[Mesa-dev] [PATCH 08/18] radeonsi: get info about VS outputs from tgsi_shader_info

Marek Olšák maraeo at gmail.com
Tue Dec 9 07:22:01 PST 2014


It looks like clip planes are deprecated, so you can only use them
with the compatibility profile.

Sure we could support 8 clip planes if ClipVertex is written, but:
- we can only support 6 clip planes if ClipVertex isn't written
- pipe_context::set_clip_state can set only 6 clip planes

Marek


On Tue, Dec 9, 2014 at 4:12 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Tue, Dec 9, 2014 at 10:05 AM, Marek Olšák <maraeo at gmail.com> wrote:
>> If clip distances are used, there can be 8 of them. Otherwise, if user
>> clip planes are used, there can only be 6 of them. If clip vertex is
>> used, there can still only be 6 clip planes - even though they are
>> lowered to clip distances.
>
> Ah cool. Didn't realize that there could only be 6 clip planes.
>
> FWIW,
>
> src/mesa/state_tracker/st_extensions.c:      consts->MaxClipPlanes = 8;
> src/mesa/main/get_hash_params.py:  [ "MAX_CLIP_PLANES",
> "CONTEXT_INT(Const.MaxClipPlanes), NO_EXTRA" ],
>
> And I see nothing limiting it to 6...
>
>>
>> So first the writemask for clip distances is computed:
>>
>> unsigned clipdist_mask =
>>    info->writes_clipvertex ? SIX_BITS : info->clipdist_writemask;
>>
>> Then, if clipdist_mask is zero and clip planes are enabled, we must be
>> using legacy user clip planes, which are enable or disabled with:
>>
>> (clipdist_mask ? 0 :
>>    sctx->queued.named.rasterizer->clip_plane_enable & SIX_BITS)
>>
>> Marek
>>
>> On Tue, Dec 9, 2014 at 3:48 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>> On Tue, Dec 9, 2014 at 6:39 AM, Marek Olšák <maraeo at gmail.com> wrote:
>>>> From: Marek Olšák <marek.olsak at amd.com>
>>>>
>>>> ---
>>>>  src/gallium/drivers/radeonsi/si_shader.c     | 27 ++++++++----------------
>>>>  src/gallium/drivers/radeonsi/si_shader.h     | 11 +++++-----
>>>>  src/gallium/drivers/radeonsi/si_state_draw.c | 31 +++++++++++++++++-----------
>>>>  3 files changed, 34 insertions(+), 35 deletions(-)
>>>>
>>>> diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
>>>> index ec37646..043a5ea 100644
>>>> --- a/src/gallium/drivers/radeonsi/si_shader.c
>>>> +++ b/src/gallium/drivers/radeonsi/si_shader.c
>>>> @@ -804,7 +804,6 @@ static void si_llvm_emit_clipvertex(struct lp_build_tgsi_context * bld_base,
>>>>                                     LLVMValueRef (*pos)[9], LLVMValueRef *out_elts)
>>>>  {
>>>>         struct si_shader_context *si_shader_ctx = si_shader_context(bld_base);
>>>> -       struct si_shader *shader = si_shader_ctx->shader;
>>>>         struct lp_build_context *base = &bld_base->base;
>>>>         struct lp_build_context *uint = &si_shader_ctx->radeon_bld.soa.bld_base.uint_bld;
>>>>         unsigned reg_index;
>>>> @@ -818,8 +817,6 @@ static void si_llvm_emit_clipvertex(struct lp_build_tgsi_context * bld_base,
>>>>         for (reg_index = 0; reg_index < 2; reg_index ++) {
>>>>                 LLVMValueRef *args = pos[2 + reg_index];
>>>>
>>>> -               shader->clip_dist_write |= 0xf << (4 * reg_index);
>>>> -
>>>>                 args[5] =
>>>>                 args[6] =
>>>>                 args[7] =
>>>> @@ -1088,18 +1085,12 @@ handle_semantic:
>>>>                 /* Select the correct target */
>>>>                 switch(semantic_name) {
>>>>                 case TGSI_SEMANTIC_PSIZE:
>>>> -                       shader->vs_out_misc_write = true;
>>>> -                       shader->vs_out_point_size = true;
>>>>                         psize_value = outputs[i].values[0];
>>>>                         continue;
>>>>                 case TGSI_SEMANTIC_EDGEFLAG:
>>>> -                       shader->vs_out_misc_write = true;
>>>> -                       shader->vs_out_edgeflag = true;
