Mesa (master): r600g/sb: Update last_cf for loops

[Dave Airlie]

Module: Mesa
Branch: master
Commit: 06bb68da4a58403e678b51511e40a7f752dfc046
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=06bb68da4a58403e678b51511e40a7f752dfc046

Author: Glenn Kennard <glenn.kennard at gmail.com>
Date:   Thu Mar 26 02:56:50 2015 +0100

r600g/sb: Update last_cf for loops

CF_END could end up emitted in the middle of a shader on cayman
when there was a loop at the very end.

Fixes glsl-1.50-geometry-end-primitive and
ext_transform_feedback-geometry-shaders-basic piglit tests.

Signed-off-by: Glenn Kennard <glenn.kennard at gmail.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>

---

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

diff --git a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
index 8d0be06..08b7d77 100644
--- a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
+++ b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
@@ -127,6 +127,14 @@ void bc_finalizer::finalize_loop(region_node* r) {
 	cf_node *loop_start = sh.create_cf(CF_OP_LOOP_START_DX10);
 	cf_node *loop_end = sh.create_cf(CF_OP_LOOP_END);
 
+	// Update last_cf, but don't overwrite it if it's outside the current loop nest since
+	// it may point to a cf that is later in program order.
+	// The single parent level check is sufficient since finalize_loop() is processed in
+	// reverse order from innermost to outermost loop nest level.
+	if (!last_cf || last_cf->get_parent_region() == r) {
+		last_cf = loop_end;
+	}
+
 	loop_start->jump_after(loop_end);
 	loop_end->jump_after(loop_start);