[Mesa-dev] [PATCH 21/28] i965/blorp: Add initial support for NIR-based blit shaders

Jason Ekstrand jason at jlekstrand.net
Fri May 13 07:18:04 UTC 2016


On Thu, May 12, 2016 at 10:04 PM, Pohjolainen, Topi <
topi.pohjolainen at intel.com> wrote:

> On Tue, May 10, 2016 at 04:16:41PM -0700, Jason Ekstrand wrote:
> > Many of the more complex cases still fall back to the old shader builder.
> > ---
> >  src/mesa/drivers/dri/i965/brw_blorp_blit.cpp | 425
> +++++++++++++++++++++++++--
> >  1 file changed, 401 insertions(+), 24 deletions(-)
> >
> > diff --git a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
> b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
> > index ea64b11..f94dd6f 100644
> > --- a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
> > +++ b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
> > @@ -25,6 +25,8 @@
> >  #include "main/teximage.h"
> >  #include "main/fbobject.h"
> >
> > +#include "compiler/nir/nir_builder.h"
> > +
> >  #include "intel_fbo.h"
> >
> >  #include "brw_blorp.h"
> > @@ -332,6 +334,226 @@ enum sampler_message_arg
> >     SAMPLER_MESSAGE_ARG_ZERO_INT,
> >  };
> >
> > +struct brw_blorp_blit_vars {
> > +   /* Uniforms values from brw_blorp_wm_push_constants */
> > +   nir_variable *u_dst_x0;
> > +   nir_variable *u_dst_x1;
> > +   nir_variable *u_dst_y0;
> > +   nir_variable *u_dst_y1;
> > +   nir_variable *u_rect_grid_x1;
> > +   nir_variable *u_rect_grid_y1;
> > +   struct {
> > +      nir_variable *multiplier;
> > +      nir_variable *offset;
> > +   } u_x_transform, u_y_transform;
> > +   nir_variable *u_src_z;
> > +
> > +   /* gl_FragCoord */
> > +   nir_variable *frag_coord;
> > +
> > +   /* gl_FragColor */
> > +   nir_variable *color_out;
> > +};
> > +
> > +static void
> > +brw_blorp_blit_vars_init(nir_builder *b, struct brw_blorp_blit_vars *v,
> > +                         const struct brw_blorp_blit_prog_key *key)
> > +{
> > +#define LOAD_UNIFORM(name, type)\
> > +   v->u_##name = nir_variable_create(b->shader, nir_var_uniform, type,
> #name); \
> > +   v->u_##name->data.location = \
> > +      offsetof(struct brw_blorp_wm_push_constants, name);
> > +
> > +   LOAD_UNIFORM(dst_x0, glsl_uint_type())
> > +   LOAD_UNIFORM(dst_x1, glsl_uint_type())
> > +   LOAD_UNIFORM(dst_y0, glsl_uint_type())
> > +   LOAD_UNIFORM(dst_y1, glsl_uint_type())
> > +   LOAD_UNIFORM(rect_grid_x1, glsl_float_type())
> > +   LOAD_UNIFORM(rect_grid_y1, glsl_float_type())
> > +   LOAD_UNIFORM(x_transform.multiplier, glsl_float_type())
> > +   LOAD_UNIFORM(x_transform.offset, glsl_float_type())
> > +   LOAD_UNIFORM(y_transform.multiplier, glsl_float_type())
> > +   LOAD_UNIFORM(y_transform.offset, glsl_float_type())
> > +   LOAD_UNIFORM(src_z, glsl_uint_type())
> > +
> > +#undef DECL_UNIFORM
> > +
> > +   v->frag_coord = nir_variable_create(b->shader, nir_var_shader_in,
> > +                                       glsl_vec4_type(),
> "gl_FragCoord");
> > +   v->frag_coord->data.location = VARYING_SLOT_POS;
> > +   v->frag_coord->data.origin_upper_left = true;
> > +
> > +   v->color_out = nir_variable_create(b->shader, nir_var_shader_out,
> > +                                      glsl_vec4_type(), "gl_FragColor");
> > +   v->color_out->data.location = FRAG_RESULT_COLOR;
