On 22 May 2012 11:31, Kenneth Graunke <kenn...@whitecape.org> wrote:
> On 05/11/2012 11:03 AM, Paul Berry wrote:
>
>> This patch modifies the "blorp" WM program so that it can be run in
>> MSDISPMODE_PERSAMPLE (which means that every single sample of a
>> multisampled render target is dispatched to the WM program, not just
>> every pixel).
>>
>> Previously we were using the ugly hack of configuring multisampled
>> destination surfaces as single-sampled, and generating sample indices
>> other than zero by swizzling the pixel coordinates in the WM program.
>> ---
>> src/mesa/drivers/dri/i965/brw_**blorp.h | 12 ++++
>> src/mesa/drivers/dri/i965/brw_**blorp_blit.cpp | 87
>> +++++++++++++++++++-------
>> src/mesa/drivers/dri/i965/**gen6_blorp.cpp | 5 +-
>> src/mesa/drivers/dri/i965/**gen7_blorp.cpp | 10 ++-
>> 4 files changed, 87 insertions(+), 27 deletions(-)
>>
>> diff --git a/src/mesa/drivers/dri/i965/**brw_blorp.h
>> b/src/mesa/drivers/dri/i965/**brw_blorp.h
>> index f14a5c7..b911356 100644
>> --- a/src/mesa/drivers/dri/i965/**brw_blorp.h
>> +++ b/src/mesa/drivers/dri/i965/**brw_blorp.h
>> @@ -132,6 +132,12 @@ const unsigned int BRW_BLORP_NUM_PUSH_CONST_REGS =
>> struct brw_blorp_prog_data
>> {
>> unsigned int first_curbe_grf;
>> +
>> + /**
>> + * True if the WM program should be run in MSDISPMODE_PERSAMPLE with
>> more
>> + * than one sample per pixel.
>> + */
>> + bool persample_msaa_dispatch;
>> };
>>
>> class brw_blorp_params
>> @@ -218,6 +224,12 @@ struct brw_blorp_blit_prog_key
>> * pixels that are outside the destination rectangle.
>> */
>> bool use_kill;
>> +
>> + /**
>> + * True if the WM program should be run in MSDISPMODE_PERSAMPLE with
>> more
>> + * than one sample per pixel.
>> + */
>> + bool persample_msaa_dispatch;
>> };
>>
>> class brw_blorp_blit_params : public brw_blorp_params
>> diff --git a/src/mesa/drivers/dri/i965/**brw_blorp_blit.cpp
>> b/src/mesa/drivers/dri/i965/**brw_blorp_blit.cpp
>> index e985fad..07e9dd7 100644
>> --- a/src/mesa/drivers/dri/i965/**brw_blorp_blit.cpp
>> +++ b/src/mesa/drivers/dri/i965/**brw_blorp_blit.cpp
>> @@ -437,13 +437,14 @@ brw_blorp_blit_program::**compile(struct
>> brw_context *brw,
>> GLuint *program_size)
>> {
>> /* Sanity checks */
>> - if (key->dst_tiled_w) {
>> - /* If the destination image is W tiled, then dst_samples must be 0.
>> - * Otherwise, after conversion between W and Y tiling, there's no
>> + 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->rt_samples == 0);
>> + assert(key->persample_msaa_**dispatch);
>> }
>>
>> if (key->blend) {
>> @@ -459,6 +460,17 @@ brw_blorp_blit_program::**compile(struct
>> brw_context *brw,
>> 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);
>> + }
>> +
>> + /* Set up prog_data */
>> + memset(&prog_data, 0, sizeof(prog_data));
>> + prog_data.persample_msaa_**dispatch = key->persample_msaa_dispatch;
>> +
>> brw_set_compression_control(&**func, BRW_COMPRESSION_NONE);
>>
>> alloc_regs();
>> @@ -658,11 +670,29 @@ brw_blorp_blit_program::**compute_frag_coords()
>> */
>> brw_ADD(&func, Y, stride(suboffset(R1, 5), 2, 4, 0),
>> brw_imm_v(0x11001100));
>>
>> - /* Since we always run the WM in a mode that causes a single fragment
>> - * dispatch per pixel, it's not meaningful to compute a sample value.
