Mesa (10.3): r600g/cayman: handle empty vertex shaders

[Emil Velikov]

Module: Mesa
Branch: 10.3
Commit: 410a6bae6a6fe752470fd0d3675d8f551490d5a3
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=410a6bae6a6fe752470fd0d3675d8f551490d5a3

Author: Dave Airlie <airlied at redhat.com>
Date:   Tue Nov 18 11:22:01 2014 +1000

r600g/cayman: handle empty vertex shaders

Some of the geom shader tests produce an empty vertex shader,
on cayman we'd crash in the finaliser because last_cf was NULL.

cayman doesn't need the NOP workaround, so if the code arrives
here with no last_cf, just emit an END.

fixes crashes in a bunch of piglit geom shader tests.

Cc: "10.3 10.4" <mesa-stable at lists.freedesktop.org>
Reviewed-by: Glenn Kennard <glenn.kennard at gmail.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>
(cherry picked from commit 4e520101e6a0b4fcd930323c32d1a8a6348c8417)

---

 src/gallium/drivers/r600/sb/sb_bc_finalize.cpp |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
index 5c22f96..f0849ca 100644
--- a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
+++ b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
@@ -83,14 +83,18 @@ int bc_finalizer::run() {
 		last_cf = c;
 	}
 
-	if (last_cf->bc.op_ptr->flags & CF_ALU) {
+	if (!ctx.is_cayman() && last_cf->bc.op_ptr->flags & CF_ALU) {
 		last_cf = sh.create_cf(CF_OP_NOP);
 		sh.root->push_back(last_cf);
 	}
 
-	if (ctx.is_cayman())
-		last_cf->insert_after(sh.create_cf(CF_OP_CF_END));
-	else
+	if (ctx.is_cayman()) {
+		if (!last_cf) {
+			cf_node *c = sh.create_cf(CF_OP_CF_END);
+			sh.root->push_back(c);
+		} else
+			last_cf->insert_after(sh.create_cf(CF_OP_CF_END));
+	} else
 		last_cf->bc.end_of_program = 1;
 
 	for (unsigned t = EXP_PIXEL; t < EXP_TYPE_COUNT; ++t) {