> > +}
> > +
> > +nir_ssa_def *
> > +blorp_blit_get_frag_coords(nir_builder *b,
> > +                           const struct brw_blorp_blit_prog_key *key,
> > +                           struct brw_blorp_blit_vars *v)
> > +{
> > +   nir_ssa_def *coord = nir_f2i(b, nir_load_var(b, v->frag_coord));
> > +
> > +   if (key->persample_msaa_dispatch) {
> > +      return nir_vec3(b, nir_channel(b, coord, 0), nir_channel(b,
> coord, 1),
> > +         nir_load_system_value(b, nir_intrinsic_load_sample_id, 0));
> > +   } else {
> > +      return nir_vec2(b, nir_channel(b, coord, 0), nir_channel(b,
> coord, 1));
> > +   }
> > +}
> > +
>
> We could keep the original comment here:
>
> /**
>  * Emit code to translate from destination (X, Y) coordinates to source
> (X, Y)
>  * coordinates.
>  */
>

Done.


> Otherwise this looks really nice, readability alone is improved a lot.
> There
> is no question that the original was written as clearly as it can be but
> now
> we are able to leave some many details into the generic compiler backend.
>
> > +nir_ssa_def *
> > +blorp_blit_apply_transform(nir_builder *b, nir_ssa_def *src_pos,
> > +                           struct brw_blorp_blit_vars *v)
> > +{
> > +   nir_ssa_def *offset = nir_vec2(b, nir_load_var(b,
> v->u_x_transform.offset),
> > +                                     nir_load_var(b,
> v->u_y_transform.offset));
> > +   nir_ssa_def *mul = nir_vec2(b, nir_load_var(b,
> v->u_x_transform.multiplier),
> > +                                  nir_load_var(b,
> v->u_y_transform.multiplier));
> > +
> > +   nir_ssa_def *pos = nir_ffma(b, src_pos, mul, offset);
> > +
> > +   if (src_pos->num_components == 3) {
> > +      /* Leave the sample id alone */
> > +      pos = nir_vec3(b, nir_channel(b, pos, 0), nir_channel(b, pos, 1),
> > +                        nir_channel(b, src_pos, 2));
> > +   }
> > +
> > +   return pos;
> > +}
> > +
> > +static nir_tex_instr *
> > +blorp_create_nir_tex_instr(nir_shader *shader, nir_texop op,
> > +                           nir_ssa_def *pos, unsigned num_srcs,
> > +                           enum brw_reg_type dst_type)
> > +{
> > +   nir_tex_instr *tex = nir_tex_instr_create(shader, num_srcs);
> > +
> > +   tex->op = op;
> > +
> > +   switch (dst_type) {
> > +   case BRW_REGISTER_TYPE_F:
> > +      tex->dest_type = nir_type_float;
> > +      break;
> > +   case BRW_REGISTER_TYPE_D:
> > +      tex->dest_type = nir_type_int;
> > +      break;
> > +   case BRW_REGISTER_TYPE_UD:
> > +      tex->dest_type = nir_type_uint;
> > +      break;
> > +   default:
> > +      unreachable("Invalid texture return type");
> > +   }
> > +
> > +   tex->is_array = false;
> > +   tex->is_shadow = false;
> > +
> > +   /* Blorp only has one texture and it's bound at unit 0 */
> > +   tex->texture = NULL;
> > +   tex->sampler = NULL;
> > +   tex->texture_index = 0;
> > +   tex->sampler_index = 0;
> > +
> > +   nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
> > +
> > +   return tex;
> > +}
> > +
> > +static nir_ssa_def *
> > +blorp_nir_tex(nir_builder *b, nir_ssa_def *pos, enum brw_reg_type
> dst_type)
> > +{
> > +   nir_tex_instr *tex =
> > +      blorp_create_nir_tex_instr(b->shader, nir_texop_tex, pos, 2,
