2540070fd4
Documents that `BikeshedIntrinsicFrom` models transmute-via-union,
which is slightly more expressive than the transmute-via-cast
implemented by `transmute_copy`. Additionally, we provide an
implementation of transmute-via-union as a method on the
`BikeshedIntrinsicFrom` trait with additional documentation on
the boundary between trait invariants and caller obligations.
Whether or not transmute-via-union is the right kind of transmute
to model remains up for discussion [1]. Regardless, it seems wise
to document the present behavior.
[1] 426331967
22 lines
587 B
Diff
22 lines
587 B
Diff
- // MIR for `transmute_inhabited` before LowerIntrinsics
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+ // MIR for `transmute_inhabited` after LowerIntrinsics
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fn transmute_inhabited(_1: std::cmp::Ordering) -> i8 {
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debug c => _1;
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let mut _0: i8;
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let mut _2: std::cmp::Ordering;
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bb0: {
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StorageLive(_2);
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_2 = copy _1;
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- _0 = std::intrinsics::transmute::<std::cmp::Ordering, i8>(move _2) -> [return: bb1, unwind unreachable];
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+ _0 = move _2 as i8 (Transmute);
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+ goto -> bb1;
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}
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bb1: {
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StorageDead(_2);
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return;
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}
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}
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