/* Conversion of SESE regions to Polyhedra. Copyright (C) 2009-2017 Free Software Foundation, Inc. Contributed by Sebastian Pop . 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 . */ #define USES_ISL #include "config.h" #ifdef HAVE_isl #include "system.h" #include "coretypes.h" #include "backend.h" #include "cfghooks.h" #include "tree.h" #include "gimple.h" #include "ssa.h" #include "params.h" #include "fold-const.h" #include "gimple-iterator.h" #include "gimplify.h" #include "gimplify-me.h" #include "tree-cfg.h" #include "tree-ssa-loop-manip.h" #include "tree-ssa-loop-niter.h" #include "tree-ssa-loop.h" #include "tree-into-ssa.h" #include "tree-pass.h" #include "cfgloop.h" #include "tree-data-ref.h" #include "tree-scalar-evolution.h" #include "domwalk.h" #include "tree-ssa-propagate.h" #include #include #include #include #include #include #include #include "graphite.h" /* Assigns to RES the value of the INTEGER_CST T. */ static inline void tree_int_to_gmp (tree t, mpz_t res) { wi::to_mpz (t, res, TYPE_SIGN (TREE_TYPE (t))); } /* Return an isl identifier for the polyhedral basic block PBB. */ static isl_id * isl_id_for_pbb (scop_p s, poly_bb_p pbb) { char name[14]; snprintf (name, sizeof (name), "S_%d", pbb_index (pbb)); return isl_id_alloc (s->isl_context, name, pbb); } static isl_pw_aff *extract_affine (scop_p, tree, __isl_take isl_space *space); /* Extract an affine expression from the chain of recurrence E. */ static isl_pw_aff * extract_affine_chrec (scop_p s, tree e, __isl_take isl_space *space) { isl_pw_aff *lhs = extract_affine (s, CHREC_LEFT (e), isl_space_copy (space)); isl_pw_aff *rhs = extract_affine (s, CHREC_RIGHT (e), isl_space_copy (space)); isl_local_space *ls = isl_local_space_from_space (space); unsigned pos = sese_loop_depth (s->scop_info->region, get_chrec_loop (e)) - 1; isl_aff *loop = isl_aff_set_coefficient_si (isl_aff_zero_on_domain (ls), isl_dim_in, pos, 1); isl_pw_aff *l = isl_pw_aff_from_aff (loop); /* Before multiplying, make sure that the result is affine. */ gcc_assert (isl_pw_aff_is_cst (rhs) || isl_pw_aff_is_cst (l)); return isl_pw_aff_add (lhs, isl_pw_aff_mul (rhs, l)); } /* Extract an affine expression from the mult_expr E. */ static isl_pw_aff * extract_affine_mul (scop_p s, tree e, __isl_take isl_space *space) { isl_pw_aff *lhs = extract_affine (s, TREE_OPERAND (e, 0), isl_space_copy (space)); isl_pw_aff *rhs = extract_affine (s, TREE_OPERAND (e, 1), space); if (!isl_pw_aff_is_cst (lhs) && !isl_pw_aff_is_cst (rhs)) { isl_pw_aff_free (lhs); isl_pw_aff_free (rhs); return NULL; } return isl_pw_aff_mul (lhs, rhs); } /* Return an isl identifier from the name of the ssa_name E. */ static isl_id * isl_id_for_ssa_name (scop_p s, tree e) { char name1[14]; snprintf (name1, sizeof (name1), "P_%d", SSA_NAME_VERSION (e)); return isl_id_alloc (s->isl_context, name1, e); } /* Return an isl identifier for the data reference DR. Data references and scalar references get the same isl_id. They need to be comparable and are distinguished through the first dimension, which contains the alias set or SSA_NAME_VERSION number. */ static isl_id * isl_id_for_dr (scop_p s) { return isl_id_alloc (s->isl_context, "", 0); } /* Extract an affine expression from the ssa_name E. */ static isl_pw_aff * extract_affine_name (scop_p s, tree e, __isl_take isl_space *space) { isl_id *id = isl_id_for_ssa_name (s, e); int dimension = isl_space_find_dim_by_id (space, isl_dim_param, id); isl_id_free (id); isl_set *dom = isl_set_universe (isl_space_copy (space)); isl_aff *aff = isl_aff_zero_on_domain (isl_local_space_from_space (space)); aff = isl_aff_add_coefficient_si (aff, isl_dim_param, dimension, 1); return isl_pw_aff_alloc (dom, aff); } /* Convert WI to a isl_val with CTX. */ static __isl_give isl_val * isl_val_int_from_wi (isl_ctx *ctx, const widest_int &wi) { if (wi::neg_p (wi, SIGNED)) { widest_int mwi = -wi; return isl_val_neg (isl_val_int_from_chunks (ctx, mwi.get_len (), sizeof (HOST_WIDE_INT), mwi.get_val ())); } return isl_val_int_from_chunks (ctx, wi.get_len (), sizeof (HOST_WIDE_INT), wi.get_val ()); } /* Extract an affine expression from the gmp constant G. */ static isl_pw_aff * extract_affine_wi (const widest_int &g, __isl_take isl_space *space) { isl_local_space *ls = isl_local_space_from_space (isl_space_copy (space)); isl_aff *aff = isl_aff_zero_on_domain (ls); isl_set *dom = isl_set_universe (space); isl_ctx *ct = isl_aff_get_ctx (aff); isl_val *v = isl_val_int_from_wi (ct, g); aff = isl_aff_add_constant_val (aff, v); return isl_pw_aff_alloc (dom, aff); } /* Extract an affine expression from the integer_cst E. */ static isl_pw_aff * extract_affine_int (tree e, __isl_take isl_space *space) { isl_pw_aff *res = extract_affine_wi (wi::to_widest (e), space); return res; } /* Compute pwaff mod 2^width. */ static isl_pw_aff * wrap (isl_pw_aff *pwaff, unsigned width) { isl_val *mod; mod = isl_val_int_from_ui (isl_pw_aff_get_ctx (pwaff), width); mod = isl_val_2exp (mod); pwaff = isl_pw_aff_mod_val (pwaff, mod); return pwaff; } /* When parameter NAME is in REGION, returns its index in SESE_PARAMS. Otherwise returns -1. */ static inline int parameter_index_in_region_1 (tree name, sese_info_p region) { int i; tree p; gcc_assert (TREE_CODE (name) == SSA_NAME); FOR_EACH_VEC_ELT (region->params, i, p) if (p == name) return i; return -1; } /* Extract an affine expression from the tree E in the scop S. */ static isl_pw_aff * extract_affine (scop_p s, tree e, __isl_take isl_space *space) { isl_pw_aff *lhs, *rhs, *res; if (e == chrec_dont_know) { isl_space_free (space); return NULL; } switch (TREE_CODE (e)) { case POLYNOMIAL_CHREC: res = extract_affine_chrec (s, e, space); break; case MULT_EXPR: res = extract_affine_mul (s, e, space); break; case PLUS_EXPR: case POINTER_PLUS_EXPR: lhs = extract_affine (s, TREE_OPERAND (e, 0), isl_space_copy (space)); rhs = extract_affine (s, TREE_OPERAND (e, 1), space); res = isl_pw_aff_add (lhs, rhs); break; case MINUS_EXPR: lhs = extract_affine (s, TREE_OPERAND (e, 0), isl_space_copy (space)); rhs = extract_affine (s, TREE_OPERAND (e, 1), space); res = isl_pw_aff_sub (lhs, rhs); break; case NEGATE_EXPR: case BIT_NOT_EXPR: lhs = extract_affine (s, TREE_OPERAND (e, 0), isl_space_copy (space)); rhs = extract_affine (s, integer_minus_one_node, space); res = isl_pw_aff_mul (lhs, rhs); break; case SSA_NAME: gcc_assert (-1 != parameter_index_in_region_1 (e, s->scop_info) || defined_in_sese_p (e, s->scop_info->region)); res = extract_affine_name (s, e, space); break; case INTEGER_CST: res = extract_affine_int (e, space); /* No need to wrap a single integer. */ return res; CASE_CONVERT: case NON_LVALUE_EXPR: res = extract_affine (s, TREE_OPERAND (e, 0), space); break; default: gcc_unreachable (); break; } tree type = TREE_TYPE (e); if (TYPE_UNSIGNED (type)) res = wrap (res, TYPE_PRECISION (type)); return res; } /* Returns a linear expression for tree T evaluated in PBB. */ static isl_pw_aff * create_pw_aff_from_tree (poly_bb_p pbb, loop_p loop, tree t) { scop_p scop = PBB_SCOP (pbb); t = scalar_evolution_in_region (scop->scop_info->region, loop, t); gcc_assert (!chrec_contains_undetermined (t)); gcc_assert (!automatically_generated_chrec_p (t)); return extract_affine (scop, t, isl_set_get_space (pbb->domain)); } /* Add conditional statement STMT to pbb. CODE is used as the comparison operator. This allows us to invert the condition or to handle inequalities. */ static void add_condition_to_pbb (poly_bb_p pbb, gcond *stmt, enum tree_code code) { loop_p loop = gimple_bb (stmt)->loop_father; isl_pw_aff *lhs = create_pw_aff_from_tree (pbb, loop, gimple_cond_lhs (stmt)); isl_pw_aff *rhs = create_pw_aff_from_tree (pbb, loop, gimple_cond_rhs (stmt)); isl_set *cond; switch (code) { case LT_EXPR: cond = isl_pw_aff_lt_set (lhs, rhs); break; case GT_EXPR: cond = isl_pw_aff_gt_set (lhs, rhs); break; case LE_EXPR: cond = isl_pw_aff_le_set (lhs, rhs); break; case GE_EXPR: cond = isl_pw_aff_ge_set (lhs, rhs); break; case EQ_EXPR: cond = isl_pw_aff_eq_set (lhs, rhs); break; case NE_EXPR: cond = isl_pw_aff_ne_set (lhs, rhs); break; default: gcc_unreachable (); } cond = isl_set_coalesce (cond); cond = isl_set_set_tuple_id (cond, isl_set_get_tuple_id (pbb->domain)); pbb->domain = isl_set_coalesce (isl_set_intersect (pbb->domain, cond)); } /* Add conditions to the domain of PBB. */ static void add_conditions_to_domain (poly_bb_p pbb) { unsigned int i; gimple *stmt; gimple_poly_bb_p gbb = PBB_BLACK_BOX (pbb); if (GBB_CONDITIONS (gbb).is_empty ()) return; FOR_EACH_VEC_ELT (GBB_CONDITIONS (gbb), i, stmt) switch (gimple_code (stmt)) { case GIMPLE_COND: { /* Don't constrain on anything else than INTEGER_TYPE. */ if (TREE_CODE (TREE_TYPE (gimple_cond_lhs (stmt))) != INTEGER_TYPE) break; gcond *cond_stmt = as_a (stmt); enum tree_code code = gimple_cond_code (cond_stmt); /* The conditions for ELSE-branches are inverted. */ if (!GBB_CONDITION_CASES (gbb)[i]) code = invert_tree_comparison (code, false); add_condition_to_pbb (pbb, cond_stmt, code); break; } default: gcc_unreachable (); break; } } /* Add constraints on the possible values of parameter P from the type of P. */ static void add_param_constraints (scop_p scop, graphite_dim_t p) { tree parameter = scop->scop_info->params[p]; tree type = TREE_TYPE (parameter); tree lb = NULL_TREE; tree ub = NULL_TREE; if (POINTER_TYPE_P (type) || !TYPE_MIN_VALUE (type)) lb = lower_bound_in_type (type, type); else lb = TYPE_MIN_VALUE (type); if (POINTER_TYPE_P (type) || !TYPE_MAX_VALUE (type)) ub = upper_bound_in_type (type, type); else ub = TYPE_MAX_VALUE (type); if (lb) { isl_space *space = isl_set_get_space (scop->param_context); isl_constraint *c; isl_val *v; c = isl_inequality_alloc (isl_local_space_from_space (space)); v = isl_val_int_from_wi (scop->isl_context, wi::to_widest (lb)); v = isl_val_neg (v); c = isl_constraint_set_constant_val (c, v); c = isl_constraint_set_coefficient_si (c, isl_dim_param, p, 1); scop->param_context = isl_set_coalesce (isl_set_add_constraint (scop->param_context, c)); } if (ub) { isl_space *space = isl_set_get_space (scop->param_context); isl_constraint *c; isl_val *v; c = isl_inequality_alloc (isl_local_space_from_space (space)); v = isl_val_int_from_wi (scop->isl_context, wi::to_widest (ub)); c = isl_constraint_set_constant_val (c, v); c = isl_constraint_set_coefficient_si (c, isl_dim_param, p, -1); scop->param_context = isl_set_coalesce (isl_set_add_constraint (scop->param_context, c)); } } /* Add a constrain to the ACCESSES polyhedron for the alias set of data reference DR. ACCESSP_NB_DIMS is the dimension of the ACCESSES polyhedron, DOM_NB_DIMS is the dimension of the iteration domain. */ static isl_map * pdr_add_alias_set (isl_map *acc, dr_info &dri) { isl_constraint *c = isl_equality_alloc (isl_local_space_from_space (isl_map_get_space (acc))); /* Positive numbers for all alias sets. */ c = isl_constraint_set_constant_si (c, -dri.alias_set); c = isl_constraint_set_coefficient_si (c, isl_dim_out, 0, 1); return isl_map_add_constraint (acc, c); } /* Add a constrain to the ACCESSES polyhedron for the alias set of data reference DR. ACCESSP_NB_DIMS is the dimension of the ACCESSES polyhedron, DOM_NB_DIMS is the dimension of the iteration domain. */ static isl_map * add_scalar_version_numbers (isl_map *acc, tree var) { isl_constraint *c = isl_equality_alloc (isl_local_space_from_space (isl_map_get_space (acc))); int max_arrays = PARAM_VALUE (PARAM_GRAPHITE_MAX_ARRAYS_PER_SCOP); /* Each scalar variables has a unique alias set number starting from max_arrays. */ c = isl_constraint_set_constant_si (c, -max_arrays - SSA_NAME_VERSION (var)); c = isl_constraint_set_coefficient_si (c, isl_dim_out, 0, 1); return isl_map_add_constraint (acc, c); } /* Assign the affine expression INDEX to the output dimension POS of MAP and return the result. */ static isl_map * set_index (isl_map *map, int pos, isl_pw_aff *index) { isl_map *index_map; int len = isl_map_dim (map, isl_dim_out); isl_id *id; index_map = isl_map_from_pw_aff (index); index_map = isl_map_insert_dims (index_map, isl_dim_out, 0, pos); index_map = isl_map_add_dims (index_map, isl_dim_out, len - pos - 1); id = isl_map_get_tuple_id (map, isl_dim_out); index_map = isl_map_set_tuple_id (index_map, isl_dim_out, id); id = isl_map_get_tuple_id (map, isl_dim_in); index_map = isl_map_set_tuple_id (index_map, isl_dim_in, id); return isl_map_intersect (map, index_map); } /* Add to ACCESSES polyhedron equalities defining the access functions to the memory. ACCESSP_NB_DIMS is the dimension of the ACCESSES polyhedron, DOM_NB_DIMS is the dimension of the iteration domain. PBB is the poly_bb_p that contains the data reference DR. */ static isl_map * pdr_add_memory_accesses (isl_map *acc, dr_info &dri) { data_reference_p dr = dri.dr; poly_bb_p pbb = dri.pbb; int i, nb_subscripts = DR_NUM_DIMENSIONS (dr); scop_p scop = PBB_SCOP (pbb); for (i = 0; i < nb_subscripts; i++) { isl_pw_aff *aff; tree afn = DR_ACCESS_FN (dr, i); aff = extract_affine (scop, afn, isl_space_domain (isl_map_get_space (acc))); acc = set_index (acc, nb_subscripts - i , aff); } return isl_map_coalesce (acc); } /* Return true when the LOW and HIGH bounds of an array reference REF are valid to extract constraints on accessed elements of the array. Returning false is the conservative answer. */ static bool bounds_are_valid (tree ref, tree low, tree high) { if (!high) return false; if (!tree_fits_shwi_p (low) || !tree_fits_shwi_p (high)) return false; /* 1-element arrays at end of structures may extend over their declared size. */ if (array_at_struct_end_p (ref) && operand_equal_p (low, high, 0)) return false; /* Fortran has some arrays where high bound is -1 and low is 0. */ if (integer_onep (fold_build2 (LT_EXPR, boolean_type_node, high, low))) return false; return true; } /* Add constrains representing the size of the accessed data to the ACCESSES polyhedron. ACCESSP_NB_DIMS is the dimension of the ACCESSES polyhedron, DOM_NB_DIMS is the dimension of the iteration domain. */ static isl_set * pdr_add_data_dimensions (isl_set *subscript_sizes, scop_p scop, data_reference_p dr) { tree ref = DR_REF (dr); int nb_subscripts = DR_NUM_DIMENSIONS (dr); for (int i = nb_subscripts - 1; i >= 0; i--, ref = TREE_OPERAND (ref, 0)) { if (TREE_CODE (ref) != ARRAY_REF) return subscript_sizes; tree low = array_ref_low_bound (ref); tree high = array_ref_up_bound (ref); if (!bounds_are_valid (ref, low, high)) continue; isl_space *space = isl_set_get_space (subscript_sizes); isl_pw_aff *lb = extract_affine_int (low, isl_space_copy (space)); isl_pw_aff *ub = extract_affine_int (high, isl_space_copy (space)); /* high >= 0 */ isl_set *valid = isl_pw_aff_nonneg_set (isl_pw_aff_copy (ub)); valid = isl_set_project_out (valid, isl_dim_set, 0, isl_set_dim (valid, isl_dim_set)); scop->param_context = isl_set_coalesce (isl_set_intersect (scop->param_context, valid)); isl_aff *aff = isl_aff_zero_on_domain (isl_local_space_from_space (space)); aff = isl_aff_add_coefficient_si (aff, isl_dim_in, i + 1, 1); isl_set *univ = isl_set_universe (isl_space_domain (isl_aff_get_space (aff))); isl_pw_aff *index = isl_pw_aff_alloc (univ, aff); isl_id *id = isl_set_get_tuple_id (subscript_sizes); lb = isl_pw_aff_set_tuple_id (lb, isl_dim_in, isl_id_copy (id)); ub = isl_pw_aff_set_tuple_id (ub, isl_dim_in, id); /* low <= sub_i <= high */ isl_set *lbs = isl_pw_aff_ge_set (isl_pw_aff_copy (index), lb); isl_set *ubs = isl_pw_aff_le_set (index, ub); subscript_sizes = isl_set_intersect (subscript_sizes, lbs); subscript_sizes = isl_set_intersect (subscript_sizes, ubs); } return isl_set_coalesce (subscript_sizes); } /* Build data accesses for DRI. */ static void build_poly_dr (dr_info &dri) { isl_map *acc; isl_set *subscript_sizes; poly_bb_p pbb = dri.pbb; data_reference_p dr = dri.dr; scop_p scop = PBB_SCOP (pbb); isl_id *id = isl_id_for_dr (scop); { isl_space *dc = isl_set_get_space (pbb->domain); int nb_out = 1 + DR_NUM_DIMENSIONS (dr); isl_space *space = isl_space_add_dims (isl_space_from_domain (dc), isl_dim_out, nb_out); acc = isl_map_universe (space); acc = isl_map_set_tuple_id (acc, isl_dim_out, isl_id_copy (id)); } acc = pdr_add_alias_set (acc, dri); acc = pdr_add_memory_accesses (acc, dri); { int nb = 1 + DR_NUM_DIMENSIONS (dr); isl_space *space = isl_space_set_alloc (scop->isl_context, 0, nb); space = isl_space_set_tuple_id (space, isl_dim_set, id); subscript_sizes = isl_set_nat_universe (space); subscript_sizes = isl_set_fix_si (subscript_sizes, isl_dim_set, 0, dri.alias_set); subscript_sizes = pdr_add_data_dimensions (subscript_sizes, scop, dr); } new_poly_dr (pbb, DR_STMT (dr), DR_IS_READ (dr) ? PDR_READ : PDR_WRITE, acc, subscript_sizes); } static void build_poly_sr_1 (poly_bb_p pbb, gimple *stmt, tree var, enum poly_dr_type kind, isl_map *acc, isl_set *subscript_sizes) { int max_arrays = PARAM_VALUE (PARAM_GRAPHITE_MAX_ARRAYS_PER_SCOP); /* Each scalar variables has a unique alias set number starting from max_arrays. */ subscript_sizes = isl_set_fix_si (subscript_sizes, isl_dim_set, 0, max_arrays + SSA_NAME_VERSION (var)); new_poly_dr (pbb, stmt, kind, add_scalar_version_numbers (acc, var), subscript_sizes); } /* Record all cross basic block scalar variables in PBB. */ static void build_poly_sr (poly_bb_p pbb) { scop_p scop = PBB_SCOP (pbb); gimple_poly_bb_p gbb = PBB_BLACK_BOX (pbb); vec &reads = gbb->read_scalar_refs; vec &writes = gbb->write_scalar_refs; isl_space *dc = isl_set_get_space (pbb->domain); int nb_out = 1; isl_space *space = isl_space_add_dims (isl_space_from_domain (dc), isl_dim_out, nb_out); isl_id *id = isl_id_for_dr (scop); space = isl_space_set_tuple_id (space, isl_dim_set, isl_id_copy (id)); isl_map *acc = isl_map_universe (isl_space_copy (space)); acc = isl_map_set_tuple_id (acc, isl_dim_out, id); isl_set *subscript_sizes = isl_set_nat_universe (space); int i; tree var; FOR_EACH_VEC_ELT (writes, i, var) build_poly_sr_1 (pbb, SSA_NAME_DEF_STMT (var), var, PDR_WRITE, isl_map_copy (acc), isl_set_copy (subscript_sizes)); scalar_use *use; FOR_EACH_VEC_ELT (reads, i, use) build_poly_sr_1 (pbb, use->first, use->second, PDR_READ, isl_map_copy (acc), isl_set_copy (subscript_sizes)); isl_map_free (acc); isl_set_free (subscript_sizes); } /* Build data references in SCOP. */ static void build_scop_drs (scop_p scop) { int i; dr_info *dri; FOR_EACH_VEC_ELT (scop->drs, i, dri) build_poly_dr (*dri); poly_bb_p pbb; FOR_EACH_VEC_ELT (scop->pbbs, i, pbb) build_poly_sr (pbb); } /* Add to the iteration DOMAIN one extra dimension for LOOP->num. */ static isl_set * add_iter_domain_dimension (__isl_take isl_set *domain, loop_p loop, scop_p scop) { int loop_index = isl_set_dim (domain, isl_dim_set); domain = isl_set_add_dims (domain, isl_dim_set, 1); char name[50]; snprintf (name, sizeof(name), "i%d", loop->num); isl_id *label = isl_id_alloc (scop->isl_context, name, NULL); return isl_set_set_dim_id (domain, isl_dim_set, loop_index, label); } /* Add constraints to DOMAIN for each loop from LOOP up to CONTEXT. */ static isl_set * add_loop_constraints (scop_p scop, __isl_take isl_set *domain, loop_p loop, loop_p context) { if (loop == context) return domain; const sese_l ®ion = scop->scop_info->region; if (!loop_in_sese_p (loop, region)) return domain; /* Recursion all the way up to the context loop. */ domain = add_loop_constraints (scop, domain, loop_outer (loop), context); /* Then, build constraints over the loop in post-order: outer to inner. */ int loop_index = isl_set_dim (domain, isl_dim_set); if (dump_file) fprintf (dump_file, "[sese-to-poly] adding one extra dimension to the " "domain for loop_%d.