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Move transmute into a separate function

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This commit is contained in:
Andy Wang 2022-05-22 22:18:22 +01:00
parent 6d27f188c2
commit dafd813c16
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1 changed files with 12 additions and 7 deletions
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19
tests/compile-fail/weak_memory/imperfectly_overlapping.rs
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@ -6,21 +6,26 @@ use std::intrinsics::atomic_load;
use std::sync::atomic::Ordering::*;
use std::sync::atomic::{AtomicU16, AtomicU32};
fn split_u32(dword: &mut u32) -> &mut [u16; 2] {
unsafe { std::mem::transmute::<&mut u32, &mut [u16; 2]>(dword) }
}
fn test_same_thread() {
let mut qword = AtomicU32::new(42);
assert_eq!(qword.load(Relaxed), 42);
qword.store(0xabbafafa, Relaxed);
let mut dword = AtomicU32::new(42);
assert_eq!(dword.load(Relaxed), 42);
dword.store(0xabbafafa, Relaxed);
let qword_mut = qword.get_mut();
let dword_mut = dword.get_mut();
let dwords_mut = unsafe { std::mem::transmute::<&mut u32, &mut [u16; 2]>(qword_mut) };
let words_mut = split_u32(dword_mut);
let (hi_mut, lo_mut) = dwords_mut.split_at_mut(1);
let (hi_mut, lo_mut) = words_mut.split_at_mut(1);
let (hi, _) = (AtomicU16::from_mut(&mut hi_mut[0]), AtomicU16::from_mut(&mut lo_mut[0]));
unsafe {
//Equivalent to: hi.load(Ordering::SeqCst)
// Equivalent to: hi.load(Ordering::SeqCst)
// We need to use intrisics to for precise error location
atomic_load(hi.get_mut() as *mut u16); //~ ERROR: mixed-size access on an existing atomic object
}
}