2 * Copyright © 2016 Intel Corporation
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:
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
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
24 #include "compiler/nir/nir_builder.h"
29 * Prior to Haswell, the hardware can't natively support GL_FIXED or
30 * 2_10_10_10_REV vertex formats. This pass inserts extra shader code
31 * to produce the correct values.
34 struct attr_wa_state
{
37 bool use_legacy_snorm_formula
;
38 const uint8_t *wa_flags
;
42 apply_attr_wa_block(nir_block
*block
, struct attr_wa_state
*state
)
44 nir_builder
*b
= &state
->builder
;
46 nir_foreach_instr_safe(instr
, block
) {
47 if (instr
->type
!= nir_instr_type_intrinsic
)
50 nir_intrinsic_instr
*intrin
= nir_instr_as_intrinsic(instr
);
51 if (intrin
->intrinsic
!= nir_intrinsic_load_input
)
54 uint8_t wa_flags
= state
->wa_flags
[intrin
->const_index
[0]];
58 b
->cursor
= nir_after_instr(instr
);
60 nir_ssa_def
*val
= &intrin
->dest
.ssa
;
62 /* Do GL_FIXED rescaling for GLES2.0. Our GL_FIXED attributes
63 * come in as floating point conversions of the integer values.
65 if (wa_flags
& BRW_ATTRIB_WA_COMPONENT_MASK
) {
67 nir_fmul(b
, val
, nir_imm_float(b
, 1.0f
/ 65536.0f
));
68 nir_ssa_def
*comps
[4];
69 for (int i
= 0; i
< val
->num_components
; i
++) {
70 bool rescale
= i
< (wa_flags
& BRW_ATTRIB_WA_COMPONENT_MASK
);
71 comps
[i
] = nir_channel(b
, rescale
? scaled
: val
, i
);
73 val
= nir_vec(b
, comps
, val
->num_components
);
76 /* Do sign recovery for 2101010 formats if required. */
77 if (wa_flags
& BRW_ATTRIB_WA_SIGN
) {
78 /* sign recovery shift: <22, 22, 22, 30> */
79 nir_ssa_def
*shift
= nir_imm_ivec4(b
, 22, 22, 22, 30);
80 val
= nir_ishr(b
, nir_ishl(b
, val
, shift
), shift
);
83 /* Apply BGRA swizzle if required. */
84 if (wa_flags
& BRW_ATTRIB_WA_BGRA
) {
85 val
= nir_swizzle(b
, val
, (unsigned[4]){2,1,0,3}, 4, true);
88 if (wa_flags
& BRW_ATTRIB_WA_NORMALIZE
) {
89 /* ES 3.0 has different rules for converting signed normalized
90 * fixed-point numbers than desktop GL.
92 if ((wa_flags
& BRW_ATTRIB_WA_SIGN
) &&
93 !state
->use_legacy_snorm_formula
) {
94 /* According to equation 2.2 of the ES 3.0 specification,
95 * signed normalization conversion is done by:
99 nir_ssa_def
*es3_normalize_factor
=
100 nir_imm_vec4(b
, 1.0f
/ ((1 << 9) - 1), 1.0f
/ ((1 << 9) - 1),
101 1.0f
/ ((1 << 9) - 1), 1.0f
/ ((1 << 1) - 1));
103 nir_fmul(b
, nir_i2f(b
, val
), es3_normalize_factor
),
104 nir_imm_float(b
, -1.0f
));
106 /* The following equations are from the OpenGL 3.2 specification:
108 * 2.1 unsigned normalization
111 * 2.2 signed normalization
114 * Both of these share a common divisor, which we handle by
115 * multiplying by 1 / (2^b - 1) for b = <10, 10, 10, 2>.
117 nir_ssa_def
*normalize_factor
=
118 nir_imm_vec4(b
, 1.0f
/ ((1 << 10) - 1), 1.0f
/ ((1 << 10) - 1),
119 1.0f
/ ((1 << 10) - 1), 1.0f
/ ((1 << 2) - 1));
121 if (wa_flags
& BRW_ATTRIB_WA_SIGN
) {
122 /* For signed normalization, the numerator is 2c+1. */
123 nir_ssa_def
*two
= nir_imm_float(b
, 2.0f
);
124 nir_ssa_def
*one
= nir_imm_float(b
, 1.0f
);
125 val
= nir_fadd(b
, nir_fmul(b
, nir_i2f(b
, val
), two
), one
);
127 /* For unsigned normalization, the numerator is just c. */
128 val
= nir_u2f(b
, val
);
130 val
= nir_fmul(b
, val
, normalize_factor
);
134 if (wa_flags
& BRW_ATTRIB_WA_SCALE
) {
135 val
= (wa_flags
& BRW_ATTRIB_WA_SIGN
) ? nir_i2f(b
, val
)
139 nir_ssa_def_rewrite_uses_after(&intrin
->dest
.ssa
, nir_src_for_ssa(val
),
141 state
->impl_progress
= true;
148 brw_nir_apply_attribute_workarounds(nir_shader
*shader
,
149 bool use_legacy_snorm_formula
,
150 const uint8_t *attrib_wa_flags
)
152 bool progress
= false;
153 struct attr_wa_state state
= {
154 .use_legacy_snorm_formula
= use_legacy_snorm_formula
,
155 .wa_flags
= attrib_wa_flags
,
158 nir_foreach_function(func
, shader
) {
162 nir_builder_init(&state
.builder
, func
->impl
);
163 state
.impl_progress
= false;
165 nir_foreach_block(block
, func
->impl
) {
166 apply_attr_wa_block(block
, &state
);
169 if (state
.impl_progress
) {
170 nir_metadata_preserve(func
->impl
, nir_metadata_block_index
|
171 nir_metadata_dominance
);