Add interfaces for targets to provide target-specific dag combiner optimizations.

llvm-svn: 26442

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Target/TargetLowering.cpp b/llvm/lib/Target/TargetLowering.cpp
index d170d6c2929..2ba754289cd 100644
--- a/llvm/lib/Target/TargetLowering.cpp
+++ b/llvm/lib/Target/TargetLowering.cpp
@@ -30,6 +30,8 @@ TargetLowering::TargetLowering(TargetMachine &tm)
   ShiftAmountTy = SetCCResultTy = PointerTy = getValueType(TD.getIntPtrType());
   ShiftAmtHandling = Undefined;
   memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*));
+  memset(TargetDAGCombineArray, 0, 
+         sizeof(TargetDAGCombineArray)/sizeof(TargetDAGCombineArray[0]));
   maxStoresPerMemset = maxStoresPerMemcpy = maxStoresPerMemmove = 8;
   allowUnalignedMemoryAccesses = false;
   UseUnderscoreSetJmpLongJmp = false;
@@ -916,6 +918,12 @@ void TargetLowering::computeMaskedBitsForTargetNode(const SDOperand Op,
   KnownOne = 0;
 }
 
+SDOperand TargetLowering::
+PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
+  // Default implementation: no optimization.
+  return SDOperand();
+}
+
 //===----------------------------------------------------------------------===//
 //  Inline Assembler Implementation Methods
 //===----------------------------------------------------------------------===//