Add support for updating LiveIntervals to MachineBasicBlock::SplitCriticalEdge().

This is currently a bit hairier than it needs to be, since depending on where the
split block resides the end ListEntry of the split block may be the end ListEntry
of the original block or a new entry. Some changes to the SlotIndexes updating
should make it possible to eliminate the two cases here.

This also isn't as optimized as it could be. In the future Liveinterval should
probably get a flag that indicates whether the LiveInterval is within a single
basic block. We could ignore all such intervals when splitting an edge.

llvm-svn: 174870

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/PHIElimination.cpp b/llvm/lib/CodeGen/PHIElimination.cpp
index bf2b95fd299..aa84a60efde 100644
--- a/llvm/lib/CodeGen/PHIElimination.cpp
+++ b/llvm/lib/CodeGen/PHIElimination.cpp
@@ -129,7 +129,7 @@ bool PHIElimination::runOnMachineFunction(MachineFunction &MF) {
 
   // Split critical edges to help the coalescer. This does not yet support
   // updating LiveIntervals, so we disable it.
-  if (!DisableEdgeSplitting && LV && !LIS) {
+  if (!DisableEdgeSplitting && (LV || LIS)) {
     MachineLoopInfo *MLI = getAnalysisIfAvailable<MachineLoopInfo>();
     for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
       Changed |= SplitPHIEdges(MF, *I, MLI);