[Mesa-dev] [PATCH 02/14] intel/compiler: new shuffle_for_32bit_write and shuffle_from_32bit_read

[Jason Ekstrand]

On Sat, Jun 9, 2018 at 4:13 AM, Jose Maria Casanova Crespo <
jmcasanova at igalia.com> wrote:

> These new shuffle functions deal with the shuffle/unshuffle operations
> needed for read/write operations using 32-bit components when the
> read/written components have a different bit-size (8, 16, 64-bits).
> Shuffle from 32-bit to 32-bit becomes a simple MOV.
>
> As the new function shuffle_src_to_dst takes of doing a shuffle or an
> unshuffle based on the different type_sz of source an destination this
> generic functions work with any source/destination assuming that writes
> use a 32-bit destination or reads use a 32-bit source.
>

I'm having a lot of trouble understanding this paragraph.  Would you mind
rephrasing it?


> To enable this new functions it is needed than there is no
> source/destination overlap in the case of shuffle_from_32bit_read.
> That never happens on shuffle_for_32bit_write as it allocates a new
> destination register as it was at shuffle_64bit_data_for_32bit_write.
> ---
>  src/intel/compiler/brw_fs.h       | 11 +++++++++
>  src/intel/compiler/brw_fs_nir.cpp | 38 +++++++++++++++++++++++++++++++
>  2 files changed, 49 insertions(+)
>
> diff --git a/src/intel/compiler/brw_fs.h b/src/intel/compiler/brw_fs.h
> index faf51568637..779170ecc95 100644
> --- a/src/intel/compiler/brw_fs.h
> +++ b/src/intel/compiler/brw_fs.h
> @@ -519,6 +519,17 @@ void shuffle_16bit_data_for_32bit_write(const
> brw::fs_builder &bld,
>                                          const fs_reg &src,
>                                          uint32_t components);
>
> +void shuffle_from_32bit_read(const brw::fs_builder &bld,
> +                             const fs_reg &dst,
> +                             const fs_reg &src,
> +                             uint32_t first_component,
> +                             uint32_t components);
> +
> +fs_reg shuffle_for_32bit_write(const brw::fs_builder &bld,
> +                               const fs_reg &src,
> +                               uint32_t first_component,
> +                               uint32_t components);
> +
>  fs_reg setup_imm_df(const brw::fs_builder &bld,
>                      double v);
>
> diff --git a/src/intel/compiler/brw_fs_nir.cpp
> b/src/intel/compiler/brw_fs_nir.cpp
> index 1a9d3c41d1d..1f684149fd5 100644
> --- a/src/intel/compiler/brw_fs_nir.cpp
> +++ b/src/intel/compiler/brw_fs_nir.cpp
> @@ -5454,6 +5454,44 @@ shuffle_src_to_dst(const fs_builder &bld,
>     }
>  }
>
> +void
> +shuffle_from_32bit_read(const fs_builder &bld,
> +                        const fs_reg &dst,
> +                        const fs_reg &src,
> +                        uint32_t first_component,
> +                        uint32_t components)
> +{
> +   assert(type_sz(src.type) == 4);
> +
>

/* This function takes components in units of the destination type while
shuffle_src_to_dst takes components in units of the smallest type */


> +   if (type_sz(dst.type) > 4) {
> +      assert(type_sz(dst.type) == 8);
> +      first_component *= 2;
> +      components *= 2;
> +   }
> +
> +   shuffle_src_to_dst(bld, dst, src, first_component, components);
> +}
> +
> +fs_reg
> +shuffle_for_32bit_write(const fs_builder &bld,
> +                        const fs_reg &src,
> +                        uint32_t first_component,
> +                        uint32_t components)
> +{
> +   fs_reg dst = bld.vgrf(BRW_REGISTER_TYPE_D,
> +                         DIV_ROUND_UP (components * type_sz(src.type),
> 4));
> +
>

/* This function takes components in units of the source type while
shuffle_src_to_dst takes components in units of the smallest type */

With those added and the commit message re-worded a bit,

Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>


> +   if (type_sz(src.type) > 4) {
> +      assert(type_sz(src.type) == 8);
> +      first_component *= 2;
> +      components *= 2;
> +   }
> +
> +   shuffle_src_to_dst(bld, dst, src, first_component, components);
> +
> +   return dst;
> +}
> +
>  fs_reg
>  setup_imm_df(const fs_builder &bld, double v)
>  {
> --
> 2.17.1
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20180613/c594515b/attachment-0001.html>