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.

llvm-svn: 62177

2 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
index fea74ca3038..6f0767aa100 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
+++ b/llvm/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);
diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index bc5443eaba8..03d3ef5feed 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -816,8 +816,12 @@ void ScheduleDAGRRList::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-tdrr scheduler doesn't yet support physreg dependencies!");
+
     ReleaseSucc(SU, &*I);
+  }
 
   SU->isScheduled = true;
   AvailableQueue->ScheduledNode(SU);