> dst_type);
> > +
> > +   assert(pos->num_components == 2);
> > +   tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
> > +   tex->coord_components = 2;
> > +   tex->src[0].src_type = nir_tex_src_coord;
> > +   tex->src[0].src = nir_src_for_ssa(pos);
> > +   tex->src[1].src_type = nir_tex_src_lod;
> > +   tex->src[1].src = nir_src_for_ssa(nir_imm_int(b, 0));
> > +
> > +   nir_builder_instr_insert(b, &tex->instr);
> > +
> > +   return &tex->dest.ssa;
> > +}
> > +
> > +static nir_ssa_def *
> > +blorp_nir_txf(nir_builder *b, struct brw_blorp_blit_vars *v,
> > +              nir_ssa_def *pos, enum brw_reg_type dst_type)
> > +{
> > +   nir_tex_instr *tex =
> > +      blorp_create_nir_tex_instr(b->shader, nir_texop_txf, pos, 2,
> dst_type);
> > +
> > +   /* In order to properly handle 3-D textures, we pull the Z component
> from
> > +    * a uniform.  TODO: This is a bit magic; we should probably make
> this
> > +    * more explicit in the future.
> > +    */
> > +   assert(pos->num_components == 2);
> > +   pos = nir_vec3(b, nir_channel(b, pos, 0), nir_channel(b, pos, 1),
> > +                     nir_load_var(b, v->u_src_z));
> > +
> > +   tex->sampler_dim = GLSL_SAMPLER_DIM_3D;
> > +   tex->coord_components = 3;
> > +   tex->src[0].src_type = nir_tex_src_coord;
> > +   tex->src[0].src = nir_src_for_ssa(pos);
> > +   tex->src[1].src_type = nir_tex_src_lod;
> > +   tex->src[1].src = nir_src_for_ssa(nir_imm_int(b, 0));
> > +
> > +   nir_builder_instr_insert(b, &tex->instr);
> > +
> > +   return &tex->dest.ssa;
> > +}
> > +
> > +static nir_ssa_def *
> > +blorp_nir_txf_ms(nir_builder *b, nir_ssa_def *pos, nir_ssa_def *mcs,
> > +                 enum brw_reg_type dst_type)
> > +{
> > +   nir_tex_instr *tex =
> > +      blorp_create_nir_tex_instr(b->shader, nir_texop_txf_ms, pos,
> > +                                 mcs != NULL ? 3 : 2, dst_type);
> > +
> > +   tex->sampler_dim = GLSL_SAMPLER_DIM_MS;
> > +   tex->coord_components = 2;
> > +   tex->src[0].src_type = nir_tex_src_coord;
> > +   tex->src[0].src = nir_src_for_ssa(pos);
> > +
> > +   tex->src[1].src_type = nir_tex_src_ms_index;
> > +   if (pos->num_components == 2) {
> > +      tex->src[1].src = nir_src_for_ssa(nir_imm_int(b, 0));
> > +   } else {
> > +      assert(pos->num_components == 3);
> > +      tex->src[1].src = nir_src_for_ssa(nir_channel(b, pos, 2));
> > +   }
> > +
> > +   if (mcs) {
> > +      tex->src[2].src_type = nir_tex_src_ms_mcs;
> > +      tex->src[2].src = nir_src_for_ssa(mcs);
> > +   }
> > +
> > +   nir_builder_instr_insert(b, &tex->instr);
> > +
> > +   return &tex->dest.ssa;
> > +}
> > +
> > +static nir_ssa_def *
> > +blorp_nir_txf_ms_mcs(nir_builder *b, nir_ssa_def *pos)
> > +{
> > +   nir_tex_instr *tex =
> > +      blorp_create_nir_tex_instr(b->shader, nir_texop_txf_ms_mcs,
> > +                                 pos, 1, BRW_REGISTER_TYPE_D);
> > +
> > +   tex->sampler_dim = GLSL_SAMPLER_DIM_MS;
> > +   tex->coord_components = 2;
> > +   tex->src[0].src_type = nir_tex_src_coord;
> > +   tex->src[0].src = nir_src_for_ssa(pos);
> > +
> > +   nir_builder_instr_insert(b, &tex->instr);
> > +
> > +   return &tex->dest.ssa;
> > +}
> > +
> >  /**
> >   * Generator for WM programs used in BLORP blits.
