Revert "[AArch64][SVE][VLS] Move extends into arguments of comparisons"

This reverts commit db04d3e, which
causes a buildbot failure.

Author: peterwaller-arm

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -15338,40 +15338,6 @@ static SDValue performIntrinsicCombine(SDNode *N,
   return SDValue();
 }
 
-static bool isCheapToExtend(const SDValue &N) {
-  unsigned OC = N->getOpcode();
-  return OC == ISD::LOAD || OC == ISD::MLOAD ||
-         ISD::isConstantSplatVectorAllZeros(N.getNode());
-}
-
-static SDValue
-performSignExtendSetCCCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI,
-                              SelectionDAG &DAG) {
-  // If we have (sext (setcc A B)) and A and B are cheap to extend,
-  // we can move the sext into the arguments and have the same result. For
-  // example, if A and B are both loads, we can make those extending loads and
-  // avoid an extra instruction. This pattern appears often in VLS code
-  // generation where the inputs to the setcc have a different size to the
-  // instruction that wants to use the result of the setcc.
-  assert(N->getOpcode() == ISD::SIGN_EXTEND &&
-         N->getOperand(0)->getOpcode() == ISD::SETCC);
-  const SDValue SetCC = N->getOperand(0);
-
-  if (isCheapToExtend(SetCC.getOperand(0)) &&
-      isCheapToExtend(SetCC.getOperand(1))) {
-    const SDValue Ext1 = DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N),
-                                     N->getValueType(0), SetCC.getOperand(0));
-    const SDValue Ext2 = DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N),
-                                     N->getValueType(0), SetCC.getOperand(1));
-
-    return DAG.getSetCC(
-        SDLoc(SetCC), N->getValueType(0), Ext1, Ext2,
-        cast<CondCodeSDNode>(SetCC->getOperand(2).getNode())->get());
-  }
-
-  return SDValue();
-}
-
 static SDValue performExtendCombine(SDNode *N,
                                     TargetLowering::DAGCombinerInfo &DCI,
                                     SelectionDAG &DAG) {
@@ -15390,11 +15356,6 @@ static SDValue performExtendCombine(SDNode *N,
 
     return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), N->getValueType(0), NewABD);
   }
-
-  if (N->getOpcode() == ISD::SIGN_EXTEND &&
-      N->getOperand(0)->getOpcode() == ISD::SETCC)
-    return performSignExtendSetCCCombine(N, DCI, DAG);
-
   return SDValue();
 }