[libcxx-commits] [PATCH] D137599: [libunwind][PowerPC] Fix saving/restoring VSX registers on LE systems

[Nemanja Ivanovic via Phabricator via libcxx-commits]

nemanjai added inline comments.


================
Comment at: libunwind/src/assembly.h:194
+// against a version that does not provide the HWCAP2.
+#define GLIBC_VERSION_SYM .quad __parse_hwcap_and_convert_at_platform
+#else
----------------
MaskRay wrote:
> This doesn't work as intended.
> 
> `.quad __parse_hwcap_and_convert_at_platform` without a definition creates an undefined symbol.
> There it is un-referenced there won't be a `undefined symbol/reference` error.
I don't follow what you mean here. Under which conditions will this fail to produce an undefined symbol/reference error?

Perhaps it is a moot point since I will be removing this code as per Xing's comment, but I am just curious (especially since GCC also does this for emitting code for `__builtin_cpu_is/__builtin_cpu_supports` and Clang will follow GCC's implementation).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137599/new/

https://reviews.llvm.org/D137599