[Mesa-dev] [PATCH v2 03/23] i965: Enable transform feedback for streams > 0

[Ian Romanick]

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

On 06/18/2014 02:51 AM, Iago Toral Quiroga wrote:
> Configure hardware to read vertex data for all streams and have all streams
> write their varyings to the corresponsing output buffers.
> ---
>  src/mesa/drivers/dri/i965/gen7_sol_state.c | 67 +++++++++++++++++++-----------
>  1 file changed, 43 insertions(+), 24 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/gen7_sol_state.c b/src/mesa/drivers/dri/i965/gen7_sol_state.c
> index 8e554af..11b2e2e 100644
> --- a/src/mesa/drivers/dri/i965/gen7_sol_state.c
> +++ b/src/mesa/drivers/dri/i965/gen7_sol_state.c
> @@ -104,12 +104,14 @@ gen7_upload_3dstate_so_decl_list(struct brw_context *brw,
>        ctx->TransformFeedback.CurrentObject;
>     const struct gl_transform_feedback_info *linked_xfb_info =
>        &xfb_obj->shader_program->LinkedTransformFeedback;
> -   uint16_t so_decl[128];
> -   int buffer_mask = 0;
> -   int next_offset[4] = {0, 0, 0, 0};
> -   int decls = 0;
> +   uint16_t so_decl[MAX_VERTEX_STREAMS][128];
> +   int buffer_mask[MAX_VERTEX_STREAMS] = {0, 0, 0, 0};
> +   int next_offset[MAX_VERTEX_STREAMS] = {0, 0, 0, 0};
> +   int decls[MAX_VERTEX_STREAMS] = {0, 0, 0, 0};
> +   int max_decls = 0;
> +   STATIC_ASSERT(ARRAY_SIZE(so_decl[0]) >= MAX_PROGRAM_OUTPUTS);
>  
> -   STATIC_ASSERT(ARRAY_SIZE(so_decl) >= MAX_PROGRAM_OUTPUTS);
> +   memset(so_decl, 0, sizeof(so_decl));
>  
>     /* Construct the list of SO_DECLs to be emitted.  The formatting of the
>      * command is feels strange -- each dword pair contains a SO_DECL per stream.
> @@ -120,6 +122,9 @@ gen7_upload_3dstate_so_decl_list(struct brw_context *brw,
>        int varying = linked_xfb_info->Outputs[i].OutputRegister;
>        const unsigned components = linked_xfb_info->Outputs[i].NumComponents;
>        unsigned component_mask = (1 << components) - 1;
> +      unsigned stream_id = linked_xfb_info->Outputs[i].StreamId;
> +
> +      assert(stream_id < MAX_VERTEX_STREAMS);
>  
>        /* gl_PointSize is stored in VARYING_SLOT_PSIZ.w
>         * gl_Layer is stored in VARYING_SLOT_PSIZ.y
> @@ -138,7 +143,7 @@ gen7_upload_3dstate_so_decl_list(struct brw_context *brw,
>           component_mask <<= linked_xfb_info->Outputs[i].ComponentOffset;
>        }
>  
> -      buffer_mask |= 1 << buffer;
> +      buffer_mask[stream_id] |= 1 << buffer;
>  
>        decl |= buffer << SO_DECL_OUTPUT_BUFFER_SLOT_SHIFT;
>        if (varying == VARYING_SLOT_LAYER || varying == VARYING_SLOT_VIEWPORT) {
> @@ -167,35 +172,41 @@ gen7_upload_3dstate_so_decl_list(struct brw_context *brw,
>        next_offset[buffer] += skip_components;
>  
>        while (skip_components >= 4) {
> -         so_decl[decls++] = SO_DECL_HOLE_FLAG | 0xf;
> +         so_decl[stream_id][decls[stream_id]++] = SO_DECL_HOLE_FLAG | 0xf;
>           skip_components -= 4;
>        }
>        if (skip_components > 0)
