Pull out repeated calls to VT.getVectorNumElements(). NFCI.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315818 91177308-0d34-0410-b5e6-96231b3b80d8

Author: RKSimon

lib/Target/X86/X86ISelLowering.cpp

@@ -31475,23 +31475,24 @@ static SDValue reduceVMULWidth(SDNode *N, SelectionDAG &DAG,
   SDValue N0 = N->getOperand(0);
   SDValue N1 = N->getOperand(1);
   EVT VT = N->getOperand(0).getValueType();
+  unsigned NumElts = VT.getVectorNumElements();
   unsigned RegSize = 128;
   MVT OpsVT = MVT::getVectorVT(MVT::i16, RegSize / 16);
-  EVT ReducedVT =
-      EVT::getVectorVT(*DAG.getContext(), MVT::i16, VT.getVectorNumElements());
+  EVT ReducedVT = EVT::getVectorVT(*DAG.getContext(), MVT::i16, NumElts);
+
   // Shrink the operands of mul.
   SDValue NewN0 = DAG.getNode(ISD::TRUNCATE, DL, ReducedVT, N0);
   SDValue NewN1 = DAG.getNode(ISD::TRUNCATE, DL, ReducedVT, N1);
 
-  if (VT.getVectorNumElements() >= OpsVT.getVectorNumElements()) {
+  if (NumElts >= OpsVT.getVectorNumElements()) {
     // Generate the lower part of mul: pmullw. For MULU8/MULS8, only the
     // lower part is needed.
     SDValue MulLo = DAG.getNode(ISD::MUL, DL, ReducedVT, NewN0, NewN1);
     if (Mode == MULU8 || Mode == MULS8) {
       return DAG.getNode((Mode == MULU8) ? ISD::ZERO_EXTEND : ISD::SIGN_EXTEND,
                          DL, VT, MulLo);
     } else {
-      MVT ResVT = MVT::getVectorVT(MVT::i32, VT.getVectorNumElements() / 2);
+      MVT ResVT = MVT::getVectorVT(MVT::i32, NumElts / 2);
       // Generate the higher part of mul: pmulhw/pmulhuw. For MULU16/MULS16,
       // the higher part is also needed.
       SDValue MulHi = DAG.getNode(Mode == MULS16 ? ISD::MULHS : ISD::MULHU, DL,
@@ -31500,18 +31501,18 @@ static SDValue reduceVMULWidth(SDNode *N, SelectionDAG &DAG,
       // Repack the lower part and higher part result of mul into a wider
       // result.
       // Generate shuffle functioning as punpcklwd.
-      SmallVector<int, 16> ShuffleMask(VT.getVectorNumElements());
-      for (unsigned i = 0; i < VT.getVectorNumElements() / 2; i++) {
+      SmallVector<int, 16> ShuffleMask(NumElts);
+      for (unsigned i = 0, e = NumElts/ 2; i < e; i++) {
         ShuffleMask[2 * i] = i;
-        ShuffleMask[2 * i + 1] = i + VT.getVectorNumElements();
+        ShuffleMask[2 * i + 1] = i + NumElts;
       }
       SDValue ResLo =
           DAG.getVectorShuffle(ReducedVT, DL, MulLo, MulHi, ShuffleMask);
       ResLo = DAG.getBitcast(ResVT, ResLo);
       // Generate shuffle functioning as punpckhwd.
-      for (unsigned i = 0; i < VT.getVectorNumElements() / 2; i++) {
-        ShuffleMask[2 * i] = i + VT.getVectorNumElements() / 2;
-        ShuffleMask[2 * i + 1] = i + VT.getVectorNumElements() * 3 / 2;
+      for (unsigned i = 0, e = NumElts / 2; i < e; i++) {
+        ShuffleMask[2 * i] = i + NumElts / 2;
+        ShuffleMask[2 * i + 1] = i + NumElts * 3 / 2;
       }
       SDValue ResHi =
           DAG.getVectorShuffle(ReducedVT, DL, MulLo, MulHi, ShuffleMask);