[llvm] [VP][RISCV] Add vp.cttz.elts intrinsic and its RISC-V codegen (PR #90502)

[Min-Yih Hsu via llvm-commits]

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@@ -9074,6 +9074,38 @@ SDValue TargetLowering::expandVPCTTZ(SDNode *Node, SelectionDAG &DAG) const {
   return DAG.getNode(ISD::VP_CTPOP, dl, VT, Tmp, Mask, VL);
 }
 
+SDValue TargetLowering::expandVPCTTZElements(SDNode *N,
+                                             SelectionDAG &DAG) const {
+  // %cond = to_bool_vec %source
+  // %splat = splat /*val=*/VL
+  // %tz = step_vector
+  // %v = vp.select %cond, /*true=*/tz, /*false=*/%splat
+  // %r = vp.reduce.umin %v
+  SDLoc DL(N);
+  SDValue Source = N->getOperand(0);
+  SDValue Mask = N->getOperand(1);
+  SDValue EVL = N->getOperand(2);
+  EVT SrcVT = Source.getValueType();
+  EVT ResVT = N->getValueType(0);
+  EVT ResVecVT =
+      EVT::getVectorVT(*DAG.getContext(), ResVT, SrcVT.getVectorElementCount());
+
+  // Convert to boolean vector.
+  if (SrcVT.getScalarType() != MVT::i1) {
+    SDValue AllZero = DAG.getConstant(0, DL, SrcVT);
+    SrcVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1,
+                             SrcVT.getVectorElementCount());
+    Source = DAG.getSetCC(DL, SrcVT, Source, AllZero, ISD::SETNE);
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mshockwave wrote:

Fixed.

https://github.com/llvm/llvm-project/pull/90502