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25 #include "compiler/nir/nir_builder.h"
28 * This pass lowers load_barycentric_at_sample to load_sample_pos_from_id
29 * plus load_barycentric_at_offset.
31 * It also lowers load_sample_pos to load_sample_pos_from_id, mostly because
32 * that needs to happen at the same early stage (before wpos_ytransform)
36 load_sample_pos(nir_builder
*b
, nir_ssa_def
*samp_id
)
38 nir_intrinsic_instr
*load_sp
=
39 nir_intrinsic_instr_create(b
->shader
,
40 nir_intrinsic_load_sample_pos_from_id
);
41 load_sp
->num_components
= 2;
42 load_sp
->src
[0] = nir_src_for_ssa(samp_id
);
43 nir_ssa_dest_init(&load_sp
->instr
, &load_sp
->dest
, 2, 32, NULL
);
44 nir_builder_instr_insert(b
, &load_sp
->instr
);
46 return &load_sp
->dest
.ssa
;
50 lower_load_barycentric_at_sample(nir_builder
*b
, nir_intrinsic_instr
*intr
)
52 nir_ssa_def
*pos
= load_sample_pos(b
, intr
->src
[0].ssa
);
54 nir_intrinsic_instr
*load_bary_at_offset
=
55 nir_intrinsic_instr_create(b
->shader
,
56 nir_intrinsic_load_barycentric_at_offset
);
57 load_bary_at_offset
->num_components
= 2;
58 load_bary_at_offset
->src
[0] = nir_src_for_ssa(pos
);
59 nir_ssa_dest_init(&load_bary_at_offset
->instr
,
60 &load_bary_at_offset
->dest
, 2, 32, NULL
);
61 nir_builder_instr_insert(b
, &load_bary_at_offset
->instr
);
63 return &load_bary_at_offset
->dest
.ssa
;
67 lower_load_sample_pos(nir_builder
*b
, nir_intrinsic_instr
*intr
)
69 nir_ssa_def
*pos
= load_sample_pos(b
, nir_load_sample_id(b
));
71 /* Note that gl_SamplePosition is offset by +vec2(0.5, 0.5) vs the
72 * offset passed to interpolateAtOffset(). See
73 * dEQP-GLES31.functional.shaders.multisample_interpolation.interpolate_at_offset.at_sample_position.default_framebuffer
76 nir_ssa_def
*half
= nir_imm_float(b
, 0.5);
77 return nir_fadd(b
, pos
, nir_vec2(b
, half
, half
));
81 ir3_nir_lower_load_barycentric_at_sample_instr(nir_builder
*b
,
82 nir_instr
*instr
, void *data
)
84 nir_intrinsic_instr
*intr
= nir_instr_as_intrinsic(instr
);
86 if (intr
->intrinsic
== nir_intrinsic_load_sample_pos
)
87 return lower_load_sample_pos(b
, intr
);
89 return lower_load_barycentric_at_sample(b
, intr
);
93 ir3_nir_lower_load_barycentric_at_sample_filter(const nir_instr
*instr
,
96 if (instr
->type
!= nir_instr_type_intrinsic
)
98 nir_intrinsic_instr
*intr
= nir_instr_as_intrinsic(instr
);
99 return (intr
->intrinsic
== nir_intrinsic_load_barycentric_at_sample
||
100 intr
->intrinsic
== nir_intrinsic_load_sample_pos
);
104 ir3_nir_lower_load_barycentric_at_sample(nir_shader
*shader
)
106 debug_assert(shader
->info
.stage
== MESA_SHADER_FRAGMENT
);
108 return nir_shader_lower_instructions(shader
,
109 ir3_nir_lower_load_barycentric_at_sample_filter
,
110 ir3_nir_lower_load_barycentric_at_sample_instr
,