> >   *
> > @@ -471,6 +693,161 @@ enum sampler_message_arg
> >   * (In these formulas, pitch is the number of bytes occupied by a
> single row
> >   * of samples).
> >   */
> > +static nir_shader *
> > +brw_blorp_build_nir_shader(struct brw_context *brw,
> > +                           const brw_blorp_blit_prog_key *key,
> > +                           struct brw_blorp_prog_data *prog_data)
> > +{
> > +   nir_ssa_def *src_pos, *dst_pos, *color;
> > +
> > +   /* Sanity checks */
> > +   if (key->dst_tiled_w && key->rt_samples > 0) {
> > +      /* If the destination image is W tiled and multisampled, then the
> thread
> > +       * must be dispatched once per sample, not once per pixel.  This
> is
> > +       * necessary because after conversion between W and Y tiling,
> there's no
> > +       * guarantee that all samples corresponding to a single pixel
> will still
> > +       * be together.
> > +       */
> > +      assert(key->persample_msaa_dispatch);
> > +   }
> > +
> > +   if (key->blend) {
> > +      /* We are blending, which means we won't have an opportunity to
> > +       * translate the tiling and sample count for the texture
> surface.  So
> > +       * the surface state for the texture must be configured with the
> correct
> > +       * tiling and sample count.
> > +       */
> > +      assert(!key->src_tiled_w);
> > +      assert(key->tex_samples == key->src_samples);
> > +      assert(key->tex_layout == key->src_layout);
> > +      assert(key->tex_samples > 0);
> > +   }
> > +
> > +   if (key->persample_msaa_dispatch) {
> > +      /* It only makes sense to do persample dispatch if the render
> target is
> > +       * configured as multisampled.
> > +       */
> > +      assert(key->rt_samples > 0);
> > +   }
> > +
> > +   /* Make sure layout is consistent with sample count */
> > +   assert((key->tex_layout == INTEL_MSAA_LAYOUT_NONE) ==
> > +          (key->tex_samples == 0));
> > +   assert((key->rt_layout == INTEL_MSAA_LAYOUT_NONE) ==
> > +          (key->rt_samples == 0));
> > +   assert((key->src_layout == INTEL_MSAA_LAYOUT_NONE) ==
> > +          (key->src_samples == 0));
> > +   assert((key->dst_layout == INTEL_MSAA_LAYOUT_NONE) ==
> > +          (key->dst_samples == 0));
> > +
> > +   /* Set up prog_data */
> > +   brw_blorp_prog_data_init(prog_data);
> > +
> > +   nir_builder b;
> > +   nir_builder_init_simple_shader(&b, NULL, MESA_SHADER_FRAGMENT, NULL);
> > +
> > +   struct brw_blorp_blit_vars v;
> > +   brw_blorp_blit_vars_init(&b, &v, key);
> > +
> > +   dst_pos = blorp_blit_get_frag_coords(&b, key, &v);
> > +
> > +   /* Render target and texture hardware don't support W tiling until
> Gen8. */
> > +   const bool rt_tiled_w = false;
> > +   const bool tex_tiled_w = brw->gen >= 8 && key->src_tiled_w;
> > +
> > +   /* The address that data will be written to is determined by the
> > +    * coordinates supplied to the WM thread and the tiling and sample
> count of
> > +    * the render target, according to the formula:
> > +    *
> > +    * (X, Y, S) = decode_msaa(rt_samples, detile(rt_tiling, offset))
> > +    *
> > +    * If the actual tiling and sample count of the destination surface
> are not
> > +    * the same as the configuration of the render target, then these
> > +    * coordinates are wrong and we have to adjust them to compensate
> for the
> > +    * difference.
