xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/tree-vrp.h (revision d90047b5d07facf36e6c01dcc0bded8997ce9cc2)
1 /* Support routines for Value Range Propagation (VRP).
2    Copyright (C) 2016-2017 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10 
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 GNU General Public License 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 /* Type of value ranges.  See value_range_d In tree-vrp.c for a
21    description of these types.  */
22 enum value_range_type { VR_UNDEFINED, VR_RANGE,
23 			VR_ANTI_RANGE, VR_VARYING, VR_LAST };
24 
25 /* Range of values that can be associated with an SSA_NAME after VRP
26    has executed.  */
27 struct GTY((for_user)) value_range
28 {
29   /* Lattice value represented by this range.  */
30   enum value_range_type type;
31 
32   /* Minimum and maximum values represented by this range.  These
33      values should be interpreted as follows:
34 
35 	- If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
36 	  be NULL.
37 
38 	- If TYPE == VR_RANGE then MIN holds the minimum value and
39 	  MAX holds the maximum value of the range [MIN, MAX].
40 
41 	- If TYPE == ANTI_RANGE the variable is known to NOT
42 	  take any values in the range [MIN, MAX].  */
43   tree min;
44   tree max;
45 
46   /* Set of SSA names whose value ranges are equivalent to this one.
47      This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
48   bitmap equiv;
49 };
50 
51 extern void vrp_intersect_ranges (value_range *vr0, value_range *vr1);
52 extern void vrp_meet (value_range *vr0, const value_range *vr1);
53 extern void dump_value_range (FILE *, const value_range *);
54 extern void extract_range_from_unary_expr (value_range *vr,
55 					   enum tree_code code,
56 					   tree type,
57 					   value_range *vr0_,
58 					   tree op0_type);
59 
60