/**
* Implements fast depth clears on gen6+.
*
* Fast clears basically work by setting a flag in each of the subspans
* represented in the HiZ buffer that says "When you need the depth values for
* this subspan, it's the hardware's current clear value." Then later rendering
* can just use the static clear value instead of referencing memory.
*
* The tricky part of the implementation is that you have to have the clear
* value that was used on the depth buffer in place for all further rendering,
* at least until a resolve to the real depth buffer happens.
*/
static bool
brw_fast_clear_depth(struct gl_context *ctx)
{
struct brw_context *brw = brw_context(ctx);
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct intel_renderbuffer *depth_irb =
intel_get_renderbuffer(fb, BUFFER_DEPTH);
struct intel_mipmap_tree *mt = depth_irb->mt;
struct gl_renderbuffer_attachment *depth_att = &fb->Attachment[BUFFER_DEPTH];
if (brw->gen < 6)
return false;
if (!intel_renderbuffer_has_hiz(depth_irb))
return false;
/* We only handle full buffer clears -- otherwise you'd have to track whether
* a previous clear had happened at a different clear value and resolve it
* first.
*/
if ((ctx->Scissor.EnableFlags & 1) && !noop_scissor(ctx, fb)) {
perf_debug("Failed to fast clear %dx%d depth because of scissors. "
"Possible 5%% performance win if avoided.\n",
mt->logical_width0, mt->logical_height0);
return false;
}
uint32_t depth_clear_value;
switch (mt->format) {
case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
case MESA_FORMAT_Z24_UNORM_S8_UINT:
/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
*
* "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
* enabled (the legacy method of clearing must be performed):
*
* - If the depth buffer format is D32_FLOAT_S8X24_UINT or
* D24_UNORM_S8_UINT.
*/
return false;
case MESA_FORMAT_Z_FLOAT32:
depth_clear_value = float_as_int(ctx->Depth.Clear);
break;
case MESA_FORMAT_Z_UNORM16:
/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
*
* "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
* enabled (the legacy method of clearing must be performed):
*
* - DevSNB{W/A}]: When depth buffer format is D16_UNORM and the
* width of the map (LOD0) is not multiple of 16, fast clear
* optimization must be disabled.
*/
if (brw->gen == 6 &&
(minify(mt->physical_width0,
depth_irb->mt_level - mt->first_level) % 16) != 0)
return false;
/* FALLTHROUGH */
default:
if (brw->gen >= 8)
depth_clear_value = float_as_int(ctx->Depth.Clear);
else
depth_clear_value = fb->_DepthMax * ctx->Depth.Clear;
break;
}
/* If we're clearing to a new clear value, then we need to resolve any clear
* flags out of the HiZ buffer into the real depth buffer.
*/
if (mt->depth_clear_value != depth_clear_value) {
intel_miptree_all_slices_resolve_depth(brw, mt);
mt->depth_clear_value = depth_clear_value;
}
/* From the Sandy Bridge PRM, volume 2 part 1, page 313:
*
* "If other rendering operations have preceded this clear, a
* PIPE_CONTROL with write cache flush enabled and Z-inhibit disabled
* must be issued before the rectangle primitive used for the depth
* buffer clear operation.
*/
brw_emit_mi_flush(brw);
if (fb->MaxNumLayers > 0) {
for (unsigned layer = 0; layer < depth_irb->layer_count; layer++) {
intel_hiz_exec(brw, mt, depth_irb->mt_level,
depth_irb->mt_layer + layer,
GEN6_HIZ_OP_DEPTH_CLEAR);
}
} else {
intel_hiz_exec(brw, mt, depth_irb->mt_level, depth_irb->mt_layer,
GEN6_HIZ_OP_DEPTH_CLEAR);
}
if (brw->gen == 6) {
/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
*
* "DevSNB, DevSNB-B{W/A}]: Depth buffer clear pass must be followed
* by a PIPE_CONTROL command with DEPTH_STALL bit set and Then
* followed by Depth FLUSH'
*/
brw_emit_mi_flush(brw);
}
/* Now, the HiZ buffer contains data that needs to be resolved to the depth
* buffer.
*/
intel_renderbuffer_att_set_needs_depth_resolve(depth_att);
return true;
}
/**
* Implements fast depth clears on gen6+.
*
* Fast clears basically work by setting a flag in each of the subspans
* represented in the HiZ buffer that says "When you need the depth values for
* this subspan, it's the hardware's current clear value." Then later rendering
* can just use the static clear value instead of referencing memory.
*
* The tricky part of the implementation is that you have to have the clear
* value that was used on the depth buffer in place for all further rendering,
* at least until a resolve to the real depth buffer happens.
