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Diffstat (limited to 'gcc-4.8.1/gcc/graphite-scop-detection.c')
| -rw-r--r-- | gcc-4.8.1/gcc/graphite-scop-detection.c | 1612 |
1 files changed, 0 insertions, 1612 deletions
diff --git a/gcc-4.8.1/gcc/graphite-scop-detection.c b/gcc-4.8.1/gcc/graphite-scop-detection.c deleted file mode 100644 index ab2897d5c..000000000 --- a/gcc-4.8.1/gcc/graphite-scop-detection.c +++ /dev/null @@ -1,1612 +0,0 @@ -/* Detection of Static Control Parts (SCoP) for Graphite. - Copyright (C) 2009-2013 Free Software Foundation, Inc. - Contributed by Sebastian Pop <sebastian.pop@amd.com> and - Tobias Grosser <grosser@fim.uni-passau.de>. - -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 <cloog/cloog.h> -#include <cloog/isl/domain.h> -#endif - -#include "system.h" -#include "coretypes.h" -#include "tree-flow.h" -#include "cfgloop.h" -#include "tree-chrec.h" -#include "tree-data-ref.h" -#include "tree-scalar-evolution.h" -#include "tree-pass.h" -#include "sese.h" - -#ifdef HAVE_cloog -#include "graphite-poly.h" -#include "graphite-scop-detection.h" - -/* Forward declarations. */ -static void make_close_phi_nodes_unique (basic_block); - -/* The type of the analyzed basic block. */ - -typedef enum gbb_type { - GBB_UNKNOWN, - GBB_LOOP_SING_EXIT_HEADER, - GBB_LOOP_MULT_EXIT_HEADER, - GBB_LOOP_EXIT, - GBB_COND_HEADER, - GBB_SIMPLE, - GBB_LAST -} gbb_type; - -/* Detect the type of BB. Loop headers are only marked, if they are - new. This means their loop_father is different to LAST_LOOP. - Otherwise they are treated like any other bb and their type can be - any other type. */ - -static gbb_type -get_bb_type (basic_block bb, struct loop *last_loop) -{ - vec<basic_block> dom; - int nb_dom; - struct loop *loop = bb->loop_father; - - /* Check, if we entry into a new loop. */ - if (loop != last_loop) - { - if (single_exit (loop) != NULL) - return GBB_LOOP_SING_EXIT_HEADER; - else if (loop->num != 0) - return GBB_LOOP_MULT_EXIT_HEADER; - else - return GBB_COND_HEADER; - } - - dom = get_dominated_by (CDI_DOMINATORS, bb); - nb_dom = dom.length (); - dom.release (); - - if (nb_dom == 0) - return GBB_LAST; - - if (nb_dom == 1 && single_succ_p (bb)) - return GBB_SIMPLE; - - return GBB_COND_HEADER; -} - -/* A SCoP detection region, defined using bbs as borders. - - All control flow touching this region, comes in passing basic_block - ENTRY and leaves passing basic_block EXIT. By using bbs instead of - edges for the borders we are able to represent also regions that do - not have a single entry or exit edge. - - But as they have a single entry basic_block and a single exit - basic_block, we are able to generate for every sd_region a single - entry and exit edge. - - 1 2 - \ / - 3 <- entry - | - 4 - / \ This region contains: {3, 4, 5, 6, 7, 8} - 5 6 - | | - 7 8 - \ / - 9 <- exit */ - - -typedef struct sd_region_p -{ - /* The entry bb dominates all bbs in the sd_region. It is part of - the region. */ - basic_block entry; - - /* The exit bb postdominates all bbs in the sd_region, but is not - part of the region. */ - basic_block exit; -} sd_region; - - - -/* Moves the scops from SOURCE to TARGET and clean up SOURCE. */ - -static void -move_sd_regions (vec<sd_region> *source, vec<sd_region> *target) -{ - sd_region *s; - int i; - - FOR_EACH_VEC_ELT (*source, i, s) - target->safe_push (*s); - - source->release (); -} - -/* Something like "n * m" is not allowed. */ - -static bool -graphite_can_represent_init (tree e) -{ - switch (TREE_CODE (e)) - { - case POLYNOMIAL_CHREC: - return graphite_can_represent_init (CHREC_LEFT (e)) - && graphite_can_represent_init (CHREC_RIGHT (e)); - - case MULT_EXPR: - if (chrec_contains_symbols (TREE_OPERAND (e, 0))) - return graphite_can_represent_init (TREE_OPERAND (e, 0)) - && host_integerp (TREE_OPERAND (e, 1), 0); - else - return graphite_can_represent_init (TREE_OPERAND (e, 1)) - && host_integerp (TREE_OPERAND (e, 0), 0); - - case PLUS_EXPR: - case POINTER_PLUS_EXPR: - case MINUS_EXPR: - return graphite_can_represent_init (TREE_OPERAND (e, 0)) - && graphite_can_represent_init (TREE_OPERAND (e, 1)); - - case NEGATE_EXPR: - case BIT_NOT_EXPR: - CASE_CONVERT: - case NON_LVALUE_EXPR: - return graphite_can_represent_init (TREE_OPERAND (e, 0)); - - default: - break; - } - - return true; -} - -/* Return true when SCEV can be represented in the polyhedral model. - - An expression can be represented, if it can be expressed as an - affine expression. For loops (i, j) and parameters (m, n) all - affine expressions are of the form: - - x1 * i + x2 * j + x3 * m + x4 * n + x5 * 1 where x1..x5 element of Z - - 1 i + 20 j + (-2) m + 25 - - Something like "i * n" or "n * m" is not allowed. */ - -static bool -graphite_can_represent_scev (tree scev) -{ - if (chrec_contains_undetermined (scev)) - return false; - - switch (TREE_CODE (scev)) - { - case PLUS_EXPR: - case MINUS_EXPR: - return graphite_can_represent_scev (TREE_OPERAND (scev, 0)) - && graphite_can_represent_scev (TREE_OPERAND (scev, 1)); - - case MULT_EXPR: - return !