[Mesa-dev] [PATCH] tgsi: handle indirect sampler arrays. (v2)

[Roland Scheidegger]

Should there be some clamping somewhere to prevent crashes due to
out-of-bound unit index?
In any case,
Reviewed-by: Roland Scheidegger <sroland at vmware.com>

Am 22.06.2015 um 05:18 schrieb Dave Airlie:
> This is required for ARB_gpu_shader5 support in softpipe.
> 
> v2: add support to txd/txf/txq paths.
> 
> Signed-off-by: Dave Airlie <airlied at redhat.com>
> ---
> 
>  src/gallium/auxiliary/tgsi/tgsi_exec.c | 42 ++++++++++++++++++++++++++++++----
>  1 file changed, 38 insertions(+), 4 deletions(-)
> 
> diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c
> index fde99b9..44000ff 100644
> --- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
> +++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
> @@ -1988,6 +1988,35 @@ fetch_assign_deriv_channel(struct tgsi_exec_machine *mach,
>     derivs[1][3] = d.f[3];
>  }
>  
> +static uint
> +fetch_sampler_unit(struct tgsi_exec_machine *mach,
> +                   const struct tgsi_full_instruction *inst,
> +                   uint sampler)
> +{
> +   uint unit;
> +
> +   if (inst->Src[sampler].Register.Indirect) {
> +      const struct tgsi_full_src_register *reg = &inst->Src[sampler];
> +      union tgsi_exec_channel indir_index, index2;
> +
> +      index2.i[0] =
> +      index2.i[1] =
> +      index2.i[2] =
> +      index2.i[3] = reg->Indirect.Index;
> +
> +      fetch_src_file_channel(mach,
> +                             0,
> +                             reg->Indirect.File,
> +                             reg->Indirect.Swizzle,
> +                             &index2,
> +                             &ZeroVec,
> +                             &indir_index);
> +      unit = inst->Src[sampler].Register.Index + indir_index.i[0];
> +   } else {
> +      unit = inst->Src[sampler].Register.Index;
> +   }
> +   return unit;
> +}
>  
>  /*
>   * execute a texture instruction.
> @@ -2001,14 +2030,15 @@ exec_tex(struct tgsi_exec_machine *mach,
>           const struct tgsi_full_instruction *inst,
>           uint modifier, uint sampler)
>  {
> -   const uint unit = inst->Src[sampler].Register.Index;
>     const union tgsi_exec_channel *args[5], *proj = NULL;
>     union tgsi_exec_channel r[5];
>     enum tgsi_sampler_control control =  tgsi_sampler_lod_none;
>     uint chan;
> +   uint unit;
>     int8_t offsets[3];
>     int dim, shadow_ref, i;
>  
> +   unit = fetch_sampler_unit(mach, inst, sampler);
>     /* always fetch all 3 offsets, overkill but keeps code simple */
>     fetch_texel_offsets(mach, inst, offsets);
>  
> @@ -2107,12 +2137,13 @@ static void
>  exec_txd(struct tgsi_exec_machine *mach,
>           const struct tgsi_full_instruction *inst)
>  {
> -   const uint unit = inst->Src[3].Register.Index;
>     union tgsi_exec_channel r[4];
>     float derivs[3][2][TGSI_QUAD_SIZE];
>     uint chan;
> +   uint unit;
>     int8_t offsets[3];
>  
> +   unit = fetch_sampler_unit(mach, inst, 3);
>     /* always fetch all 3 offsets, overkill but keeps code simple */
>     fetch_texel_offsets(mach, inst, offsets);
>  
> @@ -2214,14 +2245,15 @@ static void
>  exec_txf(struct tgsi_exec_machine *mach,
>           const struct tgsi_full_instruction *inst)
>  {
> -   const uint unit = inst->Src[1].Register.Index;
>     union tgsi_exec_channel r[4];
>     uint chan;
> +   uint unit;
>     float rgba[TGSI_NUM_CHANNELS][TGSI_QUAD_SIZE];
>     int j;
>     int8_t offsets[3];
>     unsigned target;
>  
> +   unit = fetch_sampler_unit(mach, inst, 1);
>     /* always fetch all 3 offsets, overkill but keeps code simple */
>     fetch_texel_offsets(mach, inst, offsets);
>  
> @@ -2296,12 +2328,14 @@ static void
>  exec_txq(struct tgsi_exec_machine *mach,
>           const struct tgsi_full_instruction *inst)
>  {
> -   const uint unit = inst->Src[1].Register.Index;
>     int result[4];
>     union tgsi_exec_channel r[4], src;
>     uint chan;
> +   uint unit;
>     int i,j;
>  
> +   unit = fetch_sampler_unit(mach, inst, 1);
> +
>     fetch_source(mach, &src, &inst->Src[0], TGSI_CHAN_X, TGSI_EXEC_DATA_INT);
>  
>     /* XXX: This interface can't return per-pixel values */
>