[PATCH] D108961: [RISCV] MC relaxation for out-of-range conditional branch.

[Jessica Clarke via Phabricator via llvm-commits]

jrtc27 added a comment.

To summarise my position after chatting things through with Philip, I'm in favour of landing this as-is^. For compiler-generated code, I would personally rather it not be something relied upon, but I understand the reasons it does from a practical perspective and that others have differing philosophical positions. My bigger concern was with hand-written assembly, especially with `.option norelax` (and possibly `.option norvc`) where there is the expectation that what you write is exactly what you get at the byte level, not just semantically (c.f. Linux's alternatives and static branches, which make use of that). For compatibility with GNU as on real-world code we do unfortunately need to support this, and so having it on by default is the way we have to go. I would, however, like to see both assemblers provide a standard way to turn this off in future, and perhaps an eventual path for compilers to explicitly opt-in to using this such that the default could be changed many years down the road (and thus not "surprise" developers), but that's all future work that isn't blocking for any of this.

^ NB: This is not a code review though, I haven't studied the changes themselves, hence making this just a comment and not an "official" approval


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