nvfx: simplify and correct fragment program update logic

This version should hopefully be much clearer and thus less likely
to be subtly broken.

Also fixes point sprites on nv40 and possibly some other bugs too.

1 files changed, 124 insertions, 61 deletions

diff --git a/src/gallium/drivers/nvfx/nvfx_fragprog.c b/src/gallium/drivers/nvfx/nvfx_fragprog.c
index 025989ac5b..e40a814e18 100644
--- a/src/gallium/drivers/nvfx/nvfx_fragprog.c
+++ b/src/gallium/drivers/nvfx/nvfx_fragprog.c
@@ -1101,6 +1101,35 @@ nvfx_fp_memcpy(void* dst, const void* src, size_t len)
 #endif
 }
 
+/* The hardware only supports immediate constants inside the fragment program,
+ * and at least on nv30 doesn't support an indirect linkage table.
+ *
+ * Hence, we need to patch the fragment program itself both to update constants
+ * and update linkage.
+ *
+ * Using a single fragment program would entail unacceptable stalls if the GPU is
+ * already rendering with that fragment program.
+ * Thus, we instead use a "rotating queue" of buffer objects, each of which is
+ * packed with multiple versions of the same program.
+ *
+ * Whenever we need to patch something, we move to the next program and
+ * patch it. If all buffer objects are in use by the GPU, we allocate another one,
+ * expanding the queue.
+ *
+ * As an additional optimization, we record when all the programs have the
+ * current input slot configuration, and at that point we stop patching inputs.
+ * This happens, for instance, if a given fragment program is always used with
+ * the same vertex program (i.e. always with GLSL), or if the layouts match
+ * enough (non-GLSL).
+ *
+ * Note that instead of using multiple programs, we could push commands
+ * on the FIFO to patch a single program: it's not fully clear which option is
+ * faster, but my guess is that the current way is faster.
+ *
+ * We also track the previous slot assignments for each version and don't
+ * patch if they are the same (this could perhaps be removed).
+ */
+
 void
 nvfx_fragprog_validate(struct nvfx_context *nvfx)
 {
@@ -1109,6 +1138,7 @@ nvfx_fragprog_validate(struct nvfx_context *nvfx)
 	int update = 0;
 	struct nvfx_vertex_program* vp;
 	unsigned sprite_coord_enable;
+	boolean update_pointsprite = !!(nvfx->dirty & NVFX_NEW_FRAGPROG);
 
 	if (!fp->translated)
 	{
@@ -1141,80 +1171,96 @@ nvfx_fragprog_validate(struct nvfx_context *nvfx)
 		fp->bo_prog_idx = fp->progs_per_bo - 1;
 	}
 
-	/* we must update constants even on "just" fragprog changes, because
-	   we don't check whether the current constant buffer matches the latest
-	   one bound to this fragment program */
-	if (nvfx->dirty & (NVFX_NEW_FRAGCONST | NVFX_NEW_FRAGPROG))
-		update = TRUE;
-
 	vp = nvfx->render_mode == HW ? nvfx->vertprog : nvfx->swtnl.vertprog;
-	if (fp->last_vp_id != vp->id) {
-		char* vp_sem_table = vp->generic_to_fp_input;
-		unsigned char* fp_semantics = fp->slot_to_generic;
-		unsigned diff = 0;
-		unsigned char* cur_slots;
-		fp->last_vp_id = nvfx->vertprog->id;
-		cur_slots = fp->slot_to_fp_input;
-		for(unsigned i = 0; i < fp->num_slots; ++i) {
-			unsigned char slot_mask = vp_sem_table[fp_semantics[i]];
-			diff |= (slot_mask >> 4) & (slot_mask ^ cur_slots[i]);
-		}
+        sprite_coord_enable = nvfx->rasterizer->pipe.point_quad_rasterization * nvfx->rasterizer->pipe.sprite_coord_enable;
+
+	if (fp->last_vp_id != vp->id || fp->last_sprite_coord_enable != sprite_coord_enable) {
+		int sprite_input = -1;
+		unsigned i;
+		fp->last_vp_id = vp->id;
+		fp->last_sprite_coord_enable = sprite_coord_enable;
 
