[clang] [llvm] [AArch64] Refactor implementation of FP8 types (NFC) (PR #118969)

[Momchil Velikov via cfe-commits]

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@@ -12153,8 +12166,15 @@ static QualType DecodeTypeFromStr(const char *&Str, const ASTContext &Context,
                                              RequiresICE, false);
     assert(!RequiresICE && "Can't require vector ICE");
 
-    // TODO: No way to make AltiVec vectors in builtins yet.
-    Type = Context.getVectorType(ElementType, NumElements, VectorKind::Generic);
+    if (ElementType == Context.MFloat8Ty) {
+      assert((NumElements == 8 || NumElements == 16) &&
+             "Invalid number of elements");
+      Type = NumElements == 8 ? Context.MFloat8x8Ty : Context.MFloat8x16Ty;
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momchil-velikov wrote:

I don't think it'll work because it creates a `VectorType` https://github.com/llvm/llvm-project/blob/4a44e4b192db0bb38d3eb7ff20c767e2c747d745/clang/lib/AST/ASTContext.cpp#L4503
and our FP8 vectors aren't `VectorType`s

https://github.com/llvm/llvm-project/pull/118969