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| author | Nicholas Nethercote <n.nethercote@gmail.com> | 2024-12-05 15:24:11 +1100 |
|---|---|---|
| committer | Nicholas Nethercote <n.nethercote@gmail.com> | 2024-12-05 15:29:11 +1100 |
| commit | dff5ce68816edaf8a8740db60a8aa735641939f7 (patch) | |
| tree | d34a8b0a7fb2758d9ed105ed098280cb9c940a34 /compiler/rustc_index | |
| parent | acabb5248231987ae1f0c215208d1005a5db402d (diff) | |
| download | rust-dff5ce68816edaf8a8740db60a8aa735641939f7.tar.gz rust-dff5ce68816edaf8a8740db60a8aa735641939f7.zip | |
Move some `BitSet` code blocks to a better place.
These blocks are currently interleaved with `ChunkedBitSet` blocks. It makes things hard to find and has annoyed me for a while.
Diffstat (limited to 'compiler/rustc_index')
| -rw-r--r-- | compiler/rustc_index/src/bit_set.rs | 210 |
1 files changed, 105 insertions, 105 deletions
diff --git a/compiler/rustc_index/src/bit_set.rs b/compiler/rustc_index/src/bit_set.rs index de6fa132ca0..8693c731dd0 100644 --- a/compiler/rustc_index/src/bit_set.rs +++ b/compiler/rustc_index/src/bit_set.rs @@ -296,6 +296,111 @@ impl<T: Idx> From<GrowableBitSet<T>> for BitSet<T> { } } +impl<T> Clone for BitSet<T> { + fn clone(&self) -> Self { + BitSet { domain_size: self.domain_size, words: self.words.clone(), marker: PhantomData } + } + + fn clone_from(&mut self, from: &Self) { + self.domain_size = from.domain_size; + self.words.clone_from(&from.words); + } +} + +impl<T: Idx> fmt::Debug for BitSet<T> { + fn fmt(&self, w: &mut fmt::Formatter<'_>) -> fmt::Result { + w.debug_list().entries(self.iter()).finish() + } +} + +impl<T: Idx> ToString for BitSet<T> { + fn to_string(&self) -> String { + let mut result = String::new(); + let mut sep = '['; + + // Note: this is a little endian printout of bytes. + + // i tracks how many bits we have printed so far. + let mut i = 0; + for word in &self.words { + let mut word = *word; + for _ in 0..WORD_BYTES { + // for each byte in `word`: + let remain = self.domain_size - i; + // If less than a byte remains, then mask just that many bits. + let mask = if remain <= 8 { (1 << remain) - 1 } else { 0xFF }; + assert!(mask <= 0xFF); + let byte = word & mask; + + result.push_str(&format!("{sep}{byte:02x}")); + + if remain <= 8 { + break; + } + word >>= 8; + i += 8; + sep = '-'; + } + sep = '|'; + } + result.push(']'); + + result + } +} + +pub struct BitIter<'a, T: Idx> { + /// A copy of the current word, but with any already-visited bits cleared. + /// (This lets us use `trailing_zeros()` to find the next set bit.) When it + /// is reduced to 0, we move onto the next word. + word: Word, + + /// The offset (measured in bits) of the current word. + offset: usize, + + /// Underlying iterator over the words. + iter: slice::Iter<'a, Word>, + + marker: PhantomData<T>, +} + +impl<'a, T: Idx> BitIter<'a, T> { + #[inline] + fn new(words: &'a [Word]) -> BitIter<'a, T> { + // We initialize `word` and `offset` to degenerate values. On the first + // call to `next()` we will fall through to getting the first word from + // `iter`, which sets `word` to the first word (if there is one) and + // `offset` to 0. Doing it this way saves us from having to maintain + // additional state about whether we have started. + BitIter { + word: 0, + offset: usize::MAX - (WORD_BITS - 1), + iter: words.iter(), + marker: PhantomData, + } + } +} + +impl<'a, T: Idx> Iterator for BitIter<'a, T> { + type Item = T; + fn next(&mut self) -> Option<T> { + loop { + if self.word != 0 { + // Get the position of the next set bit in the current word, + // then clear the bit. + let bit_pos = self.word.trailing_zeros() as usize; + self.word ^= 1 << bit_pos; + return Some(T::new(bit_pos + self.offset)); + } + + // Move onto the next word. `wrapping_add()` is needed to handle + // the degenerate initial value given to `offset` in `new()`. + self.word = *self.iter.next()?; + self.offset = self.offset.wrapping_add(WORD_BITS); + } + } +} + /// A fixed-size bitset type with a partially dense, partially sparse /// representation. The bitset is broken into chunks, and chunks that are all /// zeros or all ones are represented and handled very efficiently. @@ -958,117 +1063,12 @@ fn sequential_update<T: Idx>( it.fold(false, |changed, elem| self_update(elem) | changed) } -impl<T> Clone for BitSet<T> { - fn clone(&self) -> Self { - BitSet { domain_size: self.domain_size, words: self.words.clone(), marker: PhantomData } - } - - fn clone_from(&mut self, from: &Self) { - self.domain_size = from.domain_size; - self.words.clone_from(&from.words); - } -} - -impl<T: Idx> fmt::Debug for BitSet<T> { - fn fmt(&self, w: &mut fmt::Formatter<'_>) -> fmt::Result { - w.debug_list().entries(self.iter()).finish() - } -} - impl<T: Idx> fmt::Debug for ChunkedBitSet<T> { fn fmt(&self, w: &mut fmt::Formatter<'_>) -> fmt::Result { w.debug_list().entries(self.iter()).finish() } } -impl<T: Idx> ToString for BitSet<T> { - fn to_string(&self) -> String { - let mut result = String::new(); - let mut sep = '['; - - // Note: this is a little endian printout of bytes. - - // i tracks how many bits we have printed so far. - let mut i = 0; - for word in &self.words { - let mut word = *word; - for _ in 0..WORD_BYTES { - // for each byte in `word`: - let remain = self.domain_size - i; - // If less than a byte remains, then mask just that many bits. - let mask = if remain <= 8 { (1 << remain) - 1 } else { 0xFF }; - assert!(mask <= 0xFF); - let byte = word & mask; - - result.push_str(&format!("{sep}{byte:02x}")); - - if remain <= 8 { - break; - } - word >>= 8; - i += 8; - sep = '-'; - } - sep = '|'; - } - result.push(']'); - - result - } -} - -pub struct BitIter<'a, T: Idx> { - /// A copy of the current word, but with any already-visited bits cleared. - /// (This lets us use `trailing_zeros()` to find the next set bit.) When it - /// is reduced to 0, we move onto the next word. - word: Word, - - /// The offset (measured in bits) of the current word. - offset: usize, - - /// Underlying iterator over the words. - iter: slice::Iter<'a, Word>, - - marker: PhantomData<T>, -} - -impl<'a, T: Idx> BitIter<'a, T> { - #[inline] - fn new(words: &'a [Word]) -> BitIter<'a, T> { - // We initialize `word` and `offset` to degenerate values. On the first - // call to `next()` we will fall through to getting the first word from - // `iter`, which sets `word` to the first word (if there is one) and - // `offset` to 0. Doing it this way saves us from having to maintain - // additional state about whether we have started. - BitIter { - word: 0, - offset: usize::MAX - (WORD_BITS - 1), - iter: words.iter(), - marker: PhantomData, - } - } -} - -impl<'a, T: Idx> Iterator for BitIter<'a, T> { - type Item = T; - fn next(&mut self) -> Option<T> { - loop { - if self.word != 0 { - // Get the position of the next set bit in the current word, - // then clear the bit. - let bit_pos = self.word.trailing_zeros() as usize; - self.word ^= 1 << bit_pos; - return Some(T::new(bit_pos + self.offset)); - } - - // Move onto the next word. `wrapping_add()` is needed to handle - // the degenerate initial value given to `offset` in `new()`. - self.word = *self.iter.next()?; - self.offset = self.offset.wrapping_add(WORD_BITS); - } - } -} - #[inline] fn bitwise<Op>(out_vec: &mut [Word], in_vec: &[Word], op: Op) -> bool where |
