[SelectionDAG] Add getVPZeroExtendInReg. NFC (#92792)

Use it for 2 places in LegalizeIntegerTypes that created a VP_AND.

Author: topperc

llvm/include/llvm/CodeGen/SelectionDAG.h

@@ -991,6 +991,11 @@ class SelectionDAG {
   /// value assuming it was the smaller SrcTy value.
   SDValue getZeroExtendInReg(SDValue Op, const SDLoc &DL, EVT VT);
 
+  /// Return the expression required to zero extend the Op
+  /// value assuming it was the smaller SrcTy value.
+  SDValue getVPZeroExtendInReg(SDValue Op, SDValue Mask, SDValue EVL,
+                               const SDLoc &DL, EVT VT);
+
   /// Convert Op, which must be of integer type, to the integer type VT, by
   /// either truncating it or performing either zero or sign extension as
   /// appropriate extension for the pointer's semantics.

llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp

@@ -1511,10 +1511,7 @@ SDValue DAGTypeLegalizer::PromoteIntRes_VPFunnelShift(SDNode *N) {
       !TLI.isOperationLegalOrCustom(Opcode, VT)) {
     SDValue HiShift = DAG.getConstant(OldBits, DL, VT);
     Hi = DAG.getNode(ISD::VP_SHL, DL, VT, Hi, HiShift, Mask, EVL);
-    APInt Imm = APInt::getLowBitsSet(VT.getScalarSizeInBits(),
-                                     OldVT.getScalarSizeInBits());
-    Lo = DAG.getNode(ISD::VP_AND, DL, VT, Lo, DAG.getConstant(Imm, DL, VT),
-                     Mask, EVL);
+    Lo = DAG.getVPZeroExtendInReg(Lo, Mask, EVL, DL, OldVT);
     SDValue Res = DAG.getNode(ISD::VP_OR, DL, VT, Hi, Lo, Mask, EVL);
     Res = DAG.getNode(IsFSHR ? ISD::VP_LSHR : ISD::VP_SHL, DL, VT, Res, Amt,
                       Mask, EVL);
@@ -2377,10 +2374,8 @@ SDValue DAGTypeLegalizer::PromoteIntOp_VP_ZERO_EXTEND(SDNode *N) {
   // FIXME: There is no VP_ANY_EXTEND yet.
   Op = DAG.getNode(ISD::VP_ZERO_EXTEND, dl, VT, Op, N->getOperand(1),
                    N->getOperand(2));
-  APInt Imm = APInt::getLowBitsSet(VT.getScalarSizeInBits(),
-                                   N->getOperand(0).getScalarValueSizeInBits());
-  return DAG.getNode(ISD::VP_AND, dl, VT, Op, DAG.getConstant(Imm, dl, VT),
-                     N->getOperand(1), N->getOperand(2));
+  return DAG.getVPZeroExtendInReg(Op, N->getOperand(1), N->getOperand(2), dl,
+                                  N->getOperand(0).getValueType());
 }
 
 SDValue DAGTypeLegalizer::PromoteIntOp_FIX(SDNode *N) {

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -1540,6 +1540,25 @@ SDValue SelectionDAG::getZeroExtendInReg(SDValue Op, const SDLoc &DL, EVT VT) {
   return getNode(ISD::AND, DL, OpVT, Op, getConstant(Imm, DL, OpVT));
 }
 
+SDValue SelectionDAG::getVPZeroExtendInReg(SDValue Op, SDValue Mask,
+                                           SDValue EVL, const SDLoc &DL,
+                                           EVT VT) {
+  EVT OpVT = Op.getValueType();
+  assert(VT.isInteger() && OpVT.isInteger() &&
+         "Cannot getVPZeroExtendInReg FP types");
+  assert(VT.isVector() && OpVT.isVector() &&
+         "getVPZeroExtendInReg type and operand type should be vector!");
+  assert(VT.getVectorElementCount() == OpVT.getVectorElementCount() &&
+         "Vector element counts must match in getZeroExtendInReg");
+  assert(VT.bitsLE(OpVT) && "Not extending!");
+  if (OpVT == VT)
+    return Op;
+  APInt Imm = APInt::getLowBitsSet(OpVT.getScalarSizeInBits(),
+                                   VT.getScalarSizeInBits());
+  return getNode(ISD::VP_AND, DL, OpVT, Op, getConstant(Imm, DL, OpVT), Mask,
+                 EVL);
+}
+
 SDValue SelectionDAG::getPtrExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT) {
   // Only unsigned pointer semantics are supported right now. In the future this
   // might delegate to TLI to check pointer signedness.