1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
//! Lazily compute the inverse of each `SwitchInt`'s switch targets. Modeled after
//! `Predecessors`/`PredecessorCache`.
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_data_structures::sync::OnceCell;
use rustc_index::vec::IndexVec;
use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
use smallvec::SmallVec;
use crate::mir::{BasicBlock, BasicBlockData, Terminator, TerminatorKind};
pub type SwitchSources = FxHashMap<(BasicBlock, BasicBlock), SmallVec<[Option<u128>; 1]>>;
#[derive(Clone, Debug)]
pub(super) struct SwitchSourceCache {
cache: OnceCell<SwitchSources>,
}
impl SwitchSourceCache {
#[inline]
pub(super) fn new() -> Self {
SwitchSourceCache { cache: OnceCell::new() }
}
/// Invalidates the switch source cache.
#[inline]
pub(super) fn invalidate(&mut self) {
self.cache = OnceCell::new();
}
/// Returns the switch sources for this MIR.
#[inline]
pub(super) fn compute(
&self,
basic_blocks: &IndexVec<BasicBlock, BasicBlockData<'_>>,
) -> &SwitchSources {
self.cache.get_or_init(|| {
let mut switch_sources: SwitchSources = FxHashMap::default();
for (bb, data) in basic_blocks.iter_enumerated() {
if let Some(Terminator {
kind: TerminatorKind::SwitchInt { targets, .. }, ..
}) = &data.terminator
{
for (value, target) in targets.iter() {
switch_sources.entry((target, bb)).or_default().push(Some(value));
}
switch_sources.entry((targets.otherwise(), bb)).or_default().push(None);
}
}
switch_sources
})
}
}
impl<S: Encoder> Encodable<S> for SwitchSourceCache {
#[inline]
fn encode(&self, _s: &mut S) {}
}
impl<D: Decoder> Decodable<D> for SwitchSourceCache {
#[inline]
fn decode(_: &mut D) -> Self {
Self::new()
}
}
impl<CTX> HashStable<CTX> for SwitchSourceCache {
#[inline]
fn hash_stable(&self, _: &mut CTX, _: &mut StableHasher) {
// do nothing
}
}
TrivialTypeTraversalAndLiftImpls! {
SwitchSourceCache,
}
|
