[RegAllocGreedy] Provide a subtarget hook to disable the local reassignment

heuristic.
By default, no functionality change.
This is a follow-up of r212099.

This hook provides a finer grain to control the optimization.

<rdar://problem/17444599>

llvm-svn: 212204

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Target/TargetSubtargetInfo.cpp b/llvm/lib/Target/TargetSubtargetInfo.cpp
index ce00fcc..87b6b66 100644
--- a/llvm/lib/Target/TargetSubtargetInfo.cpp
+++ b/llvm/lib/Target/TargetSubtargetInfo.cpp
@@ -47,6 +47,11 @@ bool TargetSubtargetInfo::enableMachineScheduler() const {
   return false;
 }
 
+bool TargetSubtargetInfo::enableRALocalReassignment(
+    CodeGenOpt::Level OptLevel) const {
+  return true;
+}
+
 bool TargetSubtargetInfo::enablePostMachineScheduler() const {
   return false;
 }