[Mesa-dev] [PATCH 18/20] i965/fs: Translate image load, store and atomic NIR intrinsics.

Jason Ekstrand jason at jlekstrand.net
Wed Jul 22 14:37:18 PDT 2015


On Tue, Jul 21, 2015 at 9:38 AM, Francisco Jerez <currojerez at riseup.net> wrote:
> ---
>  src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 149 +++++++++++++++++++++++++++++++
>  1 file changed, 149 insertions(+)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
> index 31024b7..76297b7 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
> @@ -24,6 +24,7 @@
>  #include "glsl/ir.h"
>  #include "glsl/ir_optimization.h"
>  #include "glsl/nir/glsl_to_nir.h"
> +#include "main/shaderimage.h"
>  #include "program/prog_to_nir.h"
>  #include "brw_fs.h"
>  #include "brw_fs_surface_builder.h"
> @@ -1245,6 +1246,97 @@ fs_visitor::emit_percomp(const fs_builder &bld, const fs_inst &inst,
>     }
>  }
>
> +/**
> + * Get the matching channel register datatype for an image intrinsic of the
> + * specified GLSL image type.
> + */
> +static brw_reg_type
> +get_image_base_type(const glsl_type *type)
> +{
> +   switch ((glsl_base_type)type->sampler_type) {
> +   case GLSL_TYPE_UINT:
> +      return BRW_REGISTER_TYPE_UD;
> +   case GLSL_TYPE_INT:
> +      return BRW_REGISTER_TYPE_D;
> +   case GLSL_TYPE_FLOAT:
> +      return BRW_REGISTER_TYPE_F;
> +   default:
> +      unreachable("Not reached.");
> +   }
> +}
> +
> +/**
> + * Get the appropriate atomic op for an image atomic intrinsic.
> + */
> +static unsigned
> +get_image_atomic_op(nir_intrinsic_op op, const glsl_type *type)
> +{
> +   switch (op) {
> +   case nir_intrinsic_image_atomic_add:
> +      return BRW_AOP_ADD;
> +   case nir_intrinsic_image_atomic_min:
> +      return (get_image_base_type(type) == BRW_REGISTER_TYPE_D ?
> +              BRW_AOP_IMIN : BRW_AOP_UMIN);
> +   case nir_intrinsic_image_atomic_max:
> +      return (get_image_base_type(type) == BRW_REGISTER_TYPE_D ?
> +              BRW_AOP_IMAX : BRW_AOP_UMAX);
> +   case nir_intrinsic_image_atomic_and:
> +      return BRW_AOP_AND;
> +   case nir_intrinsic_image_atomic_or:
> +      return BRW_AOP_OR;
> +   case nir_intrinsic_image_atomic_xor:
> +      return BRW_AOP_XOR;
> +   case nir_intrinsic_image_atomic_exchange:
> +      return BRW_AOP_MOV;
> +   case nir_intrinsic_image_atomic_comp_swap:
> +      return BRW_AOP_CMPWR;
> +   default:
> +      unreachable("Not reachable.");
> +   }
> +}
> +
> +/**
> + * Return true if the image is a 1D array and the implementation
> + * requires the array index to be passed in as the Z component of the
> + * coordinate vector.
> + */
> +static bool
> +needs_zero_y_image_coordinate(const fs_builder &bld,
> +                              const nir_variable *image)
> +{
> +   const glsl_type *type = image->type->without_array();
> +   const mesa_format format =
> +      _mesa_get_shader_image_format(image->data.image.format);
> +   /* HSW in vec4 mode and our software coordinate handling for untyped
> +    * reads want the array index to be at the Z component.
> +    */
> +   const bool array_index_at_z = (!image->data.image.write_only &&
> +                                  !image_format_info::has_matching_typed_format(
> +                                     bld.shader->devinfo, format));
> +
> +   return (type->sampler_dimensionality == GLSL_SAMPLER_DIM_1D &&
> +           type->sampler_array && array_index_at_z);
> +}
> +
> +/**
> + * Transform image coordinates into the form expected by the
> + * implementation.
> + */
> +static fs_reg
> +fix_image_address(const fs_builder &bld,
> +                  const nir_variable *image, const fs_reg &addr)

Is there a good reason why this is happening here and not inside of
emit_image_load/store?  It seems to break encaptulation substantially
if the code that calls emit_image_load/store has to think about this
stuff and adjust the address type based on whether a typed or untyped
message will eventually be used.

