[DAG] visitSUB - pull out repeated getScalarSizeInBits() calls. NFC.

Author: RKSimon

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -3695,6 +3695,7 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
   SDValue N0 = N->getOperand(0);
   SDValue N1 = N->getOperand(1);
   EVT VT = N0.getValueType();
+  unsigned BitWidth = VT.getScalarSizeInBits();
   SDLoc DL(N);
 
   auto PeekThroughFreeze = [](SDValue N) {
@@ -3731,7 +3732,6 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
                        DAG.getConstant(-N1C->getAPIntValue(), DL, VT));
 
   if (isNullOrNullSplat(N0)) {
-    unsigned BitWidth = VT.getScalarSizeInBits();
     // Right-shifting everything out but the sign bit followed by negation is
     // the same as flipping arithmetic/logical shift type without the negation:
     // -(X >>u 31) -> (X >>s 31)
@@ -3931,7 +3931,7 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
       SDValue S0 = N1.getOperand(0);
       if ((X0 == S0 && X1 == N1) || (X0 == N1 && X1 == S0))
         if (ConstantSDNode *C = isConstOrConstSplat(N1.getOperand(1)))
-          if (C->getAPIntValue() == (VT.getScalarSizeInBits() - 1))
+          if (C->getAPIntValue() == (BitWidth - 1))
             return DAG.getNode(ISD::ABS, SDLoc(N), VT, S0);
     }
   }
@@ -3974,8 +3974,7 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
   if (!LegalOperations && N1.getOpcode() == ISD::SRL && N1.hasOneUse()) {
     SDValue ShAmt = N1.getOperand(1);
     ConstantSDNode *ShAmtC = isConstOrConstSplat(ShAmt);
-    if (ShAmtC &&
-        ShAmtC->getAPIntValue() == (N1.getScalarValueSizeInBits() - 1)) {
+    if (ShAmtC && ShAmtC->getAPIntValue() == (BitWidth - 1)) {
       SDValue SRA = DAG.getNode(ISD::SRA, DL, VT, N1.getOperand(0), ShAmt);
       return DAG.getNode(ISD::ADD, DL, VT, N0, SRA);
     }
@@ -3986,7 +3985,7 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
   // N0 - (X << BW-1) --> N0 + (X << BW-1)
   if (N1.getOpcode() == ISD::SHL) {
     ConstantSDNode *ShlC = isConstOrConstSplat(N1.getOperand(1));
-    if (ShlC && ShlC->getAPIntValue() == VT.getScalarSizeInBits() - 1)
+    if (ShlC && ShlC->getAPIntValue() == (BitWidth - 1))
       return DAG.getNode(ISD::ADD, DL, VT, N1, N0);
   }