The -ppc-asm-full-reg-names flag causes LLVM to generate named PPC registers instead of numbers. However, the resulting assembly code was not parsable by either GCC or LLVM due to missing percent symbols before register names. This patch inserts a percent sign before register names on PPC when -ppc-asm-full-reg-names is enabled except for the registers PPC::ZERO and other special registers that do not require the percent symbol.
The author never pinged it and it dropped off of people's radar. Is this of interest to you? The option that this helps with is seldom used - and only in testing, so this wasn't anyone's top priority. If you'd like to see this through, commandeer the patch, update it so it applies to (and passes all tests on) trunk and re-post.
I don't expect any of the reviewers will have an issue approving it.
Alright, thanks for letting us know that there was no implicit rejection to this kind of functionality. We'll take a closer look and commandeer this review when the other review is available.