> > +    */
> > +   if (rt_tiled_w != key->dst_tiled_w ||
> > +       key->rt_samples != key->dst_samples ||
> > +       key->rt_layout != key->dst_layout) {
> > +      goto fail;
> > +   }
> > +
> > +   /* Now (X, Y, S) = decode_msaa(dst_samples, detile(dst_tiling,
> offset)).
> > +    *
> > +    * That is: X, Y and S now contain the true coordinates and sample
> index of
> > +    * the data that the WM thread should output.
> > +    *
> > +    * If we need to kill pixels that are outside the destination
> rectangle,
> > +    * now is the time to do it.
> > +    */
> > +   if (key->use_kill)
> > +      goto fail;
> > +
> > +   src_pos = blorp_blit_apply_transform(&b, nir_i2f(&b, dst_pos), &v);
> > +
> > +   if (key->blit_scaled && key->blend) {
> > +      goto fail;
> > +   } else if (!key->bilinear_filter) {
> > +      /* We're going to use a texelFetch, so we need integers */
> > +      src_pos = nir_f2i(&b, src_pos);
> > +   }
> > +
> > +   /* X, Y, and S are now the coordinates of the pixel in the source
> image
> > +    * that we want to texture from.  Exception: if we are blending,
> then S is
> > +    * irrelevant, because we are going to fetch all samples.
> > +    */
> > +   if (key->blend && !key->blit_scaled) {
> > +      goto fail;
> > +   } else if (key->blend && key->blit_scaled) {
> > +      goto fail;
> > +   } else {
> > +      /* We aren't blending, which means we just want to fetch a single
> sample
> > +       * from the source surface.  The address that we want to fetch
> from is
> > +       * related to the X, Y and S values according to the formula:
> > +       *
> > +       * (X, Y, S) = decode_msaa(src_samples, detile(src_tiling,
> offset)).
> > +       *
> > +       * If the actual tiling and sample count of the source surface
> are not
> > +       * the same as the configuration of the texture, then we need to
> adjust
> > +       * the coordinates to compensate for the difference.
> > +       */
> > +      if ((tex_tiled_w != key->src_tiled_w ||
> > +           key->tex_samples != key->src_samples ||
> > +           key->tex_layout != key->src_layout) &&
> > +          !key->bilinear_filter) {
> > +         goto fail;
> > +      }
> > +
> > +      if (key->bilinear_filter) {
> > +         color = blorp_nir_tex(&b, src_pos, key->texture_data_type);
> > +      } else {
> > +         /* Now (X, Y, S) = decode_msaa(tex_samples, detile(tex_tiling,
> offset)).
> > +          *
> > +          * In other words: X, Y, and S now contain values which, when
> passed to
> > +          * the texturing unit, will cause data to be read from the
> correct
> > +          * memory location.  So we can fetch the texel now.
> > +          */
> > +         if (key->src_samples == 0) {
>
> Hmm, src_samples can be one also, right? It get its value directly from the
> miptree. I think we will end up with lossless compression to take the mcs
> fetch path. Should we instead use:
>
>             if (key->src_samples <= 1) {
>

This is a direct copy+paste from the original.  I'm not opposed to looking
into that modification.  However, I tried to keep the NIR translation as
close the the original as possible.  Is that reasonable?


