r300: Vertex program position end bits are known.

Possibly performance may improve by setting it to the last instruction that
writes result.position, rather than the last instruction in the vertex program.

3 files changed, 11 insertions, 9 deletions

diff --git a/src/mesa/drivers/dri/r300/r300_context.h b/src/mesa/drivers/dri/r300/r300_context.h
index c150053d873..44f02229b38 100644
--- a/src/mesa/drivers/dri/r300/r300_context.h
+++ b/src/mesa/drivers/dri/r300/r300_context.h
@@ -588,7 +588,7 @@ struct r300_vertex_shader_state {
 	struct r300_vertex_shader_fragment unknown2;
 
 	int program_start;
-	int unknown_ptr1;	/* pointer within program space */
+	int program_pos_end;
 	int program_end;
 
 	int param_offset;
diff --git a/src/mesa/drivers/dri/r300/r300_reg.h b/src/mesa/drivers/dri/r300/r300_reg.h
index 3ce09c16d3f..e59919be493 100644
--- a/src/mesa/drivers/dri/r300/r300_reg.h
+++ b/src/mesa/drivers/dri/r300/r300_reg.h
@@ -336,13 +336,15 @@ USE OR OTHER DEALINGS IN THE SOFTWARE.
  * The meaning of the two UNKNOWN fields is obviously not known. However,
  * experiments so far have shown that both *must* point to an instruction
  * inside the vertex program, otherwise the GPU locks up.
+ *
  * fglrx usually sets CNTL_3_UNKNOWN to the end of the program and
- * CNTL_1_UNKNOWN points to instruction where last write to position takes
- * place.
+ * R300_PVS_CNTL_1_POS_END_SHIFT points to instruction where last write to
+ * position takes place.
+ *
  * Most likely this is used to ignore rest of the program in cases
  * where group of verts arent visible. For some reason this "section"
  * is sometimes accepted other instruction that have no relationship with
- *position calculations.
+ * position calculations.
  */
 #define R300_VAP_PVS_CNTL_1                 0x22D0
 #       define R300_PVS_CNTL_1_PROGRAM_START_SHIFT   0
diff --git a/src/mesa/drivers/dri/r300/r300_state.c b/src/mesa/drivers/dri/r300/r300_state.c
index c37964957a4..8d08279b3a8 100644
--- a/src/mesa/drivers/dri/r300/r300_state.c
+++ b/src/mesa/drivers/dri/r300/r300_state.c
@@ -1531,7 +1531,7 @@ static void r300GenerateSimpleVertexShader(r300ContextPtr r300)
 	r300->state.vertex_shader.param_count = 0x4;	/* 4 vector values - 4x4 matrix */
 
 	r300->state.vertex_shader.program_start = 0x0;
-	r300->state.vertex_shader.unknown_ptr1 = 0x4;	/* magic value ? */
+	r300->state.vertex_shader.program_pos_end = 0x4;
 	r300->state.vertex_shader.program_end = 0x0;
 
 	r300->state.vertex_shader.unknown_ptr2 = 0x0;	/* magic value */
@@ -1563,7 +1563,7 @@ static void r300GenerateSimpleVertexShader(r300ContextPtr r300)
 	r300->state.vertex_shader.program.length =
 	    (r300->state.vertex_shader.program_end + 1) * 4;
 
-	r300->state.vertex_shader.unknown_ptr1 = r300->state.vertex_shader.program_end;	/* magic value ? */
+	r300->state.vertex_shader.program_pos_end = r300->state.vertex_shader.program_end;
 	r300->state.vertex_shader.unknown_ptr2 = r300->state.vertex_shader.program_end;	/* magic value ? */
 	r300->state.vertex_shader.unknown_ptr3 = r300->state.vertex_shader.program_end;	/* magic value ? */
 
@@ -1607,7 +1607,7 @@ static void r300SetupVertexProgram(r300ContextPtr rmesa)
 	  (param_count << R300_PVS_CNTL_2_PARAM_COUNT_SHIFT);
 	rmesa->hw.pvs.cmd[R300_PVS_CNTL_3] =
 	  (0 << R300_PVS_CNTL_3_PROGRAM_UNKNOWN_SHIFT) |
-	  (inst_count << 0);
+	  (inst_count << R300_PVS_CNTL_3_PROGRAM_UNKNOWN2_SHIFT);
 
 	/* This is done for vertex shader fragments, but also needs to be done for vap_pvs,
 	   so I leave it as a reminder */
@@ -1648,14 +1648,14 @@ static void r300SetupVertexShader(r300ContextPtr rmesa)
 	R300_STATECHANGE(rmesa, pvs);
 	rmesa->hw.pvs.cmd[R300_PVS_CNTL_1] =
 	  (rmesa->state.vertex_shader.program_start << R300_PVS_CNTL_1_PROGRAM_START_SHIFT) |
-	  (rmesa->state.vertex_shader.unknown_ptr1 << R300_PVS_CNTL_1_POS_END_SHIFT) |
+	  (rmesa->state.vertex_shader.program_pos_end << R300_PVS_CNTL_1_POS_END_SHIFT) |
 	  (rmesa->state.vertex_shader.program_end << R300_PVS_CNTL_1_PROGRAM_END_SHIFT);
 	rmesa->hw.pvs.cmd[R300_PVS_CNTL_2] =
 	  (rmesa->state.vertex_shader.param_offset << R300_PVS_CNTL_2_PARAM_OFFSET_SHIFT) |
 	  (rmesa->state.vertex_shader.param_count << R300_PVS_CNTL_2_PARAM_COUNT_SHIFT);
 	rmesa->hw.pvs.cmd[R300_PVS_CNTL_3] =
 	  (rmesa->state.vertex_shader.unknown_ptr2 << R300_PVS_CNTL_3_PROGRAM_UNKNOWN_SHIFT) |
-	  (rmesa->state.vertex_shader.unknown_ptr3 << 0);
+	  (rmesa->state.vertex_shader.unknown_ptr3 << R300_PVS_CNTL_3_PROGRAM_UNKNOWN2_SHIFT);
 
 	/* This is done for vertex shader fragments, but also needs to be done for vap_pvs,
 	   so I leave it as a reminder */