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Auto merge of #104054 - RalfJung:byte-provenance, r=oli-obk

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interpret: support for per-byte provenance

Also factors the provenance map into its own module.

The third commit does the same for the init mask. I can move it in a separate PR if you prefer.

Fixes https://github.com/rust-lang/miri/issues/2181

r? `@oli-obk`
This commit is contained in:
bors
2022-11-15 17:37:15 +00:00
parent 6d651a295e 68af46c112
commit a00f8ba7fc
30 changed files with 1253 additions and 959 deletions
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22
library/core/src/ptr/mod.rs
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@@ -908,21 +908,15 @@ pub const unsafe fn swap_nonoverlapping<T>(x: *mut T, y: *mut T, count: usize) {
);
}
// NOTE(scottmcm) Miri is disabled here as reading in smaller units is a
// pessimization for it. Also, if the type contains any unaligned pointers,
// copying those over multiple reads is difficult to support.
#[cfg(not(miri))]
// Split up the slice into small power-of-two-sized chunks that LLVM is able
// to vectorize (unless it's a special type with more-than-pointer alignment,
// because we don't want to pessimize things like slices of SIMD vectors.)
if mem::align_of::<T>() <= mem::size_of::<usize>()
&& (!mem::size_of::<T>().is_power_of_two()
|| mem::size_of::<T>() > mem::size_of::<usize>() * 2)
{
// Split up the slice into small power-of-two-sized chunks that LLVM is able
// to vectorize (unless it's a special type with more-than-pointer alignment,
// because we don't want to pessimize things like slices of SIMD vectors.)
if mem::align_of::<T>() <= mem::size_of::<usize>()
&& (!mem::size_of::<T>().is_power_of_two()
|| mem::size_of::<T>() > mem::size_of::<usize>() * 2)
{
attempt_swap_as_chunks!(usize);
attempt_swap_as_chunks!(u8);
}
attempt_swap_as_chunks!(usize);
attempt_swap_as_chunks!(u8);
}
// SAFETY: Same preconditions as this function