std: slice.get(i) shouldn't do bounds check twice #13917
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The `get` function already checks that `i` is within bounds, so skip the second one and use `unsafe_ref`.
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Out of curiosity, did you see a performance improvement with this? LLVM may be good enough to realize the same condition is being checked twice (although I'm not sure). |
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Asking in IRC, I was told it does not, that's why I wrote this. However, trying some benches, with |
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I looked at the generated assembly at |
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Split out hir-def attribute handling parts into hir-expand This should help with `cfg_attr` handling for macro inputs
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The
getfunction already checks thatiis within bounds, so skip thesecond one and use
unsafe_ref.