\n", loop->num); domain = add_iter_domain_dimension (domain, loop, scop); isl_space *space = isl_set_get_space (domain); /* 0 <= loop_i */ isl_local_space *ls = isl_local_space_from_space (isl_space_copy (space)); isl_constraint *c = isl_inequality_alloc (ls); c = isl_constraint_set_coefficient_si (c, isl_dim_set, loop_index, 1); if (dump_file) { fprintf (dump_file, "[sese-to-poly] adding constraint to the domain: "); print_isl_constraint (dump_file, c); } domain = isl_set_add_constraint (domain, c); tree nb_iters = number_of_latch_executions (loop); if (TREE_CODE (nb_iters) == INTEGER_CST) { /* loop_i <= cst_nb_iters */ isl_local_space *ls = isl_local_space_from_space (space); isl_constraint *c = isl_inequality_alloc (ls); c = isl_constraint_set_coefficient_si (c, isl_dim_set, loop_index, -1); isl_val *v = isl_val_int_from_wi (scop->isl_context, wi::to_widest (nb_iters)); c = isl_constraint_set_constant_val (c, v); return isl_set_add_constraint (domain, c); } /* loop_i <= expr_nb_iters */ gcc_assert (!chrec_contains_undetermined (nb_iters)); nb_iters = scalar_evolution_in_region (region, loop, nb_iters); gcc_assert (!chrec_contains_undetermined (nb_iters)); isl_pw_aff *aff_nb_iters = extract_affine (scop, nb_iters, isl_space_copy (space)); isl_set *valid = isl_pw_aff_nonneg_set (isl_pw_aff_copy (aff_nb_iters)); valid = isl_set_project_out (valid, isl_dim_set, 0, isl_set_dim (valid, isl_dim_set)); if (valid) scop->param_context = isl_set_intersect (scop->param_context, valid); ls = isl_local_space_from_space (isl_space_copy (space)); isl_aff *loop_i = isl_aff_set_coefficient_si (isl_aff_zero_on_domain (ls), isl_dim_in, loop_index, 1); isl_set *le = isl_pw_aff_le_set (isl_pw_aff_from_aff (loop_i), isl_pw_aff_copy (aff_nb_iters)); if (dump_file) { fprintf (dump_file, "[sese-to-poly] adding constraint to the domain: "); print_isl_set (dump_file, le); } domain = isl_set_intersect (domain, le); widest_int nit; if (!max_stmt_executions (loop, &nit)) { isl_pw_aff_free (aff_nb_iters); isl_space_free (space); return domain; } /* NIT is an upper bound to NB_ITERS: "NIT >= NB_ITERS", although we do not know whether the loop executes at least once. */ --nit; isl_pw_aff *approx = extract_affine_wi (nit, isl_space_copy (space)); isl_set *x = isl_pw_aff_ge_set (approx, aff_nb_iters); x = isl_set_project_out (x, isl_dim_set, 0, isl_set_dim (x, isl_dim_set)); scop->param_context = isl_set_intersect (scop->param_context, x); ls = isl_local_space_from_space (space); c = isl_inequality_alloc (ls); c = isl_constraint_set_coefficient_si (c, isl_dim_set, loop_index, -1); isl_val *v = isl_val_int_from_wi (scop->isl_context, nit); c = isl_constraint_set_constant_val (c, v); if (dump_file) { fprintf (dump_file, "[sese-to-poly] adding constraint to the domain: "); print_isl_constraint (dump_file, c); } return isl_set_add_constraint (domain, c); } /* Builds the original iteration domains for each pbb in the SCOP. */ static int build_iteration_domains (scop_p scop, __isl_keep isl_set *context, int index, loop_p context_loop) { loop_p current = pbb_loop (scop->pbbs[index]); isl_set *domain = isl_set_copy (context); domain = add_loop_constraints (scop, domain, current, context_loop); const sese_l ®ion = scop->scop_info->region; int i; poly_bb_p pbb; FOR_EACH_VEC_ELT_FROM (scop->pbbs, i, pbb, index) { loop_p loop = pbb_loop (pbb); if (current == loop) { pbb->iterators = isl_set_copy (domain); pbb->domain = isl_set_copy (domain); pbb->domain = isl_set_set_tuple_id (pbb->domain, isl_id_for_pbb (scop, pbb)); add_conditions_to_domain (pbb); if (dump_file) { fprintf (dump_file, "[sese-to-poly] set pbb_%d->domain: ", pbb_index (pbb)); print_isl_set (dump_file, domain); } continue; } while (loop_in_sese_p (loop, region) && current != loop) loop = loop_outer (loop); if (current != loop) { /* A statement in a different loop nest than CURRENT loop. */ isl_set_free (domain); return i; } /* A statement nested in the CURRENT loop. */ i = build_iteration_domains (scop, domain, i, current); i--; } isl_set_free (domain); return i; } /* Assign dimension for each parameter in SCOP and add constraints for the parameters. */ static void build_scop_context (scop_p scop) { sese_info_p region = scop->scop_info; unsigned nbp = sese_nb_params (region); isl_space *space = isl_space_set_alloc (scop->isl_context, nbp, 0); unsigned i; tree e; FOR_EACH_VEC_ELT (region->params, i, e) space = isl_space_set_dim_id (space, isl_dim_param, i, isl_id_for_ssa_name (scop, e)); scop->param_context = isl_set_universe (space); graphite_dim_t p; for (p = 0; p < nbp; p++) add_param_constraints (scop, p); } /* Return true when loop A is nested in loop B. */ static bool nested_in (loop_p a, loop_p b) { return b == find_common_loop (a, b); } /* Return the loop at a specific SCOP->pbbs[*INDEX]. */ static loop_p loop_at (scop_p scop, int *index) { return pbb_loop (scop->pbbs[*index]); } /* Return the index of any pbb belonging to loop or a subloop of A. */ static int index_outermost_in_loop (loop_p a, scop_p scop) { int i, outermost = -1; int last_depth = -1; poly_bb_p pbb; FOR_EACH_VEC_ELT (scop->pbbs, i, pbb) if (nested_in (pbb_loop (pbb), a) && (last_depth == -1 || last_depth > (int) loop_depth (pbb_loop (pbb)))) { outermost = i; last_depth = loop_depth (pbb_loop (pbb)); } return outermost; } /* Return the index of any pbb belonging to loop or a subloop of A. */ static int index_pbb_in_loop (loop_p a, scop_p scop) { int i; poly_bb_p pbb; FOR_EACH_VEC_ELT (scop->pbbs, i, pbb) if (pbb_loop (pbb) == a) return i; return -1; } static poly_bb_p outermost_pbb_in (loop_p loop, scop_p scop) { int x = index_pbb_in_loop (loop, scop); if (x == -1) x = index_outermost_in_loop (loop, scop); return scop->pbbs[x]; } static isl_schedule * add_in_sequence (__isl_take isl_schedule *a, __isl_take isl_schedule *b) { gcc_assert (a || b); if (!a) return b; if (!b) return a; return isl_schedule_sequence (a, b); } struct map_to_dimension_data { int n; isl_union_pw_multi_aff *res; }; /* Create a function that maps the elements of SET to its N-th dimension and add it to USER->res. */ static isl_stat add_outer_projection (__isl_take isl_set *set, void *user) { struct map_to_dimension_data *data = (struct map_to_dimension_data *) user; int dim = isl_set_dim (set, isl_dim_set); isl_space *space = isl_set_get_space (set); gcc_assert (dim >= data->n); isl_pw_multi_aff *pma = isl_pw_multi_aff_project_out_map (space, isl_dim_set, data->n, dim - data->n); data->res = isl_union_pw_multi_aff_add_pw_multi_aff (data->res, pma); isl_set_free (set); return isl_stat_ok; } /* Return SET in which all inner dimensions above N are removed. */ static isl_multi_union_pw_aff * outer_projection_mupa (__isl_take isl_union_set *set, int n) { gcc_assert (n >= 0); gcc_assert (set); gcc_assert (!isl_union_set_is_empty (set)); isl_space *space = isl_union_set_get_space (set); isl_union_pw_multi_aff *pwaff = isl_union_pw_multi_aff_empty (space); struct map_to_dimension_data data = {n, pwaff}; if (isl_union_set_foreach_set (set, &add_outer_projection, &data) < 0) data.res = isl_union_pw_multi_aff_free (data.res); isl_union_set_free (set); return isl_multi_union_pw_aff_from_union_pw_multi_aff (data.res); } /* Embed SCHEDULE in the constraints of the LOOP domain. */ static isl_schedule * add_loop_schedule (__isl_take isl_schedule *schedule, loop_p loop, scop_p scop) { poly_bb_p pbb = outermost_pbb_in (loop, scop); isl_set *iterators = pbb->iterators; int empty = isl_set_is_empty (iterators); if (empty < 0 || empty) return empty < 0 ? isl_schedule_free (schedule) : schedule; isl_space *space = isl_set_get_space (iterators); int loop_index = isl_space_dim (space, isl_dim_set) - 1; loop_p ploop = pbb_loop (pbb); while (loop != ploop) { --loop_index; ploop = loop_outer (ploop); } isl_local_space *ls = isl_local_space_from_space (space); isl_aff *aff = isl_aff_var_on_domain (ls, isl_dim_set, loop_index); isl_multi_aff *prefix = isl_multi_aff_from_aff (aff); char name[50]; snprintf (name, sizeof(name), "L_%d", loop->num); isl_id *label = isl_id_alloc (isl_schedule_get_ctx (schedule), name, NULL); prefix = isl_multi_aff_set_tuple_id (prefix, isl_dim_out, label); int n = isl_multi_aff_dim (prefix, isl_dim_in); isl_union_set *domain = isl_schedule_get_domain (schedule); isl_multi_union_pw_aff *mupa = outer_projection_mupa (domain, n); mupa = isl_multi_union_pw_aff_apply_multi_aff (mupa, prefix); return isl_schedule_insert_partial_schedule (schedule, mupa); } /* Build schedule for the pbb at INDEX. */ static isl_schedule * build_schedule_pbb (scop_p scop, int *index) { poly_bb_p pbb = scop->pbbs[*index]; ++*index; isl_set *domain = isl_set_copy (pbb->domain); isl_union_set *ud = isl_union_set_from_set (domain); return isl_schedule_from_domain (ud); } static isl_schedule *build_schedule_loop_nest (scop_p, int *, loop_p); /* Build the schedule of the loop containing the SCOP pbb at INDEX. */ static isl_schedule * build_schedule_loop (scop_p scop, int *index) { int max = scop->pbbs.length (); gcc_assert (*index < max); loop_p loop = loop_at (scop, index); isl_schedule *s = NULL; while (nested_in (loop_at (scop, index), loop)) { if (loop == loop_at (scop, index)) s = add_in_sequence (s, build_schedule_pbb (scop, index)); else s = add_in_sequence (s, build_schedule_loop_nest (scop, index, loop)); if (*index == max) break; } return add_loop_schedule (s, loop, scop); } /* S is the schedule of the loop LOOP. Embed the schedule S in all outer loops. When CONTEXT_LOOP is null, embed the schedule in all loops contained in the SCOP surrounding LOOP. When CONTEXT_LOOP is non null, only embed S in the maximal loop nest contained within CONTEXT_LOOP. */ static isl_schedule * embed_in_surrounding_loops (__isl_take isl_schedule *s, scop_p scop, loop_p loop, int *index, loop_p context_loop) { loop_p outer = loop_outer (loop); sese_l region = scop->scop_info->region; if (context_loop == outer || !loop_in_sese_p (outer, region)) return s; int max = scop->pbbs.length (); if (*index == max || (context_loop && !nested_in (loop_at (scop, index), context_loop)) || (!context_loop && !loop_in_sese_p (find_common_loop (outer, loop_at (scop, index)), region))) return embed_in_surrounding_loops (add_loop_schedule (s, outer, scop), scop, outer, index, context_loop); bool a_pbb; while ((a_pbb = (outer == loop_at (scop, index))) || nested_in (loop_at (scop, index), outer)) { if (a_pbb) s = add_in_sequence (s, build_schedule_pbb (scop, index)); else s = add_in_sequence (s, build_schedule_loop (scop, index)); if (*index == max) break; } /* We reached the end of the OUTER loop: embed S in OUTER. */ return embed_in_surrounding_loops (add_loop_schedule (s, outer, scop), scop, outer, index, context_loop); } /* Build schedule for the full loop nest containing the pbb at INDEX. When CONTEXT_LOOP is null, build the schedule of all loops contained in the SCOP surrounding the pbb. When CONTEXT_LOOP is non null, only build the maximal loop nest contained within CONTEXT_LOOP. */ static isl_schedule * build_schedule_loop_nest (scop_p scop, int *index, loop_p context_loop) { gcc_assert (*index != (int) scop->pbbs.length ()); loop_p loop = loop_at (scop, index); isl_schedule *s = build_schedule_loop (scop, index); return embed_in_surrounding_loops (s, scop, loop, index, context_loop); } /* Build the schedule of the SCOP. */ static bool build_original_schedule (scop_p scop) { int i = 0; int n = scop->pbbs.length (); while (i < n) { poly_bb_p pbb = scop->pbbs[i]; isl_schedule *s = NULL; if (!loop_in_sese_p (pbb_loop (pbb), scop->scop_info->region)) s = build_schedule_pbb (scop, &i); else s = build_schedule_loop_nest (scop, &i, NULL); scop->original_schedule = add_in_sequence (scop->original_schedule, s); } if (dump_file) { fprintf (dump_file, "[sese-to-poly] original schedule:\n"); print_isl_schedule (dump_file, scop->original_schedule); } if (!scop->original_schedule) return false; return true; } /* Builds the polyhedral representation for a SESE region. */ bool build_poly_scop (scop_p scop) { build_scop_context (scop); unsigned i = 0; unsigned n = scop->pbbs.length (); while (i < n) i = build_iteration_domains (scop, scop->param_context, i, NULL); build_scop_drs (scop); build_original_schedule (scop); return true; } #endif /* HAVE_isl */