[clang] [CIR] floating-point, pointer, and function types (PR #120484)

[Bruno Cardoso Lopes via cfe-commits]

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@@ -18,6 +21,87 @@ mlir::MLIRContext &CIRGenTypes::getMLIRContext() const {
   return *builder.getContext();
 }
 
+/// Return true if the specified type in a function parameter or result position
+/// can be converted to a CIR type at this point. This boils down to being
+/// whether it is complete, as well as whether we've temporarily deferred
+/// expanding the type because we're in a recursive context.
+bool CIRGenTypes::isFuncParamTypeConvertible(clang::QualType type) {
+  // Some ABIs cannot have their member pointers represented in LLVM IR unless
+  // certain circumstances have been reached.
+  assert(!type->getAs<MemberPointerType>() && "NYI");
+
+  // If this isn't a tagged type, we can convert it!
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bcardosolopes wrote:

I think it's totally fine to be conservative about assumptions, we need asserts for both things that are NYI but also for things we assume as invariants, IMO the more the merrier cause it's easier to catch miscompilations.

> Neither of which mention those types specifically? It seems it USED to have an assert for not-tag-type, though it isn't clear that the authors considered the above types.

I don't remember the full context anymore, but assertion on a assumed invariant in the incubator to be even more protective also sounds good to me (guess running the tests upon such change will give us the final answer).

https://github.com/llvm/llvm-project/pull/120484