> -         so_decl[decls++] = SO_DECL_HOLE_FLAG | ((1 << skip_components) - 1);
> +         so_decl[stream_id][decls[stream_id]++] =
> +            SO_DECL_HOLE_FLAG | ((1 << skip_components) - 1);
>  
>        assert(linked_xfb_info->Outputs[i].DstOffset == next_offset[buffer]);
>  
>        next_offset[buffer] += components;
>  
> -      so_decl[decls++] = decl;
> +      so_decl[stream_id][decls[stream_id]++] = decl;
> +
> +      if (decls[stream_id] > max_decls)
> +         max_decls = decls[stream_id];
>     }
>  
> -   BEGIN_BATCH(decls * 2 + 3);
> -   OUT_BATCH(_3DSTATE_SO_DECL_LIST << 16 | (decls * 2 + 1));
> +   BEGIN_BATCH(max_decls * 2 + 3);
> +   OUT_BATCH(_3DSTATE_SO_DECL_LIST << 16 | (max_decls * 2 + 1));
>  
> -   OUT_BATCH((buffer_mask << SO_STREAM_TO_BUFFER_SELECTS_0_SHIFT) |
> -	     (0 << SO_STREAM_TO_BUFFER_SELECTS_1_SHIFT) |
> -	     (0 << SO_STREAM_TO_BUFFER_SELECTS_2_SHIFT) |
> -	     (0 << SO_STREAM_TO_BUFFER_SELECTS_3_SHIFT));
> +   OUT_BATCH((buffer_mask[0] << SO_STREAM_TO_BUFFER_SELECTS_0_SHIFT) |
> +             (buffer_mask[1] << SO_STREAM_TO_BUFFER_SELECTS_1_SHIFT) |
> +             (buffer_mask[2] << SO_STREAM_TO_BUFFER_SELECTS_2_SHIFT) |
> +             (buffer_mask[3] << SO_STREAM_TO_BUFFER_SELECTS_3_SHIFT));
>  
> -   OUT_BATCH((decls << SO_NUM_ENTRIES_0_SHIFT) |
> -	     (0 << SO_NUM_ENTRIES_1_SHIFT) |
> -	     (0 << SO_NUM_ENTRIES_2_SHIFT) |
> -	     (0 << SO_NUM_ENTRIES_3_SHIFT));
> +   OUT_BATCH((decls[0] << SO_NUM_ENTRIES_0_SHIFT) |
> +             (decls[1] << SO_NUM_ENTRIES_1_SHIFT) |
> +             (decls[2] << SO_NUM_ENTRIES_2_SHIFT) |
> +             (decls[3] << SO_NUM_ENTRIES_3_SHIFT));
>  
> -   for (int i = 0; i < decls; i++) {
> -      OUT_BATCH(so_decl[i]);
> -      OUT_BATCH(0);
> +   for (int i = 0; i < max_decls; i++) {
> +      /* Stream 1 | Stream 0 */
> +      OUT_BATCH(((uint32_t) so_decl[1][i]) << 16 | so_decl[0][i]);
> +      /* Stream 3 | Stream 2 */
> +      OUT_BATCH(((uint32_t) so_decl[3][i]) << 16 | so_decl[2][i]);
>     }
>  
>     ADVANCE_BATCH();
> @@ -235,8 +246,16 @@ upload_3dstate_streamout(struct brw_context *brw, bool active,
>         * SO_DECLs.
>         */
>        dw2 |= urb_entry_read_offset << SO_STREAM_0_VERTEX_READ_OFFSET_SHIFT;
> -      dw2 |= (urb_entry_read_length - 1) <<
> -	 SO_STREAM_0_VERTEX_READ_LENGTH_SHIFT;
> +      dw2 |= (urb_entry_read_length - 1) << SO_STREAM_0_VERTEX_READ_LENGTH_SHIFT;
> +
> +      dw2 |= urb_entry_read_offset << SO_STREAM_1_VERTEX_READ_OFFSET_SHIFT;
> +      dw2 |= (urb_entry_read_length - 1) << SO_STREAM_1_VERTEX_READ_LENGTH_SHIFT;
> +
> +      dw2 |= urb_entry_read_offset << SO_STREAM_2_VERTEX_READ_OFFSET_SHIFT;
> +      dw2 |= (urb_entry_read_length - 1) << SO_STREAM_2_VERTEX_READ_LENGTH_SHIFT;
> +
> +      dw2 |= urb_entry_read_offset << SO_STREAM_3_VERTEX_READ_OFFSET_SHIFT;
> +      dw2 |= (urb_entry_read_length - 1) << SO_STREAM_3_VERTEX_READ_LENGTH_SHIFT;
>     }
>  
>     BEGIN_BATCH(3);
>