diff options
Diffstat (limited to 'vendor/packed_simd/src/api/into_bits/macros.rs')
-rw-r--r-- | vendor/packed_simd/src/api/into_bits/macros.rs | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/vendor/packed_simd/src/api/into_bits/macros.rs b/vendor/packed_simd/src/api/into_bits/macros.rs new file mode 100644 index 000000000..265ab34ae --- /dev/null +++ b/vendor/packed_simd/src/api/into_bits/macros.rs @@ -0,0 +1,74 @@ +//! Macros implementing `FromBits` + +macro_rules! impl_from_bits_ { + ($id:ident[$test_tt:tt]: $from_ty:ident) => { + impl crate::api::into_bits::FromBits<$from_ty> for $id { + #[inline] + fn from_bits(x: $from_ty) -> Self { + unsafe { crate::mem::transmute(x) } + } + } + + test_if! { + $test_tt: + paste::item! { + pub mod [<$id _from_bits_ $from_ty>] { + use super::*; + #[cfg_attr(not(target_arch = "wasm32"), test)] + #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)] + fn test() { + use crate::{ + ptr::{read_unaligned}, + mem::{size_of, zeroed} + }; + use crate::IntoBits; + assert_eq!(size_of::<$id>(), + size_of::<$from_ty>()); + // This is safe because we never create a reference to + // uninitialized memory: + let a: $from_ty = unsafe { zeroed() }; + + let b_0: $id = crate::FromBits::from_bits(a); + let b_1: $id = a.into_bits(); + + // Check that these are byte-wise equal, that is, + // that the bit patterns are identical: + for i in 0..size_of::<$id>() { + // This is safe because we only read initialized + // memory in bounds. Also, taking a reference to + // `b_i` is ok because the fields are initialized. + unsafe { + let b_0_v: u8 = read_unaligned( + (&b_0 as *const $id as *const u8) + .wrapping_add(i) + ); + let b_1_v: u8 = read_unaligned( + (&b_1 as *const $id as *const u8) + .wrapping_add(i) + ); + assert_eq!(b_0_v, b_1_v); + } + } + } + } + } + } + }; +} + +macro_rules! impl_from_bits { + ($id:ident[$test_tt:tt]: $($from_ty:ident),*) => { + $( + impl_from_bits_!($id[$test_tt]: $from_ty); + )* + } +} + +#[allow(unused)] +macro_rules! impl_into_bits { + ($id:ident[$test_tt:tt]: $($from_ty:ident),*) => { + $( + impl_from_bits_!($from_ty[$test_tt]: $id); + )* + } +} |