Added -stress-sched flag in the Asserts build.
Added a test case for handling physreg aliases during pre-RA-sched.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133063 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 9f2f012..0d656ef 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -435,7 +435,7 @@
         // it requires a cross class copy (cost < 0). That means we are only
         // treating "expensive to copy" register dependency as physical register
         // dependency. This may change in the future though.
-        if (Cost >= 0)
+        if (Cost >= 0 && !StressSched)
           PhysReg = 0;
 
         // If this is a ctrl dep, latency is 1.