The list-td and list-tdrr schedulers don't yet support physreg

scheduling dependencies. Add assertion checks to help catch
this.

It appears the Mips target defaults to list-td, and it has a
regression test that uses a physreg dependence. Such code was
liable to be miscompiled, and now evokes an assertion failure.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62177 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
index fea74ca..6f0767a 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
@@ -140,8 +140,12 @@ void ScheduleDAGList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
 
   // Top down: release successors.
   for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
-       I != E; ++I)
+       I != E; ++I) {
+    assert(!I->isAssignedRegDep() &&
+           "The list-td scheduler doesn't yet support physreg dependencies!");
+
     ReleaseSucc(SU, *I);
+  }
 
   SU->isScheduled = true;
   AvailableQueue->ScheduledNode(SU);