xref: /dflybsd-src/contrib/gcc-8.0/gcc/tree-ssa-loop.h (revision 38fd149817dfbff97799f62fcb70be98c4e32523)
1*38fd1498Szrj /* Header file for SSA loop optimizations.
2*38fd1498Szrj    Copyright (C) 2013-2018 Free Software Foundation, Inc.
3*38fd1498Szrj 
4*38fd1498Szrj This file is part of GCC.
5*38fd1498Szrj 
6*38fd1498Szrj GCC is free software; you can redistribute it and/or modify it under
7*38fd1498Szrj the terms of the GNU General Public License as published by the Free
8*38fd1498Szrj Software Foundation; either version 3, or (at your option) any later
9*38fd1498Szrj version.
10*38fd1498Szrj 
11*38fd1498Szrj GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12*38fd1498Szrj WARRANTY; without even the implied warranty of MERCHANTABILITY or
13*38fd1498Szrj FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14*38fd1498Szrj  for more details.
15*38fd1498Szrj 
16*38fd1498Szrj You should have received a copy of the GNU General Public License
17*38fd1498Szrj along with GCC; see the file COPYING3.  If not see
18*38fd1498Szrj <http://www.gnu.org/licenses/>.  */
19*38fd1498Szrj 
20*38fd1498Szrj #ifndef GCC_TREE_SSA_LOOP_H
21*38fd1498Szrj #define GCC_TREE_SSA_LOOP_H
22*38fd1498Szrj 
23*38fd1498Szrj 
24*38fd1498Szrj /* Affine iv.  */
25*38fd1498Szrj 
26*38fd1498Szrj struct affine_iv
27*38fd1498Szrj {
28*38fd1498Szrj   /* Iv = BASE + STEP * i.  */
29*38fd1498Szrj   tree base, step;
30*38fd1498Szrj 
31*38fd1498Szrj   /* True if this iv does not overflow.  */
32*38fd1498Szrj   bool no_overflow;
33*38fd1498Szrj };
34*38fd1498Szrj 
35*38fd1498Szrj /* Description of number of iterations of a loop.  All the expressions inside
36*38fd1498Szrj    the structure can be evaluated at the end of the loop's preheader
37*38fd1498Szrj    (and due to ssa form, also anywhere inside the body of the loop).  */
38*38fd1498Szrj 
39*38fd1498Szrj struct tree_niter_desc
40*38fd1498Szrj {
41*38fd1498Szrj   tree assumptions;	/* The boolean expression.  If this expression evaluates
42*38fd1498Szrj 			   to false, then the other fields in this structure
43*38fd1498Szrj 			   should not be used; there is no guarantee that they
44*38fd1498Szrj 			   will be correct.  */
45*38fd1498Szrj   tree may_be_zero;	/* The boolean expression.  If it evaluates to true,
46*38fd1498Szrj 			   the loop will exit in the first iteration (i.e.
47*38fd1498Szrj 			   its latch will not be executed), even if the niter
48*38fd1498Szrj 			   field says otherwise.  */
49*38fd1498Szrj   tree niter;		/* The expression giving the number of iterations of
50*38fd1498Szrj 			   a loop (provided that assumptions == true and
51*38fd1498Szrj 			   may_be_zero == false), more precisely the number
52*38fd1498Szrj 			   of executions of the latch of the loop.  */
53*38fd1498Szrj   widest_int max;	/* The upper bound on the number of iterations of
54*38fd1498Szrj 			   the loop.  */
55*38fd1498Szrj 
56*38fd1498Szrj   /* The simplified shape of the exit condition.  The loop exits if
57*38fd1498Szrj      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
58*38fd1498Szrj      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
59*38fd1498Szrj      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
60*38fd1498Szrj      by loop unrolling.  */
61*38fd1498Szrj   affine_iv control;
62*38fd1498Szrj   tree bound;
63*38fd1498Szrj   enum tree_code cmp;
64*38fd1498Szrj };
65*38fd1498Szrj 
66*38fd1498Szrj extern bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
67*38fd1498Szrj extern char *get_lsm_tmp_name (tree ref, unsigned n, const char *suffix = NULL);
68*38fd1498Szrj extern unsigned tree_num_loop_insns (struct loop *, struct eni_weights *);
69*38fd1498Szrj 
70*38fd1498Szrj /* Returns the loop of the statement STMT.  */
71*38fd1498Szrj 
72*38fd1498Szrj static inline struct loop *
loop_containing_stmt(gimple * stmt)73*38fd1498Szrj loop_containing_stmt (gimple *stmt)
74*38fd1498Szrj {
75*38fd1498Szrj   basic_block bb = gimple_bb (stmt);
76*38fd1498Szrj   if (!bb)
77*38fd1498Szrj     return NULL;
78*38fd1498Szrj 
79*38fd1498Szrj   return bb->loop_father;
80*38fd1498Szrj }
81*38fd1498Szrj 
82*38fd1498Szrj #endif /* GCC_TREE_SSA_LOOP_H */
83