fix

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

while (E && isFusedOp(TmpFMA) && TmpFMA.hasOneUse()) {
 
       TmpFMA = TmpFMA->getOperand(2);
     }
   }
 
   // Look through FP_EXTEND nodes to do more combining.
 
   // fold (fadd (fpext (fmul x, y)), z) -> (fma (fpext x), (fpext y), z)
-  if (matcher.match(N1, ISD::FP_EXTEND)) {
+  if (matcher.match(N0, ISD::FP_EXTEND)) {
     SDValue N00 = N0.getOperand(0);
     if (isContractableFMUL(N00) &&
         TLI.isFPExtFoldable(DAG, PreferredFusedOpcode, VT,
                             N00.getValueType())) {
       return matcher.getNode(
           PreferredFusedOpcode, SL, VT,
           matcher.getNode(ISD::FP_EXTEND, SL, VT, N00.getOperand(0)),
           matcher.getNode(ISD::FP_EXTEND, SL, VT, N00.getOperand(1)), N1);