1 /*
2  * Copyright © 2015 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  */
24 
25 #include "nir.h"
26 #include "nir_builder.h"
27 
28 /*
29  * lowers:
30  *
31  * packDouble2x32(foo) -> packDouble2x32Split(foo.x, foo.y)
32  * unpackDouble2x32(foo) -> vec2(unpackDouble2x32_x(foo), unpackDouble2x32_y(foo))
33  * packInt2x32(foo) -> packInt2x32Split(foo.x, foo.y)
34  * unpackInt2x32(foo) -> vec2(unpackInt2x32_x(foo), unpackInt2x32_y(foo))
35  */
36 
37 static nir_ssa_def *
lower_pack_64_from_32(nir_builder * b,nir_ssa_def * src)38 lower_pack_64_from_32(nir_builder *b, nir_ssa_def *src)
39 {
40    return nir_pack_64_2x32_split(b, nir_channel(b, src, 0),
41                                     nir_channel(b, src, 1));
42 }
43 
44 static nir_ssa_def *
lower_unpack_64_to_32(nir_builder * b,nir_ssa_def * src)45 lower_unpack_64_to_32(nir_builder *b, nir_ssa_def *src)
46 {
47    return nir_vec2(b, nir_unpack_64_2x32_split_x(b, src),
48                       nir_unpack_64_2x32_split_y(b, src));
49 }
50 
51 static nir_ssa_def *
lower_pack_32_from_16(nir_builder * b,nir_ssa_def * src)52 lower_pack_32_from_16(nir_builder *b, nir_ssa_def *src)
53 {
54    return nir_pack_32_2x16_split(b, nir_channel(b, src, 0),
55                                     nir_channel(b, src, 1));
56 }
57 
58 static nir_ssa_def *
lower_unpack_32_to_16(nir_builder * b,nir_ssa_def * src)59 lower_unpack_32_to_16(nir_builder *b, nir_ssa_def *src)
60 {
61    return nir_vec2(b, nir_unpack_32_2x16_split_x(b, src),
62                       nir_unpack_32_2x16_split_y(b, src));
63 }
64 
65 static nir_ssa_def *
lower_pack_64_from_16(nir_builder * b,nir_ssa_def * src)66 lower_pack_64_from_16(nir_builder *b, nir_ssa_def *src)
67 {
68    nir_ssa_def *xy = nir_pack_32_2x16_split(b, nir_channel(b, src, 0),
69                                                nir_channel(b, src, 1));
70 
71    nir_ssa_def *zw = nir_pack_32_2x16_split(b, nir_channel(b, src, 2),
72                                                nir_channel(b, src, 3));
73 
74    return nir_pack_64_2x32_split(b, xy, zw);
75 }
76 
77 static nir_ssa_def *
lower_unpack_64_to_16(nir_builder * b,nir_ssa_def * src)78 lower_unpack_64_to_16(nir_builder *b, nir_ssa_def *src)
79 {
80    nir_ssa_def *xy = nir_unpack_64_2x32_split_x(b, src);
81    nir_ssa_def *zw = nir_unpack_64_2x32_split_y(b, src);
82 
83    return nir_vec4(b, nir_unpack_32_2x16_split_x(b, xy),
84                       nir_unpack_32_2x16_split_y(b, xy),
85                       nir_unpack_32_2x16_split_x(b, zw),
86                       nir_unpack_32_2x16_split_y(b, zw));
87 }
88 
89 static bool
lower_pack_impl(nir_function_impl * impl)90 lower_pack_impl(nir_function_impl *impl)
91 {
92    nir_builder b;
93    nir_builder_init(&b, impl);
94    bool progress = false;
95 
96    nir_foreach_block(block, impl) {
97       nir_foreach_instr_safe(instr, block) {
98          if (instr->type != nir_instr_type_alu)
99             continue;
100 
101          nir_alu_instr *alu_instr = (nir_alu_instr *) instr;
102 
103          if (alu_instr->op != nir_op_pack_64_2x32 &&
104              alu_instr->op != nir_op_unpack_64_2x32 &&
105              alu_instr->op != nir_op_pack_64_4x16 &&
106              alu_instr->op != nir_op_unpack_64_4x16 &&
107              alu_instr->op != nir_op_pack_32_2x16 &&
108              alu_instr->op != nir_op_unpack_32_2x16)
109             continue;
110 
111          b.cursor = nir_before_instr(&alu_instr->instr);
112 
113          nir_ssa_def *src = nir_ssa_for_alu_src(&b, alu_instr, 0);
114          nir_ssa_def *dest;
115 
116          switch (alu_instr->op) {
117          case nir_op_pack_64_2x32:
118             dest = lower_pack_64_from_32(&b, src);
119             break;
120          case nir_op_unpack_64_2x32:
121             dest = lower_unpack_64_to_32(&b, src);
122             break;
123          case nir_op_pack_64_4x16:
124             dest = lower_pack_64_from_16(&b, src);
125             break;
126          case nir_op_unpack_64_4x16:
127             dest = lower_unpack_64_to_16(&b, src);
128             break;
129          case nir_op_pack_32_2x16:
130             dest = lower_pack_32_from_16(&b, src);
131             break;
132          case nir_op_unpack_32_2x16:
133             dest = lower_unpack_32_to_16(&b, src);
134             break;
135          default:
136             unreachable("Impossible opcode");
137          }
138 
139          nir_ssa_def_rewrite_uses(&alu_instr->dest.dest.ssa, nir_src_for_ssa(dest));
140          nir_instr_remove(&alu_instr->instr);
141          progress = true;
142       }
143    }
144 
145    if (progress) {
146       nir_metadata_preserve(impl, nir_metadata_block_index |
147                                   nir_metadata_dominance);
148    } else {
149       nir_metadata_preserve(impl, nir_metadata_all);
150    }
151 
152    return progress;
153 }
154 
155 bool
nir_lower_pack(nir_shader * shader)156 nir_lower_pack(nir_shader *shader)
157 {
158    bool progress = false;
159 
160    nir_foreach_function(function, shader) {
161       if (function->impl)
162          progress |= lower_pack_impl(function->impl);
163    }
164 
165    return false;
166 }
167