[clang] [Sparc][clang] Match GCC's SPARC V8 vector return convention (PR #222264)

[Folkert de Vries via cfe-commits]

================
@@ -71,6 +71,17 @@ ABIArgInfo SparcV8ABIInfo::classifyReturnType(QualType Ty) const {
   if (const auto *CT = Ty->getAs<ComplexType>())
     return classifyComplexType(CT, /*IsRet=*/true);
 
+  if (const auto *VT = Ty->getAs<VectorType>()) {
+    uint64_t Size = getContext().getTypeSize(Ty);
+    if (VT->getElementType()->isRealFloatingType() || Size > 64)
+      return getNaturalAlignIndirect(Ty, getDataLayout().getAllocaAddrSpace());
+
+    llvm::Type *FloatTy = llvm::Type::getFloatTy(getVMContext());
+    llvm::Type *CoerceTy =
+        Size <= 32 ? FloatTy : llvm::StructType::get(FloatTy, FloatTy);
----------------
folkertdev wrote:

I think it would be more accurate to use `double` (if that works):
```suggestion
        Size <= 32 ? FloatTy : DoubleTy
```

https://github.com/llvm/llvm-project/pull/222264