rjmccall added a comment. Having some sort of reliable marker here emitted after the call is currently a correctness condition for using the ObjC ARC autorelease optimization. Apple's x86_64 ObjC runtime is constrained by ABI limitations, so we sniff for a particular, fairly reasonable code pattern that looks like moving the return value to the first argument register and then making a specific call; on other platforms, we look for a specific non-standard NOP. Non-Apple runtimes that don't have the same ABI concerns probably ought to just use a NOP marker, but if that's not an option, then yeah, I guess you just need the compiler to emit the right register-register move, and then make sure the runtime is sniffing for that.
It's possible the GNU runtime generally uses a different approach and doesn't need these markers at all; David Chisnall might know. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D134441/new/ https://reviews.llvm.org/D134441 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
