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author | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
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committer | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
commit | 1bc5aee63eb72b341f506ad058502cd0361f0d10 (patch) | |
tree | c607e8252f3405424ff15bc2d00aa38dadbb2518 /gcc-4.9/gcc/graphite-sese-to-poly.c | |
parent | 283a0bf58fcf333c58a2a92c3ebbc41fb9eb1fdb (diff) | |
download | toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.gz toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.bz2 toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.zip |
Initial checkin of GCC 4.9.0 from trunk (r208799).
Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba
Diffstat (limited to 'gcc-4.9/gcc/graphite-sese-to-poly.c')
-rw-r--r-- | gcc-4.9/gcc/graphite-sese-to-poly.c | 3179 |
1 files changed, 3179 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/graphite-sese-to-poly.c b/gcc-4.9/gcc/graphite-sese-to-poly.c new file mode 100644 index 000000000..d4a1bb2df --- /dev/null +++ b/gcc-4.9/gcc/graphite-sese-to-poly.c @@ -0,0 +1,3179 @@ +/* Conversion of SESE regions to Polyhedra. + Copyright (C) 2009-2014 Free Software Foundation, Inc. + Contributed by Sebastian Pop <sebastian.pop@amd.com>. + +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/constraint.h> +#include <isl/aff.h> +#include <cloog/cloog.h> +#include <cloog/cloog.h> +#include <cloog/isl/domain.h> +#endif + +#include "system.h" +#include "coretypes.h" +#include "tree.h" +#include "basic-block.h" +#include "tree-ssa-alias.h" +#include "internal-fn.h" +#include "gimple-expr.h" +#include "is-a.h" +#include "gimple.h" +#include "gimple-iterator.h" +#include "gimplify.h" +#include "gimplify-me.h" +#include "gimple-ssa.h" +#include "tree-cfg.h" +#include "tree-phinodes.h" +#include "ssa-iterators.h" +#include "stringpool.h" +#include "tree-ssanames.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-chrec.h" +#include "tree-data-ref.h" +#include "tree-scalar-evolution.h" +#include "domwalk.h" +#include "sese.h" +#include "tree-ssa-propagate.h" + +#ifdef HAVE_cloog +#include "expr.h" +#include "graphite-poly.h" +#include "graphite-sese-to-poly.h" + + +/* Assigns to RES the value of the INTEGER_CST T. */ + +static inline void +tree_int_to_gmp (tree t, mpz_t res) +{ + double_int di = tree_to_double_int (t); + mpz_set_double_int (res, di, TYPE_UNSIGNED (TREE_TYPE (t))); +} + +/* Returns the index of the PHI argument defined in the outermost + loop. */ + +static size_t +phi_arg_in_outermost_loop (gimple phi) +{ + loop_p loop = gimple_bb (phi)->loop_father; + size_t i, res = 0; + + for (i = 0; i < gimple_phi_num_args (phi); i++) + if (!flow_bb_inside_loop_p (loop, gimple_phi_arg_edge (phi, i)->src)) + { + loop = gimple_phi_arg_edge (phi, i)->src->loop_father; + res = i; + } + + return res; +} + +/* Removes a simple copy phi node "RES = phi (INIT, RES)" at position + PSI by inserting on the loop ENTRY edge assignment "RES = INIT". */ + +static void +remove_simple_copy_phi (gimple_stmt_iterator *psi) +{ + gimple phi = gsi_stmt (*psi); + tree res = gimple_phi_result (phi); + size_t entry = phi_arg_in_outermost_loop (phi); + tree init = gimple_phi_arg_def (phi, entry); + gimple stmt = gimple_build_assign (res, init); + edge e = gimple_phi_arg_edge (phi, entry); + + remove_phi_node (psi, false); + gsi_insert_on_edge_immediate (e, stmt); +} + +/* Removes an invariant phi node at position PSI by inserting on the + loop ENTRY edge the assignment RES = INIT. */ + +static void +remove_invariant_phi (sese region, gimple_stmt_iterator *psi) +{ + gimple phi = gsi_stmt (*psi); + loop_p loop = loop_containing_stmt (phi); + tree res = gimple_phi_result (phi); + tree scev = scalar_evolution_in_region (region, loop, res); + size_t entry = phi_arg_in_outermost_loop (phi); + edge e = gimple_phi_arg_edge (phi, entry); + tree var; + gimple stmt; + gimple_seq stmts = NULL; + + if (tree_contains_chrecs (scev, NULL)) + scev = gimple_phi_arg_def (phi, entry); + + var = force_gimple_operand (scev, &stmts, true, NULL_TREE); + stmt = gimple_build_assign (res, var); + remove_phi_node (psi, false); + + gimple_seq_add_stmt (&stmts, stmt); + gsi_insert_seq_on_edge (e, stmts); + gsi_commit_edge_inserts (); + SSA_NAME_DEF_STMT (res) = stmt; +} + +/* Returns true when the phi node at PSI is of the form "a = phi (a, x)". */ + +static inline bool +simple_copy_phi_p (gimple phi) +{ + tree res; + + if (gimple_phi_num_args (phi) != 2) + return false; + + res = gimple_phi_result (phi); + return (res == gimple_phi_arg_def (phi, 0) + || res == gimple_phi_arg_def (phi, 1)); +} + +/* Returns true when the phi node at position PSI is a reduction phi + node in REGION. Otherwise moves the pointer PSI to the next phi to + be considered. */ + +static bool +reduction_phi_p (sese region, gimple_stmt_iterator *psi) +{ + loop_p loop; + gimple phi = gsi_stmt (*psi); + tree res = gimple_phi_result (phi); + + loop = loop_containing_stmt (phi); + + if (simple_copy_phi_p (phi)) + { + /* PRE introduces phi nodes like these, for an example, + see id-5.f in the fortran graphite testsuite: + + # prephitmp.85_265 = PHI <prephitmp.85_258(33), prephitmp.85_265(18)> + */ + remove_simple_copy_phi (psi); + return false; + } + + if (scev_analyzable_p (res, region)) + { + tree scev = scalar_evolution_in_region (region, loop, res); + + if (evolution_function_is_invariant_p (scev, loop->num)) + remove_invariant_phi (region, psi); + else + gsi_next (psi); + + return false; + } + + /* All the other cases are considered reductions. */ + return true; +} + +/* Store the GRAPHITE representation of BB. */ + +static gimple_bb_p +new_gimple_bb (basic_block bb, vec<data_reference_p> drs) +{ + struct gimple_bb *gbb; + + gbb = XNEW (struct gimple_bb); + bb->aux = gbb; + GBB_BB (gbb) = bb; + GBB_DATA_REFS (gbb) = drs; + GBB_CONDITIONS (gbb).create (0); + GBB_CONDITION_CASES (gbb).create (0); + + return gbb; +} + +static void +free_data_refs_aux (vec<data_reference_p> datarefs) +{ + unsigned int i; + struct data_reference *dr; + + FOR_EACH_VEC_ELT (datarefs, i, dr) + if (dr->aux) + { + base_alias_pair *bap = (base_alias_pair *)(dr->aux); + + free (bap->alias_set); + + free (bap); + dr->aux = NULL; + } +} +/* Frees GBB. */ + +static void +free_gimple_bb (struct gimple_bb *gbb) +{ + free_data_refs_aux (GBB_DATA_REFS (gbb)); + free_data_refs (GBB_DATA_REFS (gbb)); + + GBB_CONDITIONS (gbb).release (); + GBB_CONDITION_CASES (gbb).release (); + GBB_BB (gbb)->aux = 0; + XDELETE (gbb); +} + +/* Deletes all gimple bbs in SCOP. */ + +static void +remove_gbbs_in_scop (scop_p scop) +{ + int i; + poly_bb_p pbb; + + FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb) + free_gimple_bb (PBB_BLACK_BOX (pbb)); +} + +/* Deletes all scops in SCOPS. */ + +void +free_scops (vec<scop_p> scops) +{ + int i; + scop_p scop; + + FOR_EACH_VEC_ELT (scops, i, scop) + { + remove_gbbs_in_scop (scop); + free_sese (SCOP_REGION (scop)); + free_scop (scop); + } + + scops.release (); +} + +/* Same as outermost_loop_in_sese, returns the outermost loop + containing BB in REGION, but makes sure that the returned loop + belongs to the REGION, and so this returns the first loop in the + REGION when the loop containing BB does not belong to REGION. */ + +static loop_p +outermost_loop_in_sese_1 (sese region, basic_block bb) +{ + loop_p nest = outermost_loop_in_sese (region, bb); + + if (loop_in_sese_p (nest, region)) + return nest; + + /* When the basic block BB does not belong to a loop in the region, + return the first loop in the region. */ + nest = nest->inner; + while (nest) + if (loop_in_sese_p (nest, region)) + break; + else + nest = nest->next; + + gcc_assert (nest); + return nest; +} + +/* Generates a polyhedral black box only if the bb contains interesting + information. */ + +static gimple_bb_p +try_generate_gimple_bb (scop_p scop, basic_block bb) +{ + vec<data_reference_p> drs; + drs.create (5); + sese region = SCOP_REGION (scop); + loop_p nest = outermost_loop_in_sese_1 (region, bb); + gimple_stmt_iterator gsi; + + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple stmt = gsi_stmt (gsi); + loop_p loop; + + if (is_gimple_debug (stmt)) + continue; + + loop = loop_containing_stmt (stmt); + if (!loop_in_sese_p (loop, region)) + loop = nest; + + graphite_find_data_references_in_stmt (nest, loop, stmt, &drs); + } + + return new_gimple_bb (bb, drs); +} + +/* Returns true if all predecessors of BB, that are not dominated by BB, are + marked in MAP. The predecessors dominated by BB are loop latches and will + be handled after BB. */ + +static bool +all_non_dominated_preds_marked_p (basic_block bb, sbitmap map) +{ + edge e; + edge_iterator ei; + + FOR_EACH_EDGE (e, ei, bb->preds) + if (!bitmap_bit_p (map, e->src->index) + && !dominated_by_p (CDI_DOMINATORS, e->src, bb)) + return false; + + return true; +} + +/* Compare the depth of two basic_block's P1 and P2. */ + +static int +compare_bb_depths (const void *p1, const void *p2) +{ + const_basic_block const bb1 = *(const_basic_block const*)p1; + const_basic_block const bb2 = *(const_basic_block