[llvm] [RISCV] Support VP_SPLAT mask operations (PR #132345)

[via llvm-commits]

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@@ -12773,8 +12774,29 @@ SDValue RISCVTargetLowering::lowerVPSplatExperimental(SDValue Op,
     Mask = convertToScalableVector(MaskVT, Mask, DAG, Subtarget);
   }
 
-  SDValue Result =
-      lowerScalarSplat(SDValue(), Val, VL, ContainerVT, DL, DAG, Subtarget);
+  SDValue Result;
+  if (VT.getScalarType() == MVT::i1) {
+    if (auto *C = dyn_cast<ConstantSDNode>(Val)) {
+      Result = C->isZero()
+                   ? DAG.getNode(RISCVISD::VMCLR_VL, DL, ContainerVT, VL)
+                   : DAG.getNode(RISCVISD::VMSET_VL, DL, ContainerVT, VL);
+      if (!ISD::isConstantSplatVectorAllOnes(Mask.getNode()))
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NexMing wrote:

Alright

https://github.com/llvm/llvm-project/pull/132345