[PATCH] D80064: [X86] Disable LVI load hardening pass at O0

Wed May 27 13:02:51 PDT 2020

nikic added a comment.

I'm not really convinced that erroring in that case makes sense though. I expect that a typical use of this functionality is something like https://github.com/rust-lang/rust/pull/72655/files#diff-23a2e218f0f24d0c63cc4347012d83ff, in which case making `+lvi-load-hardening` at optnone an error doesn't help anyone. It just means extra complexity to not set the target features at optnone, leading to exactly the same place as we would with this patch, just reimplemented at a higher level in the frontend (or the user of the frontend).

I think this should either be silently disabled at optnone (as this patch does), or as @craig.topper suggests, it should fence every load as a conservative approach.

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https://reviews.llvm.org/D80064