> +{
> +   if (needs_zero_y_image_coordinate(bld, image)) {
> +      assert(image->type->without_array()->coordinate_components() == 2);
> +      const fs_reg srcs[] = { addr, fs_reg(0), offset(addr, bld, 1) };
> +      const fs_reg tmp = bld.vgrf(addr.type, ARRAY_SIZE(srcs));
> +      bld.LOAD_PAYLOAD(tmp, srcs, ARRAY_SIZE(srcs), 0);
> +      return tmp;
> +   } else {
> +      return addr;
> +   }
> +}
> +
>  void
>  fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr)
>  {
> @@ -1319,6 +1411,63 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
>        break;
>     }
>
> +   case nir_intrinsic_image_load:
> +   case nir_intrinsic_image_store:
> +   case nir_intrinsic_image_atomic_add:
> +   case nir_intrinsic_image_atomic_min:
> +   case nir_intrinsic_image_atomic_max:
> +   case nir_intrinsic_image_atomic_and:
> +   case nir_intrinsic_image_atomic_or:
> +   case nir_intrinsic_image_atomic_xor:
> +   case nir_intrinsic_image_atomic_exchange:
> +   case nir_intrinsic_image_atomic_comp_swap: {
> +      using namespace image_access;
> +
> +      /* Get the referenced image variable and type. */
> +      const nir_variable *var = instr->variables[0]->var;
> +      const glsl_type *type = var->type->without_array();
> +      const brw_reg_type base_type = get_image_base_type(type);
> +
> +      /* Get some metadata from the image intrinsic. */
> +      const nir_intrinsic_info *info = &nir_intrinsic_infos[instr->intrinsic];
> +      const unsigned dims = (type->coordinate_components() +
> +                             (needs_zero_y_image_coordinate(bld, var) ? 1 : 0));
> +      const mesa_format format =
> +         (var->data.image.write_only ? MESA_FORMAT_NONE :
> +          _mesa_get_shader_image_format(var->data.image.format));
> +
> +      /* Get the arguments of the image intrinsic. */
> +      const fs_reg image = get_nir_image_deref(instr->variables[0]);
> +      const fs_reg addr = fix_image_address(bld, var,
> +                                            retype(get_nir_src(instr->src[0]),
> +                                                   BRW_REGISTER_TYPE_UD));
> +      const fs_reg src0 = (info->num_srcs >= 3 ?
> +                           retype(get_nir_src(instr->src[2]), base_type) :
> +                           fs_reg());
> +      const fs_reg src1 = (info->num_srcs >= 4 ?
> +                           retype(get_nir_src(instr->src[3]), base_type) :
> +                           fs_reg());
> +      fs_reg tmp;
> +
> +      /* Emit an image load, store or atomic op. */
> +      if (instr->intrinsic == nir_intrinsic_image_load)
> +         tmp = emit_image_load(bld, image, addr, format, dims);
> +
> +      else if (instr->intrinsic == nir_intrinsic_image_store)
> +         emit_image_store(bld, image, addr, src0, format, dims);
> +
> +      else
> +         tmp = emit_image_atomic(bld, image, addr, src0, src1,
> +                                 dims, info->dest_components,
> +                                 get_image_atomic_op(instr->intrinsic, type));
> +
> +      /* Assign the result. */
> +      for (unsigned c = 0; c < info->dest_components; ++c)
> +         bld.MOV(offset(retype(dest, base_type), bld, c),
> +                 offset(tmp, bld, c));
> +      break;
> +   }
> +
>     case nir_intrinsic_load_front_face:
>        bld.MOV(retype(dest, BRW_REGISTER_TYPE_D),
>                *emit_frontfacing_interpolation());
> --
> 2.4.3
>
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