AMDGPU: Fixed '!NodePtr->isKnownSentinel()' assert

Caused by dereferencing end iterator when trying to const cast the iterator.

Patch by Martin Sherburn

llvm-svn: 290347

1 files changed, 4 insertions, 17 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp b/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
index b867aff3705..da86bbf9dd2 100644
--- a/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
+++ b/llvm/lib/Target/AMDGPU/SIMachineScheduler.cpp
@@ -1114,30 +1114,17 @@ void SIScheduleBlockCreator::createBlocksForVariant(SISchedulerBlockCreatorVaria
 
 // Two functions taken from Codegen/MachineScheduler.cpp
 
-/// If this iterator is a debug value, increment until reaching the End or a
-/// non-debug instruction.
-static MachineBasicBlock::const_iterator
-nextIfDebug(MachineBasicBlock::const_iterator I,
+/// Non-const version.
+static MachineBasicBlock::iterator
+nextIfDebug(MachineBasicBlock::iterator I,
             MachineBasicBlock::const_iterator End) {
-  for(; I != End; ++I) {
+  for (; I != End; ++I) {
     if (!I->isDebugValue())
       break;
   }
   return I;
 }
 
-/// Non-const version.
-static MachineBasicBlock::iterator
-nextIfDebug(MachineBasicBlock::iterator I,
-            MachineBasicBlock::const_iterator End) {
-  // Cast the return value to nonconst MachineInstr, then cast to an
-  // instr_iterator, which does not check for null, finally return a
-  // bundle_iterator.
-  return MachineBasicBlock::instr_iterator(
-    const_cast<MachineInstr*>(
-      &*nextIfDebug(MachineBasicBlock::const_iterator(I), End)));
-}
-
 void SIScheduleBlockCreator::topologicalSort() {
   unsigned DAGSize = CurrentBlocks.size();
   std::vector<int> WorkList;