>>>>                         edgeflag_value = outputs[i].values[0];
>>>>                         continue;
>>>>                 case TGSI_SEMANTIC_LAYER:
>>>> -                       shader->vs_out_misc_write = true;
>>>> -                       shader->vs_out_layer = true;
>>>>                         layer_value = outputs[i].values[0];
>>>>                         continue;
>>>>                 case TGSI_SEMANTIC_POSITION:
>>>> @@ -1112,8 +1103,6 @@ handle_semantic:
>>>>                         param_count++;
>>>>                         break;
>>>>                 case TGSI_SEMANTIC_CLIPDIST:
>>>> -                       shader->clip_dist_write |=
>>>> -                               0xf << (semantic_index * 4);
>>>>                         target = V_008DFC_SQ_EXP_POS + 2 + semantic_index;
>>>>                         break;
>>>>                 case TGSI_SEMANTIC_CLIPVERTEX:
>>>> @@ -1166,11 +1155,13 @@ handle_semantic:
>>>>         }
>>>>
>>>>         /* Write the misc vector (point size, edgeflag, layer, viewport). */
>>>> -       if (shader->vs_out_misc_write) {
>>>> +       if (shader->selector->info.writes_psize ||
>>>> +           shader->selector->info.writes_edgeflag ||
>>>> +           shader->selector->info.writes_layer) {
>>>>                 pos_args[1][0] = lp_build_const_int32(base->gallivm, /* writemask */
>>>> -                                                     shader->vs_out_point_size |
>>>> -                                                     (shader->vs_out_edgeflag << 1) |
>>>> -                                                     (shader->vs_out_layer << 2));
>>>> +                                                     shader->selector->info.writes_psize |
>>>> +                                                     (shader->selector->info.writes_edgeflag << 1) |
>>>> +                                                     (shader->selector->info.writes_layer << 2));
>>>>                 pos_args[1][1] = uint->zero; /* EXEC mask */
>>>>                 pos_args[1][2] = uint->zero; /* last export? */
>>>>                 pos_args[1][3] = lp_build_const_int32(base->gallivm, V_008DFC_SQ_EXP_POS + 1);
>>>> @@ -1180,10 +1171,10 @@ handle_semantic:
>>>>                 pos_args[1][7] = base->zero; /* Z */
>>>>                 pos_args[1][8] = base->zero; /* W */
>>>>
>>>> -               if (shader->vs_out_point_size)
>>>> +               if (shader->selector->info.writes_psize)
>>>>                         pos_args[1][5] = psize_value;
>>>>
>>>> -               if (shader->vs_out_edgeflag) {
>>>> +               if (shader->selector->info.writes_edgeflag) {
>>>>                         /* The output is a float, but the hw expects an integer
>>>>                          * with the first bit containing the edge flag. */
>>>>                         edgeflag_value = LLVMBuildFPToUI(base->gallivm->builder,
>>>> @@ -1199,7 +1190,7 @@ handle_semantic:
>>>>                                                           base->elem_type, "");
>>>>                 }
>>>>
>>>> -               if (shader->vs_out_layer)
>>>> +               if (shader->selector->info.writes_layer)
>>>>                         pos_args[1][7] = layer_value;
>>>>         }
>>>>
>>>> diff --git a/src/gallium/drivers/radeonsi/si_shader.h b/src/gallium/drivers/radeonsi/si_shader.h
>>>> index 5e8c9e6..124615e 100644
>>>> --- a/src/gallium/drivers/radeonsi/si_shader.h
>>>> +++ b/src/gallium/drivers/radeonsi/si_shader.h
>>>> @@ -159,15 +159,16 @@ struct si_shader {
>>>>         unsigned                ps_input_param_offset[PIPE_MAX_SHADER_INPUTS];
>>>>
>>>>         bool                    uses_instanceid;
>>>> -       bool                    vs_out_misc_write;
>>>> -       bool                    vs_out_point_size;
>>>> -       bool                    vs_out_edgeflag;
>>>> -       bool                    vs_out_layer;
