[LegalizeVectorTypes] Enable WidenVecRes_SETCC work for scalable vector

[Jimerlife]

Summary

Replace getVectorNumElements with getVectorElementCount to enable WidenVecRes_SETCC work for scalable vector.

[frasercrmck]

LGTM but I don't think you need to say [RISCV] in the title.

[Jimerlife]

In D125359#3505528, @frasercrmck wrote:

LGTM but I don't think you need to say [RISCV] in the title.

Thanks, removed [RISCV] in the title.

llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp

SDValue DAGTypeLegalizer::WidenVecRes_VECTOR_SHUFFLE(ShuffleVectorSDNode *N) {
   return DAG.getVectorShuffle(WidenVT, dl, InOp1, InOp2, NewMask);
 }
 
 SDValue DAGTypeLegalizer::WidenVecRes_SETCC(SDNode *N) {
   assert(N->getValueType(0).isVector() &&
          N->getOperand(0).getValueType().isVector() &&
          "Operands must be vectors");
   EVT WidenVT = TLI.getTypeToTransformTo(*DAG.getContext(), N->getValueType(0));
-  unsigned WidenNumElts = WidenVT.getVectorNumElements();
+  ElementCount WidenEC = WidenVT.getVectorElementCount();
 
   SDValue InOp1 = N->getOperand(0);
   EVT InVT = InOp1.getValueType();
   assert(InVT.isVector() && "can not widen non-vector type");
-  EVT WidenInVT = EVT::getVectorVT(*DAG.getContext(),
-                                   InVT.getVectorElementType(), WidenNumElts);
+  EVT WidenInVT =
+      EVT::getVectorVT(*DAG.getContext(), InVT.getVectorElementType(), WidenEC);
 
   // The input and output types often differ here, and it could be that while
   // we'd prefer to widen the result type, the input operands have been split.
   // In this case, we also need to split the result of this node as well.
   if (getTypeAction(InVT) == TargetLowering::TypeSplitVector) {
     SDValue SplitVSetCC = SplitVecOp_VSETCC(N);
     SDValue Res = ModifyToType(SplitVSetCC, WidenVT);
     return Res;

llvm/test/CodeGen/RISCV/rvv/setcc-integer.ll

 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: sed 's/iXLen/i32/g' %s | llc -mtriple=riscv32 -mattr=+m,+v \
 ; RUN:   -verify-machineinstrs | FileCheck %s --check-prefixes=CHECK,RV32
 ; RUN: sed 's/iXLen/i64/g' %s | llc -mtriple=riscv64 -mattr=+m,+v \
 ; RUN:   -verify-machineinstrs | FileCheck %s --check-prefixes=CHECK,RV64
 
+define <vscale x 3 x i1> @icmp_eq_vv_nxv3i8(<vscale x 3 x i8> %va, <vscale x 3 x i8> %vb) {
+; CHECK-LABEL: icmp_eq_vv_nxv3i8:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vsetvli a0, zero, e8, mf2, ta, mu
+; CHECK-NEXT:    vmseq.vv v0, v8, v9
+; CHECK-NEXT:    ret
+  %vc = icmp eq <vscale x 3 x i8> %va, %vb
+  ret <vscale x 3 x i1> %vc
+}
+
+define <vscale x 3 x i1> @icmp_eq_vx_nxv3i8(<vscale x 3 x i8> %va, i8 %b) {
+; CHECK-LABEL: icmp_eq_vx_nxv3i8:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vsetvli a1, zero, e8, mf2, ta, mu
+; CHECK-NEXT:    vmseq.vx v0, v8, a0
+; CHECK-NEXT:    ret
+  %head = insertelement <vscale x 3 x i8> poison, i8 %b, i32 0
+  %splat = shufflevector <vscale x 3 x i8> %head, <vscale x 3 x i8> poison, <vscale x 3 x i32> zeroinitializer
+  %vc = icmp eq <vscale x 3 x i8> %va, %splat
+  ret <vscale x 3 x i1> %vc
+}
+
+define <vscale x 3 x i1> @icmp_eq_xv_nxv3i8(<vscale x 3 x i8> %va, i8 %b) {
+; CHECK-LABEL: icmp_eq_xv_nxv3i8:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vsetvli a1, zero, e8, mf2, ta, mu
+; CHECK-NEXT:    vmseq.vx v0, v8, a0
+; CHECK-NEXT:    ret
+  %head = insertelement <vscale x 3 x i8> poison, i8 %b, i32 0
+  %splat = shufflevector <vscale x 3 x i8> %head, <vscale x 3 x i8> poison, <vscale x 3 x i32> zeroinitializer
+  %vc = icmp eq <vscale x 3 x i8> %splat, %va
+  ret <vscale x 3 x i1> %vc
+}
+
 define <vscale x 8 x i1> @icmp_eq_vv_nxv8i8(<vscale x 8 x i8> %va, <vscale x 8 x i8> %vb) {
 ; CHECK-LABEL: icmp_eq_vv_nxv8i8:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    vsetvli a0, zero, e8, m1, ta, mu
 ; CHECK-NEXT:    vmseq.vv v0, v8, v9
 ; CHECK-NEXT:    ret
   %vc = icmp eq <vscale x 8 x i8> %va, %vb
   ret <vscale x 8 x i1> %vc