ERROR_ABORT);
+
+ if (!schedule)
+ return false;
+
+ schedule_map = getScheduleMap (schedule);
+
+ apply_schedule_map_to_scop (scop, schedule_map);
+
+ isl_schedule_free (schedule);
+ isl_union_map_free (schedule_map);
+
+ return true;
+}
+
+#endif
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