[Mesa-dev] [PATCH 10/12] nir: Add lowering support for unpacking opcodes.

[Iago Toral]

On Mon, 2016-01-25 at 15:18 -0800, Matt Turner wrote:
> ---
>  src/glsl/nir/nir.h                |  4 ++++
>  src/glsl/nir/nir_opt_algebraic.py | 28 ++++++++++++++++++++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
> index bbd5b1a..3b90b51 100644
> --- a/src/glsl/nir/nir.h
> +++ b/src/glsl/nir/nir.h
> @@ -1474,6 +1474,10 @@ typedef struct nir_shader_compiler_options {
>     bool lower_pack_unorm_4x8;
>     bool lower_pack_snorm_4x8;
>     bool lower_unpack_half_2x16;
> +   bool lower_unpack_unorm_2x16;
> +   bool lower_unpack_snorm_2x16;
> +   bool lower_unpack_unorm_4x8;
> +   bool lower_unpack_snorm_4x8;
>  
>     bool lower_extract_byte;
>     bool lower_extract_word;
> diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
> index 56b0f5e..a0d6c07 100644
> --- a/src/glsl/nir/nir_opt_algebraic.py
> +++ b/src/glsl/nir/nir_opt_algebraic.py
> @@ -278,6 +278,34 @@ optimizations = [
>       ('pack_uvec4_to_uint',
>          ('f2i', ('fround_even', ('fmul', ('fmin', 1.0, ('fmax', -1.0, 'v')), 127.0)))),
>       'options->lower_pack_snorm_4x8'),
> +
> +    (('unpack_unorm_2x16', 'v'),
> +     ('fdiv', ('u2f', ('vec4', ('extract_uword', 'v', 0),
> +                               ('extract_uword', 'v', 1), 0, 0)),
> +              65535.0),
> +     'options->lower_unpack_unorm_2x16'),

This should return a vec2 not a vec4, right?

> +    (('unpack_unorm_4x8', 'v'),
> +     ('fdiv', ('u2f', ('vec4', ('extract_ubyte', 'v', 0),
> +                               ('extract_ubyte', 'v', 1),
> +                               ('extract_ubyte', 'v', 2),
> +                               ('extract_ubyte', 'v', 3))),
> +              255.0),
> +     'options->lower_unpack_unorm_4x8'),
> +
> +    (('unpack_snorm_2x16', 'v'),
> +     ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_iword', 'v', 0),
> +                                                            ('extract_iword', 'v', 1), 0, 0)),
> +                                           32767.0))),
> +     'options->lower_unpack_snorm_2x16'),

Same comment here.

> +    (('unpack_snorm_4x8', 'v'),
> +     ('fmin', 1.0, ('fmax', -1.0, ('fdiv', ('i2f', ('vec4', ('extract_ibyte', 'v', 0),
> +                                                            ('extract_ibyte', 'v', 1),
> +                                                            ('extract_ibyte', 'v', 2),
> +                                                            ('extract_ibyte', 'v', 3))),
> +                                           127.0))),
> +     'options->lower_unpack_snorm_4x8'),
>  ]
>  
>  # Add optimizations to handle the case where the result of a ternary is