[LegalizeTypes] Use VP_AND for zext_inreg in PromoteIntRes_VPFunnelShift.

I may eventually add getVPZeroExtendInReg to SelectionDAG if there are
other cases, but for now just hardcode it.

Author: topperc

llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp

@@ -1511,8 +1511,10 @@ 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);
-    // FIXME: Replace it by vp operations.
-    Lo = DAG.getZeroExtendInReg(Lo, DL, OldVT);
+    APInt Imm = APInt::getLowBitsSet(VT.getScalarSizeInBits(),
+                                     OldVT.getScalarSizeInBits());
+    Lo = DAG.getNode(ISD::VP_AND, DL, VT, Lo, DAG.getConstant(Imm, DL, VT),
+                     Mask, EVL);
     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);

llvm/test/CodeGen/RISCV/rvv/fshr-fshl-vp.ll

@@ -1318,10 +1318,8 @@ define <vscale x 1 x i8> @fshr_v1i4(<vscale x 1 x i8> %a, <vscale x 1 x i8> %b,
 ; CHECK-NEXT:    li a1, 4
 ; CHECK-NEXT:    vsetvli zero, a0, e8, mf8, ta, ma
 ; CHECK-NEXT:    vremu.vx v10, v10, a1, v0.t
+; CHECK-NEXT:    vand.vi v9, v9, 15, v0.t
 ; CHECK-NEXT:    vsll.vi v8, v8, 4, v0.t
-; CHECK-NEXT:    vsetvli a1, zero, e8, mf8, ta, ma
-; CHECK-NEXT:    vand.vi v9, v9, 15
-; CHECK-NEXT:    vsetvli zero, a0, e8, mf8, ta, ma
 ; CHECK-NEXT:    vor.vv v8, v8, v9, v0.t
 ; CHECK-NEXT:    vsrl.vv v8, v8, v10, v0.t
 ; CHECK-NEXT:    vand.vi v8, v8, 15, v0.t
@@ -1343,10 +1341,8 @@ define <vscale x 1 x i8> @fshl_v1i4(<vscale x 1 x i8> %a, <vscale x 1 x i8> %b,
 ; CHECK-NEXT:    li a1, 4
 ; CHECK-NEXT:    vsetvli zero, a0, e8, mf8, ta, ma
 ; CHECK-NEXT:    vremu.vx v10, v10, a1, v0.t
+; CHECK-NEXT:    vand.vi v9, v9, 15, v0.t
 ; CHECK-NEXT:    vsll.vi v8, v8, 4, v0.t
-; CHECK-NEXT:    vsetvli a1, zero, e8, mf8, ta, ma
-; CHECK-NEXT:    vand.vi v9, v9, 15
-; CHECK-NEXT:    vsetvli zero, a0, e8, mf8, ta, ma
 ; CHECK-NEXT:    vor.vv v8, v8, v9, v0.t
 ; CHECK-NEXT:    vsll.vv v8, v8, v10, v0.t
 ; CHECK-NEXT:    vsrl.vi v8, v8, 4, v0.t