> Other than that:
>
> Reviewed-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
>
> > +            color = blorp_nir_txf(&b, &v, src_pos,
> key->texture_data_type);
> > +         } else {
> > +            nir_ssa_def *mcs = NULL;
> > +            if (key->tex_layout == INTEL_MSAA_LAYOUT_CMS)
> > +               mcs = blorp_nir_txf_ms_mcs(&b, src_pos);
> > +
> > +            color = blorp_nir_txf_ms(&b, src_pos, mcs,
> key->texture_data_type);
> > +         }
> > +      }
> > +   }
> > +
> > +   nir_store_var(&b, v.color_out, color, 0xf);
> > +
> > +   return b.shader;
> > +
> > +fail:
> > +   ralloc_free(b.shader);
> > +   return NULL;
> > +}
> > +
> >  class brw_blorp_blit_program : public brw_blorp_eu_emitter
> >  {
> >  public:
> > @@ -1307,25 +1684,6 @@ brw_blorp_blit_program::clamp_tex_coords(struct
> brw_reg regX,
> >     emit_min(regY, regY, clampY1);
> >  }
> >
> > -/**
> > - * Emit code to transform the X and Y coordinates as needed for blending
> > - * together the different samples in an MSAA texture.
> > - */
> > -void
> > -brw_blorp_blit_program::single_to_blend()
> > -{
> > -   /* When looking up samples in an MSAA texture using the SAMPLE
> message,
> > -    * Gen6 requires the texture coordinates to be odd integers (so that
> they
> > -    * correspond to the center of a 2x2 block representing the four
> samples
> > -    * that maxe up a pixel).  So we need to multiply our X and Y
> coordinates
> > -    * each by 2 and then add 1.
> > -    */
> > -   emit_shl(t1, X, brw_imm_w(1));
> > -   emit_shl(t2, Y, brw_imm_w(1));
> > -   emit_add(Xp, t1, brw_imm_w(1));
> > -   emit_add(Yp, t2, brw_imm_w(1));
> > -   SWAP_XY_AND_XPYP();
> > -}
> >
> >
> >  /**
> > @@ -1747,14 +2105,33 @@ brw_blorp_get_blit_kernel(struct brw_context
> *brw,
> >                          &params->wm_prog_kernel, &params->wm_prog_data))
> >        return;
> >
> > -   brw_blorp_blit_program prog(brw, prog_key);
> > -   GLuint program_size;
> > -   const GLuint *program = prog.compile(brw, INTEL_DEBUG & DEBUG_BLORP,
> > -                                        &program_size);
> > +   const unsigned *program;
> > +   unsigned program_size;
> > +   struct brw_blorp_prog_data prog_data;
> > +
> > +   /* Try and compile with NIR first.  If that fails, fall back to the
> old
> > +    * method of building shaders manually.
> > +    */
> > +   nir_shader *nir = brw_blorp_build_nir_shader(brw, prog_key,
> &prog_data);
> > +   if (nir) {
> > +      struct brw_wm_prog_key wm_key;
> > +      brw_blorp_init_wm_prog_key(&wm_key);
> > +      wm_key.tex.compressed_multisample_layout_mask =
> > +         prog_key->tex_layout == INTEL_MSAA_LAYOUT_CMS;
> > +      wm_key.multisample_fbo = prog_key->rt_samples > 1;
> > +
> > +      program = brw_blorp_compile_nir_shader(brw, nir, &wm_key, false,
> > +                                             &prog_data, &program_size);
> > +   } else {
> > +      brw_blorp_blit_program prog(brw, prog_key);
> > +      program = prog.compile(brw, INTEL_DEBUG & DEBUG_BLORP,
> &program_size);
> > +      prog_data = prog.prog_data;
> > +   }
> > +
> >     brw_upload_cache(&brw->cache, BRW_CACHE_BLORP_PROG,
> >                      prog_key, sizeof(*prog_key),
> >                      program, program_size,
> > -                    &prog.prog_data, sizeof(prog.prog_data),
> > +                    &prog_data, sizeof(prog_data),
> >                      &params->wm_prog_kernel, &params->wm_prog_data);
> >  }
> >
> > --
> > 2.5.0.400.gff86faf
> >
> > _______________________________________________
> > mesa-dev mailing list
> > mesa-dev at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>
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