i965/gen6/gs: implement GS_OPCODE_FF_SYNC_SET_PRIMITIVES opcode

This opcode will be used when filling FF_SYNC header before
emitting vertices and their data.

Signed-off-by: Samuel Iglesias Gonsalvez <[email protected]>
Acked-by: Kenneth Graunke <[email protected]>
Reviewed-by: Jordan Justen <[email protected]>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index 7039174e078..e4868d1c292 100644
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -1064,6 +1064,21 @@ enum opcode {
     * - src is the register that holds the destination indices value.
     */
    GS_OPCODE_SVB_SET_DST_INDEX,
+
+   /**
+    * Prepare Mx.0 subregister for being used in the FF_SYNC message header.
+    * Used in gen6 for transform feedback.
+    *
+    * - dst will hold the register with the final Mx.0 value.
+    *
+    * - src0 has the number of vertices emitted in SO (NumSOVertsToWrite)
+    *
+    * - src1 has the number of needed primitives for SO (NumSOPrimsNeeded)
+    *
+    * - src2 is the value to hold in M0: number of SO vertices to write
+    *   and number of SO primitives needed.
+    */
+   GS_OPCODE_FF_SYNC_SET_PRIMITIVES,
 };
 
 enum brw_derivative_quality {