>> Just
>> - * set it to 0.
>> - */
>> - s_is_zero = true;
>> + if (key->persample_msaa_dispatch) {
>> + /* The WM will be run in MSDISPMODE_PERSAMPLE with num_samples> 0.
>> + * Therefore, subspan 0 will represent sample 0, subspan 1 will
>> + * represent sample 1, and so on.
>> + *
>> + * So we need to populate S with the sequence (0, 0, 0, 0, 1, 1,
>> 1, 1,
>> + * 2, 2, 2, 2, 3, 3, 3, 3). The easiest way to do this is to
>> populate a
>> + * temporary variable with the sequence (0, 1, 2, 3), and then
>> copy from
>> + * it using vstride=1, width=4, hstride=0.
>> + *
>> + * TODO: implement appropriate calculation for Gen7.
>> + */
>>
>
> I think you mean:
>
> TODO: implement the necessary calculation for 8x multisampling.
>
You're right. Good catch.
>
> Otherwise,
> Reviewed-by: Kenneth Graunke <kenn...@whitecape.org>
>
> + brw_MOV(&func, t1, brw_imm_v(0x3210));
>> + brw_MOV(&func, S, stride(t1, 1, 4, 0));
>> + s_is_zero = false;
>> + } else {
>> + /* Either the destination surface is single-sampled, or the WM
>> will be
>> + * run in MSDISPMODE_PERPIXEL (which causes a single fragment
>> dispatch
>> + * per pixel). In either case, it's not meaningful to compute a
>> sample
>> + * value. Just set it to 0.
>> + */
>> + s_is_zero = true;
>> + }
>> }
>>
>> /**
>> @@ -1065,22 +1095,23 @@ brw_blorp_blit_params::brw_**blorp_blit_params(struct
>> intel_mipmap_tree *src_mt,
>> use_wm_prog = true;
>> memset(&wm_prog_key, 0, sizeof(wm_prog_key));
>>
>> - if (dst.map_stencil_as_y_tiled) {
>> - /* If the destination surface is a W-tiled stencil buffer that
>> we're
>> - * mapping as Y tiled, then we need to set up the surface state as
>> - * single-sampled, because the memory layout of related samples
>> doesn't
>> - * match between W and Y tiling.
>> + if (dst.map_stencil_as_y_tiled&& dst.num_samples> 0) {
>>
>> + /* If the destination surface is a W-tiled multisampled stencil
>> buffer
>> + * that we're mapping as Y tiled, then we need to arrange for the
>> WM
>> + * program to run once per sample rather than once per pixel,
>> because
>> + * the memory layout of related samples doesn't match between W
>> and Y
>> + * tiling.
>> */
>> - dst.num_samples = 0;
>> + wm_prog_key.persample_msaa_**dispatch = true;
>> }
>>
>> - if (src_mt->num_samples> 0&& dst_mt->num_samples> 0) {
>> + if (src.num_samples> 0&& dst.num_samples> 0) {
>>
>> /* We are blitting from a multisample buffer to a multisample
>> buffer, so
>> * we must preserve samples within a pixel. This means we have to
>> - * configure the render target as single-sampled, so that the WM
>> program
>> - * generate each sample separately.
>> + * arrange for the WM program to run once per sample rather than
>> once
>> + * per pixel.
>> */
>> - dst.num_samples = 0;
>> + wm_prog_key.persample_msaa_**dispatch = true;
>> }
>>
>> /* The render path must be configured to use the same number of
>> samples as
>> @@ -1138,12 +1169,22 @@ brw_blorp_blit_params::brw_**blorp_blit_params(struct
>> intel_mipmap_tree *src_mt,
>> * dimensions 64x64. We must also align it to a multiple of the
>> tile
>> * size, because the differences between W and Y tiling formats
>> will
>> * mean that pixels are scrambled within the tile.
>> + *
>> + * Note: if the destination surface configured as an MSAA surface,
>> then
>> + * the effective tile size we need to align it to is smaller,
>> because
>> + * each pixel covers a 2x2 or a 4x2 block of samples.
>> + *
>> * TODO: what if this makes the coordinates too large?
