[Mesa-dev] [PATCH 4/4] r600g: avoid redundant CB updates

Constantine Kharlamov Hi-Angel at yandex.ru
Tue Apr 25 11:59:47 UTC 2017


It finishes the work started by 0c2eed0edec, quoting:

> The main idea is to avoid setting CB_COLORi_INFO = 0 for i>0 repeatedly
> when those colorbuffers aren't used. This is mainly for glamor.

After 0c2eed0edec the r600g was passing null as the dirty_cbufs pointer,
and the current patch makes the actual use of the argument. In
particular, the check for null dirty_cbufs pointer in
evergreen_do_fast_color_clear() is removed.

I didn't change r600_state.c because evergreen_do_fast_color_clear() is
only used for eg and higher, thus checks in there are useless.

In addition to radeonsi-like modifications I also do reset in
r600_bind_blend_state_internal(), otherwise there're blend
arb_blend_func_extended regressions. Besides, I keep dirty_cbufs in
cb_misc_state, because it rather seem belonging there.

Some statistics: skips ≈70 updates of CB registers per frame in
Kane&Lynch2.

Signed-off-by: Constantine Kharlamov <Hi-Angel at yandex.ru>
---
 src/gallium/drivers/r600/evergreen_state.c   | 15 +++++++++++++--
 src/gallium/drivers/r600/r600_blit.c         |  3 ++-
 src/gallium/drivers/r600/r600_hw_context.c   |  1 +
 src/gallium/drivers/r600/r600_pipe.h         |  1 +
 src/gallium/drivers/r600/r600_state_common.c |  1 +
 src/gallium/drivers/radeon/r600_texture.c    |  3 +--
 6 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index 9a6bb4e4c9..916270ec4b 100644
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -1426,6 +1426,11 @@ static void evergreen_set_framebuffer_state(struct pipe_context *ctx,
 			 R600_CONTEXT_FLUSH_AND_INV_DB_META |
 			 R600_CONTEXT_INV_TEX_CACHE;
 
+	/* Take the maximum of the old and new count. If the new count is lower,
+	 * dirtying is needed to disable the unbound colorbuffers.
+	 */
+	rctx->cb_misc_state.dirty_cbufs |=
+		(1 << MAX2(rctx->framebuffer.state.nr_cbufs, state->nr_cbufs)) - 1;
 	rctx->framebuffer.dirty_zsbuf |= rctx->framebuffer.state.zsbuf != state->zsbuf;
 	util_copy_framebuffer_state(&rctx->framebuffer.state, state);
 
@@ -1684,6 +1689,9 @@ static void evergreen_emit_framebuffer_state(struct r600_context *rctx, struct r
 	for (i = 0; i < nr_cbufs; i++) {
 		unsigned reloc, cmask_reloc;
 
+		if (!(rctx->cb_misc_state.dirty_cbufs & (1 << i)))
+			continue;
+
 		cb = (struct r600_surface*)state->cbufs[i];
 		if (!cb) {
 			radeon_set_context_reg(cs, R_028C70_CB_COLOR0_INFO + i * 0x3C,
@@ -1736,13 +1744,15 @@ static void evergreen_emit_framebuffer_state(struct r600_context *rctx, struct r
 		radeon_emit(cs, reloc);
 	}
 	/* set CB_COLOR1_INFO for possible dual-src blending */
-	if (rctx->framebuffer.dual_src_blend && i == 1 && state->cbufs[0]) {
+	if (rctx->framebuffer.dual_src_blend && i == 1 && state->cbufs[0] &&
+	    rctx->cb_misc_state.dirty_cbufs & (1 << 0)) {
 		radeon_set_context_reg(cs, R_028C70_CB_COLOR0_INFO + 1 * 0x3C,
 				       cb->cb_color_info | tex->cb_color_info);
 		i++;
 	}
 	for (; i < 8 ; i++)
-		radeon_set_context_reg(cs, R_028C70_CB_COLOR0_INFO + i * 0x3C, 0);
+		if (rctx->cb_misc_state.dirty_cbufs & (1 << i))
+			radeon_set_context_reg(cs, R_028C70_CB_COLOR0_INFO + i * 0x3C, 0);
 	for (; i < 12; i++)
 		radeon_set_context_reg(cs, R_028E50_CB_COLOR8_INFO + (i - 8) * 0x1C, 0);
 
@@ -1810,6 +1820,7 @@ static void evergreen_emit_framebuffer_state(struct r600_context *rctx, struct r
 					rctx->ps_iter_samples, 0, sc_mode_cntl_1);
 	}
 	rctx->framebuffer.dirty_zsbuf = false;
+	rctx->cb_misc_state.dirty_cbufs = 0;
 }
 
 static void evergreen_emit_polygon_offset(struct r600_context *rctx, struct r600_atom *a)
diff --git a/src/gallium/drivers/r600/r600_blit.c b/src/gallium/drivers/r600/r600_blit.c
index 62035a7bee..a4434b77c2 100644
--- a/src/gallium/drivers/r600/r600_blit.c
+++ b/src/gallium/drivers/r600/r600_blit.c
@@ -407,7 +407,8 @@ static void r600_clear(struct pipe_context *ctx, unsigned buffers,
 
 	if (buffers & PIPE_CLEAR_COLOR && rctx->b.chip_class >= EVERGREEN) {
 		evergreen_do_fast_color_clear(&rctx->b, fb, &rctx->framebuffer.atom,
-					      &buffers, NULL, color);
+					      &buffers,
+					      &rctx->cb_misc_state.dirty_cbufs, color);
 		if (!buffers)
 			return; /* all buffers have been fast cleared */
 	}
diff --git a/src/gallium/drivers/r600/r600_hw_context.c b/src/gallium/drivers/r600/r600_hw_context.c
index c85e346307..4054896393 100644
--- a/src/gallium/drivers/r600/r600_hw_context.c
+++ b/src/gallium/drivers/r600/r600_hw_context.c
@@ -375,6 +375,7 @@ void r600_begin_new_cs(struct r600_context *ctx)
 	assert(!ctx->b.gfx.cs->prev_dw);
 	ctx->b.initial_gfx_cs_size = ctx->b.gfx.cs->current.cdw;
 	ctx->framebuffer.dirty_zsbuf = true;
+	ctx->cb_misc_state.dirty_cbufs = (1 << 8) - 1;
 }
 
 void r600_emit_pfp_sync_me(struct r600_context *rctx)
diff --git a/src/gallium/drivers/r600/r600_pipe.h b/src/gallium/drivers/r600/r600_pipe.h
index aeba1f2635..8f1c1a8095 100644
--- a/src/gallium/drivers/r600/r600_pipe.h
+++ b/src/gallium/drivers/r600/r600_pipe.h
@@ -133,6 +133,7 @@ struct r600_cb_misc_state {
 	unsigned blend_colormask; /* 8*4 bits for 8 RGBA colorbuffers */
 	unsigned nr_cbufs;
 	unsigned nr_ps_color_outputs;
+	unsigned dirty_cbufs;
 	bool multiwrite;
 	bool dual_src_blend;
 };
diff --git a/src/gallium/drivers/r600/r600_state_common.c b/src/gallium/drivers/r600/r600_state_common.c
index ffb0f5a811..7716c83f84 100644
--- a/src/gallium/drivers/r600/r600_state_common.c
+++ b/src/gallium/drivers/r600/r600_state_common.c
@@ -187,6 +187,7 @@ static void r600_bind_blend_state_internal(struct r600_context *rctx,
 	}
 	if (update_cb) {
 		r600_mark_atom_dirty(rctx, &rctx->cb_misc_state.atom);
+		rctx->cb_misc_state.dirty_cbufs |= (1 << rctx->framebuffer.state.nr_cbufs) - 1;
 	}
 	if (rctx->framebuffer.dual_src_blend != blend->dual_src_blend) {
 		rctx->framebuffer.dual_src_blend = blend->dual_src_blend;
diff --git a/src/gallium/drivers/radeon/r600_texture.c b/src/gallium/drivers/radeon/r600_texture.c
index 8110ec1484..ca8c75639a 100644
--- a/src/gallium/drivers/radeon/r600_texture.c
+++ b/src/gallium/drivers/radeon/r600_texture.c
@@ -2753,8 +2753,7 @@ void evergreen_do_fast_color_clear(struct r600_common_context *rctx,
 
 		evergreen_set_clear_color(tex, fb->cbufs[i]->format, color);
 
-		if (dirty_cbufs)
-			*dirty_cbufs |= 1 << i;
+		*dirty_cbufs |= 1 << i;
 		rctx->set_atom_dirty(rctx, fb_state, true);
 		*buffers &= ~clear_bit;
 	}
-- 
2.12.2



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