}
impl Align {
+ #[inline]
pub fn from_bits(bits: u64) -> Result<Align, String> {
Align::from_bytes(Size::from_bits(bits).bytes())
}
+ #[inline]
pub fn from_bytes(align: u64) -> Result<Align, String> {
// Treat an alignment of 0 bytes like 1-byte alignment.
if align == 0 {
return Ok(Align { pow2: 0 });
}
+ #[cold]
+ fn not_power_of_2(align: u64) -> String {
+ format!("`{}` is not a power of 2", align)
+ }
+
+ #[cold]
+ fn too_large(align: u64) -> String {
+ format!("`{}` is too large", align)
+ }
+
let mut bytes = align;
let mut pow2: u8 = 0;
while (bytes & 1) == 0 {
bytes >>= 1;
}
if bytes != 1 {
- return Err(format!("`{}` is not a power of 2", align));
+ return Err(not_power_of_2(align));
}
if pow2 > 29 {
- return Err(format!("`{}` is too large", align));
+ return Err(too_large(align));
}
Ok(Align { pow2 })
}
+ #[inline]
pub fn bytes(self) -> u64 {
1 << self.pow2
}
+ #[inline]
pub fn bits(self) -> u64 {
self.bytes() * 8
}
/// (the largest power of two that the offset is a multiple of).
///
/// N.B., for an offset of `0`, this happens to return `2^64`.
+ #[inline]
pub fn max_for_offset(offset: Size) -> Align {
Align { pow2: offset.bytes().trailing_zeros() as u8 }
}
/// Lower the alignment, if necessary, such that the given offset
/// is aligned to it (the offset is a multiple of the alignment).
+ #[inline]
pub fn restrict_for_offset(self, offset: Size) -> Align {
self.min(Align::max_for_offset(offset))
}