*/
static bool
brw_fast_clear_depth(struct gl_context *ctx)
{
struct intel_context *intel = intel_context(ctx);
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct intel_renderbuffer *depth_irb =
intel_get_renderbuffer(fb, BUFFER_DEPTH);
struct intel_mipmap_tree *mt = depth_irb->mt;
if (intel->gen < 6)
return false;
if (!mt->hiz_mt)
return false;
/* We only handle full buffer clears -- otherwise you'd have to track whether
* a previous clear had happened at a different clear value and resolve it
* first.
*/
if (ctx->Scissor.Enabled && !noop_scissor(ctx, fb)) {
perf_debug("Failed to fast clear depth due to scissor being enabled. "
"Possible 5%% performance win if avoided.\n");
return false;
}
/* The rendered area has to be 8x4 samples, not resolved pixels, so we look
* at the miptree slice dimensions instead of renderbuffer size.
*/
if (mt->level[depth_irb->mt_level].width % 8 != 0 ||
mt->level[depth_irb->mt_level].height % 4 != 0) {
perf_debug("Failed to fast clear depth due to width/height %d,%d not "
"being aligned to 8,4. Possible 5%% performance win if "
"avoided\n",
mt->level[depth_irb->mt_level].width,
mt->level[depth_irb->mt_level].height);
return false;
}
uint32_t depth_clear_value;
switch (mt->format) {
case MESA_FORMAT_Z32_FLOAT_X24S8:
case MESA_FORMAT_S8_Z24:
/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
*
* "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
* enabled (the legacy method of clearing must be performed):
*
* - If the depth buffer format is D32_FLOAT_S8X24_UINT or
* D24_UNORM_S8_UINT.
*/
return false;
case MESA_FORMAT_Z32_FLOAT:
depth_clear_value = float_as_int(ctx->Depth.Clear);
break;
case MESA_FORMAT_Z16:
/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
*
* "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
* enabled (the legacy method of clearing must be performed):
*
* - DevSNB{W/A}]: When depth buffer format is D16_UNORM and the
* width of the map (LOD0) is not multiple of 16, fast clear
* optimization must be disabled.
*/
if (intel->gen == 6 && (mt->level[depth_irb->mt_level].width % 16) != 0)
return false;
/* FALLTHROUGH */
default:
depth_clear_value = fb->_DepthMax * ctx->Depth.Clear;
break;
}
/* If we're clearing to a new clear value, then we need to resolve any clear
* flags out of the HiZ buffer into the real depth buffer.
*/
if (mt->depth_clear_value != depth_clear_value) {
intel_miptree_all_slices_resolve_depth(intel, mt);
mt->depth_clear_value = depth_clear_value;
}
/* From the Sandy Bridge PRM, volume 2 part 1, page 313:
*
* "If other rendering operations have preceded this clear, a
* PIPE_CONTROL with write cache flush enabled and Z-inhibit disabled
* must be issued before the rectangle primitive used for the depth
* buffer clear operation.
*/
intel_batchbuffer_emit_mi_flush(intel);
intel_hiz_exec(intel, mt, depth_irb->mt_level, depth_irb->mt_layer,
GEN6_HIZ_OP_DEPTH_CLEAR);
if (intel->gen == 6) {
/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
*
* "DevSNB, DevSNB-B{W/A}]: Depth buffer clear pass must be followed
* by a PIPE_CONTROL command with DEPTH_STALL bit set and Then
* followed by Depth FLUSH'
*/
intel_batchbuffer_emit_mi_flush(intel);
}
/* Now, the HiZ buffer contains data that needs to be resolved to the depth
* buffer.
*/
intel_renderbuffer_set_needs_depth_resolve(depth_irb);
return true;
}
/**
* Implements fast depth clears on gen6+.
*
* Fast clears basically work by setting a flag in each of the subspans
* represented in the HiZ buffer that says "When you need the depth values for
* this subspan, it's the hardware's current clear value." Then later rendering
* can just use the static clear value instead of referencing memory.
*
* The tricky part of the implementation is that you have to have the clear
* value that was used on the depth buffer in place for all further rendering,
* at least until a resolve to the real depth buffer happens.
*/
static bool
brw_fast_clear_depth(struct gl_context *ctx)
{
struct brw_context *brw = brw_context(ctx);
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct intel_renderbuffer *depth_irb =
intel_get_renderbuffer(fb, BUFFER_DEPTH);
struct intel_mipmap_tree *mt = depth_irb->mt;
struct gl_renderbuffer_attachment *depth_att = &fb->Attachment[BUFFER_DEPTH];
const struct gen_device_info *devinfo = &brw->screen->devinfo;
if (devinfo->gen < 6)
return false;
if (!intel_renderbuffer_has_hiz(depth_irb))
return false;
/* We only handle full buffer clears -- otherwise you'd have to track whether
* a previous clear had happened at a different clear value and resolve it
* first.