const*)p2; + int d1 = loop_depth (bb1->loop_father); + int d2 = loop_depth (bb2->loop_father); + + if (d1 < d2) + return 1; + + if (d1 > d2) + return -1; + + return 0; +} + +/* Sort the basic blocks from DOM such that the first are the ones at + a deepest loop level. */ + +static void +graphite_sort_dominated_info (vec<basic_block> dom) +{ + dom.qsort (compare_bb_depths); +} + +/* Recursive helper function for build_scops_bbs. */ + +static void +build_scop_bbs_1 (scop_p scop, sbitmap visited, basic_block bb) +{ + sese region = SCOP_REGION (scop); + vec<basic_block> dom; + poly_bb_p pbb; + + if (bitmap_bit_p (visited, bb->index) + || !bb_in_sese_p (bb, region)) + return; + + pbb = new_poly_bb (scop, try_generate_gimple_bb (scop, bb)); + SCOP_BBS (scop).safe_push (pbb); + bitmap_set_bit (visited, bb->index); + + dom = get_dominated_by (CDI_DOMINATORS, bb); + + if (!dom.exists ()) + return; + + graphite_sort_dominated_info (dom); + + while (!dom.is_empty ()) + { + int i; + basic_block dom_bb; + + FOR_EACH_VEC_ELT (dom, i, dom_bb) + if (all_non_dominated_preds_marked_p (dom_bb, visited)) + { + build_scop_bbs_1 (scop, visited, dom_bb); + dom.unordered_remove (i); + break; + } + } + + dom.release (); +} + +/* Gather the basic blocks belonging to the SCOP. */ + +static void +build_scop_bbs (scop_p scop) +{ + sbitmap visited = sbitmap_alloc (last_basic_block_for_fn (cfun)); + sese region = SCOP_REGION (scop); + + bitmap_clear (visited); + build_scop_bbs_1 (scop, visited, SESE_ENTRY_BB (region)); + sbitmap_free (visited); +} + +/* 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[50]; + snprintf (name, sizeof (name), "S_%d", pbb_index (pbb)); + return isl_id_alloc (s->ctx, name, pbb); +} + +/* Converts the STATIC_SCHEDULE of PBB into a scattering polyhedron. + We generate SCATTERING_DIMENSIONS scattering dimensions. + + CLooG 0.15.0 and previous versions require, that all + scattering functions of one CloogProgram have the same number of + scattering dimensions, therefore we allow to specify it. This + should be removed in future versions of CLooG. + + The scattering polyhedron consists of these dimensions: scattering, + loop_iterators, parameters. + + Example: + + | scattering_dimensions = 5 + | used_scattering_dimensions = 3 + | nb_iterators = 1 + | scop_nb_params = 2 + | + | Schedule: + | i + | 4 5 + | + | Scattering polyhedron: + | + | scattering: {s1, s2, s3, s4, s5} + | loop_iterators: {i} + | parameters: {p1, p2} + | + | s1 s2 s3 s4 s5 i p1 p2 1 + | 1 0 0 0 0 0 0 0 -4 = 0 + | 0 1 0 0 0 -1 0 0 0 = 0 + | 0 0 1 0 0 0 0 0 -5 = 0 */ + +static void +build_pbb_scattering_polyhedrons (isl_aff *static_sched, + poly_bb_p pbb, int scattering_dimensions) +{ + int i; + int nb_iterators = pbb_dim_iter_domain (pbb); + int used_scattering_dimensions = nb_iterators * 2 + 1; + isl_int val; + isl_space *dc, *dm; + + gcc_assert (scattering_dimensions >= used_scattering_dimensions); + + isl_int_init (val); + + dc = isl_set_get_space (pbb->domain); + dm = isl_space_add_dims (isl_space_from_domain (dc), + isl_dim_out, scattering_dimensions); + pbb->schedule = isl_map_universe (dm); + + for (i = 0; i < scattering_dimensions; i++) + { + /* Textual order inside this loop. */ + if ((i % 2) == 0) + { + isl_constraint *c = isl_equality_alloc + (isl_local_space_from_space (isl_map_get_space (pbb->schedule))); + + if (0 != isl_aff_get_coefficient (static_sched, isl_dim_in, + i / 2, &val)) + gcc_unreachable (); + + isl_int_neg (val, val); + c = isl_constraint_set_constant (c, val); + c = isl_constraint_set_coefficient_si (c, isl_dim_out, i, 1); + pbb->schedule = isl_map_add_constraint (pbb->schedule, c); + } + + /* Iterations of this loop. */ + else /* if ((i % 2) == 1) */ + { + int loop = (i - 1) / 2; + pbb->schedule = isl_map_equate (pbb->schedule, isl_dim_in, loop, + isl_dim_out, i); + } + } + + isl_int_clear (val); + + pbb->transformed = isl_map_copy (pbb->schedule); +} + +/* Build for BB the static schedule. + + The static schedule is a Dewey numbering of the abstract syntax + tree: http://en.wikipedia.org/wiki/Dewey_Decimal_Classification + + The following example informally defines the static schedule: + + A + for (i: ...) + { + for (j: ...) + { + B + C + } + + for (k: ...) + { + D + E + } + } + F + + Static schedules for A to F: + + DEPTH + 0 1 2 + A 0 + B 1 0 0 + C 1 0 1 + D 1 1 0 + E 1 1 1 + F 2 +*/ + +static void +build_scop_scattering (scop_p scop) +{ + int i; + poly_bb_p pbb; + gimple_bb_p previous_gbb = NULL; + isl_space *dc = isl_set_get_space (scop->context); + isl_aff *static_sched; + + dc = isl_space_add_dims (dc, isl_dim_set, number_of_loops (cfun)); + static_sched = isl_aff_zero_on_domain (isl_local_space_from_space (dc)); + + /* We have to start schedules at 0 on the first component and + because we cannot compare_prefix_loops against a previous loop, + prefix will be equal to zero, and that index will be + incremented before copying. */ + static_sched = isl_aff_add_coefficient_si (static_sched, isl_dim_in, 0, -1); + + FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb) + { + gimple_bb_p gbb = PBB_BLACK_BOX (pbb); + int prefix; + int nb_scat_dims = pbb_dim_iter_domain (pbb) * 2 + 1; + + if (previous_gbb) + prefix = nb_common_loops (SCOP_REGION (scop), previous_gbb, gbb); + else + prefix = 0; + + previous_gbb = gbb; + + static_sched = isl_aff_add_coefficient_si (static_sched, isl_dim_in, + prefix, 1); + build_pbb_scattering_polyhedrons (static_sched, pbb, nb_scat_dims); + } + + isl_aff_free (static_sched); +} + +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 ((sese) s->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) +{ + const char *name = get_name (e); + isl_id *id; + + if (name) + id = isl_id_alloc (s->ctx, name, e); + else + { + char name1[50]; + snprintf (name1, sizeof (name1), "P_%d", SSA_NAME_VERSION (e)); + id = isl_id_alloc (s->ctx, name1, e); + } + + return id; +} + +/* Return an ISL identifier for the data reference DR. */ + +static isl_id * +isl_id_for_dr (scop_p s, data_reference_p dr ATTRIBUTE_UNUSED) +{ + /* Data references all get the same isl_id. They need to be comparable + and are distinguished through the first dimension, which contains the + alias set number. */ + return isl_id_alloc (s->ctx, "", 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_aff *aff; + isl_set *dom; + isl_id *id; + int dimension; + + id = isl_id_for_ssa_name (s, e); + dimension = isl_space_find_dim_by_id (space, isl_dim_param, id); + isl_id_free (id); + dom = isl_set_universe (isl_space_copy (space)); + 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); +} + +/* Extract an affine expression from the gmp constant G. */ + +static isl_pw_aff * +extract_affine_gmp (mpz_t 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_int v; + + isl_int_init (v); + isl_int_set_gmp (v, g); + aff = isl_aff_add_constant (aff, v); + isl_int_clear (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; + mpz_t g; + + mpz_init (g); + tree_int_to_gmp (e, g); + res = extract_affine_gmp (g, space); + mpz_clear (g); + + return res; +} + +/* Compute pwaff mod 2^width. */ + +static isl_pw_aff * +wrap (isl_pw_aff *pwaff, unsigned width) +{ + isl_int mod; + + isl_int_init (mod); + isl_int_set_si (mod, 1); + isl_int_mul_2exp (mod, mod, width); + + pwaff = isl_pw_aff_mod (pwaff, mod); + + isl_int_clear (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 region) +{ + int i; + tree p; + + gcc_assert (TREE_CODE (name) == SSA_NAME); + + FOR_EACH_VEC_ELT (SESE_PARAMS (region), i, p) + if (p == name) + return i; + + return -1; +} + +/* When the parameter NAME is in REGION, returns its index in + SESE_PARAMS. Otherwise this function inserts NAME in SESE_PARAMS + and returns the index of NAME. */ + +static int +parameter_index_in_region (tree name, sese region) +{ + int i; + + gcc_assert (TREE_CODE (name) == SSA_NAME); + + i = parameter_index_in_region_1 (name, region); + if (i != -1) + return i; + + gcc_assert (SESE_ADD_PARAMS (region)); + + i = SESE_PARAMS (region).length (); + SESE_PARAMS (region).safe_push (name); + return i; +} + +/* 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; + tree type; + + 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, SCOP_REGION (s))); + 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; + } + + type = TREE_TYPE (e); + if (TYPE_UNSIGNED (type)) + res = wrap (res, TYPE_PRECISION (type)); + + return res; +} + +/* In the context of sese S, scan the expression E and translate it to + a linear expression C. When parsing a symbolic multiplication, K + represents the constant multiplier of an expression containing + parameters. */ + +static void +scan_tree_for_params (sese s, tree e) +{ + if (e == chrec_dont_know) + return; + + switch (TREE_CODE (e)) + { + case POLYNOMIAL_CHREC: + scan_tree_for_params (s, CHREC_LEFT (e)); + break; + + case MULT_EXPR: + if (chrec_contains_symbols (TREE_OPERAND (e, 0))) + scan_tree_for_params (s, TREE_OPERAND (e, 0)); + else + scan_tree_for_params (s, TREE_OPERAND (e, 1)); + break; + + case PLUS_EXPR: + case POINTER_PLUS_EXPR: + case MINUS_EXPR: + scan_tree_for_params (s, TREE_OPERAND (e, 