[RISCV] Use setcc to truncate results in widenVectorOpsToi8

[luke]

Summary

To avoid an unnecessary vand.vi

[craig.topper]

LGTM with that one comment.

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

7298

While you're here

SDValue(WideN.getNode(), I) -> WidenN.getValue(I)

[luke]

Use getValue

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

static SDValue widenVectorOpsToi8(SDValue N, SDLoc &DL, SelectionDAG &DAG) {
 
   unsigned NumVals = N->getNumValues();
 
   SDVTList VTs = DAG.getVTList(SmallVector<EVT, 4>(
       NumVals, N.getValueType().changeVectorElementType(MVT::i8)));
   SDValue WideN = DAG.getNode(N.getOpcode(), DL, VTs, WideOps);
   SmallVector<SDValue, 4> TruncVals;
   for (unsigned I = 0; I < NumVals; I++) {
-    TruncVals.push_back(DAG.getNode(ISD::TRUNCATE, DL,
-                                    N->getSimpleValueType(I),
-                                    SDValue(WideN.getNode(), I)));
+    TruncVals.push_back(
+        DAG.getSetCC(DL, N->getSimpleValueType(I), WideN.getValue(I),
+                     DAG.getConstant(0, DL, WideVT), ISD::SETNE));
   }
 
   if (TruncVals.size() > 1)
     return DAG.getMergeValues(TruncVals, DL);
   return TruncVals.front();
 }
 
 SDValue RISCVTargetLowering::lowerVECTOR_DEINTERLEAVE(SDValue Op,

llvm/test/CodeGen/RISCV/rvv/vector-deinterleave.ll

 ; CHECK-NEXT:    vsetvli a1, zero, e8, mf2, ta, ma
 ; CHECK-NEXT:    vslidedown.vx v0, v0, a0
 ; CHECK-NEXT:    vsetvli a0, zero, e8, m2, ta, ma
 ; CHECK-NEXT:    vmv.v.i v10, 0
 ; CHECK-NEXT:    vmerge.vim v14, v10, 1, v0
 ; CHECK-NEXT:    vmv1r.v v0, v8
 ; CHECK-NEXT:    vmerge.vim v12, v10, 1, v0
 ; CHECK-NEXT:    vnsrl.wi v8, v12, 0
-; CHECK-NEXT:    vand.vi v8, v8, 1
 ; CHECK-NEXT:    vmsne.vi v0, v8, 0
-; CHECK-NEXT:    vnsrl.wi v8, v12, 8
-; CHECK-NEXT:    vand.vi v10, v8, 1
+; CHECK-NEXT:    vnsrl.wi v10, v12, 8
 ; CHECK-NEXT:    vmsne.vi v8, v10, 0
 ; CHECK-NEXT:    ret
 %retval = call {<vscale x 16 x i1>, <vscale x 16 x i1>} @llvm.experimental.vector.deinterleave2.nxv32i1(<vscale x 32 x i1> %vec)
 ret {<vscale x 16 x i1>, <vscale x 16 x i1>} %retval
 }
 
 define {<vscale x 16 x i8>, <vscale x 16 x i8>} @vector_deinterleave_nxv16i8_nxv32i8(<vscale x 32 x i8> %vec) {
 ; CHECK-LABEL: vector_deinterleave_nxv16i8_nxv32i8:

llvm/test/CodeGen/RISCV/rvv/vector-interleave.ll

 ; CHECK-NEXT:    vmv.v.i v10, 0
 ; CHECK-NEXT:    vmv1r.v v0, v8
 ; CHECK-NEXT:    vmerge.vim v12, v10, 1, v0
 ; CHECK-NEXT:    vmv1r.v v0, v9
 ; CHECK-NEXT:    vmerge.vim v8, v10, 1, v0
 ; CHECK-NEXT:    vwaddu.vv v16, v8, v12
 ; CHECK-NEXT:    li a0, -1
 ; CHECK-NEXT:    vwmaccu.vx v16, a0, v12
-; CHECK-NEXT:    vand.vi v8, v18, 1
-; CHECK-NEXT:    vmsne.vi v10, v8, 0
-; CHECK-NEXT:    vand.vi v8, v16, 1
-; CHECK-NEXT:    vmsne.vi v0, v8, 0
+; CHECK-NEXT:    vmsne.vi v8, v18, 0
+; CHECK-NEXT:    vmsne.vi v0, v16, 0
 ; CHECK-NEXT:    csrr a0, vlenb
 ; CHECK-NEXT:    srli a0, a0, 2
 ; CHECK-NEXT:    add a1, a0, a0
 ; CHECK-NEXT:    vsetvli zero, a1, e8, mf2, tu, ma
-; CHECK-NEXT:    vslideup.vx v0, v10, a0
+; CHECK-NEXT:    vslideup.vx v0, v8, a0
 ; CHECK-NEXT:    ret
      %res = call <vscale x 32 x i1> @llvm.experimental.vector.interleave2.nxv32i1(<vscale x 16 x i1> %a, <vscale x 16 x i1> %b)
      ret <vscale x 32 x i1> %res
 }
 
 define <vscale x 16 x i16> @vector_interleave_nxv16i16_nxv8i16(<vscale x 8 x i16> %a, <vscale x 8 x i16> %b) {
 ; CHECK-LABEL: vector_interleave_nxv16i16_nxv8i16:
 ; CHECK:       # %bb.0: