1/*
2 * Copyright (C) 2019 Collabora, Ltd.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 *
23 * Authors (Collabora):
24 *      Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
25 */
26
27#ifndef __LCRA_H
28#define __LCRA_H
29
30#include <stdbool.h>
31#include <stdint.h>
32
33struct lcra_state {
34        unsigned node_count;
35
36        /* Alignment for node in log2(bytes)+1. Since alignment must be
37         * non-negative power-of-two, the elements are strictly positive
38         * integers. Zero is the sentinel for a missing node. In upper word,
39         * bound. */
40        unsigned *alignment;
41
42        /* Linear constraints imposed. Nested array sized upfront, organized as
43         * linear[node_left][node_right]. That is, calculate indices as:
44         *
45         * Each element is itself a bit field denoting whether (c_j - c_i) bias
46         * is present or not, including negative biases.
47         *
48         * Note for Midgard, there are 16 components so the bias is in range
49         * [-15, 15] so encoded by 32-bit field. */
50
51        uint32_t *linear;
52
53        /* Per node max modulus constraints */
54        uint8_t *modulus;
55
56        /* Classes allow nodes to be partitioned with a starting register.
57         * Classes cannot interfere; that is, they are true partitions in the
58         * usual sense of the word. class_count is the number of classes.
59         * class[] is indexed by a node to get the mapped class. class_start is
60         * biased to all solutions in the class. */
61
62        unsigned class_count;
63        unsigned *class;
64        unsigned *class_start;
65        unsigned *class_size;
66        bool *class_disjoint;
67
68        /* Before solving, forced registers; after solving, solutions. */
69        unsigned *solutions;
70
71        /* For register spilling, the costs to spill nodes (as set by the user)
72         * are in spill_cost[], negative if a node is unspillable. Internally,
73         * spill_class specifies which class to spill (whichever class failed
74         * to allocate) */
75
76        signed *spill_cost;
77        unsigned spill_class;
78};
79
80struct lcra_state *
81lcra_alloc_equations(
82                unsigned node_count, unsigned class_count);
83
84void
85lcra_free(struct lcra_state *l);
86
87void
88lcra_set_disjoint_class(struct lcra_state *l, unsigned c1, unsigned c2);
89
90void
91lcra_set_alignment(struct lcra_state *l, unsigned node, unsigned align_log2, unsigned bound);
92
93void
94lcra_restrict_range(struct lcra_state *l, unsigned node, unsigned len);
95
96void
97lcra_add_node_interference(struct lcra_state *l, unsigned i, unsigned cmask_i, unsigned j, unsigned cmask_j);
98
99bool
100lcra_solve(struct lcra_state *l);
101
102void
103lcra_set_node_spill_cost(struct lcra_state *l, unsigned node, signed cost);
104
105signed
106lcra_get_best_spill_node(struct lcra_state *l);
107
108#endif
109