0)); + scan_tree_for_params (s, TREE_OPERAND (e, 1)); + break; + + case NEGATE_EXPR: + case BIT_NOT_EXPR: + CASE_CONVERT: + case NON_LVALUE_EXPR: + scan_tree_for_params (s, TREE_OPERAND (e, 0)); + break; + + case SSA_NAME: + parameter_index_in_region (e, s); + break; + + case INTEGER_CST: + case ADDR_EXPR: + break; + + default: + gcc_unreachable (); + break; + } +} + +/* Find parameters with respect to REGION in BB. We are looking in memory + access functions, conditions and loop bounds. */ + +static void +find_params_in_bb (sese region, gimple_bb_p gbb) +{ + int i; + unsigned j; + data_reference_p dr; + gimple stmt; + loop_p loop = GBB_BB (gbb)->loop_father; + + /* Find parameters in the access functions of data references. */ + FOR_EACH_VEC_ELT (GBB_DATA_REFS (gbb), i, dr) + for (j = 0; j < DR_NUM_DIMENSIONS (dr); j++) + scan_tree_for_params (region, DR_ACCESS_FN (dr, j)); + + /* Find parameters in conditional statements. */ + FOR_EACH_VEC_ELT (GBB_CONDITIONS (gbb), i, stmt) + { + tree lhs = scalar_evolution_in_region (region, loop, + gimple_cond_lhs (stmt)); + tree rhs = scalar_evolution_in_region (region, loop, + gimple_cond_rhs (stmt)); + + scan_tree_for_params (region, lhs); + scan_tree_for_params (region, rhs); + } +} + +/* Record the parameters used in the SCOP. A variable is a parameter + in a scop if it does not vary during the execution of that scop. */ + +static void +find_scop_parameters (scop_p scop) +{ + poly_bb_p pbb; + unsigned i; + sese region = SCOP_REGION (scop); + struct loop *loop; + int nbp; + + /* Find the parameters used in the loop bounds. */ + FOR_EACH_VEC_ELT (SESE_LOOP_NEST (region), i, loop) + { + tree nb_iters = number_of_latch_executions (loop); + + if (!chrec_contains_symbols (nb_iters)) + continue; + + nb_iters = scalar_evolution_in_region (region, loop, nb_iters); + scan_tree_for_params (region, nb_iters); + } + + /* Find the parameters used in data accesses. */ + FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb) + find_params_in_bb (region, PBB_BLACK_BOX (pbb)); + + nbp = sese_nb_params (region); + scop_set_nb_params (scop, nbp); + SESE_ADD_PARAMS (region) = false; + + { + tree e; + isl_space *space = isl_space_set_alloc (scop->ctx, nbp, 0); + + FOR_EACH_VEC_ELT (SESE_PARAMS (region), i, e) + space = isl_space_set_dim_id (space, isl_dim_param, i, + isl_id_for_ssa_name (scop, e)); + + scop->context = isl_set_universe (space); + } +} + +/* Builds the constraint polyhedra for LOOP in SCOP. OUTER_PH gives + the constraints for the surrounding loops. */ + +static void +build_loop_iteration_domains (scop_p scop, struct loop *loop, + int nb, + isl_set *outer, isl_set **doms) +{ + tree nb_iters = number_of_latch_executions (loop); + sese region = SCOP_REGION (scop); + + isl_set *inner = isl_set_copy (outer); + isl_space *space; + isl_constraint *c; + int pos = isl_set_dim (outer, isl_dim_set); + isl_int v; + mpz_t g; + + mpz_init (g); + isl_int_init (v); + + inner = isl_set_add_dims (inner, isl_dim_set, 1); + space = isl_set_get_space (inner); + + /* 0 <= loop_i */ + c = isl_inequality_alloc + (isl_local_space_from_space (isl_space_copy (space))); + c = isl_constraint_set_coefficient_si (c, isl_dim_set, pos, 1); + inner = isl_set_add_constraint (inner, c); + + /* loop_i <= cst_nb_iters */ + if (TREE_CODE (nb_iters) == INTEGER_CST) + { + c = isl_inequality_alloc + (isl_local_space_from_space (isl_space_copy (space))); + c = isl_constraint_set_coefficient_si (c, isl_dim_set, pos, -1); + tree_int_to_gmp (nb_iters, g); + isl_int_set_gmp (v, g); + c = isl_constraint_set_constant (c, v); + inner = isl_set_add_constraint (inner, c); + } + + /* loop_i <= expr_nb_iters */ + else if (!chrec_contains_undetermined (nb_iters)) + { + double_int nit; + isl_pw_aff *aff; + isl_set *valid; + isl_local_space *ls; + isl_aff *al; + isl_set *le; + + nb_iters = scalar_evolution_in_region (region, loop, nb_iters); + + aff = extract_affine (scop, nb_iters, isl_set_get_space (inner)); + valid = isl_pw_aff_nonneg_set (isl_pw_aff_copy (aff)); + valid = isl_set_project_out (valid, isl_dim_set, 0, + isl_set_dim (valid, isl_dim_set)); + scop->context = isl_set_intersect (scop->context, valid); + + ls = isl_local_space_from_space (isl_space_copy (space)); + al = isl_aff_set_coefficient_si (isl_aff_zero_on_domain (ls), + isl_dim_in, pos, 1); + le = isl_pw_aff_le_set (isl_pw_aff_from_aff (al), + isl_pw_aff_copy (aff)); + inner = isl_set_intersect (inner, le); + + if (max_stmt_executions (loop, &nit)) + { + /* Insert in the context the constraints from the + estimation of the number of iterations NIT and the + symbolic number of iterations (involving parameter + names) NB_ITERS. First, build the affine expression + "NIT - NB_ITERS" and then say that it is positive, + i.e., NIT approximates NB_ITERS: "NIT >= NB_ITERS". */ + isl_pw_aff *approx; + mpz_t g; + isl_set *x; + isl_constraint *c; + + mpz_init (g); + mpz_set_double_int (g, nit, false); + mpz_sub_ui (g, g, 1); + approx = extract_affine_gmp (g, isl_set_get_space (inner)); + x = isl_pw_aff_ge_set (approx, aff); + x = isl_set_project_out (x, isl_dim_set, 0, + isl_set_dim (x, isl_dim_set)); + scop->context = isl_set_intersect (scop->context, x); + + c = isl_inequality_alloc + (isl_local_space_from_space (isl_space_copy (space))); + c = isl_constraint_set_coefficient_si (c, isl_dim_set, pos, -1); + isl_int_set_gmp (v, g); + mpz_clear (g); + c = isl_constraint_set_constant (c, v); + inner = isl_set_add_constraint (inner, c); + } + else + isl_pw_aff_free (aff); + } + else + gcc_unreachable (); + + if (loop->inner && loop_in_sese_p (loop->inner, region)) + build_loop_iteration_domains (scop, loop->inner, nb + 1, + isl_set_copy (inner), doms); + + if (nb != 0 + && loop->next + && loop_in_sese_p (loop->next, region)) + build_loop_iteration_domains (scop, loop->next, nb, + isl_set_copy (outer), doms); + + doms[loop->num] = inner; + + isl_set_free (outer); + isl_space_free (space); + isl_int_clear (v); + mpz_clear (g); +} + +/* Returns a linear expression for tree T evaluated in PBB. */ + +static isl_pw_aff * +create_pw_aff_from_tree (poly_bb_p pbb, tree t) +{ + scop_p scop = PBB_SCOP (pbb); + + t = scalar_evolution_in_region (SCOP_REGION (scop), pbb_loop (pbb), 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, gimple stmt, enum tree_code code) +{ + isl_pw_aff *lhs = create_pw_aff_from_tree (pbb, gimple_cond_lhs (stmt)); + isl_pw_aff *rhs = create_pw_aff_from_tree (pbb, 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: + isl_pw_aff_free (lhs); + isl_pw_aff_free (rhs); + return; + } + + cond = isl_set_coalesce (cond); + cond = isl_set_set_tuple_id (cond, isl_set_get_tuple_id (pbb->domain)); + pbb->domain = 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_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: + { + enum tree_code code = gimple_cond_code (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, stmt, code); + break; + } + + case GIMPLE_SWITCH: + /* Switch statements are not supported right now - fall through. */ + + default: + gcc_unreachable (); + break; + } +} + +/* Traverses all the GBBs of the SCOP and add their constraints to the + iteration domains. */ + +static void +add_conditions_to_constraints (scop_p scop) +{ + int i; + poly_bb_p pbb; + + FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb) + add_conditions_to_domain (pbb); +} + +/* Returns a COND_EXPR statement when BB has a single predecessor, the + edge between BB and its predecessor is not a loop exit edge, and + the last statement of the single predecessor is a COND_EXPR. */ + +static gimple +single_pred_cond_non_loop_exit (basic_block bb) +{ + if (single_pred_p (bb)) + { + edge e = single_pred_edge (bb); + basic_block pred = e->src; + gimple stmt; + + if (loop_depth (pred->loop_father) > loop_depth (bb->loop_father)) + return NULL; + + stmt = last_stmt (pred); + + if (stmt && gimple_code (stmt) == GIMPLE_COND) + return stmt; + } + + return NULL; +} + +class sese_dom_walker : public dom_walker +{ +public: + sese_dom_walker (cdi_direction, sese); + + virtual void before_dom_children (basic_block); + virtual void after_dom_children (basic_block); + +private: + auto_vec<gimple, 3> m_conditions, m_cases; + sese m_region; +}; + +sese_dom_walker::sese_dom_walker (cdi_direction direction, sese region) + : dom_walker (direction), m_region (region) +{ +} + +/* Call-back for dom_walk executed before visiting the dominated + blocks. */ + +void +sese_dom_walker::before_dom_children (basic_block bb) +{ + gimple_bb_p gbb; + gimple stmt; + + if (!bb_in_sese_p (bb, m_region)) + return; + + stmt = single_pred_cond_non_loop_exit (bb); + + if (stmt) + { + edge e = single_pred_edge (bb); + + m_conditions.safe_push (stmt); + + if (e->flags & EDGE_TRUE_VALUE) + m_cases.safe_push (stmt); + else + m_cases.safe_push (NULL); + } + + gbb = gbb_from_bb (bb); + + if (gbb) + { + GBB_CONDITIONS (gbb) = m_conditions.copy (); + GBB_CONDITION_CASES (gbb) = m_cases.copy (); + } +} + +/* Call-back for dom_walk executed after visiting the dominated + blocks. */ + +void +sese_dom_walker::after_dom_children (basic_block bb) +{ + if (!bb_in_sese_p (bb, m_region)) + return; + + if (single_pred_cond_non_loop_exit (bb)) + { + m_conditions.pop (); + m_cases.pop (); + } +} + +/* 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 = SESE_PARAMS (SCOP_REGION (scop))[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->context); + isl_constraint *c; + mpz_t g; + isl_int v; + + c = isl_inequality_alloc (isl_local_space_from_space (space)); + mpz_init (g); + isl_int_init (v); + tree_int_to_gmp (lb, g); + isl_int_set_gmp (v, g); + isl_int_neg (v, v); + mpz_clear (g); + c = isl_constraint_set_constant (c, v); + isl_int_clear (v); + c = isl_constraint_set_coefficient_si (c, isl_dim_param, p, 1); + + scop->context = isl_set_add_constraint (scop->context, c); + } + + if (ub) + { + isl_space *space = isl_set_get_space (scop->context); + isl_constraint *c; + mpz_t g; + isl_int v; + + c = isl_inequality_alloc (isl_local_space_from_space (space)); + + mpz_init (g); + isl_int_init (v); + tree_int_to_gmp (ub, g); + isl_int_set_gmp (v, g); + mpz_clear (g); + c = isl_constraint_set_constant (c, v); + isl_int_clear (v); + c = isl_constraint_set_coefficient_si (c, isl_dim_param, p, -1); + + scop->context = isl_set_add_constraint (scop->context, c); + } +} + +/* Build the context of the SCOP. The context usually contains extra + constraints that are added to the iteration domains that constrain + some parameters. */ + +static void +build_scop_context (scop_p scop) +{ + graphite_dim_t p, n = scop_nb_params (scop); + + for (p = 0; p < n; p++) + add_param_constraints (scop, p); +} + +/* Build the iteration domains: the loops belonging to the current + SCOP, and that vary for the execution of the current basic block. + Returns false if there is no loop in SCOP. */ + +static void +build_scop_iteration_domain (scop_p scop) +{ + struct loop *loop; + sese region = SCOP_REGION (scop); + int i; + poly_bb_p pbb; + int nb_loops = number_of_loops (cfun); + isl_set **doms = XCNEWVEC (isl_set *, nb_loops); + + FOR_EACH_VEC_ELT (SESE_LOOP_NEST (region), i, loop) + if (!loop_in_sese_p (loop_outer (loop), region)) + build_loop_iteration_domains (scop, loop, 0, + isl_set_copy (scop->context), doms); + + FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb) + { + loop = pbb_loop (pbb); + + if (doms[loop->num]) + pbb->domain = isl_set_copy (doms[loop->num]); + else + pbb->domain = isl_set_copy (scop->context); + + pbb->domain = isl_set_set_tuple_id (pbb->domain, + isl_id_for_pbb (scop, pbb)); + } + + for (i = 0; i < nb_loops; i++) + if (doms[i]) + isl_set_free (doms[i]); + + free (doms); +} + +/* 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, data_reference_p dr) +{ + isl_constraint *c; + int alias_set_num = 0; + base_alias_pair *bap = (base_alias_pair *)(dr->aux); + + if (bap && bap->alias_set) + alias_set_num = *(bap->alias_set); + + c = isl_equality_alloc + (isl_local_space_from_space (isl_map_get_space (acc))); + c = isl_constraint_set_constant_si (c, -alias_set_num); + 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, data_reference_p dr, poly_bb_p 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, nb_subscripts - 1 - i); + + aff = extract_affine (scop, afn, + isl_space_domain (isl_map_get_space (acc))); + acc = set_index (acc, i + 1, aff); + } + + return acc; +} + +/* 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 *extent, scop_p scop, data_reference_p dr) +{ + tree ref = DR_REF (dr); + int i, nb_subscripts = DR_NUM_DIMENSIONS (dr); + + for (i = nb_subscripts - 1; i >= 0; i--, ref = TREE_OPERAND (ref, 0)) + { + tree low, high; + + if (TREE_CODE (ref) != ARRAY_REF) + break; + + low = array_ref_low_bound (ref); + high = array_ref_up_bound (ref); + + /* XXX The PPL code dealt separately with + subscript - low >= 0 and high - subscript >= 0 in case one of + the two bounds isn't known. Do the same here? */ + + if (tree_fits_shwi_p (low) + && high + && tree_fits_shwi_p (high) + /* 1-element arrays at end of structures may extend over + their declared size. */ + && !(array_at_struct_end_p (ref) + && operand_equal_p (low, high, 0))) + { + isl_id *id; + isl_aff *aff; + isl_set *univ, *lbs, *ubs; + isl_pw_aff *index; + isl_space *space; + isl_set *valid; + isl_pw_aff *lb = extract_affine_int (low, isl_set_get_space (extent)); + isl_pw_aff *ub = extract_affine_int (high, isl_set_get_space (extent)); + + /* high >= 0 */ + 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->context = isl_set_intersect (scop->context, valid); + + space = isl_set_get_space (extent); + 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); + univ = isl_set_universe (isl_space_domain (isl_aff_get_space (aff))); + index = isl_pw_aff_alloc (univ, aff); + + id = isl_set_get_tuple_id (extent); + 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 */ + lbs = isl_pw_aff_ge_set (isl_pw_aff_copy (index), lb); + ubs = isl_pw_aff_le_set (index, ub); + extent = isl_set_intersect (extent, lbs); + extent = isl_set_intersect (extent, ubs); + } + } + + return extent; +} + +/* Build data accesses for DR in PBB. */ + +static void +build_poly_dr (data_reference_p dr, poly_bb_p pbb) +{ + int dr_base_object_set; + isl_map *acc; + isl_set *extent; + scop_p scop = PBB_SCOP (pbb); + + { + 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_for_dr (scop, dr)); + } + + acc = pdr_add_alias_set (acc, dr); + acc = pdr_add_memory_accesses (acc, dr, pbb); + + { + isl_id *id = isl_id_for_dr (scop, dr); + int nb = 1 + DR_NUM_DIMENSIONS (dr); + isl_space *space = isl_space_set_alloc (scop->ctx, 0, nb); + int alias_set_num = 0; + base_alias_pair *bap = (base_alias_pair *)(dr->aux); + + if (bap && bap->alias_set) + alias_set_num = *(bap->alias_set); + + space = isl_space_set_tuple_id (space, isl_dim_set, id); + extent = isl_set_nat_universe (space); + extent = isl_set_fix_si (extent, isl_dim_set, 0, alias_set_num); + extent = pdr_add_data_dimensions (extent, scop, dr); + } + + gcc_assert (dr->aux); + dr_base_object_set = ((base_alias_pair *)(dr->aux))->base_obj_set; + + new_poly_dr (pbb, dr_base_object_set, + DR_IS_READ (dr) ? PDR_READ : PDR_WRITE, + dr, DR_NUM_DIMENSIONS (dr), acc, extent); +} + +/* Write to FILE the alias graph of data references in DIMACS format. */ + +static inline bool +write_alias_graph_to_ascii_dimacs (FILE *file, char *comment, + vec<data_reference_p> drs) +{ + int num_vertex = drs.length (); + int edge_num = 0; + data_reference_p dr1, dr2; + int i, j; + + if (num_vertex == 0) + return true; + + FOR_EACH_VEC_ELT (drs, i, dr1) + for (j = i + 1; drs.iterate (j, &dr2); j++) + if (dr_may_alias_p (dr1, dr2, true)) + edge_num++; + + fprintf (file, "$\n"); + + if (comment) + fprintf (file, "c %s\n", comment); + + fprintf (file, "p edge %d %d\n", num_vertex, edge_num); + + FOR_EACH_VEC_ELT (drs, i, dr1) + for (j = i + 1; drs.iterate (j, &dr2); j++) + if (dr_may_alias_p (dr1, dr2, true)) + fprintf (file, "e %d %d\n", i + 1, j + 1); + + return true; +} + +/* Write to FILE the alias graph of data references in DOT format. */ + +static inline bool +write_alias_graph_to_ascii_dot (FILE *file, char *comment, + vec<data_reference_p> drs) +{ + int num_vertex = drs.length (); + data_reference_p dr1, dr2; + int i, j; + + if (num_vertex == 0) + return true; + + fprintf (file, "$\n"); + + if (comment) + fprintf (file, "c %s\n", comment); + + /* First print all the vertices. */ + FOR_EACH_VEC_ELT (drs, i, dr1) + fprintf (file, "n%d;\n", i); + + FOR_EACH_VEC_ELT (drs, i, dr1) + for (j = i + 1; drs.iterate (j, &dr2); j++) + if (dr_may_alias_p (dr1, dr2, true)) + fprintf (file, "n%d n%d\n", i, j); + + return true; +} + +/* Write to FILE the alias graph of data references in ECC format. */ + +static inline bool +write_alias_graph_to_ascii_ecc (FILE *file, char *comment, + vec<data_reference_p> drs) +{ + int num_vertex = drs.length (); + data_reference_p dr1, dr2; + int i, j; + + if (num_vertex == 0) + return true; + + fprintf (file, "$\n"); + + if (comment) + fprintf (file, "c %s\n", comment); + + FOR_EACH_VEC_ELT (drs, i, dr1) + for (j = i + 1; drs.iterate (j, &dr2); j++) + if (dr_may_alias_p (dr1, dr2, true)) + fprintf (file, "%d %d\n", i, j); + + return true; +} + +/* Check if DR1 and DR2 are in the same object set. */ + +static bool +dr_same_base_object_p (const struct data_reference *dr1, + const struct data_reference *dr2) +{ + return operand_equal_p (DR_BASE_OBJECT (dr1), DR_BASE_OBJECT (dr2), 0); +} + +/* Uses DFS component number as representative of alias-sets. Also tests for + optimality by verifying if every connected component is a clique. Returns + true (1) if the above test is true, and false (0) otherwise. */ + +static int +build_alias_set_optimal_p (vec<data_reference_p> drs) +{ + int num_vertices = drs.length (); + struct graph *g = new_graph (num_vertices); + data_reference_p dr1, dr2; + int i, j; + int num_connected_components; + int v_indx1, v_indx2, num_vertices_in_component; + int *all_vertices; + int *vertices; + struct graph_edge *e; + int this_component_is_clique; + int all_components_are_cliques = 1; + + FOR_EACH_VEC_ELT (drs, i, dr1) + for (j = i+1; drs.iterate (j, &dr2); j++) + if (dr_may_alias_p (dr1, dr2, true)) + { + add_edge (g, i, j); + add_edge (g, j, i); + } + + all_vertices = XNEWVEC (int, num_vertices); + vertices = XNEWVEC (int, num_vertices); + for (i = 0; i < num_vertices; i++) + all_vertices[i] = i; + + num_connected_components = graphds_dfs (g, all_vertices, num_vertices, + NULL, true, NULL); + for (i = 0; i < g->n_vertices; i++) + { + data_reference_p dr = drs[i]; + base_alias_pair *bap; + + gcc_assert (dr->aux); + bap = (base_alias_pair *)(dr->aux); + + bap->alias_set = XNEW (int); + *(bap->alias_set) = g->vertices[i].component + 1; + } + + /* Verify if the DFS numbering results in optimal solution. */ + for (i = 0; i < num_connected_components; i++) + { + num_vertices_in_component = 0; + /* Get all vertices whose DFS component number is the same as i. */ + for (j = 0; j < num_vertices; j++) + if (g->vertices[j].component == i) + vertices[num_vertices_in_component++] = j; + + /* Now test if the vertices in 'vertices' form a clique, by testing + for edges among each pair. */ + this_component_is_clique = 1; + for (v_indx1 = 0; v_indx1 < num_vertices_in_component; v_indx1++) + { + for (v_indx2 = v_indx1+1; v_indx2 < num_vertices_in_component; v_indx2++) + { + /* Check if the two vertices are connected by iterating + through all the edges which have one of these are source. */ + e = g->vertices[vertices[v_indx2]].pred; + while (e) + { + if (e->src == vertices[v_indx1]) + break; + e = e->pred_next; + } + if (!e) + { + this_component_is_clique = 0; + break; + } + } + if (!this_component_is_clique) + all_components_are_cliques = 0; + } + } + + free (all_vertices); + free (vertices); + free_graph (g); + return all_components_are_cliques; +} + +/* Group each data reference in DRS with its base object set num. */ + +static void +build_base_obj_set_for_drs (vec<data_reference_p> drs) +{ + int num_vertex = drs.length (); + struct graph *g = new_graph (num_vertex); + data_reference_p dr1, dr2; + int i, j; + int *queue; + + FOR_EACH_VEC_ELT (drs, i, dr1) + for (j = i + 1; drs.iterate (j, &dr2); j++) + if (dr_same_base_object_p (dr1, dr2)) + { + add_edge (g, i, j); + add_edge (g, j, i); + } + + queue = XNEWVEC (int, num_vertex); + for (i = 0; i < num_vertex; i++) + queue[i] = i; + + graphds_dfs (g, queue, num_vertex, NULL, true, NULL); + + for (i = 0; i < g->n_vertices; i++) + { + data_reference_p dr = drs[i]; + base_alias_pair *bap; + + gcc_assert (dr->aux); + bap = (base_alias_pair *)(dr->aux); + + bap->base_obj_set = g->vertices[i].component + 1; + } + + free (queue); + free_graph (g); +} + +/* Build the data references for PBB. */ + +static void +build_pbb_drs (poly_bb_p pbb) +{ + int j; + data_reference_p dr; + vec<data_reference_p> gbb_drs = GBB_DATA_REFS (PBB_BLACK_BOX (pbb)); + + FOR_EACH_VEC_ELT (gbb_drs, j, dr) + build_poly_dr (dr, pbb); +} + +/* Dump to file the alias graphs for the data references in DRS. */ + +static void +dump_alias_graphs (vec<data_reference_p> drs) +{ + char comment[100]; + FILE *file_dimacs, *file_ecc, *file_dot; + + file_dimacs = fopen ("/tmp/dr_alias_graph_dimacs", "ab"); + if (file_dimacs) + { + snprintf (comment, sizeof (comment), "%s %s", main_input_filename, + current_function_name ()); + write_alias_graph_to_ascii_dimacs (file_dimacs, comment, drs); + fclose (file_dimacs); + } + + file_ecc = fopen ("/tmp/dr_alias_graph_ecc", "ab"); + if (file_ecc) + { + snprintf (comment, sizeof (comment), "%s %s", main_input_filename, + current_function_name ()); + write_alias_graph_to_ascii_ecc (file_ecc, comment, drs); + fclose (file_ecc); + } + + file_dot = fopen ("/tmp/dr_alias_graph_dot", "ab"); + if (file_dot) + { + snprintf (comment, sizeof (comment), "%s %s", main_input_filename, + current_function_name ()); + write_alias_graph_to_ascii_dot (file_dot, comment, drs); + fclose (file_dot); + } +} + +/* Build data references in SCOP. */ + +static void +build_scop_drs (scop_p scop) +{ + int i, j; + poly_bb_p pbb; + data_reference_p dr; + auto_vec<data_reference_p, 3> drs; + + /* Remove all the PBBs that do not have data references: these basic + blocks are not handled in the polyhedral representation. */ + for (i = 0; SCOP_BBS (scop).iterate (i, &pbb); i++) + if (GBB_DATA_REFS (PBB_BLACK_BOX (pbb)).is_empty ()) + { + free_gimple_bb (PBB_BLACK_BOX (pbb)); + free_poly_bb (pbb); + SCOP_BBS (scop).ordered_remove (i); + i--; + } + + FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb) + for (j = 0; GBB_DATA_REFS (PBB_BLACK_BOX (pbb)).iterate (j, &dr); j++) + drs.safe_push (dr); + + FOR_EACH_VEC_ELT (drs, i, dr) + dr->aux = XNEW (base_alias_pair); + + if (!build_alias_set_optimal_p (drs)) + { + /* TODO: Add support when building alias set is not optimal. */ + ; + } + + build_base_obj_set_for_drs (drs); + + /* When debugging, enable the following code. This cannot be used + in production compilers. */ + if (0) + dump_alias_graphs (drs); + + drs.release (); + + FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb) + build_pbb_drs (pbb); +} + +/* Return a gsi at the position of the phi node STMT. */ + +static gimple_stmt_iterator +gsi_for_phi_node (gimple stmt) +{ + gimple_stmt_iterator psi; + basic_block bb = gimple_bb (stmt); + + for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) + if (stmt == gsi_stmt (psi)) + return psi; + + gcc_unreachable (); + return psi; +} + +/* Analyze all the data references of STMTS and add them to the + GBB_DATA_REFS vector of BB. */ + +static void +analyze_drs_in_stmts (scop_p scop, basic_block bb, vec<gimple> stmts) +{ + loop_p nest; + gimple_bb_p gbb; + gimple stmt; + int i; + sese region = SCOP_REGION (scop); + + if (!bb_in_sese_p (bb, region)) + return; + + nest = outermost_loop_in_sese_1 (region, bb); + gbb = gbb_from_bb (bb); + + FOR_EACH_VEC_ELT (stmts, i, stmt) + { + loop_p loop; + + if (is_gimple_debug (stmt)) + continue; + + loop = loop_containing_stmt (stmt); + if (!loop_in_sese_p (loop, region)) + loop = nest; + + graphite_find_data_references_in_stmt (nest, loop, stmt, + &GBB_DATA_REFS (gbb)); + } +} + +/* Insert STMT at the end of the STMTS sequence and then insert the + statements from STMTS at INSERT_GSI and call analyze_drs_in_stmts + on STMTS. */ + +static void +insert_stmts (scop_p scop, gimple stmt, gimple_seq stmts, + gimple_stmt_iterator insert_gsi) +{ + gimple_stmt_iterator gsi; + auto_vec<gimple, 3> x; + + gimple_seq_add_stmt (&stmts, stmt); + for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi)) + x.safe_push (gsi_stmt (gsi)); + + gsi_insert_seq_before (&insert_gsi, stmts, GSI_SAME_STMT); + analyze_drs_in_stmts (scop, gsi_bb (insert_gsi), x); +} + +/* Insert the assignment "RES := EXPR" just after AFTER_STMT. */ + +static void +insert_out_of_ssa_copy (scop_p scop, tree res, tree expr, gimple after_stmt) +{ + gimple_seq stmts; + gimple_stmt_iterator gsi; + tree var = force_gimple_operand (expr, &stmts, true, NULL_TREE); + gimple stmt = gimple_build_assign (unshare_expr (res), var); + auto_vec<gimple, 3> x; + + gimple_seq_add_stmt (&stmts, stmt); + for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi)) + x.safe_push (gsi_stmt (gsi)); + + if (gimple_code (after_stmt) == GIMPLE_PHI) + { + gsi = gsi_after_labels (gimple_bb (after_stmt)); + gsi_insert_seq_before (&gsi, stmts, GSI_NEW_STMT); + } + else + { + gsi = gsi_for_stmt (after_stmt); + gsi_insert_seq_after (&gsi, stmts, GSI_NEW_STMT); + } + + analyze_drs_in_stmts (scop, gimple_bb (after_stmt), x); +} + +/* Creates a poly_bb_p for basic_block BB from the existing PBB. */ + +static void +new_pbb_from_pbb (scop_p scop, poly_bb_p pbb, basic_block bb) +{ + vec<data_reference_p> drs; + drs.create (3); + gimple_bb_p gbb = PBB_BLACK_BOX (pbb); + gimple_bb_p gbb1 = new_gimple_bb (bb, drs); + poly_bb_p pbb1 = new_poly_bb (scop, gbb1); + int index, n = SCOP_BBS (scop).length (); + + /* The INDEX of PBB in SCOP_BBS. */ + for (index = 0; index < n; index++) + if (SCOP_BBS (scop)[index] == pbb) + break; + + pbb1->domain = isl_set_copy (pbb->domain); + + GBB_PBB (gbb1) = pbb1; + GBB_CONDITIONS (gbb1) = GBB_CONDITIONS (gbb).copy (); + GBB_CONDITION_CASES (gbb1) = GBB_CONDITION_CASES (gbb).copy (); + SCOP_BBS (scop).safe_insert (index + 1, pbb1); +} + +/* Insert on edge E the assignment "RES := EXPR". */ + +static void +insert_out_of_ssa_copy_on_edge (scop_p scop, edge e, tree res, tree expr) +{ + gimple_stmt_iterator gsi; + gimple_seq stmts = NULL; + tree var = force_gimple_operand (expr, &stmts, true, NULL_TREE); + gimple stmt = gimple_build_assign (unshare_expr (res), var); + basic_block bb; + auto_vec<gimple, 3> x; + + gimple_seq_add_stmt (&stmts, stmt); + for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi)) + x.safe_push (gsi_stmt (gsi)); + + gsi_insert_seq_on_edge (e, stmts); + gsi_commit_edge_inserts (); + bb = gimple_bb (stmt); + + if (!bb_in_sese_p (bb, SCOP_REGION (scop))) + return; + + if (!gbb_from_bb (bb)) + new_pbb_from_pbb (scop, pbb_from_bb (e->src), bb); + + analyze_drs_in_stmts (scop, bb, x); +} + +/* Creates a zero dimension array of the same type as VAR. */ + +static tree +create_zero_dim_array (tree var, const char *base_name) +{ + tree index_type = build_index_type (integer_zero_node); + tree elt_type = TREE_TYPE (var); + tree array_type = build_array_type (elt_type, index_type); + tree base = create_tmp_var (array_type, base_name); + + return build4 (ARRAY_REF, elt_type, base, integer_zero_node, NULL_TREE, + NULL_TREE); +} + +/* Returns true when PHI is a loop close phi node. */ + +static bool +scalar_close_phi_node_p (gimple phi) +{ + if (gimple_code (phi) != GIMPLE_PHI + || virtual_operand_p (gimple_phi_result (phi))) + return false; + + /* Note that loop close phi nodes should have a single argument + because we translated the representation into a canonical form + before Graphite: see canonicalize_loop_closed_ssa_form. */ + return (gimple_phi_num_args (phi) == 1); +} + +/* For a definition DEF in REGION, propagates the expression EXPR in + all the uses of DEF outside REGION. */ + +static void +propagate_expr_outside_region (tree def, tree expr, sese region) +{ + imm_use_iterator imm_iter; + gimple use_stmt; + gimple_seq stmts; + bool replaced_once = false; + + gcc_assert (TREE_CODE (def) == SSA_NAME); + + expr = force_gimple_operand (unshare_expr (expr), &stmts, true, + NULL_TREE); + + FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, def) + if (!is_gimple_debug (use_stmt) + && !bb_in_sese_p (gimple_bb (use_stmt), region)) + { + ssa_op_iter iter; + use_operand_p use_p; + + FOR_EACH_PHI_OR_STMT_USE (use_p, use_stmt, iter, SSA_OP_ALL_USES) + if (operand_equal_p (def, USE_FROM_PTR (use_p), 0) + && (replaced_once = true)) + replace_exp (use_p, expr); + + update_stmt (use_stmt); + } + + if (replaced_once) + { + gsi_insert_seq_on_edge (SESE_ENTRY (region), stmts); + gsi_commit_edge_inserts (); + } +} + +/* Rewrite out of SSA the reduction phi node at PSI by creating a zero + dimension array for it. */ + +static void +rewrite_close_phi_out_of_ssa (scop_p scop, gimple_stmt_iterator *psi) +{ + sese region = SCOP_REGION (scop); + gimple phi = gsi_stmt (*psi); + tree res = gimple_phi_result (phi); + basic_block bb = gimple_bb (phi); + gimple_stmt_iterator gsi = gsi_after_labels (bb); + tree arg = gimple_phi_arg_def (phi, 0); + gimple stmt; + + /* Note that loop close phi nodes should have a single argument + because we translated the representation into a canonical form + before Graphite: see canonicalize_loop_closed_ssa_form. */ + gcc_assert (gimple_phi_num_args (phi) == 1); + + /* The phi node can be a non close phi node, when its argument is + invariant, or a default definition. */ + if (is_gimple_min_invariant (arg) + || SSA_NAME_IS_DEFAULT_DEF (arg)) + { + propagate_expr_outside_region (res, arg, region); + gsi_next (psi); + return; + } + + else if (gimple_bb (SSA_NAME_DEF_STMT (arg))->loop_father == bb->loop_father) + { + propagate_expr_outside_region (res, arg, region); + stmt = gimple_build_assign (res, arg); + remove_phi_node (psi, false); + gsi_insert_before (&gsi, stmt, GSI_NEW_STMT); + return; + } + + /* If res is scev analyzable and is not a scalar value, it is safe + to ignore the close phi node: it will be code generated in the + out of Graphite pass. */ + else if (scev_analyzable_p (res, region)) + { + loop_p loop = loop_containing_stmt (SSA_NAME_DEF_STMT (res)); + tree scev; + + if (!loop_in_sese_p (loop, region)) + { + loop = loop_containing_stmt (SSA_NAME_DEF_STMT (arg)); + scev = scalar_evolution_in_region (region, loop, arg); + scev = compute_overall_effect_of_inner_loop (loop, scev); + } + else + scev = scalar_evolution_in_region (region, loop, res); + + if (tree_does_not_contain_chrecs (scev)) + propagate_expr_outside_region (res, scev, region); + + gsi_next (psi); + return; + } + else + { + tree zero_dim_array = create_zero_dim_array (res, "Close_Phi"); + + stmt = gimple_build_assign (res, unshare_expr (zero_dim_array)); + + if (TREE_CODE (arg) == SSA_NAME) + insert_out_of_ssa_copy (scop, zero_dim_array, arg, + SSA_NAME_DEF_STMT (arg)); + else + insert_out_of_ssa_copy_on_edge (scop, single_pred_edge (bb), + zero_dim_array, arg); + } + + remove_phi_node (psi, false); + SSA_NAME_DEF_STMT (res) = stmt; + + insert_stmts (scop, stmt, NULL, gsi_after_labels (bb)); +} + +/* Rewrite out of SSA the reduction phi node at PSI by creating a zero + dimension array for it. */ + +static void +rewrite_phi_out_of_ssa (scop_p scop, gimple_stmt_iterator *psi) +{ + size_t i; + gimple phi = gsi_stmt (*psi); + basic_block bb = gimple_bb (phi); + tree res = gimple_phi_result (phi); + tree zero_dim_array = create_zero_dim_array (res, "phi_out_of_ssa"); + gimple stmt; + + for (i = 0; i < gimple_phi_num_args (phi); i++) + { + tree arg = gimple_phi_arg_def (phi, i); + edge e = gimple_phi_arg_edge (phi, i); + + /* Avoid the insertion of code in the loop latch to please the + pattern matching of the vectorizer. */ + if (TREE_CODE (arg) == SSA_NAME + && e->src == bb->loop_father->latch) + insert_out_of_ssa_copy (scop, zero_dim_array, arg, + SSA_NAME_DEF_STMT (arg)); + else + insert_out_of_ssa_copy_on_edge (scop, e, zero_dim_array, arg); + } + + stmt = gimple_build_assign (res, unshare_expr (zero_dim_array)); + remove_phi_node (psi, false); + insert_stmts (scop, stmt, NULL, gsi_after_labels (bb)); +} + +/* Rewrite the degenerate phi node at position PSI from the degenerate + form "x = phi (y, y, ..., y)" to "x = y". */ + +static void +rewrite_degenerate_phi (gimple_stmt_iterator *psi) +{ + tree rhs; + gimple stmt; + gimple_stmt_iterator gsi; + gimple phi = gsi_stmt (*psi); + tree res = gimple_phi_result (phi); + basic_block bb; + + bb = gimple_bb (phi); + rhs = degenerate_phi_result (phi); + gcc_assert (rhs); + + stmt = gimple_build_assign (res, rhs); + remove_phi_node (psi, false); + + gsi = gsi_after_labels (bb); + gsi_insert_before (&gsi, stmt, GSI_NEW_STMT); +} + +/* Rewrite out of SSA all the reduction phi nodes of SCOP. */ + +static void +rewrite_reductions_out_of_ssa (scop_p scop) +{ + basic_block bb; + gimple_stmt_iterator psi; + sese region = SCOP_REGION (scop); + + FOR_EACH_BB_FN (bb, cfun) + if (bb_in_sese_p (bb, region)) + for (psi = gsi_start_phis (bb); !gsi_end_p (psi);) + { + gimple phi = gsi_stmt (psi); + + if (virtual_operand_p (gimple_phi_result (phi))) + { + gsi_next (&psi); + continue; + } + + if (gimple_phi_num_args (phi) > 1 + && degenerate_phi_result (phi)) + rewrite_degenerate_phi (&psi); + + else if (scalar_close_phi_node_p (phi)) + rewrite_close_phi_out_of_ssa (scop, &psi); + + else if (reduction_phi_p (region, &psi)) + rewrite_phi_out_of_ssa (scop, &psi); + } + + update_ssa (TODO_update_ssa); +#ifdef ENABLE_CHECKING + verify_loop_closed_ssa (true); +#endif +} + +/* Rewrite the scalar dependence of DEF used in USE_STMT with a memory + read from ZERO_DIM_ARRAY. */ + +static void +rewrite_cross_bb_scalar_dependence (scop_p scop, tree zero_dim_array, + tree def, gimple use_stmt) +{ + gimple name_stmt; + tree name; + ssa_op_iter iter; + use_operand_p use_p; + + gcc_assert (gimple_code (use_stmt) != GIMPLE_PHI); + + name = copy_ssa_name (def, NULL); + name_stmt = gimple_build_assign (name, zero_dim_array); + + gimple_assign_set_lhs (name_stmt, name); + insert_stmts (scop, name_stmt, NULL, gsi_for_stmt (use_stmt)); + + FOR_EACH_SSA_USE_OPERAND (use_p, use_stmt, iter, SSA_OP_ALL_USES) + if (operand_equal_p (def, USE_FROM_PTR (use_p), 0)) + replace_exp (use_p, name); + + update_stmt (use_stmt); +} + +/* For every definition DEF in the SCOP that is used outside the scop, + insert a closing-scop definition in the basic block just after this + SCOP. */ + +static void +handle_scalar_deps_crossing_scop_limits (scop_p scop, tree def, gimple stmt) +{ + tree var = create_tmp_reg (TREE_TYPE (def), NULL); + tree new_name = make_ssa_name (var, stmt); + bool needs_copy = false; + use_operand_p use_p; + imm_use_iterator imm_iter; + gimple use_stmt; + sese region = SCOP_REGION (scop); + + FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, def) + { + if (!bb_in_sese_p (gimple_bb (use_stmt), region)) + { + FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) + { + SET_USE (use_p, new_name); + } + update_stmt (use_stmt); + needs_copy = true; + } + } + + /* Insert in the empty BB just after the scop a use of DEF such + that the rewrite of cross_bb_scalar_dependences won't insert + arrays everywhere else. */ + if (needs_copy) + { + gimple assign = gimple_build_assign (new_name, def); + gimple_stmt_iterator psi = gsi_after_labels (SESE_EXIT (region)->dest); + + update_stmt (assign); + gsi_insert_before (&psi, assign, GSI_SAME_STMT); + } +} + +/* Rewrite the scalar dependences crossing the boundary of the BB + containing STMT with an array. Return true when something has been + changed. */ + +static bool +rewrite_cross_bb_scalar_deps (scop_p scop, gimple_stmt_iterator *gsi) +{ + sese region = SCOP_REGION (scop); + gimple stmt = gsi_stmt (*gsi); + imm_use_iterator imm_iter; + tree def; + basic_block def_bb; + tree zero_dim_array = NULL_TREE; + gimple use_stmt; + bool res = false; + + switch (gimple_code (stmt)) + { + case GIMPLE_ASSIGN: + def = gimple_assign_lhs (stmt); + break; + + case GIMPLE_CALL: + def = gimple_call_lhs (stmt); + break; + + default: + return false; + } + + if (!def + || !is_gimple_reg (def)) + return false; + + if (scev_analyzable_p (def, region)) + { + loop_p loop = loop_containing_stmt (SSA_NAME_DEF_STMT (def)); + tree scev = scalar_evolution_in_region (region, loop, def); + + if (tree_contains_chrecs (scev, NULL)) + return false; + + propagate_expr_outside_region (def, scev, region); + return true; + } + + def_bb = gimple_bb (stmt); + + handle_scalar_deps_crossing_scop_limits (scop, def, stmt); + + FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, def) + if (gimple_code (use_stmt) == GIMPLE_PHI + && (res = true)) + { + gimple_stmt_iterator psi = gsi_for_stmt (use_stmt); + + if (scalar_close_phi_node_p (gsi_stmt (psi))) + rewrite_close_phi_out_of_ssa (scop, &psi); + else + rewrite_phi_out_of_ssa (scop, &psi); + } + + FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, def) + if (gimple_code (use_stmt) != GIMPLE_PHI + && def_bb != gimple_bb (use_stmt) + && !is_gimple_debug (use_stmt) + && (res = true)) + { + if (!zero_dim_array) + { + zero_dim_array = create_zero_dim_array + (def, "Cross_BB_scalar_dependence"); + insert_out_of_ssa_copy (scop, zero_dim_array, def, + SSA_NAME_DEF_STMT (def)); + gsi_next (gsi); + } + + rewrite_cross_bb_scalar_dependence (scop, zero_dim_array, + def, use_stmt); + } + + return res; +} + +/* Rewrite out of SSA all the reduction phi nodes of SCOP. */ + +static void +rewrite_cross_bb_scalar_deps_out_of_ssa (scop_p scop) +{ + basic_block bb; + gimple_stmt_iterator psi; + sese region = SCOP_REGION (scop); + bool changed = false; + + /* Create an extra empty BB after the scop. */ + split_edge (SESE_EXIT (region)); + + FOR_EACH_BB_FN (bb, cfun) + if (bb_in_sese_p (bb, region)) + for (psi = gsi_start_bb (bb); !gsi_end_p (psi); gsi_next (&psi)) + changed |= rewrite_cross_bb_scalar_deps (scop, &psi); + + if (changed) + { + scev_reset_htab (); + update_ssa (TODO_update_ssa); +#ifdef ENABLE_CHECKING + verify_loop_closed_ssa (true); +#endif + } +} + +/* Returns the number of pbbs that are in loops contained in SCOP. */ + +static int +nb_pbbs_in_loops (scop_p scop) +{ + int i; + poly_bb_p pbb; + int res = 0; + + FOR_EACH_VEC_ELT (SCOP_BBS (scop), i, pbb) + if (loop_in_sese_p (gbb_loop (PBB_BLACK_BOX (pbb)), SCOP_REGION (scop))) + res++; + + return res; +} + +/* Return the number of data references in BB that write in + memory. */ + +static int +nb_data_writes_in_bb (basic_block bb) +{ + int res = 0; + gimple_stmt_iterator gsi; + + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + if (gimple_vdef (gsi_stmt (gsi))) + res++; + + return res; +} + +/* Splits at STMT the basic block BB represented as PBB in the + polyhedral form. */ + +static edge +split_pbb (scop_p scop, poly_bb_p pbb, basic_block bb, gimple stmt) +{ + edge e1 = split_block (bb, stmt); + new_pbb_from_pbb (scop, pbb, e1->dest); + return e1; +} + +/* Splits STMT out of its current BB. This is done for reduction + statements for which we want to ignore data dependences. */ + +static basic_block +split_reduction_stmt (scop_p scop, gimple stmt) +{ + basic_block bb = gimple_bb (stmt); + poly_bb_p pbb = pbb_from_bb (bb); + gimple_bb_p gbb = gbb_from_bb (bb); + edge e1; + int i; + data_reference_p dr; + + /* Do not split basic blocks with no writes to memory: the reduction + will be the only write to memory. */ + if (nb_data_writes_in_bb (bb) == 0 + /* Or if we have already marked BB as a reduction. */ + || PBB_IS_REDUCTION (pbb_from_bb (bb))) + return bb; + + e1 = split_pbb (scop, pbb, bb, stmt); + + /* Split once more only when the reduction stmt is not the only one + left in the original BB. */ + if (!gsi_one_before_end_p (gsi_start_nondebug_bb (bb))) + { + gimple_stmt_iterator gsi = gsi_last_bb (bb); + gsi_prev (&gsi); + e1 = split_pbb (scop, pbb, bb, gsi_stmt (gsi)); + } + + /* A part of the data references will end in a different basic block + after the split: move the DRs from the original GBB to the newly + created GBB1. */ + FOR_EACH_VEC_ELT (GBB_DATA_REFS (gbb), i, dr) + { + basic_block bb1 = gimple_bb (DR_STMT (dr)); + + if (bb1 != bb) + { + gimple_bb_p gbb1 = gbb_from_bb (bb1); + GBB_DATA_REFS (gbb1).safe_push (dr); + GBB_DATA_REFS (gbb).ordered_remove (i); + i--; + } + } + + return e1->dest; +} + +/* Return true when stmt is a reduction operation. */ + +static inline bool +is_reduction_operation_p (gimple stmt) +{ + enum tree_code code; + + gcc_assert (is_gimple_assign (stmt)); + code = gimple_assign_rhs_code (stmt); + + return flag_associative_math + && commutative_tree_code (code) + && associative_tree_code (code); +} + +/* Returns true when PHI contains an argument ARG. */ + +static bool +phi_contains_arg (gimple phi, tree arg) +{ + size_t i; + + for (i = 0; i < gimple_phi_num_args (phi); i++) + if (operand_equal_p (arg, gimple_phi_arg_def (phi, i), 0)) + return true; + + return false; +} + +/* Return a loop phi node that corresponds to a reduction containing LHS. */ + +static gimple +follow_ssa_with_commutative_ops (tree arg, tree lhs) +{ + gimple stmt; + + if (TREE_CODE (arg) != SSA_NAME) + return NULL; + + stmt = SSA_NAME_DEF_STMT (arg); + + if (gimple_code (stmt) == GIMPLE_NOP + || gimple_code (stmt) == GIMPLE_CALL) + return NULL; + + if (gimple_code (stmt) == GIMPLE_PHI) + { + if (phi_contains_arg (stmt, lhs)) + return stmt; + return NULL; + } + + if (!is_gimple_assign (stmt)) + return NULL; + + if (gimple_num_ops (stmt) == 2) + return follow_ssa_with_commutative_ops (gimple_assign_rhs1 (stmt), lhs); + + if (is_reduction_operation_p (stmt)) + { + gimple res = follow_ssa_with_commutative_ops (gimple_assign_rhs1 (stmt), lhs); + + return res ? res : + follow_ssa_with_commutative_ops (gimple_assign_rhs2 (stmt), lhs); + } + + return NULL; +} + +/* Detect commutative and associative scalar reductions starting at + the STMT. Return the phi node of the reduction cycle, or NULL. */ + +static gimple +detect_commutative_reduction_arg (tree lhs, gimple stmt, tree arg, + vec<gimple> *in, + vec<gimple> *out) +{ + gimple phi = follow_ssa_with_commutative_ops (arg, lhs); + + if (!phi) + return NULL; + + in->safe_push (stmt); + out->safe_push (stmt); + return phi; +} + +/* Detect commutative and associative scalar reductions starting at + STMT. Return the phi node of the reduction cycle, or NULL. */ + +static gimple +detect_commutative_reduction_assign (gimple stmt, vec<gimple> *in, + vec<gimple> *out) +{ + tree lhs = gimple_assign_lhs (stmt); + + if (gimple_num_ops (stmt) == 2) + return detect_commutative_reduction_arg (lhs, stmt, + gimple_assign_rhs1 (stmt), + in, out); + + if (is_reduction_operation_p (stmt)) + { + gimple res = detect_commutative_reduction_arg (lhs, stmt, + gimple_assign_rhs1 (stmt), + in, out); + return res ? res + : detect_commutative_reduction_arg (lhs, stmt, + gimple_assign_rhs2 (stmt), + in, out); + } + + return NULL; +} + +/* Return a loop phi node that corresponds to a reduction containing LHS. */ + +static gimple +follow_inital_value_to_phi (tree arg, tree lhs) +{ + gimple stmt; + + if (!arg || TREE_CODE (arg) != SSA_NAME) + return NULL; + + stmt = SSA_NAME_DEF_STMT (arg); + + if (gimple_code (stmt) == GIMPLE_PHI + && phi_contains_arg (stmt, lhs)) + return stmt; + + return NULL; +} + + +/* Return the argument of the loop PHI that is the initial value coming + from outside the loop. */ + +static edge +edge_initial_value_for_loop_phi (gimple phi) +{ + size_t i; + + for (i = 0; i < gimple_phi_num_args (phi); i++) + { + edge e = gimple_phi_arg_edge (phi, i); + + if (loop_depth (e->src->loop_father) + < loop_depth (e->dest->loop_father)) + return e; + } + + return NULL; +} + +/* Return the argument of the loop PHI that is the initial value coming + from outside the loop. */ + +static tree +initial_value_for_loop_phi (gimple phi) +{ + size_t i; + + for (i = 0; i < gimple_phi_num_args (phi); i++) + { + edge e = gimple_phi_arg_edge (phi, i); + + if (loop_depth (e->src->loop_father) + < loop_depth (e->dest->loop_father)) + return gimple_phi_arg_def (phi, i); + } + + return NULL_TREE; +} + +/* Returns true when DEF is used outside the reduction cycle of + LOOP_PHI. */ + +static bool +used_outside_reduction (tree def, gimple loop_phi) +{ + use_operand_p use_p; + imm_use_iterator imm_iter; + loop_p loop = loop_containing_stmt (loop_phi); + + /* In LOOP, DEF should be used only in LOOP_PHI. */ + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, def) + { + gimple stmt = USE_STMT (use_p); + + if (stmt != loop_phi + && !is_gimple_debug (stmt) + && flow_bb_inside_loop_p (loop, gimple_bb (stmt))) + return true; + } + + return false; +} + +/* Detect commutative and associative scalar reductions belonging to + the SCOP starting at the loop closed phi node STMT. Return the phi + node of the reduction cycle, or NULL. */ + +static gimple +detect_commutative_reduction (scop_p scop, gimple stmt, vec<gimple> *in, + vec<gimple> *out) +{ + if (scalar_close_phi_node_p (stmt)) + { + gimple def, loop_phi, phi, close_phi = stmt; + tree init, lhs, arg = gimple_phi_arg_def (close_phi, 0); + + if (TREE_CODE (arg) != SSA_NAME) + return NULL; + + /* Note that loop close phi nodes should have a single argument + because we translated the representation into a canonical form + before Graphite: see canonicalize_loop_closed_ssa_form. */ + gcc_assert (gimple_phi_num_args (close_phi) == 1); + + def = SSA_NAME_DEF_STMT (arg); + if (!stmt_in_sese_p (def, SCOP_REGION (scop)) + || !