PostRA scheduler fix. Clear stale loop dependencies.

Fixes <rdar://problem/10235725> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141357 91177308-0d34-0410-b5e6-96231b3b80d8
m-labs · Oct 7, 2011 · e8deca8 · e8deca8
1 parent 4563bba
commit e8deca8
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Showing 2 changed files with 3 additions and 1 deletion.
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -134,6 +134,7 @@ static const Value *getUnderlyingObjectForInstr(const MachineInstr *MI,
 }
 
 void ScheduleDAGInstrs::StartBlock(MachineBasicBlock *BB) {
+  LoopRegs.Deps.clear();
   if (MachineLoop *ML = MLI.getLoopFor(BB))
     if (BB == ML->getLoopLatch()) {
       MachineBasicBlock *Header = ML->getHeader();

diff --git a/lib/CodeGen/ScheduleDAGInstrs.h b/lib/CodeGen/ScheduleDAGInstrs.h
@@ -48,7 +48,8 @@ namespace llvm {
     /// VisitLoop - Clear out any previous state and analyze the given loop.
     ///
     void VisitLoop(const MachineLoop *Loop) {
-      Deps.clear();
+      assert(Deps.empty() && "stale loop dependencies");
+
       MachineBasicBlock *Header = Loop->getHeader();
       SmallSet<unsigned, 8> LoopLiveIns;
       for (MachineBasicBlock::livein_iterator LI = Header->livein_begin(),