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
35struct nir_builder;
36
37typedef enum {
38   nir_search_value_expression,
39   nir_search_value_variable,
40   nir_search_value_constant,
41} nir_search_value_type;
42
43typedef struct {
44   nir_search_value_type type;
45
46   /**
47    * Bit size of the value. It is interpreted as follows:
48    *
49    * For a search expression:
50    * - If bit_size > 0, then the value only matches an SSA value with the
51    *   given bit size.
52    * - If bit_size <= 0, then the value matches any size SSA value.
53    *
54    * For a replace expression:
55    * - If bit_size > 0, then the value is constructed with the given bit size.
56    * - If bit_size == 0, then the value is constructed with the same bit size
57    *   as the search value.
58    * - If bit_size < 0, then the value is constructed with the same bit size
59    *   as variable (-bit_size - 1).
60    */
61   int bit_size;
62} nir_search_value;
63
64typedef struct {
65   nir_search_value value;
66
67   /** The variable index;  Must be less than NIR_SEARCH_MAX_VARIABLES */
68   unsigned variable;
69
70   /** Indicates that the given variable must be a constant
71    *
72    * This is only allowed in search expressions and indicates that the
73    * given variable is only allowed to match constant values.
74    */
75   bool is_constant;
76
77   /** Indicates that the given variable must have a certain type
78    *
79    * This is only allowed in search expressions and indicates that the
80    * given variable is only allowed to match values that come from an ALU
81    * instruction with the given output type.  A type of nir_type_void
82    * means it can match any type.
83    *
84    * Note: A variable that is both constant and has a non-void type will
85    * never match anything.
86    */
87   nir_alu_type type;
88
89   /** Optional condition fxn ptr
90    *
91    * This is only allowed in search expressions, and allows additional
92    * constraints to be placed on the match.  Typically used for 'is_constant'
93    * variables to require, for example, power-of-two in order for the search
94    * to match.
95    */
96   bool (*cond)(nir_alu_instr *instr, unsigned src,
97                unsigned num_components, const uint8_t *swizzle);
98} nir_search_variable;
99
100typedef struct {
101   nir_search_value value;
102
103   nir_alu_type type;
104
105   union {
106      uint64_t u;
107      int64_t i;
108      double d;
109   } data;
110} nir_search_constant;
111
112enum nir_search_op {
113   nir_search_op_i2f = nir_last_opcode + 1,
114   nir_search_op_u2f,
115   nir_search_op_f2f,
116   nir_search_op_f2u,
117   nir_search_op_f2i,
118   nir_search_op_u2u,
119   nir_search_op_i2i,
120   nir_search_op_b2f,
121   nir_search_op_b2i,
122   nir_search_op_i2b,
123   nir_search_op_f2b,
124   nir_num_search_ops,
125};
126
127uint16_t nir_search_op_for_nir_op(nir_op op);
128
129typedef struct {
130   nir_search_value value;
131
132   /* When set on a search expression, the expression will only match an SSA
133    * value that does *not* have the exact bit set.  If unset, the exact bit
134    * on the SSA value is ignored.
135    */
136   bool inexact;
137
138   /* Commutative expression index.  This is assigned by opt_algebraic.py when
139    * search structures are constructed and is a unique (to this structure)
140    * index within the commutative operation bitfield used for searching for
141    * all combinations of expressions containing commutative operations.
142    */
143   int8_t comm_expr_idx;
144
145   /* Number of commutative expressions in this expression including this one
146    * (if it is commutative).
147    */
148   uint8_t comm_exprs;
149
150   /* One of nir_op or nir_search_op */
151   uint16_t opcode;
152   const nir_search_value *srcs[4];
153
154   /** Optional condition fxn ptr
155    *
156    * This allows additional constraints on expression matching, it is
157    * typically used to match an expressions uses such as the number of times
158    * the expression is used, and whether its used by an if.
159    */
160   bool (*cond)(nir_alu_instr *instr);
161} nir_search_expression;
162
163NIR_DEFINE_CAST(nir_search_value_as_variable, nir_search_value,
164                nir_search_variable, value,
165                type, nir_search_value_variable)
166NIR_DEFINE_CAST(nir_search_value_as_constant, nir_search_value,
167                nir_search_constant, value,
168                type, nir_search_value_constant)
169NIR_DEFINE_CAST(nir_search_value_as_expression, nir_search_value,
170                nir_search_expression, value,
171                type, nir_search_value_expression)
172
173nir_ssa_def *
174nir_replace_instr(struct nir_builder *b, nir_alu_instr *instr,
175                  const nir_search_expression *search,
176                  const nir_search_value *replace);
177
178#endif /* _NIR_SEARCH_ */
179