[Mesa-dev] [PATCH 1/5] i965: Extend dead control flow to remove useless ELSE.

[Matt Turner]

total instructions in shared programs: 1500212 -> 1500153 (-0.00%)
instructions in affected programs:     17777 -> 17718 (-0.33%)
---
 src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp b/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp
index 63a3e5b..82e83b8 100644
--- a/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp
+++ b/src/mesa/drivers/dri/i965/brw_dead_control_flow.cpp
@@ -33,6 +33,7 @@
  *
  *   - if/endif
  *   - if/else/endif
+ *   - .../else/endif
  */
 bool
 dead_control_flow_eliminate(backend_visitor *v)
@@ -59,16 +60,17 @@ dead_control_flow_eliminate(backend_visitor *v)
          found = true;
       } else if (prev_inst->opcode == BRW_OPCODE_ELSE) {
          else_inst = prev_inst;
+         found = true;
 
          prev_inst = (backend_instruction *) prev_inst->prev;
          if (prev_inst->opcode == BRW_OPCODE_IF) {
             if_inst = prev_inst;
-            found = true;
          }
       }
 
       if (found) {
-         if_inst->remove();
+         if (if_inst)
+            if_inst->remove();
          if (else_inst)
             else_inst->remove();
          endif_inst->remove();
-- 
1.8.3.2