nordic-dev.net/bytemuck
2
0
Fork 0
mirror of https://github.com/Lokathor/bytemuck.git synced 2024-11-21 22:32:23 +00:00
Code Issues Packages Projects Releases Wiki Activity

Create align_offset feature so that we can continue to work on 1.34

Browse Source
This commit is contained in:
Lokathor 2023-09-05 14:08:36 -06:00
parent caff759066
commit 1ba4215050
2 changed files with 23 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
Cargo.toml
View File

@ -18,12 +18,19 @@ extern_crate_alloc = []
extern_crate_std = ["extern_crate_alloc"] extern_crate_std = ["extern_crate_alloc"]
zeroable_maybe_uninit = [] zeroable_maybe_uninit = []
zeroable_atomics = [] zeroable_atomics = []
min_const_generics = []
wasm_simd = [] # Until >= 1.54.0 is MSRV this is an off-by-default feature. # Causes MSRV 1.36, use `align_offset` method instead of casting to `usize` to
must_cast = [] # Until >= 1.57.0 is MSRV this is an off-by-default feature. # check alignment of pointers, this *may* improve codegen in some cases (but it
# has never been formally benchmarked!)
align_offset = []
min_const_generics = [] # Causes MSRV 1.51
wasm_simd = [] # Until >= 1.54.0 is MSRV this is an off-by-default feature.
must_cast = [] # Until >= 1.57.0 is MSRV this is an off-by-default feature.
aarch64_simd = [] # Until >= 1.59.0 is MSRV this is an off-by-default feature. aarch64_simd = [] # Until >= 1.59.0 is MSRV this is an off-by-default feature.
# Do not use if you can avoid it, because this is unsound. # Do not use if you can avoid it, because this is **unsound**!!!!
unsound_ptr_pod_impl = [] unsound_ptr_pod_impl = []
# NOT SEMVER SUPPORTED! TEMPORARY ONLY! # NOT SEMVER SUPPORTED! TEMPORARY ONLY!

17
src/internal.rs
View File

@ -136,11 +136,18 @@ pub(crate) unsafe fn pod_read_unaligned<T: Copy>(bytes: &[u8]) -> T {
/// * If `align` is not a power of two. This includes when `align` is zero. /// * If `align` is not a power of two. This includes when `align` is zero.
#[inline] #[inline]
pub(crate) fn is_aligned_to(ptr: *const (), align: usize) -> bool { pub(crate) fn is_aligned_to(ptr: *const (), align: usize) -> bool {
// This is in a way better than `ptr as usize % align == 0`, #[cfg(feature = "align_offset")]
// because casting a pointer to an integer has the side effect that it exposes {
// the pointer's provenance, which may theoretically inhibit some compiler // This is in a way better than `ptr as usize % align == 0`,
// optimizations. // because casting a pointer to an integer has the side effect that it
ptr.align_offset(align) == 0 // exposes the pointer's provenance, which may theoretically inhibit
// some compiler optimizations.
ptr.align_offset(align) == 0
}
#[cfg(not(feature = "align_offset"))]
{
((ptr as usize) % align) == 0
}
} }
/// Re-interprets `&[u8]` as `&T`. /// Re-interprets `&[u8]` as `&T`.