[MachineBasicBlock] Make the pass argument truly mandatory when

splitting edges.

MachineBasicBlock::SplitCriticalEdges will crash if a nullptr would have
been passed for the Pass argument. Do not allow that by turning this
argument into a reference.
The alternative would have been to make the Pass a truly optional
argument, but although this is easy to do, I was afraid users using it
like this would not be aware the livness information, dominator tree and
such would silently be broken.

llvm-svn: 267052

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
index c42281b1455..13924edbb94 100644
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -284,7 +284,7 @@ bool MachineSinking::runOnMachineFunction(MachineFunction &MF) {
 
     // If we have anything we marked as toSplit, split it now.
     for (auto &Pair : ToSplit) {
-      auto NewSucc = Pair.first->SplitCriticalEdge(Pair.second, this);
+      auto NewSucc = Pair.first->SplitCriticalEdge(Pair.second, *this);
       if (NewSucc != nullptr) {
         DEBUG(dbgs() << " *** Splitting critical edge:"
               " BB#" << Pair.first->getNumber()