Enable the use of a transform feedback overflow query with
glBeginConditionalRender. The render commands will only execute if the
query is true (i.e. if there was an overflow).
Use ARB_conditional_render_inverted to change this behavior.
Signed-off-by: Rafael Antognolli <rafael.antogno...@intel.com>
---
src/mesa/drivers/dri/i965/brw_conditional_render.c | 111 +++++++++++++++++++--
1 file changed, 101 insertions(+), 10 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_conditional_render.c
b/src/mesa/drivers/dri/i965/brw_conditional_render.c
index 122a4ec..db2b722 100644
--- a/src/mesa/drivers/dri/i965/brw_conditional_render.c
+++ b/src/mesa/drivers/dri/i965/brw_conditional_render.c
@@ -48,20 +48,83 @@ set_predicate_enable(struct brw_context *brw,
}
static void
-set_predicate_for_result(struct brw_context *brw,
- struct brw_query_object *query,
- bool inverted)
+set_predicate_for_overflow_query(struct brw_context *brw,
+ struct brw_query_object *query,
+ int stream_start, int count)
{
- int load_op;
+ /* R3 = R4 - R3; generated vertices
+ * R1 = R2 - R1; written vertices
+ * R1 = R3 - R1; there was an overflow on this stream
+ * R0 = R0 | R1; accumulate whether there was any overflow
+ */
+ static const uint32_t maths[] = {
+ MI_MATH_ALU2(LOAD, SRCA, R4),
+ MI_MATH_ALU2(LOAD, SRCB, R3),
+ MI_MATH_ALU0(SUB),
+ MI_MATH_ALU2(STORE, R3, ACCU),
+ MI_MATH_ALU2(LOAD, SRCA, R2),
+ MI_MATH_ALU2(LOAD, SRCB, R1),
+ MI_MATH_ALU0(SUB),
+ MI_MATH_ALU2(STORE, R1, ACCU),
+ MI_MATH_ALU2(LOAD, SRCA, R3),
+ MI_MATH_ALU2(LOAD, SRCB, R1),
+ MI_MATH_ALU0(SUB),
+ MI_MATH_ALU2(STORE, R1, ACCU),
+ MI_MATH_ALU2(LOAD, SRCA, R1),
+ MI_MATH_ALU2(LOAD, SRCB, R0),
+ MI_MATH_ALU0(OR),
+ MI_MATH_ALU2(STORE, R0, ACCU),
+ };
- assert(query->bo != NULL);
+ brw_load_register_imm64(brw, HSW_CS_GPR(0), 0ull);
- /* Needed to ensure the memory is coherent for the MI_LOAD_REGISTER_MEM
- * command when loading the values into the predicate source registers for
- * conditional rendering.
- */
- brw_emit_pipe_control_flush(brw, PIPE_CONTROL_FLUSH_ENABLE);
+ for (int i = stream_start; i < stream_start + count; i++) {
+ int offset = 32 * i;
+ brw_load_register_mem64(brw,
+ HSW_CS_GPR(1),
+ query->bo,
+ I915_GEM_DOMAIN_INSTRUCTION,
+ 0, /* write domain */
+ offset);
+ offset += 8;
+ brw_load_register_mem64(brw,
+ HSW_CS_GPR(2),
+ query->bo,
+ I915_GEM_DOMAIN_INSTRUCTION,
+ 0, /* write domain */
+ offset);
+ offset += 8;
+ brw_load_register_mem64(brw,
+ HSW_CS_GPR(3),
+ query->bo,
+ I915_GEM_DOMAIN_INSTRUCTION,
+ 0, /* write domain */
+ offset);
+ offset += 8;
+ brw_load_register_mem64(brw,
+ HSW_CS_GPR(4),
+ query->bo,
+ I915_GEM_DOMAIN_INSTRUCTION,
+ 0, /* write domain */
+ offset);
+ BEGIN_BATCH(1 + ARRAY_SIZE(maths));
+ OUT_BATCH(HSW_MI_MATH | (1 + ARRAY_SIZE(maths) - 2));
+
+ for (int m = 0; m < ARRAY_SIZE(maths); m++)
+ OUT_BATCH(maths[m]);
+
+ ADVANCE_BATCH();
+ }
+
+ brw_load_register_reg64(brw, HSW_CS_GPR(0), MI_PREDICATE_SRC0);
+ brw_load_register_imm64(brw, MI_PREDICATE_SRC1, 0ull);
+}
+
+static void
+set_predicate_for_occlusion_query(struct brw_context *brw,
+ struct brw_query_object *query)
+{
brw_load_register_mem64(brw,
MI_PREDICATE_SRC0,
query->bo,
@@ -74,6 +137,34 @@ set_predicate_for_result(struct brw_context *brw,
I915_GEM_DOMAIN_INSTRUCTION,
0, /* write domain */
8 /* offset */);
+}
+
+static void
+set_predicate_for_result(struct brw_context *brw,
+ struct brw_query_object *query,
+ bool inverted)
+{
+
+ int load_op;
+
+ assert(query->bo != NULL);
+
+ /* Needed to ensure the memory is coherent for the MI_LOAD_REGISTER_MEM
+ * command when loading the values into the predicate source registers for
+ * conditional rendering.
+ */
+ brw_emit_pipe_control_flush(brw, PIPE_CONTROL_FLUSH_ENABLE);
+
+ switch (query->Base.Target) {
+ case GL_TRANSFORM_FEEDBACK_STREAM_OVERFLOW_ARB:
+ set_predicate_for_overflow_query(brw, query, 0, 1);
+ break;
+ case GL_TRANSFORM_FEEDBACK_OVERFLOW_ARB:
+ set_predicate_for_overflow_query(brw, query, 0, MAX_VERTEX_STREAMS);
+ break;
+ default:
+ set_predicate_for_occlusion_query(brw, query);
+ }
if (inverted)
load_op = MI_PREDICATE_LOADOP_LOAD;
--
2.7.4
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