[PATCH] D10416: Use function attribute "arm-restrict-it"

[Jim Grosbach via llvm-commits]

grosbach added a comment.

For the backend attribute, having -arm-restrict-it (or equivalent) transitively disable HasV8Ops is really, really bad. Those should be completely independent selections. The former is about tuning instruction selection (via if-conversion in this case) based on the microarchitecture. The latter is about which instructions are available in the first place. The former does not imply the latter.

I don't think there's much point to disabling restrict-it when targeting v8 from an end-user POV, but it's pretty useful for the backend. We want to be able to write test cases that make sure it's working, for example.

Do I understand right there's a frontend option, too? That's the only context in which gcc compatibility makes much sense. I don't see any value other than slavishly following gcc's option list to having this be exposed to end users in clang. I'd much rather it be entirely in the backend.


http://reviews.llvm.org/D10416