-		if(diff)
+		if(sprite_coord_enable)
 		{
-			for(unsigned i = 0; i < fp->num_slots; ++i) {
-				/* if 0xff, then this will write to the dummy value at fp->last_layout_mask[0] */
-				fp->slot_to_fp_input[i] = vp_sem_table[fp_semantics[i]] & 0xf;
-				//printf("fp: GENERIC[%i] from fpreg %i\n", fp_semantics[i], fp->slot_to_fp_input[i]);
+			sprite_input = vp->sprite_fp_input;
+			if(sprite_input < 0)
+			{
+				unsigned used_texcoords = 0;
+				for(unsigned i = 0; i < fp->num_slots; ++i) {
+					unsigned generic = fp->slot_to_generic[i];
+					if(!((1 << generic) & sprite_coord_enable))
+					{
+						unsigned char slot_mask = vp->generic_to_fp_input[generic];
+						if(slot_mask >= 0xf0)
+							used_texcoords |= 1 << ((slot_mask & 0xf) - NVFX_FP_OP_INPUT_SRC_TC0);
+					}
+				}
+
+				sprite_input = NVFX_FP_OP_INPUT_SRC_TC(__builtin_ctz(~used_texcoords));
 			}
 
-			fp->progs_left_with_obsolete_slot_assignments = fp->progs;
-			update = TRUE;
+			fp->point_sprite_control |= (1 << (sprite_input - NVFX_FP_OP_INPUT_SRC_TC0 + 8));
 		}
-	}
+		else
+			fp->point_sprite_control = 0;
 
-	// last_sprite_coord_enable
-	sprite_coord_enable = nvfx->rasterizer->pipe.point_quad_rasterization * nvfx->rasterizer->pipe.sprite_coord_enable;
-	if(fp->last_sprite_coord_enable != sprite_coord_enable)
-	{
-		unsigned texcoord_mask = vp->texcoord_ouput_mask;
-		fp->last_sprite_coord_enable = sprite_coord_enable;
-		fp->point_sprite_control = 0;
-		for(unsigned i = 0; i < fp->num_slots; ++i) {
-			if((1 << fp->slot_to_generic[i]) & sprite_coord_enable)
+		for(i = 0; i < fp->num_slots; ++i) {
+			unsigned generic = fp->slot_to_generic[i];
+			if((1 << generic) & sprite_coord_enable)
 			{
-				unsigned fpin = fp->slot_to_fp_input[i];
-				//printf("sprite: slot %i generic %i had texcoord %i\n", i, fp->slot_to_generic[i], fpin - NVFX_FP_OP_INPUT_SRC_TC0);
-				if(fpin >= 0x0f)
-				{
-					unsigned tc = __builtin_ctz(~texcoord_mask);
-					texcoord_mask |= (1 << tc);
-					fp->slot_to_fp_input[i] = fpin = NVFX_FP_OP_INPUT_SRC_TC(tc);
-
-					fp->progs_left_with_obsolete_slot_assignments = fp->progs;
-					update = TRUE;
-				}
-				//printf("sprite: slot %i texcoord %i\n", i, fpin - NVFX_FP_OP_INPUT_SRC_TC0);
-				fp->point_sprite_control |= (1 << (fpin - NVFX_FP_OP_INPUT_SRC_TC0 + 8));
+				if(fp->slot_to_fp_input[i] != sprite_input)
+					goto update_slots;
 			}
 			else
 			{
-				unsigned fpin = fp->slot_to_fp_input[i];
-				if(!(vp->texcoord_ouput_mask & (1 << (fpin - NVFX_FP_OP_INPUT_SRC_TC0))))
-				{
-					fp->slot_to_fp_input[i] = 0x0f;
+				unsigned char slot_mask = vp->generic_to_fp_input[generic];
+				if((slot_mask >> 4) & (slot_mask ^ fp->slot_to_fp_input[i]))
+					goto update_slots;
+			}
+		}
+
+		if(0)
+		{
+update_slots:
+			/* optimization: we start updating from the slot we found the first difference in */
+			for(; i < fp->num_slots; ++i)
+			{
+				unsigned generic = fp->slot_to_generic[i];
+				if((1 << generic) & sprite_coord_enable)
+					fp->slot_to_fp_input[i] = sprite_input;
+				else
+					fp->slot_to_fp_input[i] = vp->generic_to_fp_input[generic] & 0xf;
+			}
 
