1 files changed, 6 insertions, 0 deletions
diff --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp
index b98be4ae4b75..4dfc16526a00 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -1192,6 +1192,12 @@ bool MipsTargetLowering::hasBitTest(SDValue X, SDValue Y) const {
 
 bool MipsTargetLowering::shouldFoldConstantShiftPairToMask(
     const SDNode *N, CombineLevel Level) const {
+  assert(((N->getOpcode() == ISD::SHL &&
+           N->getOperand(0).getOpcode() == ISD::SRL) ||
+          (N->getOpcode() == ISD::SRL &&
+           N->getOperand(0).getOpcode() == ISD::SHL)) &&
+         "Expected shift-shift mask");
+
   if (N->getOperand(0).getValueType().isVector())
     return false;
   return true;