Mesa (master): r600/sb: insert the else clause when we might depart from a loop

[Dave Airlie]

Module: Mesa
Branch: master
Commit: 8d633f067b8a3d74e3f39faea0773a229d4b93b3
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=8d633f067b8a3d74e3f39faea0773a229d4b93b3

Author: Dave Airlie <airlied at redhat.com>
Date:   Tue Jan 30 16:38:51 2018 +1000

r600/sb: insert the else clause when we might depart from a loop

If there is a break inside the else clause and this means we
are breaking from a loop, the loop finalise will want to insert
the LOOP_BREAK/CONTINUE instruction, however if we don't emit
the else there is no where for these to end up, so they will end
up in the wrong place.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101442
Tested-By: Gert Wollny <gw.fossdev at gmail.com>
Cc: <mesa-stable at lists.freedesktop.org>
Reviewed-by: Roland Scheidegger <sroland at vmware.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>

---

 src/gallium/drivers/r600/sb/sb_bc_finalize.cpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
index 099b295f18..d3fab80020 100644
--- a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
+++ b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
@@ -208,8 +208,25 @@ void bc_finalizer::finalize_if(region_node* r) {
 		r->push_front(if_jump);
 		r->push_back(if_pop);
 
+		/* the depart/repeat 1 is actually part of the "else" code.
+		 * if it's a depart for an outer loop region it will want to
+		 * insert a LOOP_BREAK or LOOP_CONTINUE in here, so we need
+		 * to emit the else clause.
+		 */
 		bool has_else = n_if->next;
 
+		if (repdep1->is_depart()) {
+			depart_node *dep1 = static_cast<depart_node*>(repdep1);
+			if (dep1->target != r && dep1->target->is_loop())
+				has_else = true;
+		}
+
+		if (repdep1->is_repeat()) {
+			repeat_node *rep1 = static_cast<repeat_node*>(repdep1);
+			if (rep1->target != r && rep1->target->is_loop())
+				has_else = true;
+		}
+
 		if (has_else) {
 			cf_node *nelse = sh.create_cf(CF_OP_ELSE);
 			n_if->insert_after(nelse);