[SVE ACLE] Allow default zero initialisation for svcount_t. (#69321)

This matches the behaviour of the other SVE ACLE types.

2 files changed, 8 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 4bb0ba6..eabc763 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1738,6 +1738,12 @@ SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
     if (const auto *NC = dyn_cast<NoCFIValue>(C))
       return getValue(NC->getGlobalValue());
 
+    if (VT == MVT::aarch64svcount) {
+      assert(C->isNullValue() && "Can only zero this target type!");
+      return DAG.getNode(ISD::BITCAST, getCurSDLoc(), VT,
+                         DAG.getConstant(0, getCurSDLoc(), MVT::nxv16i1));
+    }
+
     VectorType *VecTy = cast<VectorType>(V->getType());
 
     // Now that we know the number and type of the elements, get that number of
diff --git a/llvm/lib/IR/Type.cpp b/llvm/lib/IR/Type.cpp
index 97febcd..006278d 100644
--- a/llvm/lib/IR/Type.cpp
+++ b/llvm/lib/IR/Type.cpp
@@ -841,7 +841,8 @@ static TargetTypeInfo getTargetTypeInfo(const TargetExtType *Ty) {
 
   // Opaque types in the AArch64 name space.
   if (Name == "aarch64.svcount")
-    return TargetTypeInfo(ScalableVectorType::get(Type::getInt1Ty(C), 16));
+    return TargetTypeInfo(ScalableVectorType::get(Type::getInt1Ty(C), 16),
+                          TargetExtType::HasZeroInit);
 
   return TargetTypeInfo(Type::getVoidTy(C));
 }