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 0))) - && !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 1))) - && !(chrec_contains_symbols (TREE_OPERAND (scev, 0)) - && chrec_contains_symbols (TREE_OPERAND (scev, 1))) - && graphite_can_represent_init (scev) - && graphite_can_represent_scev (TREE_OPERAND (scev, 0)) - && graphite_can_represent_scev (TREE_OPERAND (scev, 1)); - - case POLYNOMIAL_CHREC: - /* Check for constant strides. With a non constant stride of - 'n' we would have a value of 'iv * n'. Also check that the - initial value can represented: for example 'n * m' cannot be - represented. */ - if (!evolution_function_right_is_integer_cst (scev) - || !graphite_can_represent_init (scev)) - return false; - - default: - break; - } - - /* Only affine functions can be represented. */ - if (!scev_is_linear_expression (scev)) - return false; - - return true; -} - - -/* Return true when EXPR can be represented in the polyhedral model. - - This means an expression can be represented, if it is linear with - respect to the loops and the strides are non parametric. - LOOP is the place where the expr will be evaluated. SCOP_ENTRY defines the - entry of the region we analyse. */ - -static bool -graphite_can_represent_expr (basic_block scop_entry, loop_p loop, - tree expr) -{ - tree scev = analyze_scalar_evolution (loop, expr); - - scev = instantiate_scev (scop_entry, loop, scev); - - return graphite_can_represent_scev (scev); -} - -/* Return true if the data references of STMT can be represented by - Graphite. */ - -static bool -stmt_has_simple_data_refs_p (loop_p outermost_loop ATTRIBUTE_UNUSED, - gimple stmt) -{ - data_reference_p dr; - unsigned i; - int j; - bool res = true; - vec<data_reference_p> drs = vNULL; - loop_p outer; - - for (outer = loop_containing_stmt (stmt); outer; outer = loop_outer (outer)) - { - graphite_find_data_references_in_stmt (outer, - loop_containing_stmt (stmt), - stmt, &drs); - - FOR_EACH_VEC_ELT (drs, j, dr) - for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++) - if (!graphite_can_represent_scev (DR_ACCESS_FN (dr, i))) - { - res = false; - goto done; - } - - free_data_refs (drs); - drs.create (0); - } - - done: - free_data_refs (drs); - return res; -} - -/* Return true only when STMT is simple enough for being handled by - Graphite. This depends on SCOP_ENTRY, as the parameters are - initialized relatively to this basic block, the linear functions - are initialized to OUTERMOST_LOOP and BB is the place where we try - to evaluate the STMT. */ - -static bool -stmt_simple_for_scop_p (basic_block scop_entry, loop_p outermost_loop, - gimple stmt, basic_block bb) -{ - loop_p loop = bb->loop_father; - - gcc_assert (scop_entry); - - /* GIMPLE_ASM and GIMPLE_CALL may embed arbitrary side effects. - Calls have side-effects, except those to const or pure - functions. */ - if (gimple_has_volatile_ops (stmt) - || (gimple_code (stmt) == GIMPLE_CALL - && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE))) - || (gimple_code (stmt) == GIMPLE_ASM)) - return false; - - if (is_gimple_debug (stmt)) - return true; - - if (!stmt_has_simple_data_refs_p (outermost_loop, stmt)) - return false; - - switch (gimple_code (stmt)) - { - case GIMPLE_RETURN: - case GIMPLE_LABEL: - return true; - - case GIMPLE_COND: - { - tree op; - ssa_op_iter op_iter; - enum tree_code code = gimple_cond_code (stmt); - - /* We can handle all binary comparisons. Inequalities are - also supported as they can be represented with union of - polyhedra. */ - if (!(code == LT_EXPR - || code == GT_EXPR - || code == LE_EXPR - || code == GE_EXPR - || code == EQ_EXPR - || code == NE_EXPR)) - return false; - - FOR_EACH_SSA_TREE_OPERAND (op, stmt, op_iter, SSA_OP_ALL_USES) - if (!graphite_can_represent_expr (scop_entry, loop, op) - /* We can not handle REAL_TYPE. Failed for pr39260. */ - || TREE_CODE (TREE_TYPE (op)) == REAL_TYPE) - return false; - - return true; - } - - case GIMPLE_ASSIGN: - case GIMPLE_CALL: - return true; - - default: - /* These nodes cut a new scope. */ - return false; - } - - return false; -} - -/* Returns the statement of BB that contains a harmful operation: that - can be a function call with side effects, the induction variables - are not linear with respect to SCOP_ENTRY, etc. The current open - scop should end before this statement. The evaluation is limited using - OUTERMOST_LOOP as outermost loop that may change. */ - -static gimple -harmful_stmt_in_bb (basic_block scop_entry, loop_p outer_loop, basic_block bb) -{ - gimple_stmt_iterator gsi; - - for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) - if (!stmt_simple_for_scop_p (scop_entry, outer_loop, gsi_stmt (gsi), bb)) - return gsi_stmt (gsi); - - return NULL; -} - -/* Return true if LOOP can be represented in the polyhedral - representation. This is evaluated taking SCOP_ENTRY and - OUTERMOST_LOOP in mind. */ - -static bool -graphite_can_represent_loop (basic_block scop_entry, loop_p loop) -{ - tree niter; - struct tree_niter_desc niter_desc; - - /* FIXME: For the moment, graphite cannot be used on loops that - iterate using induction variables that wrap. */ - - return number_of_iterations_exit (loop, single_exit (loop), &niter_desc, false) - && niter_desc.control.no_overflow - && (niter = number_of_latch_executions (loop)) - && !chrec_contains_undetermined (niter) - && graphite_can_represent_expr (scop_entry, loop, niter); -} - -/* Store information needed by scopdet_* functions. */ - -struct scopdet_info -{ - /* Exit of the open scop would stop if the current BB is harmful. */ - basic_block exit; - - /* Where the next scop would start if the current BB is harmful. */ - basic_block next; - - /* The bb or one of its children contains open loop exits. That means - loop exit nodes that are not surrounded by a loop dominated by bb. */ - bool exits; - - /* The bb or one of its children contains only structures we can handle. */ - bool difficult; -}; - -static struct scopdet_info build_scops_1 (basic_block, loop_p, - vec<sd_region> *, loop_p); - -/* Calculates BB infos. If bb is difficult we add valid SCoPs dominated by BB - to SCOPS. TYPE is the gbb_type of BB. */ - -static struct scopdet_info -scopdet_basic_block_info (basic_block bb, loop_p outermost_loop, - vec<sd_region> *scops, gbb_type type) -{ - loop_p loop = bb->loop_father; - struct scopdet_info result; - gimple stmt; - - /* XXX: ENTRY_BLOCK_PTR could be optimized in later steps. */ - basic_block entry_block = ENTRY_BLOCK_PTR; - stmt = harmful_stmt_in_bb (entry_block, outermost_loop, bb); - result.difficult = (stmt != NULL); - result.exit = NULL; - - switch (type) - { - case GBB_LAST: - result.next = NULL; - result.exits = false; - - /* Mark bbs terminating a SESE region difficult, if they start - a condition. */ - if (!single_succ_p (bb)) - result.difficult = true; - else - result.exit = single_succ (bb); - - break; - - case GBB_SIMPLE: - result.next = single_succ (bb); - result.exits = false; - result.exit = single_succ (bb); - break; - - case GBB_LOOP_SING_EXIT_HEADER: - { - vec<sd_region> regions; - regions.create (3); - struct scopdet_info sinfo; - edge exit_e = single_exit (loop); - - sinfo = build_scops_1 (bb, outermost_loop, ®ions, loop); - - if (!graphite_can_represent_loop (entry_block, loop)) - result.difficult = true; - - result.difficult |= sinfo.difficult; - - /* Try again with another loop level. */ - if (result.difficult - && loop_depth (outermost_loop) + 1 == loop_depth (loop)) - { - outermost_loop = loop; - - regions.release (); - regions.create (3); - - sinfo = scopdet_basic_block_info (bb, outermost_loop, scops, type); - - result = sinfo; - result.difficult = true; - - if (sinfo.difficult) - move_sd_regions (®ions, scops); - else - { - sd_region open_scop; - open_scop.entry = bb; - open_scop.exit = exit_e->dest; - scops->safe_push (open_scop); - regions.release (); - } - } - else - { - result.exit = exit_e->dest; - result.next = exit_e->dest; - - /* If we do not dominate result.next, remove it. It's either - the EXIT_BLOCK_PTR, or another bb dominates it and will - call the scop detection for this bb. */ - if (!dominated_by_p (CDI_DOMINATORS, result.next, bb)) - result.next = NULL; - - if (exit_e->src->loop_father != loop) - result.next = NULL; - - result.exits = false; - - if (result.difficult) - move_sd_regions (®ions, scops); - else - regions.release (); - } - - break; - } - - case GBB_LOOP_MULT_EXIT_HEADER: - { - /* XXX: For now we just do not join loops with multiple exits. If the - exits lead to the same bb it may be possible to join the loop. */ - vec<sd_region> regions; - regions.create (3); - vec<edge> exits = get_loop_exit_edges (loop); - edge e; - int i; - build_scops_1 (bb, loop, ®ions, loop); - - /* Scan the code dominated by this loop. This means all bbs, that are - are dominated by a bb in this loop, but are not part of this loop. - - The easiest case: - - The loop exit destination is dominated by the exit sources. - - TODO: We miss here the more complex cases: - - The exit destinations are dominated by another bb inside - the loop. - - The loop dominates bbs, that are not exit destinations. */ - FOR_EACH_VEC_ELT (exits, i, e) - if (e->src->loop_father == loop - && dominated_by_p (CDI_DOMINATORS, e->dest, e->src)) - { - if (loop_outer (outermost_loop)) - outermost_loop = loop_outer (outermost_loop); - - /* Pass loop_outer to recognize e->dest as loop header in - build_scops_1. */ - if (e->dest->loop_father->header == e->dest) - build_scops_1 (e->dest, outermost_loop, ®ions, - loop_outer (e->dest->loop_father)); - else - build_scops_1 (e->dest, outermost_loop, ®ions, - e->dest->loop_father); - } - - result.next = NULL; - result.exit = NULL; - result.difficult = true; - result.exits = false; - move_sd_regions (®ions, scops); - exits.release (); - break; - } - case GBB_COND_HEADER: - { - vec<sd_region> regions; - regions.create (3); - struct scopdet_info sinfo; - vec<basic_block> dominated; - int i; - basic_block dom_bb; - basic_block last_exit = NULL; - edge e; - result.exits = false; - - /* First check the successors of BB, and check if it is - possible to join the different branches. */ - FOR_EACH_VEC_SAFE_ELT (bb->succs, i, e) - { - /* Ignore loop exits. They will be handled after the loop - body. */ - if (loop_exits_to_bb_p (loop, e->dest)) - { - result.exits = true; - continue; - } - - /* Do not follow edges that lead to the end of the - conditions block. For example, in - - | 0 - | /|\ - | 1 2 | - | | | | - | 3 4 | - | \|/ - | 6 - - the edge from 0 => 6. Only check if all paths lead to - the same node 6. */ - - if (!single_pred_p (e->dest)) - { - /* Check, if edge leads directly to the end of this - condition. */ - if (!last_exit) - last_exit = e->dest; - - if (e->dest != last_exit) - result.difficult = true; - - continue; - } - - if (!dominated_by_p (CDI_DOMINATORS, e->dest, bb)) - { - result.difficult = true; - continue; - } - - sinfo = build_scops_1 (e->dest, outermost_loop, ®ions, loop); - - result.exits |= sinfo.exits; - result.difficult |= sinfo.difficult; - - /* Checks, if all branches end at the same point. - If that is true, the condition stays joinable. - Have a look at the example above. */ - if (sinfo.exit) - { - if (!last_exit) - last_exit = sinfo.exit; - - if (sinfo.exit != last_exit) - result.difficult = true; - } - else - result.difficult = true; - } - - if (!last_exit) - result.difficult = true; - - /* Join the branches of the condition if possible. */ - if (!result.exits && !result.difficult) - { - /* Only return a next pointer if we dominate this pointer. - Otherwise it will be handled by the bb dominating it. */ - if (dominated_by_p (CDI_DOMINATORS, last_exit, bb) - && last_exit != bb) - result.next = last_exit; - else - result.next = NULL; - - result.exit = last_exit; - - regions.release (); - break; - } - - /* Scan remaining bbs dominated by BB. */ - dominated = get_dominated_by (CDI_DOMINATORS, bb); - - FOR_EACH_VEC_ELT (dominated, i, dom_bb) - { - /* Ignore loop exits: they will be handled after the loop body. */ - if (loop_depth (find_common_loop (loop, dom_bb->loop_father)) - < loop_depth (loop)) - { - result.exits = true; - continue; - } - - /* Ignore the bbs processed above. */ - if (single_pred_p (dom_bb) && single_pred (dom_bb) == bb) - continue; - - if (loop_depth (loop) > loop_depth (dom_bb->loop_father)) - sinfo = build_scops_1 (dom_bb, outermost_loop, ®ions, - loop_outer (loop)); - else - sinfo = build_scops_1 (dom_bb, outermost_loop, ®ions, loop); - - result.exits |= sinfo.exits; - result.difficult = true; - result.exit = NULL; - } - - dominated.release (); - - result.next = NULL; - move_sd_regions (®ions, scops); - - break; - } - - default: - gcc_unreachable (); - } - - return result; -} - -/* Starting from CURRENT we walk the dominance tree and add new sd_regions to - SCOPS. The analyse if a sd_region can be handled is based on the value - of OUTERMOST_LOOP. Only loops inside OUTERMOST loops may change. LOOP - is the loop in which CURRENT is handled. - - TODO: These functions got a little bit big. They definitely should be cleaned - up. */ - -static struct scopdet_info -build_scops_1 (basic_block current, loop_p outermost_loop, - vec<sd_region> *scops, loop_p loop) -{ - bool in_scop = false; - sd_region open_scop; - struct scopdet_info sinfo; - - /* Initialize result. */ - struct scopdet_info result; - result.exits = false; - result.difficult = false; - result.next = NULL; - result.exit = NULL; - open_scop.entry = NULL; - open_scop.exit = NULL; - sinfo.exit = NULL; - - /* Loop over the dominance tree. If we meet a difficult bb, close - the current SCoP. Loop and condition header start a new layer, - and can only be added if all bbs in deeper layers are simple. */ - while (current != NULL) - { - sinfo = scopdet_basic_block_info (current, outermost_loop, scops, - get_bb_type (current, loop)); - - if (!in_scop && !