rust/compiler/rustc_data_structures/src/macros.rs
Nicholas Nethercote 36b495f3cf Introduce ChunkedBitSet and use it for some dataflow analyses.
This reduces peak memory usage significantly for some programs with very
large functions, such as:
- `keccak`, `unicode_normalization`, and `match-stress-enum`, from
  the `rustc-perf` benchmark suite;
- `http-0.2.6` from crates.io.

The new type is used in the analyses where the bitsets can get huge
(e.g. 10s of thousands of bits): `MaybeInitializedPlaces`,
`MaybeUninitializedPlaces`, and `EverInitializedPlaces`.

Some refactoring was required in `rustc_mir_dataflow`. All existing
analysis domains are either `BitSet` or a trivial wrapper around
`BitSet`, and access in a few places is done via `Borrow<BitSet>` or
`BorrowMut<BitSet>`. Now that some of these domains are `ClusterBitSet`,
that no longer works. So this commit replaces the `Borrow`/`BorrowMut`
usage with a new trait `BitSetExt` containing the needed bitset
operations. The impls just forward these to the underlying bitset type.
This required fiddling with trait bounds in a few places.

The commit also:
- Moves `static_assert_size` from `rustc_data_structures` to
  `rustc_index` so it can be used in the latter; the former now
  re-exports it so existing users are unaffected.
- Factors out some common "clear excess bits in the final word"
  functionality in `bit_set.rs`.
- Uses `fill` in a few places instead of loops.
2022-02-23 10:18:49 +11:00

38 lines
973 B
Rust

#[macro_export]
macro_rules! enum_from_u32 {
($(#[$attr:meta])* pub enum $name:ident {
$($(#[$var_attr:meta])* $variant:ident = $e:expr,)*
}) => {
$(#[$attr])*
pub enum $name {
$($(#[$var_attr])* $variant = $e),*
}
impl $name {
pub fn from_u32(u: u32) -> Option<$name> {
$(if u == $name::$variant as u32 {
return Some($name::$variant)
})*
None
}
}
};
($(#[$attr:meta])* pub enum $name:ident {
$($(#[$var_attr:meta])* $variant:ident,)*
}) => {
$(#[$attr])*
pub enum $name {
$($(#[$var_attr])* $variant,)*
}
impl $name {
pub fn from_u32(u: u32) -> Option<$name> {
$(if u == $name::$variant as u32 {
return Some($name::$variant)
})*
None
}
}
}
}