1 /*
2  * Copyright © 2014 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  *    Jason Ekstrand (jason@jlekstrand.net)
25  *
26  */
27 
28 #ifndef _NIR_SEARCH_
29 #define _NIR_SEARCH_
30 
31 #include "nir.h"
32 
33 #define NIR_SEARCH_MAX_VARIABLES 16
34 
35 typedef enum {
36    nir_search_value_expression,
37    nir_search_value_variable,
38    nir_search_value_constant,
39 } nir_search_value_type;
40 
41 typedef struct {
42    nir_search_value_type type;
43 
44    unsigned bit_size;
45 } nir_search_value;
46 
47 typedef struct {
48    nir_search_value value;
49 
50    /** The variable index;  Must be less than NIR_SEARCH_MAX_VARIABLES */
51    unsigned variable;
52 
53    /** Indicates that the given variable must be a constant
54     *
55     * This is only allowed in search expressions and indicates that the
56     * given variable is only allowed to match constant values.
57     */
58    bool is_constant;
59 
60    /** Indicates that the given variable must have a certain type
61     *
62     * This is only allowed in search expressions and indicates that the
63     * given variable is only allowed to match values that come from an ALU
64     * instruction with the given output type.  A type of nir_type_void
65     * means it can match any type.
66     *
67     * Note: A variable that is both constant and has a non-void type will
68     * never match anything.
69     */
70    nir_alu_type type;
71 
72    /** Optional condition fxn ptr
73     *
74     * This is only allowed in search expressions, and allows additional
75     * constraints to be placed on the match.  Typically used for 'is_constant'
76     * variables to require, for example, power-of-two in order for the search
77     * to match.
78     */
79    bool (*cond)(nir_alu_instr *instr, unsigned src,
80                 unsigned num_components, const uint8_t *swizzle);
81 } nir_search_variable;
82 
83 typedef struct {
84    nir_search_value value;
85 
86    nir_alu_type type;
87 
88    union {
89       uint64_t u;
90       int64_t i;
91       double d;
92    } data;
93 } nir_search_constant;
94 
95 typedef struct {
96    nir_search_value value;
97 
98    /* When set on a search expression, the expression will only match an SSA
99     * value that does *not* have the exact bit set.  If unset, the exact bit
100     * on the SSA value is ignored.
101     */
102    bool inexact;
103 
104    nir_op opcode;
105    const nir_search_value *srcs[4];
106 
107    /** Optional condition fxn ptr
108     *
109     * This allows additional constraints on expression matching, it is
110     * typically used to match an expressions uses such as the number of times
111     * the expression is used, and whether its used by an if.
112     */
113    bool (*cond)(nir_alu_instr *instr);
114 } nir_search_expression;
115 
116 NIR_DEFINE_CAST(nir_search_value_as_variable, nir_search_value,
117                 nir_search_variable, value,
118                 type, nir_search_value_variable)
119 NIR_DEFINE_CAST(nir_search_value_as_constant, nir_search_value,
120                 nir_search_constant, value,
121                 type, nir_search_value_constant)
122 NIR_DEFINE_CAST(nir_search_value_as_expression, nir_search_value,
123                 nir_search_expression, value,
124                 type, nir_search_value_expression)
125 
126 nir_alu_instr *
127 nir_replace_instr(nir_alu_instr *instr, const nir_search_expression *search,
128                   const nir_search_value *replace, void *mem_ctx);
129 
130 #endif /* _NIR_SEARCH_ */
131