rust/compiler/rustc_abi
bors 2b094b1ede Auto merge of #105446 - erikdesjardins:vt-size, r=nikic
Add 0..=isize::MAX range metadata to size loads from vtables

This is the (much belated) size counterpart to #91569.

Inspired by https://rust-lang.zulipchat.com/#narrow/stream/187780-t-compiler.2Fwg-llvm/topic/Range.20metadata.20for.20.60size_of_val.60.20and.20other.20isize.3A.3AMAX.20limits. This could help optimize layout computations based on the size of a dyn trait. Though, admittedly, adding this to vtables wouldn't be as beneficial as adding it to slice len, which is used much more often.

Miri detects this UB already: b7cc99142a/compiler/rustc_const_eval/src/interpret/traits.rs (L119-L121)
(In fact Miri goes further, [assuming a 48-bit address space on 64-bit platforms](9db224fc90/compiler/rustc_abi/src/lib.rs (L312-L331)), but I don't think we can assume that in an optimization.)
2022-12-18 22:01:39 +00:00
..
src Auto merge of #105446 - erikdesjardins:vt-size, r=nikic 2022-12-18 22:01:39 +00:00
Cargo.toml move things from rustc_target::abi to rustc_abi 2022-11-24 16:26:13 +03:30