[thirdparty/gcc.git] / gcc / tree-ssa-loop.h

/* Header file for SSA loop optimizations.
   Copyright (C) 2013-2020 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 */
Commit	Line	Data
71343877	1	/* Header file for SSA loop optimizations.
8d9254fc	2	Copyright (C) 2013-2020 Free Software Foundation, Inc.
71343877 AM	3
	4	This file is part of GCC.
	5
	6	GCC is free software; you can redistribute it and/or modify it under
	7	the terms of the GNU General Public License as published by the Free
	8	Software Foundation; either version 3, or (at your option) any later
	9	version.
	10
	11	GCC is distributed in the hope that it will be useful, but WITHOUT ANY
	12	WARRANTY; without even the implied warranty of MERCHANTABILITY or
	13	FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	14	for more details.
	15
	16	You should have received a copy of the GNU General Public License
	17	along with GCC; see the file COPYING3. If not see
	18	<http://www.gnu.org/licenses/>. */
	19
	20	#ifndef GCC_TREE_SSA_LOOP_H
	21	#define GCC_TREE_SSA_LOOP_H
	22
807e902e	23
71343877 AM	24	/* Affine iv. */
71343877 AM	25
84562394	26	struct affine_iv
71343877 AM	27	{
	28	/* Iv = BASE + STEP * i. */
	29	tree base, step;
	30
	31	/* True if this iv does not overflow. */
	32	bool no_overflow;
84562394	33	};
71343877 AM	34
	35	/* Description of number of iterations of a loop. All the expressions inside
	36	the structure can be evaluated at the end of the loop's preheader
	37	(and due to ssa form, also anywhere inside the body of the loop). */
	38
6c1dae73	39	class tree_niter_desc
71343877	40	{
6c1dae73	41	public:
71343877 AM	42	tree assumptions; /* The boolean expression. If this expression evaluates
	43	to false, then the other fields in this structure
	44	should not be used; there is no guarantee that they
	45	will be correct. */
	46	tree may_be_zero; /* The boolean expression. If it evaluates to true,
	47	the loop will exit in the first iteration (i.e.
	48	its latch will not be executed), even if the niter
	49	field says otherwise. */
	50	tree niter; /* The expression giving the number of iterations of
	51	a loop (provided that assumptions == true and
	52	may_be_zero == false), more precisely the number
	53	of executions of the latch of the loop. */
807e902e	54	widest_int max; /* The upper bound on the number of iterations of
71343877 AM	55	the loop. */
	56
	57	/* The simplified shape of the exit condition. The loop exits if
	58	CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
	59	LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
	60	LE_EXPR and negative if CMP is GE_EXPR. This information is used
	61	by loop unrolling. */
	62	affine_iv control;
	63	tree bound;
	64	enum tree_code cmp;
	65	};
	66
	67	extern bool for_each_index (tree , bool () (tree, tree , void ), void *);
	68	extern char get_lsm_tmp_name (tree ref, unsigned n, const char suffix = NULL);
99b1c316	69	extern unsigned tree_num_loop_insns (class loop , struct eni_weights );
71343877 AM	70
	71	/* Returns the loop of the statement STMT. */
	72
99b1c316	73	static inline class loop *
355fe088	74	loop_containing_stmt (gimple *stmt)
71343877 AM	75	{
	76	basic_block bb = gimple_bb (stmt);
	77	if (!bb)
	78	return NULL;
	79
	80	return bb->loop_father;
	81	}
	82
	83	#endif /* GCC_TREE_SSA_LOOP_H */