>>>>         unsigned                nr_pos_exports;
>>>> -       unsigned                clip_dist_write;
>>>>         bool                    is_gs_copy_shader;
>>>>  };
>>>>
>>>> +static inline struct tgsi_shader_info *si_get_vs_info(struct si_context *sctx)
>>>> +{
>>>> +       return sctx->gs_shader ? &sctx->gs_shader->info
>>>> +                               : &sctx->vs_shader->info;
>>>> +}
>>>> +
>>>>  static inline struct si_shader* si_get_vs_state(struct si_context *sctx)
>>>>  {
>>>>         if (sctx->gs_shader)
>>>> diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c b/src/gallium/drivers/radeonsi/si_state_draw.c
>>>> index 57c651f..563d9ab 100644
>>>> --- a/src/gallium/drivers/radeonsi/si_state_draw.c
>>>> +++ b/src/gallium/drivers/radeonsi/si_state_draw.c
>>>> @@ -149,27 +149,34 @@ static unsigned si_get_ia_multi_vgt_param(struct si_context *sctx,
>>>>                 S_028AA8_WD_SWITCH_ON_EOP(sctx->b.chip_class >= CIK ? wd_switch_on_eop : 0);
>>>>  }
>>>>
>>>> +#define SIX_BITS 0x3F
>>>
>>> Just curious... why 6 bits? Can't there be 8 clip planes/distances?
>>>
>>>> +
>>>>  static void si_emit_clip_state(struct si_context *sctx)
>>>>  {
>>>>         struct radeon_winsys_cs *cs = sctx->b.rings.gfx.cs;
>>>> +       struct tgsi_shader_info *info = si_get_vs_info(sctx);
>>>>         struct si_shader *vs = si_get_vs_state(sctx);
>>>>         unsigned window_space =
>>>>            vs->selector->info.properties[TGSI_PROPERTY_VS_WINDOW_SPACE_POSITION];
>>>> +       unsigned clipdist_mask =
>>>> +               info->writes_clipvertex ? SIX_BITS : info->clipdist_writemask;
>>>>
>>>>         r600_write_context_reg(cs, R_02881C_PA_CL_VS_OUT_CNTL,
>>>> -                      S_02881C_USE_VTX_POINT_SIZE(vs->vs_out_point_size) |
>>>> -                      S_02881C_USE_VTX_EDGE_FLAG(vs->vs_out_edgeflag) |
>>>> -                      S_02881C_USE_VTX_RENDER_TARGET_INDX(vs->vs_out_layer) |
>>>> -                      S_02881C_VS_OUT_CCDIST0_VEC_ENA((vs->clip_dist_write & 0x0F) != 0) |
>>>> -                      S_02881C_VS_OUT_CCDIST1_VEC_ENA((vs->clip_dist_write & 0xF0) != 0) |
>>>> -                      S_02881C_VS_OUT_MISC_VEC_ENA(vs->vs_out_misc_write) |
>>>> -                      (sctx->queued.named.rasterizer->clip_plane_enable &
>>>> -                       vs->clip_dist_write));
>>>> +               S_02881C_USE_VTX_POINT_SIZE(info->writes_psize) |
>>>> +               S_02881C_USE_VTX_EDGE_FLAG(info->writes_edgeflag) |
>>>> +               S_02881C_USE_VTX_RENDER_TARGET_INDX(info->writes_layer) |
>>>> +               S_02881C_VS_OUT_CCDIST0_VEC_ENA((clipdist_mask & 0x0F) != 0) |
>>>> +               S_02881C_VS_OUT_CCDIST1_VEC_ENA((clipdist_mask & 0xF0) != 0) |
>>>> +               S_02881C_VS_OUT_MISC_VEC_ENA(info->writes_psize ||
>>>> +                                           info->writes_edgeflag ||
>>>> +                                           info->writes_layer) |
>>>> +               (sctx->queued.named.rasterizer->clip_plane_enable &
>>>> +                clipdist_mask));
>>>>         r600_write_context_reg(cs, R_028810_PA_CL_CLIP_CNTL,
>>>> -                      sctx->queued.named.rasterizer->pa_cl_clip_cntl |
>>>> -                      (vs->clip_dist_write ? 0 :
>>>> -                       sctx->queued.named.rasterizer->clip_plane_enable & 0x3F) |
>>>> -                      S_028810_CLIP_DISABLE(window_space));
>>>> +               sctx->queued.named.rasterizer->pa_cl_clip_cntl |
>>>> +               (clipdist_mask ? 0 :
>>>> +                sctx->queued.named.rasterizer->clip_plane_enable & SIX_BITS) |
>>>> +               S_028810_CLIP_DISABLE(window_space));
>>>>  }
>>>>
>>>>  static void si_emit_rasterizer_prim_state(struct si_context *sctx, unsigned mode)
>>>> --
>>>> 2.1.0
>>>>
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