[PATCH] D78636: [CodeGen] Use SPLAT_VECTOR for zeroinitialiser with scalable types

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:1562
     if (const ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
-      for (unsigned i = 0; i != NumElements; ++i)
+      assert(!EltCnt.Scalable && "ConstantVector used for scalable types");
+      for (unsigned i = 0; i != EltCnt.Min; ++i)
----------------
D77587 introduced FixedVectorType and ScalableVectorType, which means you can instead write:
  cast<FixedVectorType>(VecTy)->getNumElements()
That also removes the need for an additional assert.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:1570
 
       SDValue Op;
       if (EltVT.isFloatingPoint())
----------------
I'd prefer to see the Scalable and FixedWidth cases more separated here, something like

  if (isa<ScalableVectorType>(...))
    // Op = splat vector
  else {
    if (EltVT.isFloatingPoint())
      ...
    ...
  }


================
Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:1576
+
+      if (EltCnt.Scalable)
+        return NodeMap[V] = DAG.getSplatVector(VT, getCurSDLoc(), Op);
----------------
You can then write:

  if (isa<ScalableVectorType>(VecTy))
    Op = DAG.getSplatVector(VT, getCurSDLoc(), Op);


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D78636/new/

https://reviews.llvm.org/D78636