*/
if ((ctx->Scissor.EnableFlags & 1) && !noop_scissor(fb)) {
perf_debug("Failed to fast clear %dx%d depth because of scissors. "
"Possible 5%% performance win if avoided.\n",
mt->surf.logical_level0_px.width,
mt->surf.logical_level0_px.height);
return false;
}
switch (mt->format) {
case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
case MESA_FORMAT_Z24_UNORM_S8_UINT:
/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
*
* "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
* enabled (the legacy method of clearing must be performed):
*
* - If the depth buffer format is D32_FLOAT_S8X24_UINT or
* D24_UNORM_S8_UINT.
*/
return false;
case MESA_FORMAT_Z_UNORM16:
/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
*
* "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
* enabled (the legacy method of clearing must be performed):
*
* - DevSNB{W/A}]: When depth buffer format is D16_UNORM and the
* width of the map (LOD0) is not multiple of 16, fast clear
* optimization must be disabled.
*/
if (devinfo->gen == 6 &&
(minify(mt->surf.phys_level0_sa.width,
depth_irb->mt_level - mt->first_level) % 16) != 0)
return false;
break;
default:
break;
}
/* Quantize the clear value to what can be stored in the actual depth
* buffer. This makes the following check more accurate because it now
* checks if the actual depth bits will match. It also prevents us from
* getting a too-accurate depth value during depth testing or when sampling
* with HiZ enabled.
*/
float clear_value =
mt->format == MESA_FORMAT_Z_FLOAT32 ? ctx->Depth.Clear :
(unsigned)(ctx->Depth.Clear * fb->_DepthMax) / (float)fb->_DepthMax;
const uint32_t num_layers = depth_att->Layered ? depth_irb->layer_count : 1;
/* If we're clearing to a new clear value, then we need to resolve any clear
* flags out of the HiZ buffer into the real depth buffer.
*/
if (mt->fast_clear_color.f32[0] != clear_value) {
for (uint32_t level = mt->first_level; level <= mt->last_level; level++) {
if (!intel_miptree_level_has_hiz(mt, level))
continue;
const unsigned level_layers = brw_get_num_logical_layers(mt, level);
for (uint32_t layer = 0; layer < level_layers; layer++) {
if (level == depth_irb->mt_level &&
layer >= depth_irb->mt_layer &&
layer < depth_irb->mt_layer + num_layers) {
/* We're going to clear this layer anyway. Leave it alone. */
continue;
}
enum isl_aux_state aux_state =
intel_miptree_get_aux_state(mt, level, layer);
if (aux_state != ISL_AUX_STATE_CLEAR &&
aux_state != ISL_AUX_STATE_COMPRESSED_CLEAR) {
/* This slice doesn't have any fast-cleared bits. */
continue;
}
/* If we got here, then the level may have fast-clear bits that
* use the old clear value. We need to do a depth resolve to get
* rid of their use of the clear value before we can change it.
* Fortunately, few applications ever change their depth clear
* value so this shouldn't happen often.
*/
intel_hiz_exec(brw, mt, level, layer, 1,
ISL_AUX_OP_FULL_RESOLVE);
intel_miptree_set_aux_state(brw, mt, level, layer, 1,
ISL_AUX_STATE_RESOLVED);
}
}
intel_miptree_set_depth_clear_value(ctx, mt, clear_value);
}
bool need_clear = false;
for (unsigned a = 0; a < num_layers; a++) {
enum isl_aux_state aux_state =
intel_miptree_get_aux_state(mt, depth_irb->mt_level,
depth_irb->mt_layer + a);
if (aux_state != ISL_AUX_STATE_CLEAR) {
need_clear = true;
break;
}
}
if (!need_clear) {
/* If all of the layers we intend to clear are already in the clear
* state then simply updating the miptree fast clear value is sufficient
* to change their clear value.
*/
return true;
}
for (unsigned a = 0; a < num_layers; a++) {
enum isl_aux_state aux_state =
intel_miptree_get_aux_state(mt, depth_irb->mt_level,
depth_irb->mt_layer + a);
if (aux_state != ISL_AUX_STATE_CLEAR) {
intel_hiz_exec(brw, mt, depth_irb->mt_level,
depth_irb->mt_layer + a, 1,
ISL_AUX_OP_FAST_CLEAR);
}
}
/* Now, the HiZ buffer contains data that needs to be resolved to the depth
* buffer.
*/
intel_miptree_set_aux_state(brw, mt, depth_irb->mt_level,
depth_irb->mt_layer, num_layers,
ISL_AUX_STATE_CLEAR);
return true;
}
