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/* Header file for SSA loop optimizations.
Copyright (C) 2013-2022 Free Software Foundation, Inc.
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/>. */
#ifndef GCC_TREE_SSA_LOOP_H
#define GCC_TREE_SSA_LOOP_H
/* Affine iv. */
struct affine_iv
{
/* Iv = BASE + STEP * i. */
tree base, step;
/* True if this iv does not overflow. */
bool no_overflow;
};
/* Description of number of iterations of a loop. All the expressions inside
the structure can be evaluated at the end of the loop's preheader
(and due to ssa form, also anywhere inside the body of the loop). */
class tree_niter_desc
{
public:
tree assumptions; /* The boolean expression. If this expression evaluates
to false, then the other fields in this structure
should not be used; there is no guarantee that they
will be correct. */
tree may_be_zero; /* The boolean expression. If it evaluates to true,
the loop will exit in the first iteration (i.e.
its latch will not be executed), even if the niter
field says otherwise. */
tree niter; /* The expression giving the number of iterations of
a loop (provided that assumptions == true and
may_be_zero == false), more precisely the number
of executions of the latch of the loop. */
widest_int max; /* The upper bound on the number of iterations of
the loop. */
/* The simplified shape of the exit condition. The loop exits if
CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
LE_EXPR and negative if CMP is GE_EXPR. This information is used
by loop unrolling. */
affine_iv control;
tree bound;
enum tree_code cmp;
};
extern bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
extern char *get_lsm_tmp_name (tree ref, unsigned n, const char *suffix = NULL);
extern unsigned tree_num_loop_insns (class loop *, struct eni_weights *);
/* Returns the loop of the statement STMT. */
static inline class loop *
loop_containing_stmt (gimple *stmt)
{
basic_block bb = gimple_bb (stmt);
if (!bb)
return NULL;
return bb->loop_father;
}
#endif /* GCC_TREE_SSA_LOOP_H */