(sinfo.exits || sinfo.difficult)) - { - open_scop.entry = current; - open_scop.exit = NULL; - in_scop = true; - } - else if (in_scop && (sinfo.exits || sinfo.difficult)) - { - open_scop.exit = current; - scops->safe_push (open_scop); - in_scop = false; - } - - result.difficult |= sinfo.difficult; - result.exits |= sinfo.exits; - - current = sinfo.next; - } - - /* Try to close open_scop, if we are still in an open SCoP. */ - if (in_scop) - { - open_scop.exit = sinfo.exit; - gcc_assert (open_scop.exit); - scops->safe_push (open_scop); - } - - result.exit = sinfo.exit; - return result; -} - -/* Checks if a bb is contained in REGION. */ - -static bool -bb_in_sd_region (basic_block bb, sd_region *region) -{ - return bb_in_region (bb, region->entry, region->exit); -} - -/* Returns the single entry edge of REGION, if it does not exits NULL. */ - -static edge -find_single_entry_edge (sd_region *region) -{ - edge e; - edge_iterator ei; - edge entry = NULL; - - FOR_EACH_EDGE (e, ei, region->entry->preds) - if (!bb_in_sd_region (e->src, region)) - { - if (entry) - { - entry = NULL; - break; - } - - else - entry = e; - } - - return entry; -} - -/* Returns the single exit edge of REGION, if it does not exits NULL. */ - -static edge -find_single_exit_edge (sd_region *region) -{ - edge e; - edge_iterator ei; - edge exit = NULL; - - FOR_EACH_EDGE (e, ei, region->exit->preds) - if (bb_in_sd_region (e->src, region)) - { - if (exit) - { - exit = NULL; - break; - } - - else - exit = e; - } - - return exit; -} - -/* Create a single entry edge for REGION. */ - -static void -create_single_entry_edge (sd_region *region) -{ - if (find_single_entry_edge (region)) - return; - - /* There are multiple predecessors for bb_3 - - | 1 2 - | | / - | |/ - | 3 <- entry - | |\ - | | | - | 4 ^ - | | | - | |/ - | 5 - - There are two edges (1->3, 2->3), that point from outside into the region, - and another one (5->3), a loop latch, lead to bb_3. - - We split bb_3. - - | 1 2 - | | / - | |/ - |3.0 - | |\ (3.0 -> 3.1) = single entry edge - |3.1 | <- entry - | | | - | | | - | 4 ^ - | | | - | |/ - | 5 - - If the loop is part of the SCoP, we have to redirect the loop latches. - - | 1 2 - | | / - | |/ - |3.0 - | | (3.0 -> 3.1) = entry edge - |3.1 <- entry - | |\ - | | | - | 4 ^ - | | | - | |/ - | 5 */ - - if (region->entry->loop_father->header != region->entry - || dominated_by_p (CDI_DOMINATORS, - loop_latch_edge (region->entry->loop_father)->src, - region->exit)) - { - edge forwarder = split_block_after_labels (region->entry); - region->entry = forwarder->dest; - } - else - /* This case is never executed, as the loop headers seem always to have a - single edge pointing from outside into the loop. */ - gcc_unreachable (); - - gcc_checking_assert (find_single_entry_edge (region)); -} - -/* Check if the sd_region, mentioned in EDGE, has no exit bb. */ - -static bool -sd_region_without_exit (edge e) -{ - sd_region *r = (sd_region *) e->aux; - - if (r) - return r->exit == NULL; - else - return false; -} - -/* Create a single exit edge for REGION. */ - -static void -create_single_exit_edge (sd_region *region) -{ - edge e; - edge_iterator ei; - edge forwarder = NULL; - basic_block exit; - - /* We create a forwarder bb (5) for all edges leaving this region - (3->5, 4->5). All other edges leading to the same bb, are moved - to a new bb (6). If these edges where part of another region (2->5) - we update the region->exit pointer, of this region. - - To identify which edge belongs to which region we depend on the e->aux - pointer in every edge. It points to the region of the edge or to NULL, - if the edge is not part of any region. - - 1 2 3 4 1->5 no region, 2->5 region->exit = 5, - \| |/ 3->5 region->exit = NULL, 4->5 region->exit = NULL - 5 <- exit - - changes to - - 1 2 3 4 1->6 no region, 2->6 region->exit = 6, - | | \/ 3->5 no region, 4->5 no region, - | | 5 - \| / 5->6 region->exit = 6 - 6 - - Now there is only a single exit edge (5->6). */ - exit = region->exit; - region->exit = NULL; - forwarder = make_forwarder_block (exit, &sd_region_without_exit, NULL); - - /* Unmark the edges, that are no longer exit edges. */ - FOR_EACH_EDGE (e, ei, forwarder->src->preds) - if (e->aux) - e->aux = NULL; - - /* Mark the new exit edge. */ - single_succ_edge (forwarder->src)->aux = region; - - /* Update the exit bb of all regions, where exit edges lead to - forwarder->dest. */ - FOR_EACH_EDGE (e, ei, forwarder->dest->preds) - if (e->aux) - ((sd_region *) e->aux)->exit = forwarder->dest; - - gcc_checking_assert (find_single_exit_edge (region)); -} - -/* Unmark the exit edges of all REGIONS. - See comment in "create_single_exit_edge". */ - -static void -unmark_exit_edges (vec<sd_region> regions) -{ - int i; - sd_region *s; - edge e; - edge_iterator ei; - - FOR_EACH_VEC_ELT (regions, i, s) - FOR_EACH_EDGE (e, ei, s->exit->preds) - e->aux = NULL; -} - - -/* Mark the exit edges of all REGIONS. - See comment in "create_single_exit_edge". */ - -static void -mark_exit_edges (vec<sd_region> regions) -{ - int i; - sd_region *s; - edge e; - edge_iterator ei; - - FOR_EACH_VEC_ELT (regions, i, s) - FOR_EACH_EDGE (e, ei, s->exit->preds) - if (bb_in_sd_region (e->src, s)) - e->aux = s; -} - -/* Create for all scop regions a single entry and a single exit edge. */ - -static void -create_sese_edges (vec<sd_region> regions) -{ - int i; - sd_region *s; - - FOR_EACH_VEC_ELT (regions, i, s) - create_single_entry_edge (s); - - mark_exit_edges (regions); - - FOR_EACH_VEC_ELT (regions, i, s) - /* Don't handle multiple edges exiting the function. */ - if (!find_single_exit_edge (s) - && s->exit != EXIT_BLOCK_PTR) - create_single_exit_edge (s); - - unmark_exit_edges (regions); - - calculate_dominance_info (CDI_DOMINATORS); - fix_loop_structure (NULL); - -#ifdef ENABLE_CHECKING - verify_loop_structure (); - verify_ssa (false); -#endif -} - -/* Create graphite SCoPs from an array of scop detection REGIONS. */ - -static void -build_graphite_scops (vec<sd_region> regions, - vec<scop_p> *scops) -{ - int i; - sd_region *s; - - FOR_EACH_VEC_ELT (regions, i, s) - { - edge entry = find_single_entry_edge (s); - edge exit = find_single_exit_edge (s); - scop_p scop; - - if (!exit) - continue; - - scop = new_scop (new_sese (entry, exit)); - scops->safe_push (scop); - - /* Are there overlapping SCoPs? */ -#ifdef ENABLE_CHECKING - { - int j; - sd_region *s2; - - FOR_EACH_VEC_ELT (regions, j, s2) - if (s != s2) - gcc_assert (!bb_in_sd_region (s->entry, s2)); - } -#endif - } -} - -/* Returns true when BB contains only close phi nodes. */ - -static bool -contains_only_close_phi_nodes (basic_block bb) -{ - gimple_stmt_iterator gsi; - - for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) - if (gimple_code (gsi_stmt (gsi)) != GIMPLE_LABEL) - return false; - - return true; -} - -/* Print statistics for SCOP to FILE. */ - -static void -print_graphite_scop_statistics (FILE* file, scop_p scop) -{ - long n_bbs = 0; - long n_loops = 0; - long n_stmts = 0; - long n_conditions = 0; - long n_p_bbs = 0; - long n_p_loops = 0; - long n_p_stmts = 0; - long n_p_conditions = 0; - - basic_block bb; - - FOR_ALL_BB (bb) - { - gimple_stmt_iterator psi; - loop_p loop = bb->loop_father; - - if (!bb_in_sese_p (bb, SCOP_REGION (scop))) - continue; - - n_bbs++; - n_p_bbs += bb->count; - - if (EDGE_COUNT (bb->succs) > 1) - { - n_conditions++; - n_p_conditions += bb->count; - } - - for (psi = gsi_start_bb (bb); !gsi_end_p (psi); gsi_next (&psi)) - { - n_stmts++; - n_p_stmts += bb->count; - } - - if (loop->header == bb && loop_in_sese_p (loop, SCOP_REGION (scop))) - { - n_loops++; - n_p_loops += bb->count; - } - - } - - fprintf (file, "\nBefore limit_scops SCoP statistics ("); - fprintf (file, "BBS:%ld, ", n_bbs); - fprintf (file, "LOOPS:%ld, ", n_loops); - fprintf (file, "CONDITIONS:%ld, ", n_conditions); - fprintf (file, "STMTS:%ld)\n", n_stmts); - fprintf (file, "\nBefore limit_scops SCoP profiling statistics ("); - fprintf (file, "BBS:%ld, ", n_p_bbs); - fprintf (file, "LOOPS:%ld, ", n_p_loops); - fprintf (file, "CONDITIONS:%ld, ", n_p_conditions); - fprintf (file, "STMTS:%ld)\n", n_p_stmts); -} - -/* Print statistics for SCOPS to FILE. */ - -static void -print_graphite_statistics (FILE* file, vec<scop_p> scops) -{ - int i; - scop_p scop; - - FOR_EACH_VEC_ELT (scops, i, scop) - print_graphite_scop_statistics (file, scop); -} - -/* We limit all SCoPs to SCoPs, that are completely surrounded by a loop. - - Example: - - for (i | - { | - for (j | SCoP 1 - for (k | - } | - - * SCoP frontier, as this line is not surrounded by any loop. * - - for (l | SCoP 2 - - This is necessary as scalar evolution and parameter detection need a - outermost loop to initialize parameters correctly. - - TODO: FIX scalar evolution and parameter detection to allow more flexible - SCoP frontiers. */ - -static void -limit_scops (vec<scop_p> *scops) -{ - vec<sd_region> regions; - regions.create (3); - - int i; - scop_p scop; - - FOR_EACH_VEC_ELT (*scops, i, scop) - { - int j; - loop_p loop; - sese region = SCOP_REGION (scop); - build_sese_loop_nests (region); - - FOR_EACH_VEC_ELT (SESE_LOOP_NEST (region), j, loop) - if (!loop_in_sese_p (loop_outer (loop), region) - && single_exit (loop)) - { - sd_region open_scop; - open_scop.entry = loop->header; - open_scop.exit = single_exit (loop)->dest; - - /* This is a hack on top of the limit_scops hack. The - limit_scops hack should disappear all together. */ - if (single_succ_p (open_scop.exit) - && contains_only_close_phi_nodes (open_scop.exit)) - open_scop.exit = single_succ_edge (open_scop.exit)->dest; - - regions.safe_push (open_scop); - } - } - - free_scops (*scops); - scops->create (3); - - create_sese_edges (regions); - build_graphite_scops (regions, scops); - regions.release (); -} - -/* Returns true when P1 and P2 are close phis with the same - argument. */ - -static inline bool -same_close_phi_node (gimple p1, gimple p2) -{ - return operand_equal_p (gimple_phi_arg_def (p1, 0), - gimple_phi_arg_def (p2, 0), 0); -} - -/* Remove the close phi node at GSI and replace its rhs with the rhs - of PHI. */ - -static void -remove_duplicate_close_phi (gimple phi, gimple_stmt_iterator *gsi) -{ - gimple use_stmt; - use_operand_p use_p; - imm_use_iterator imm_iter; - tree res = gimple_phi_result (phi); - tree def = gimple_phi_result (gsi_stmt (*gsi)); - - gcc_assert (same_close_phi_node (phi, gsi_stmt (*gsi))); - - FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, def) - { - FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) - SET_USE (use_p, res); - - update_stmt (use_stmt); - - /* It is possible that we just created a duplicate close-phi - for an already-processed containing loop. Check for this - case and clean it up. */ - if (gimple_code (use_stmt) == GIMPLE_PHI - && gimple_phi_num_args (use_stmt) == 1) - make_close_phi_nodes_unique (gimple_bb (use_stmt)); - } - - remove_phi_node (gsi, true); -} - -/* Removes all the close phi duplicates from BB. */ - -static void -make_close_phi_nodes_unique (basic_block bb) -{ - gimple_stmt_iterator psi; - - for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) - { - gimple_stmt_iterator gsi = psi; - gimple phi = gsi_stmt (psi); - - /* At this point, PHI should be a close phi in normal form. */ - gcc_assert (gimple_phi_num_args (phi) == 1); - - /* Iterate over the next phis and remove duplicates. */ - gsi_next (&gsi); - while (!gsi_end_p (gsi)) - if (same_close_phi_node (phi, gsi_stmt (gsi))) - remove_duplicate_close_phi (phi, &gsi); - else - gsi_next (&gsi); - } -} - -/* Transforms LOOP to the canonical loop closed SSA form. */ - -static void -canonicalize_loop_closed_ssa (loop_p loop) -{ - edge e = single_exit (loop); - basic_block bb; - - if (!e || e->flags & EDGE_ABNORMAL) - return; - - bb = e->dest; - - if (single_pred_p (bb)) - { - e = split_block_after_labels (bb); - make_close_phi_nodes_unique (e->src); - } - else - { - gimple_stmt_iterator psi; - basic_block close = split_edge (e); - - e = single_succ_edge (close); - - for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) - { - gimple phi = gsi_stmt (psi); - unsigned i; - - for (i = 0; i < gimple_phi_num_args (phi); i++) - if (gimple_phi_arg_edge (phi, i) == e) - { - tree res, arg = gimple_phi_arg_def (phi, i); - use_operand_p use_p; - gimple close_phi; - - if (TREE_CODE (arg) != SSA_NAME) - continue; - - close_phi = create_phi_node (NULL_TREE, close); - res = create_new_def_for (arg, close_phi, - gimple_phi_result_ptr (close_phi)); - add_phi_arg (close_phi, arg, - gimple_phi_arg_edge (close_phi, 0), - UNKNOWN_LOCATION); - use_p = gimple_phi_arg_imm_use_ptr (phi, i); - replace_exp (use_p, res); - update_stmt (phi); - } - } - - make_close_phi_nodes_unique (close); - } - - /* The code above does not properly handle changes in the post dominance - information (yet). */ - free_dominance_info (CDI_POST_DOMINATORS); -} - -/* Converts the current loop closed SSA form to a canonical form - expected by the Graphite code generation. - - The loop closed SSA form has the following invariant: a variable - defined in a loop that is used outside the loop appears only in the - phi nodes in the destination of the loop exit. These phi nodes are - called close phi nodes. - - The canonical loop closed SSA form contains the extra invariants: - - - when the loop contains only one exit, the close phi nodes contain - only one argument. That implies that the basic block that contains - the close phi nodes has only one predecessor, that is a basic block - in the loop. - - - the basic block containing the close phi nodes does not contain - other statements. - - - there exist only one phi node per definition in the loop. -*/ - -static void -canonicalize_loop_closed_ssa_form (void) -{ - loop_iterator li; - loop_p loop; - -#ifdef ENABLE_CHECKING - verify_loop_closed_ssa (true); -#endif - - FOR_EACH_LOOP (li, loop, 0) - canonicalize_loop_closed_ssa (loop); - - rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); - update_ssa (TODO_update_ssa); - -#ifdef ENABLE_CHECKING - verify_loop_closed_ssa (true); -#endif -} - -/* Find Static Control Parts (SCoP) in the current function and pushes - them to SCOPS. */ - -void -build_scops (vec<scop_p> *scops) -{ - struct loop *loop = current_loops->tree_root; - vec<sd_region> regions; - regions.create (3); - - canonicalize_loop_closed_ssa_form (); - build_scops_1 (single_succ (ENTRY_BLOCK_PTR), ENTRY_BLOCK_PTR->loop_father, - ®ions, loop); - create_sese_edges (regions); - build_graphite_scops (regions, scops); - - if (dump_file && (dump_flags & TDF_DETAILS)) - print_graphite_statistics (dump_file, *scops); - - limit_scops (scops); - regions.release (); - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "\nnumber of SCoPs: %d\n", - scops ? scops->length () : 0); -} - -/* Pretty print to FILE all the SCoPs in DOT format and mark them with - different colors. If there are not enough colors, paint the - remaining SCoPs in gray. - - Special nodes: - - "*" after the node number denotes the entry of a SCoP, - - "#" after the node number denotes the exit of a SCoP, - - "()" around the node number denotes the entry or the - exit nodes of the SCOP. These are not part of SCoP. */ - -static void -dot_all_scops_1 (FILE *file, vec<scop_p> scops) -{ - basic_block bb; - edge e; - edge_iterator ei; - scop_p scop; - const char* color; - int i; - - /* Disable debugging while printing graph. */ - int tmp_dump_flags = dump_flags; - dump_flags = 0; - - fprintf (file, "digraph all {\n"); - - FOR_ALL_BB (bb) - { - int part_of_scop = false; - - /* Use HTML for every bb label. So we are able to print bbs - which are part of two different SCoPs, with two different - background colors. */ - fprintf (file, "%d [label=<\n <TABLE BORDER=\"0\" CELLBORDER=\"1\" ", - bb->index); - fprintf (file, "CELLSPACING=\"0\">\n"); - - /* Select color for SCoP. */ - FOR_EACH_VEC_ELT (scops, i, scop) - { - sese region = SCOP_REGION (scop); - if (bb_in_sese_p (bb, region) - || (SESE_EXIT_BB (region) == bb) - || (SESE_ENTRY_BB (region) == bb)) - { - switch (i % 17) - { - case 0: /* red */ - color = "#e41a1c"; - break; - case 1: /* blue */ - color = "#377eb8"; - break; - case 2: /* green */ - color = "#4daf4a"; - break; - case 3: /* purple */ - color = "#984ea3"; - break; - case 4: /* orange */ - color = "#ff7f00"; - break; - case 5: /* yellow */ - color = "#ffff33"; - break; - case 6: /* brown */ - color = "#a65628"; - break; - case 7: /* rose */ - color = "#f781bf"; - break; - case 8: - color = "#8dd3c7"; - break; - case 9: - color = "#ffffb3"; - break; - case 10: - color = "#bebada"; - break; - case 11: - color = "#fb8072"; - break; - case 12: - color = "#80b1d3"; - break; - case 13: - color = "#fdb462"; - break; - case 14: - color = "#b3de69"; - break; - case 15: - color = "#fccde5"; - break; - case 16: - color = "#bc80bd"; - break; - default: /* gray */ - color = "#999999"; - } - - fprintf (file, " <TR><TD WIDTH=\"50\" BGCOLOR=\"%s\">", color); - - if (!bb_in_sese_p (bb, region)) - fprintf (file, " ("); - - if (bb == SESE_ENTRY_BB (region) - && bb == SESE_EXIT_BB (region)) - fprintf (file, " %d*# ", bb->index); - else if (bb == SESE_ENTRY_BB (region)) - fprintf (file, " %d* ", bb->index); - else if (bb == SESE_EXIT_BB (region)) - fprintf (file, " %d# ", bb->index); - else - fprintf (file, " %d ", bb->index); - - if (!bb_in_sese_p (bb,region)) - fprintf (file, ")"); - - fprintf (file, "</TD></TR>\n"); - part_of_scop = true; - } - } - - if (!part_of_scop) - { - fprintf (file, " <TR><TD WIDTH=\"50\" BGCOLOR=\"#ffffff\">"); - fprintf (file, " %d </TD></TR>\n", bb->index); - } - fprintf (file, " </TABLE>>, shape=box, style=\"setlinewidth(0)\"]\n"); - } - - FOR_ALL_BB (bb) - { - FOR_EACH_EDGE (e, ei, bb->succs) - fprintf (file, "%d -> %d;\n", bb->index, e->dest->index); - } - - fputs ("}\n\n", file); - - /* Enable debugging again. */ - dump_flags = tmp_dump_flags; -} - -/* Display all SCoPs using dotty. */ - -DEBUG_FUNCTION void -dot_all_scops (vec<scop_p> scops) -{ - /* When debugging, enable the following code. This cannot be used - in production compilers because it calls "system". */ -#if 0 - int x; - FILE *stream = fopen ("/tmp/allscops.dot", "w"); - gcc_assert (stream); - - dot_all_scops_1 (stream, scops); - fclose (stream); - - x = system ("dotty /tmp/allscops.dot &"); -#else - dot_all_scops_1 (stderr, scops); -#endif -} - -/* Display all SCoPs using dotty. */ - -DEBUG_FUNCTION void -dot_scop (scop_p scop) -{ - vec<scop_p> scops = vNULL; - - if (scop) - scops.safe_push (scop); - - /* When debugging, enable the following code. This cannot be used - in production compilers because it calls "system". */ -#if 0 - { - int x; - FILE *stream = fopen ("/tmp/allscops.dot", "w"); - gcc_assert (stream); - - dot_all_scops_1 (stream, scops); - fclose (stream); - x = system ("dotty /tmp/allscops.dot &"); - } -#else - dot_all_scops_1 (stderr, scops); -#endif - - scops.release (); -} - -#endif |