forked from M-Labs/humpback-dds
58 lines
1.8 KiB
Rust
58 lines
1.8 KiB
Rust
/*
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* Macro builder for bit masks
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* $collection: Name for the bit mask collection
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* $unsigned_type: Unsigned type for the data that the bit mask will be applied onto
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* ($name: name of a bit mask, $shift: shift of the bit field, $width: no. of bits in the bit field)
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* Note: All bit masks must concern a set of contiguous bits
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*/
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macro_rules! construct_bitmask {
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($collection: ident; $unsigned_type: ty; $($name: ident, $shift: expr, $width: expr),+) => {
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#[derive(Debug, Copy, Clone, PartialEq, Eq)]
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#[allow(non_camel_case_types)]
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pub enum $collection {
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$(
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$name,
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)*
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}
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impl $collection {
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pub(crate) fn get_width(self) -> u8 {
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match self {
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$(
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$collection::$name => $width,
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)*
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}
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}
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pub(crate) fn get_shift(self) -> u8 {
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match self {
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$(
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$collection::$name => $shift,
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)*
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}
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}
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pub(crate) fn get_bitmask(self) -> $unsigned_type {
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let mut mask: $unsigned_type = 0;
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for bit in 0..self.get_width() {
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mask |= (1 << (self.get_shift() + bit) % ((size_of::<$unsigned_type>() as u8) * 8));
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}
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mask
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}
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pub(crate) fn get_shifted_bits(self, arg: $unsigned_type) -> $unsigned_type {
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assert!(arg < (2 << self.get_width()));
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(arg << (self.get_shift() % ((size_of::<$unsigned_type>() as u8) * 8)))
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}
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#[allow(dead_code)]
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pub(crate) fn set_data_by_arg(self, data: &mut $unsigned_type, arg: $unsigned_type) {
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// Clear bits in field, then insert shifted argument
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*data &= (!self.get_bitmask());
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*data |= self.get_shifted_bits(arg);
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}
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pub(crate) fn get_filtered_content(self, data: $unsigned_type) -> $unsigned_type {
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// Filter everything then shift bits
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((data & self.get_bitmask()) >> (self.get_shift() % ((size_of::<$unsigned_type>() as u8) * 8)))
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}
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}
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}
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}
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