>> */
>> - x0 = (x0 * 2)& ~127;
>> - y0 = (y0 / 2)& ~31;
>>
>> - x1 = ALIGN(x1 * 2, 128);
>> - y1 = ALIGN(y1 / 2, 32);
>> + unsigned x_align = 64, y_align = 64;
>> + if (dst_mt->num_samples> 0) {
>> + x_align /= (dst_mt->num_samples == 4 ? 2 : 4);
>> + y_align /= 2;
>> + }
>> + x0 = (x0& ~(x_align - 1)) * 2;
>> + y0 = (y0& ~(y_align - 1)) / 2;
>>
>> + x1 = ALIGN(x1, x_align) * 2;
>> + y1 = ALIGN(y1, y_align) / 2;
>> wm_prog_key.use_kill = true;
>> }
>> }
>> diff --git a/src/mesa/drivers/dri/i965/**gen6_blorp.cpp
>> b/src/mesa/drivers/dri/i965/**gen6_blorp.cpp
>> index 8eed9dc..85a8ee6 100644
>> --- a/src/mesa/drivers/dri/i965/**gen6_blorp.cpp
>> +++ b/src/mesa/drivers/dri/i965/**gen6_blorp.cpp
>> @@ -742,7 +742,10 @@ gen6_blorp_emit_wm_config(**struct brw_context *brw,
>>
>> if (params->num_samples> 0) {
>> dw6 |= GEN6_WM_MSRAST_ON_PATTERN;
>> - dw6 |= GEN6_WM_MSDISPMODE_PERPIXEL;
>> + if (prog_data&& prog_data->persample_msaa_**dispatch)
>>
>> + dw6 |= GEN6_WM_MSDISPMODE_PERSAMPLE;
>> + else
>> + dw6 |= GEN6_WM_MSDISPMODE_PERPIXEL;
>> } else {
>> dw6 |= GEN6_WM_MSRAST_OFF_PIXEL;
>> dw6 |= GEN6_WM_MSDISPMODE_PERSAMPLE;
>> diff --git a/src/mesa/drivers/dri/i965/**gen7_blorp.cpp
>> b/src/mesa/drivers/dri/i965/**gen7_blorp.cpp
>> index fbb94df..e5b27dd 100644
>> --- a/src/mesa/drivers/dri/i965/**gen7_blorp.cpp
>> +++ b/src/mesa/drivers/dri/i965/**gen7_blorp.cpp
>> @@ -399,7 +399,8 @@ gen7_blorp_emit_sf_config(**struct brw_context *brw,
>> */
>> static void
>> gen7_blorp_emit_wm_config(**struct brw_context *brw,
>> - const brw_blorp_params *params)
>> + const brw_blorp_params *params,
>> + brw_blorp_prog_data *prog_data)
>> {
>> struct intel_context *intel =&brw->intel;
>>
>>
>> @@ -431,7 +432,10 @@ gen7_blorp_emit_wm_config(**struct brw_context *brw,
>>
>> if (params->num_samples> 0) {
>> dw1 |= GEN7_WM_MSRAST_ON_PATTERN;
>> - dw2 |= GEN7_WM_MSDISPMODE_PERPIXEL;
>> + if (prog_data&& prog_data->persample_msaa_**dispatch)
>>
>> + dw2 |= GEN7_WM_MSDISPMODE_PERSAMPLE;
>> + else
>> + dw2 |= GEN7_WM_MSDISPMODE_PERPIXEL;
>> } else {
>> dw1 |= GEN7_WM_MSRAST_OFF_PIXEL;
>> dw2 |= GEN7_WM_MSDISPMODE_PERSAMPLE;
>> @@ -757,7 +761,7 @@ gen7_blorp_exec(struct intel_context *intel,
>> gen7_blorp_emit_streamout_**disable(brw, params);
>> gen6_blorp_emit_clip_disable(**brw, params);
>> gen7_blorp_emit_sf_config(brw, params);
>> - gen7_blorp_emit_wm_config(brw, params);
>> + gen7_blorp_emit_wm_config(brw, params, prog_data);
>> if (params->use_wm_prog) {
>> gen7_blorp_emit_binding_table_**pointers_ps(brw, params,
>> wm_bind_bo_offset);
>>
>
>
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