(loop_phi = detect_commutative_reduction (scop, def, in, out))) + return NULL; + + lhs = gimple_phi_result (close_phi); + init = initial_value_for_loop_phi (loop_phi); + phi = follow_inital_value_to_phi (init, lhs); + + if (phi && (used_outside_reduction (lhs, phi) + || !has_single_use (gimple_phi_result (phi)))) + return NULL; + + in->safe_push (loop_phi); + out->safe_push (close_phi); + return phi; + } + + if (gimple_code (stmt) == GIMPLE_ASSIGN) + return detect_commutative_reduction_assign (stmt, in, out); + + return NULL; +} + +/* Translate the scalar reduction statement STMT to an array RED + knowing that its recursive phi node is LOOP_PHI. */ + +static void +translate_scalar_reduction_to_array_for_stmt (scop_p scop, tree red, + gimple stmt, gimple loop_phi) +{ + tree res = gimple_phi_result (loop_phi); + gimple assign = gimple_build_assign (res, unshare_expr (red)); + gimple_stmt_iterator gsi; + + insert_stmts (scop, assign, NULL, gsi_after_labels (gimple_bb (loop_phi))); + + assign = gimple_build_assign (unshare_expr (red), gimple_assign_lhs (stmt)); + gsi = gsi_for_stmt (stmt); + gsi_next (&gsi); + insert_stmts (scop, assign, NULL, gsi); +} + +/* Removes the PHI node and resets all the debug stmts that are using + the PHI_RESULT. */ + +static void +remove_phi (gimple phi) +{ + imm_use_iterator imm_iter; + tree def; + use_operand_p use_p; + gimple_stmt_iterator gsi; + auto_vec<gimple, 3> update; + unsigned int i; + gimple stmt; + + def = PHI_RESULT (phi); + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, def) + { + stmt = USE_STMT (use_p); + + if (is_gimple_debug (stmt)) + { + gimple_debug_bind_reset_value (stmt); + update.safe_push (stmt); + } + } + + FOR_EACH_VEC_ELT (update, i, stmt) + update_stmt (stmt); + + gsi = gsi_for_phi_node (phi); + remove_phi_node (&gsi, false); +} + +/* Helper function for for_each_index. For each INDEX of the data + reference REF, returns true when its indices are valid in the loop + nest LOOP passed in as DATA. */ + +static bool +dr_indices_valid_in_loop (tree ref ATTRIBUTE_UNUSED, tree *index, void *data) +{ + loop_p loop; + basic_block header, def_bb; + gimple stmt; + + if (TREE_CODE (*index) != SSA_NAME) + return true; + + loop = *((loop_p *) data); + header = loop->header; + stmt = SSA_NAME_DEF_STMT (*index); + + if (!stmt) + return true; + + def_bb = gimple_bb (stmt); + + if (!def_bb) + return true; + + return dominated_by_p (CDI_DOMINATORS, header, def_bb); +} + +/* When the result of a CLOSE_PHI is written to a memory location, + return a pointer to that memory reference, otherwise return + NULL_TREE. */ + +static tree +close_phi_written_to_memory (gimple close_phi) +{ + imm_use_iterator imm_iter; + use_operand_p use_p; + gimple stmt; + tree res, def = gimple_phi_result (close_phi); + + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, def) + if ((stmt = USE_STMT (use_p)) + && gimple_code (stmt) == GIMPLE_ASSIGN + && (res = gimple_assign_lhs (stmt))) + { + switch (TREE_CODE (res)) + { + case VAR_DECL: + case PARM_DECL: + case RESULT_DECL: + return res; + + case ARRAY_REF: + case MEM_REF: + { + tree arg = gimple_phi_arg_def (close_phi, 0); + loop_p nest = loop_containing_stmt (SSA_NAME_DEF_STMT (arg)); + + /* FIXME: this restriction is for id-{24,25}.f and + could be handled by duplicating the computation of + array indices before the loop of the close_phi. */ + if (for_each_index (&res, dr_indices_valid_in_loop, &nest)) + return res; + } + /* Fallthru. */ + + default: + continue; + } + } + return NULL_TREE; +} + +/* Rewrite out of SSA the reduction described by the loop phi nodes + IN, and the close phi nodes OUT. IN and OUT are structured by loop + levels like this: + + IN: stmt, loop_n, ..., loop_0 + OUT: stmt, close_n, ..., close_0 + + the first element is the reduction statement, and the next elements + are the loop and close phi nodes of each of the outer loops. */ + +static void +translate_scalar_reduction_to_array (scop_p scop, + vec<gimple> in, + vec<gimple> out) +{ + gimple loop_phi; + unsigned int i = out.length () - 1; + tree red = close_phi_written_to_memory (out[i]); + + FOR_EACH_VEC_ELT (in, i, loop_phi) + { + gimple close_phi = out[i]; + + if (i == 0) + { + gimple stmt = loop_phi; + basic_block bb = split_reduction_stmt (scop, stmt); + poly_bb_p pbb = pbb_from_bb (bb); + PBB_IS_REDUCTION (pbb) = true; + gcc_assert (close_phi == loop_phi); + + if (!red) + red = create_zero_dim_array + (gimple_assign_lhs (stmt), "Commutative_Associative_Reduction"); + + translate_scalar_reduction_to_array_for_stmt (scop, red, stmt, in[1]); + continue; + } + + if (i == in.length () - 1) + { + insert_out_of_ssa_copy (scop, gimple_phi_result (close_phi), + unshare_expr (red), close_phi); + insert_out_of_ssa_copy_on_edge + (scop, edge_initial_value_for_loop_phi (loop_phi), + unshare_expr (red), initial_value_for_loop_phi (loop_phi)); + } + + remove_phi (loop_phi); + remove_phi (close_phi); + } +} + +/* Rewrites out of SSA a commutative reduction at CLOSE_PHI. Returns + true when something has been changed. */ + +static bool +rewrite_commutative_reductions_out_of_ssa_close_phi (scop_p scop, + gimple close_phi) +{ + bool res; + auto_vec<gimple, 10> in; + auto_vec<gimple, 10> out; + + detect_commutative_reduction (scop, close_phi, &in, &out); + res = in.length () > 1; + if (res) + translate_scalar_reduction_to_array (scop, in, out); + + return res; +} + +/* Rewrites all the commutative reductions from LOOP out of SSA. + Returns true when something has been changed. */ + +static bool +rewrite_commutative_reductions_out_of_ssa_loop (scop_p scop, + loop_p loop) +{ + gimple_stmt_iterator gsi; + edge exit = single_exit (loop); + tree res; + bool changed = false; + + if (!exit) + return false; + + for (gsi = gsi_start_phis (exit->dest); !gsi_end_p (gsi); gsi_next (&gsi)) + if ((res = gimple_phi_result (gsi_stmt (gsi))) + && !virtual_operand_p (res) + && !scev_analyzable_p (res, SCOP_REGION (scop))) + changed |= rewrite_commutative_reductions_out_of_ssa_close_phi + (scop, gsi_stmt (gsi)); + + return changed; +} + +/* Rewrites all the commutative reductions from SCOP out of SSA. */ + +static void +rewrite_commutative_reductions_out_of_ssa (scop_p scop) +{ + loop_p loop; + bool changed = false; + sese region = SCOP_REGION (scop); + + FOR_EACH_LOOP (loop, 0) + if (loop_in_sese_p (loop, region)) + changed |= rewrite_commutative_reductions_out_of_ssa_loop (scop, loop); + + if (changed) + { + scev_reset_htab (); + gsi_commit_edge_inserts (); + update_ssa (TODO_update_ssa); +#ifdef ENABLE_CHECKING + verify_loop_closed_ssa (true); +#endif + } +} + +/* Can all ivs be represented by a signed integer? + As CLooG might generate negative values in its expressions, signed loop ivs + are required in the backend. */ + +static bool +scop_ivs_can_be_represented (scop_p scop) +{ + loop_p loop; + gimple_stmt_iterator psi; + bool result = true; + + FOR_EACH_LOOP (loop, 0) + { + if (!loop_in_sese_p (loop, SCOP_REGION (scop))) + continue; + + for (psi = gsi_start_phis (loop->header); + !gsi_end_p (psi); gsi_next (&psi)) + { + gimple phi = gsi_stmt (psi); + tree res = PHI_RESULT (phi); + tree type = TREE_TYPE (res); + + if (TYPE_UNSIGNED (type) + && TYPE_PRECISION (type) >= TYPE_PRECISION (long_long_integer_type_node)) + { + result = false; + break; + } + } + if (!result) + break; + } + + return result; +} + +/* Builds the polyhedral representation for a SESE region. */ + +void +build_poly_scop (scop_p scop) +{ + sese region = SCOP_REGION (scop); + graphite_dim_t max_dim; + + build_scop_bbs (scop); + + /* FIXME: This restriction is needed to avoid a problem in CLooG. + Once CLooG is fixed, remove this guard. Anyways, it makes no + sense to optimize a scop containing only PBBs that do not belong + to any loops. */ + if (nb_pbbs_in_loops (scop) == 0) + return; + + if (!scop_ivs_can_be_represented (scop)) + return; + + if (flag_associative_math) + rewrite_commutative_reductions_out_of_ssa (scop); + + build_sese_loop_nests (region); + /* Record all conditions in REGION. */ + sese_dom_walker (CDI_DOMINATORS, region).walk (cfun->cfg->x_entry_block_ptr); + find_scop_parameters (scop); + + max_dim = PARAM_VALUE (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS); + if (scop_nb_params (scop) > max_dim) + return; + + build_scop_iteration_domain (scop); + build_scop_context (scop); + add_conditions_to_constraints (scop); + + /* Rewrite out of SSA only after having translated the + representation to the polyhedral representation to avoid scev + analysis failures. That means that these functions will insert + new data references that they create in the right place. */ + rewrite_reductions_out_of_ssa (scop); + rewrite_cross_bb_scalar_deps_out_of_ssa (scop); + + build_scop_drs (scop); + scop_to_lst (scop); + build_scop_scattering (scop); + + /* This SCoP has been translated to the polyhedral + representation. */ + POLY_SCOP_P (scop) = true; +} +#endif |