-					fp->progs_left_with_obsolete_slot_assignments = fp->progs;
-					update = TRUE;
+			if(nvfx->is_nv4x)
+			{
+				fp->or = 0;
+				for(i = 0; i < fp->num_slots; ++i) {
+					unsigned fp_input = fp->slot_to_fp_input[i];
+					if(fp_input == NVFX_FP_OP_INPUT_SRC_TC(8))
+						fp->or |= (1 << 12);
+					else if(fp_input == NVFX_FP_OP_INPUT_SRC_TC(9))
+						fp->or |= (1 << 13);
+					else if(fp_input != 0xf)
+						fp->or |= (1 << (fp_input - NVFX_FP_OP_INPUT_SRC_TC0 + 14));
 				}
 			}
+
+			fp->progs_left_with_obsolete_slot_assignments = fp->progs;
+			goto update;
 		}
 	}
 
-	if(update) {
+	/* We must update constants even on "just" fragprog changes, because
+	  * we don't check whether the current constant buffer matches the latest
+	  * one bound to this fragment program.
+	  * Doing such a check would likely be a pessimization.
+	  */
+	if (nvfx->dirty & (NVFX_NEW_FRAGCONST | NVFX_NEW_FRAGPROG)) {
 		int offset;
 		uint32_t* fpmap;
 
+update:
 		++fp->bo_prog_idx;
 		if(fp->bo_prog_idx >= fp->progs_per_bo)
 		{
@@ -1278,6 +1324,9 @@ nvfx_fragprog_validate(struct nvfx_context *nvfx)
 			}
 		}
 
+		/* we only do this if we aren't sure that all program versions have the
+		 * current slot assignments, otherwise we just update constants for speed
+		 */
 		if(fp->progs_left_with_obsolete_slot_assignments) {
 			unsigned char* fpbo_slots = &fp->fpbo->slots[fp->bo_prog_idx * 8];
 			for(unsigned i = 0; i < fp->num_slots; ++i) {
@@ -1296,10 +1345,7 @@ nvfx_fragprog_validate(struct nvfx_context *nvfx)
 			}
 			--fp->progs_left_with_obsolete_slot_assignments;
 		}
-	}
 
-	if(update || (nvfx->dirty & NVFX_NEW_FRAGPROG)) {
-		int offset = fp->bo_prog_idx * fp->prog_size;
 		MARK_RING(chan, 8, 1);
 		OUT_RING(chan, RING_3D(NV34TCL_FP_ACTIVE_PROGRAM, 1));
 		OUT_RELOC(chan, fp->fpbo->bo, offset, NOUVEAU_BO_VRAM |
@@ -1316,11 +1362,28 @@ nvfx_fragprog_validate(struct nvfx_context *nvfx)
 		}
 	}
 
-	if(nvfx->dirty & (NVFX_NEW_FRAGPROG | NVFX_NEW_SPRITE))
 	{
-		WAIT_RING(chan, 2);
-		OUT_RING(chan, RING_3D(NV34TCL_POINT_SPRITE, 1));
-		OUT_RING(chan, fp->point_sprite_control | nvfx->rasterizer->pipe.point_quad_rasterization);
+		unsigned pointsprite_control = fp->point_sprite_control | nvfx->rasterizer->pipe.point_quad_rasterization;
+		if(pointsprite_control != nvfx->hw_pointsprite_control)
+		{
+			WAIT_RING(chan, 2);
+			OUT_RING(chan, RING_3D(NV34TCL_POINT_SPRITE, 1));
+			OUT_RING(chan, pointsprite_control);
+			nvfx->hw_pointsprite_control = pointsprite_control;
+		}
+	}
+
+	if(nvfx->is_nv4x)
+	{
+		unsigned vp_output = vp->or | fp->or;
+
+		if(vp_output != nvfx->hw_vp_output)
+		{
+			WAIT_RING(chan, 2);
+			OUT_RING(chan, RING_3D(NV40TCL_VP_RESULT_EN, 1));
+			OUT_RING(chan, vp_output);
+			nvfx->hw_vp_output = vp_output;
+		}
 	}
 }