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/* Single entry single exit control flow regions.
Copyright (C) 2008-2013 Free Software Foundation, Inc.
Contributed by Jan Sjodin <> and
Sebastian Pop <>.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
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
<>. */
#ifndef GCC_SESE_H
#define GCC_SESE_H
/* A Single Entry, Single Exit region is a part of the CFG delimited
by two edges. */
typedef struct sese_s
/* Single ENTRY and single EXIT from the SESE region. */
edge entry, exit;
/* Parameters used within the SCOP. */
vec<tree> params;
/* Loops completely contained in the SCOP. */
bitmap loops;
vec<loop_p> loop_nest;
/* Are we allowed to add more params? This is for debugging purpose. We
can only add new params before generating the bb domains, otherwise they
become invalid. */
bool add_params;
} *sese;
#define SESE_ENTRY(S) (S->entry)
#define SESE_ENTRY_BB(S) (S->entry->dest)
#define SESE_EXIT(S) (S->exit)
#define SESE_EXIT_BB(S) (S->exit->dest)
#define SESE_PARAMS(S) (S->params)
#define SESE_LOOPS(S) (S->loops)
#define SESE_LOOP_NEST(S) (S->loop_nest)
#define SESE_ADD_PARAMS(S) (S->add_params)
extern sese new_sese (edge, edge);
extern void free_sese (sese);
extern void sese_insert_phis_for_liveouts (sese, basic_block, edge, edge);
extern void build_sese_loop_nests (sese);
extern edge copy_bb_and_scalar_dependences (basic_block, sese, edge,
vec<tree> , bool *);
extern struct loop *outermost_loop_in_sese (sese, basic_block);
extern void insert_loop_close_phis (htab_t, loop_p);
extern void insert_guard_phis (basic_block, edge, edge, htab_t, htab_t);
extern tree scalar_evolution_in_region (sese, loop_p, tree);
/* Check that SESE contains LOOP. */
static inline bool
sese_contains_loop (sese sese, struct loop *loop)
return bitmap_bit_p (SESE_LOOPS (sese), loop->num);
/* The number of parameters in REGION. */
static inline unsigned
sese_nb_params (sese region)
return SESE_PARAMS (region).length ();
/* Checks whether BB is contained in the region delimited by ENTRY and
EXIT blocks. */
static inline bool
bb_in_region (basic_block bb, basic_block entry, basic_block exit)
edge e;
edge_iterator ei;
/* Check that there are no edges coming in the region: all the
predecessors of EXIT are dominated by ENTRY. */
FOR_EACH_EDGE (e, ei, exit->preds)
dominated_by_p (CDI_DOMINATORS, e->src, entry);
return dominated_by_p (CDI_DOMINATORS, bb, entry)
&& !(dominated_by_p (CDI_DOMINATORS, bb, exit)
&& !dominated_by_p (CDI_DOMINATORS, entry, exit));
/* Checks whether BB is contained in the region delimited by ENTRY and
EXIT blocks. */
static inline bool
bb_in_sese_p (basic_block bb, sese region)
basic_block entry = SESE_ENTRY_BB (region);
basic_block exit = SESE_EXIT_BB (region);
return bb_in_region (bb, entry, exit);
/* Returns true when STMT is defined in REGION. */
static inline bool
stmt_in_sese_p (gimple stmt, sese region)
basic_block bb = gimple_bb (stmt);
return bb && bb_in_sese_p (bb, region);
/* Returns true when NAME is defined in REGION. */
static inline bool
defined_in_sese_p (tree name, sese region)
gimple stmt = SSA_NAME_DEF_STMT (name);
return stmt_in_sese_p (stmt, region);
/* Returns true when LOOP is in REGION. */
static inline bool
loop_in_sese_p (struct loop *loop, sese region)
return (bb_in_sese_p (loop->header, region)
&& bb_in_sese_p (loop->latch, region));
/* Returns the loop depth of LOOP in REGION. The loop depth
is the same as the normal loop depth, but limited by a region.
