1/*
2 * Copyright © 2010 Intel Corporation
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
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 *    Eric Anholt <eric@anholt.net>
25 *
26 */
27
28#ifndef REGISTER_ALLOCATE_H
29#define REGISTER_ALLOCATE_H
30
31#include <stdbool.h>
32#include "util/bitset.h"
33
34#ifdef __cplusplus
35extern "C" {
36#endif
37
38
39struct ra_class;
40struct ra_regs;
41
42struct blob;
43struct blob_reader;
44
45/* @{
46 * Register set setup.
47 *
48 * This should be done once at backend initializaion, as
49 * ra_set_finalize is O(r^2*c^2).  The registers may be virtual
50 * registers, such as aligned register pairs that conflict with the
51 * two real registers from which they are composed.
52 */
53struct ra_regs *ra_alloc_reg_set(void *mem_ctx, unsigned int count,
54                                 bool need_conflict_lists);
55void ra_set_allocate_round_robin(struct ra_regs *regs);
56struct ra_class *ra_alloc_reg_class(struct ra_regs *regs);
57struct ra_class *ra_alloc_contig_reg_class(struct ra_regs *regs, int contig_len);
58unsigned int ra_class_index(struct ra_class *c);
59void ra_add_reg_conflict(struct ra_regs *regs,
60                         unsigned int r1, unsigned int r2);
61void ra_add_transitive_reg_conflict(struct ra_regs *regs,
62                                    unsigned int base_reg, unsigned int reg);
63
64void
65ra_add_transitive_reg_pair_conflict(struct ra_regs *regs,
66                                    unsigned int base_reg, unsigned int reg0, unsigned int reg1);
67
68void ra_make_reg_conflicts_transitive(struct ra_regs *regs, unsigned int reg);
69void ra_class_add_reg(struct ra_class *c, unsigned int reg);
70struct ra_class *ra_get_class_from_index(struct ra_regs *regs, unsigned int c);
71void ra_set_num_conflicts(struct ra_regs *regs, unsigned int class_a,
72                          unsigned int class_b, unsigned int num_conflicts);
73void ra_set_finalize(struct ra_regs *regs, unsigned int **conflicts);
74
75void ra_set_serialize(const struct ra_regs *regs, struct blob *blob);
76struct ra_regs *ra_set_deserialize(void *mem_ctx, struct blob_reader *blob);
77/** @} */
78
79/** @{ Interference graph setup.
80 *
81 * Each interference graph node is a virtual variable in the IL.  It
82 * is up to the user to ra_set_node_class() for the virtual variable,
83 * and compute live ranges and ra_node_interfere() between conflicting
84 * live ranges. Note that an interference *must not* be added between
85 * two nodes if their classes haven't been assigned yet. The user
86 * should set the class of each node before building the interference
87 * graph.
88 */
89struct ra_graph *ra_alloc_interference_graph(struct ra_regs *regs,
90                                             unsigned int count);
91void ra_resize_interference_graph(struct ra_graph *g, unsigned int count);
92void ra_set_node_class(struct ra_graph *g, unsigned int n, struct ra_class *c);
93struct ra_class *ra_get_node_class(struct ra_graph *g, unsigned int n);
94unsigned int ra_add_node(struct ra_graph *g, struct ra_class *c);
95
96/** @{ Register selection callback.
97 *
98 * The register allocator can use either one of two built-in register
99 * selection behaviors (ie. lowest-available or round-robin), or the
100 * user can implement it's own selection policy by setting an register
101 * selection callback.  The parameters to the callback are:
102 *
103 *  - n       the graph node, ie. the virtual variable to select a
104 *            register for
105 *  - regs    bitset of available registers to choose; this bitset
106 *            contains *all* registers, but registers of different
107 *            classes will not have their corresponding bit set.
108 *  - data    callback data specified in ra_set_select_reg_callback()
109 */
110typedef unsigned int (*ra_select_reg_callback)(
111      unsigned int n,        /* virtual variable to choose a physical reg for */
112      BITSET_WORD *regs,     /* available physical regs to choose from */
113      void *data);
114
115void ra_set_select_reg_callback(struct ra_graph *g,
116                                ra_select_reg_callback callback,
117                                void *data);
118void ra_add_node_interference(struct ra_graph *g,
119                              unsigned int n1, unsigned int n2);
120void ra_reset_node_interference(struct ra_graph *g, unsigned int n);
121/** @} */
122
123/** @{ Graph-coloring register allocation */
124bool ra_allocate(struct ra_graph *g);
125
126#define NO_REG ~0U
127/**
128 * Returns NO_REG for a node that has not (yet) been assigned.
129 */
130unsigned int ra_get_node_reg(struct ra_graph *g, unsigned int n);
131void ra_set_node_reg(struct ra_graph * g, unsigned int n, unsigned int reg);
132void ra_set_node_spill_cost(struct ra_graph *g, unsigned int n, float cost);
133int ra_get_best_spill_node(struct ra_graph *g);
134/** @} */
135
136
137#ifdef __cplusplus
138}  // extern "C"
139#endif
140
141#endif /* REGISTER_ALLOCATE_H */
142