[DAG][NFC] Use SDPatternMatch for VScale in some instances

Author: michaelmaitland

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -1086,10 +1086,9 @@ bool DAGCombiner::reassociationCanBreakAddressingModePattern(unsigned Opc,
   // (load/store (add/sub (add x, y), vscale))
   // (load/store (add/sub (add x, y), (lsl vscale, C)))
   // (load/store (add/sub (add x, y), (mul vscale, C)))
-  if ((N1.getOpcode() == ISD::VSCALE ||
-       ((N1.getOpcode() == ISD::SHL || N1.getOpcode() == ISD::MUL) &&
-        N1.getOperand(0).getOpcode() == ISD::VSCALE &&
-        isa<ConstantSDNode>(N1.getOperand(1)))) &&
+  if (sd_match(N1, m_AnyOf(m_VScale(m_Value()),
+                           m_Shl(m_VScale(m_Value()), m_ConstInt()),
+                           m_Mul(m_VScale(m_Value()), m_ConstInt()))) &&
       N1.getValueType().getFixedSizeInBits() <= 64) {
     int64_t ScalableOffset = N1.getOpcode() == ISD::VSCALE
                                  ? N1.getConstantOperandVal(0)
@@ -2975,8 +2974,7 @@ SDValue DAGCombiner::visitADD(SDNode *N) {
   }
 
   // fold a+vscale(c1)+vscale(c2) -> a+vscale(c1+c2)
-  if (N0.getOpcode() == ISD::ADD &&
-      N0.getOperand(1).getOpcode() == ISD::VSCALE &&
+  if (sd_match(N0, m_Add(m_Value(), m_VScale(m_Value()))) &&
       N1.getOpcode() == ISD::VSCALE) {
     const APInt &VS0 = N0.getOperand(1)->getConstantOperandAPInt(0);
     const APInt &VS1 = N1->getConstantOperandAPInt(0);