rjmccall added a comment. Is it acceptable to leave this as a -cc1 option while we're pursuing this with the language committee? Do we have any intent to pursue this with the language committee?
================ Comment at: clang/include/clang/Basic/LangOptions.def:372 +LANGOPT(PassByValueIsNoAlias, 1, 0, "assumption that by-value parameters do " + "not alias any other values") ---------------- This should be a code-gen option, I think. I can't really imagine how this would affect language processing. ================ Comment at: clang/include/clang/Driver/Options.td:4287-4290 +def fpass_by_value_noalias: Flag<["-"], "fpass-by-value-noalias">, + HelpText<"Allows assuming no references to passed by value escape before " + "transferring execution to the called function. Note that this " + "does not hold for C++">; ---------------- rsmith wrote: > This should be in `Group<f_Group>`. The "Note" clause seems to muddy more than it clarifies. Maybe "has no effect on non-trivially-copyable classes in C++"? Or add proper documentation somewhere instead of trying to jam this into the help text. ================ Comment at: clang/lib/CodeGen/CGCall.cpp:2198 + // reference to the underlying object. Mark it accordingly. + Attrs.addAttribute(llvm::Attribute::NoAlias); + ---------------- This definitely can't be added unconditionally to all types; you need to rule out non-trivial C++ class types, as well as types with ObjC weak references. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D85473/new/ https://reviews.llvm.org/D85473 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