<- region start
<- region end
loop_0 does not exist in the region -> invalid
loop_1 exists, but is not completely contained in the region -> depth 0
loop_2 is completely contained -> depth 1 */
static inline unsigned int
sese_loop_depth (sese region, loop_p loop)
unsigned int depth = 0;
gcc_assert ((!loop_in_sese_p (loop, region)
&& (SESE_ENTRY_BB (region)->loop_father == loop
|| SESE_EXIT (region)->src->loop_father == loop))
|| loop_in_sese_p (loop, region));
while (loop_in_sese_p (loop, region))
loop = loop_outer (loop);
return depth;
/* Splits BB to make a single entry single exit region. */
static inline sese
split_region_for_bb (basic_block bb)
edge entry, exit;
if (single_pred_p (bb))
entry = single_pred_edge (bb);
entry = split_block_after_labels (bb);
bb = single_succ (bb);
if (single_succ_p (bb))
exit = single_succ_edge (bb);
gimple_stmt_iterator gsi = gsi_last_bb (bb);
gsi_prev (&gsi);
exit = split_block (bb, gsi_stmt (gsi));
return new_sese (entry, exit);
/* Returns the block preceding the entry of a SESE. */
static inline basic_block
block_before_sese (sese sese)
return SESE_ENTRY (sese)->src;
/* A single entry single exit specialized for conditions. */
typedef struct ifsese_s {
sese region;
sese true_region;
sese false_region;
} *ifsese;
extern void if_region_set_false_region (ifsese, sese);
extern ifsese move_sese_in_condition (sese);
extern edge get_true_edge_from_guard_bb (basic_block);
extern edge get_false_edge_from_guard_bb (basic_block);
extern void set_ifsese_condition (ifsese, tree);
static inline edge
if_region_entry (ifsese if_region)
return SESE_ENTRY (if_region->region);
static inline edge
if_region_exit (ifsese if_region)
return SESE_EXIT (if_region->region);
static inline basic_block
if_region_get_condition_block (ifsese if_region)
return if_region_entry (if_region)->dest;
/* Structure containing the mapping between the old names and the new
names used after block copy in the new loop context. */
typedef struct rename_map_elt_s
tree old_name, expr;
} *rename_map_elt;
extern void debug_rename_map (htab_t);
extern hashval_t rename_map_elt_info (const void *);
extern int eq_rename_map_elts (const void *, const void *);
/* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW. */
static inline rename_map_elt
new_rename_map_elt (tree old_name, tree expr)
rename_map_elt res;
res = XNEW (struct rename_map_elt_s);
res->old_name = old_name;
res->expr = expr;
return res;
/* Structure containing the mapping between the CLooG's induction
variable and the type of the old induction variable. */
typedef struct ivtype_map_elt_s
tree type;
const char *cloog_iv;
} *ivtype_map_elt;
extern void debug_ivtype_map (htab_t);
extern hashval_t ivtype_map_elt_info (const void *);
extern int eq_ivtype_map_elts (const void *, const void *);
/* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW. */
static inline ivtype_map_elt
new_ivtype_map_elt (const char *cloog_iv, tree type)
ivtype_map_elt res;
res = XNEW (struct ivtype_map_elt_s);
res->cloog_iv = cloog_iv;
res->type = type;
return res;
/* Free and compute again all the dominators information. */
static inline void
recompute_all_dominators (void)
mark_irreducible_loops ();
free_dominance_info (CDI_DOMINATORS);
calculate_dominance_info (CDI_DOMINATORS);
typedef struct gimple_bb
basic_block bb;
struct poly_bb *pbb;
/* Lists containing the restrictions of the conditional statements
dominating this bb. This bb can only be executed, if all conditions
are true.
for (i = 0; i <= 20; i++)
if (2i <= 8)
So for B there is an additional condition (2i <= 8).
List of COND_EXPR and SWITCH_EXPR. A COND_EXPR is true only if the
corresponding element in CONDITION_CASES is not NULL_TREE. For a
SWITCH_EXPR the corresponding element in CONDITION_CASES is a
vec<gimple> conditions;
vec<gimple> condition_cases;
vec<data_reference_p> data_refs;
} *gimple_bb_p;
#define GBB_BB(GBB) (GBB)->bb
#define GBB_PBB(GBB) (GBB)->pbb
#define GBB_DATA_REFS(GBB) (GBB)->data_refs
#define GBB_CONDITIONS(GBB) (GBB)->conditions
#define GBB_CONDITION_CASES(GBB) (GBB)->condition_cases
/* Return the innermost loop that contains the basic block GBB. */
static inline struct loop *
gbb_loop (struct gimple_bb *gbb)
return GBB_BB (gbb)->loop_father;
/* Returns the gimple loop, that corresponds to the loop_iterator_INDEX.
If there is no corresponding gimple loop, we return NULL. */
static inline loop_p
gbb_loop_at_index (gimple_bb_p gbb, sese region, int index)
loop_p loop = gbb_loop (gbb);
int depth = sese_loop_depth (region, loop);
while (--depth > index)
loop = loop_outer (loop);
gcc_assert (sese_contains_loop (region, loop));
return loop;
/* The number of common loops in REGION for GBB1 and GBB2. */
static inline int
nb_common_loops (sese region, gimple_bb_p gbb1, gimple_bb_p gbb2)
loop_p l1 = gbb_loop (gbb1);
loop_p l2 = gbb_loop (gbb2);
loop_p common = find_common_loop (l1, l2);
return sese_loop_depth (region, common);
/* Return true when DEF can be analyzed in REGION by the scalar
evolution analyzer. */
static inline bool
scev_analyzable_p (tree def, sese region)
loop_p loop;
tree scev;
tree type = TREE_TYPE (def);
/* When Graphite generates code for a scev, the code generator
expresses the scev in function of a single induction variable.
This is unsafe for floating point computations, as it may replace
a floating point sum reduction with a multiplication. The
following test returns false for non integer types to avoid such
problems. */
if (!INTEGRAL_TYPE_P (type)
&& !POINTER_TYPE_P (type))
return false;
loop = loop_containing_stmt (SSA_NAME_DEF_STMT (def));
scev = scalar_evolution_in_region (region, loop, def);
return !chrec_contains_undetermined (scev)
&& (TREE_CODE (scev) != SSA_NAME
|| !defined_in_sese_p (scev, region))
&& (tree_does_not_contain_chrecs (scev)
|| evolution_function_is_affine_p (scev));