aaron.ballman added a comment. In D124998#3494814 <https://reviews.llvm.org/D124998#3494814>, @erichkeane wrote:
> First: I care very little about `FunctionNoProtoType`. I care insomuch as it doesn't break valid user code. > Second, it is used only in "C" afaik, where our memory pressure isn't that > big of a deal. I'd be OK with having the `FunctionTypeExtraBits` be just > added to `FunctionNoProtoType`, but stay in `FunctionProtoType` trailing > storage. I agree that the memory pressure here shouldn't be overly concerning, and I would most likely be okay if we adds the bits that way. However, I think we could also just make `FunctionNoProtoType` have the same memory layout as `FunctionProtoType` by using trailing objects again. > It WOULD be more work, but I would wonder if we could combine all 3 classes > into `FunctionType` and replace the `NoProtoType`-ness with a single bit to > differentiate. The result is the non-prototyped versions needing to carry > around extra information, but since: > a- our C implementation has low memory pressure > b- prototypeless functions were a mistake > > I would think the extra memory they end up carrying might be ok? We do a fair amount of checks via `isa<FunctionProtoType>()` (or similar) that would need to be updated to check for a `FunctionType` and whether that bit is set, and I don't have a good handle on what that would do to the code. If it doesn't cause significant maintenance issues, I would still want to see some measurements for what it does to compiler performance on large projects (it'd be a good thing to try on http://llvm-compile-time-tracker.com/). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D124998/new/ https://reviews.llvm.org/D124998 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
