From: Dave Airlie <airlied@redhat.com>
Date: Tue, 24 Feb 2015 04:09:40 +0000 (+1000)
Subject: r600: workaround empty geom shader.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4f347225752b48f3dc5a59a6be71fe78616252a7;p=mesa.git

r600: workaround empty geom shader.

We need to emit at least one cut/emit in every
geometry shader, the easiest workaround it to
stick a single CUT at the top of each geom shader.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Cc: "10.6 11.0 11.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---

diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index 6233753e716..9fe20b02861 100644
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -2219,6 +2219,11 @@ static int r600_shader_from_tgsi(struct r600_context *rctx,
 		if (ctx.type == TGSI_PROCESSOR_GEOMETRY) {
 			struct r600_bytecode_alu alu;
 			int r;
+
+			/* GS thread with no output workaround - emit a cut at start of GS */
+			if (ctx.bc->chip_class == R600)
+				r600_bytecode_add_cfinst(ctx.bc, CF_OP_CUT_VERTEX);
+
 			for (j = 0; j < 4; j++) {
 				memset(&alu, 0, sizeof(struct r600_bytecode_alu));
 				alu.op = ALU_OP1_MOV;