Struct rustc_mir_transform::dest_prop::FilterInformation

struct FilterInformation<'a, 'body, 'alloc, 'tcx> {
    body: &'body Body<'tcx>,
    points: &'a DenseLocationMap,
    live: &'a SparseIntervalMatrix<Local, PointIndex>,
    candidates: &'a mut Candidates<'alloc>,
    write_info: &'alloc mut WriteInfo,
    at: Location,
}

Fields

body: &'body Body<'tcx>

points: &'a DenseLocationMap

live: &'a SparseIntervalMatrix<Local, PointIndex>

candidates: &'a mut Candidates<'alloc>

write_info: &'alloc mut WriteInfo

at: Location

Implementations

impl<'a, 'body, 'alloc, 'tcx> FilterInformation<'a, 'body, 'alloc, 'tcx>

fn filter_liveness<'b>( candidates: &mut Candidates<'alloc>, points: &DenseLocationMap, live: &SparseIntervalMatrix<Local, PointIndex>, write_info_alloc: &'alloc mut WriteInfo, body: &'b Body<'tcx> )

Filters the set of candidates to remove those that conflict.

The steps we take are exactly those that are outlined at the top of the file. For each statement/terminator, we collect the set of locals that are written to in that statement/terminator, and then we remove all pairs of candidates that contain one such local and another one that is live.

We need to be careful about the ordering of operations within each statement/terminator here. Many statements might write and read from more than one place, and we need to consider them all. The strategy for doing this is as follows: We first gather all the places that are written to within the statement/terminator via WriteInfo. Then, we use the liveness analysis from before the statement/terminator (in the control flow sense) to eliminate candidates - this is because we want to conservatively treat a pair of locals that is both read and written in the statement/terminator to be conflicting, and the liveness analysis before the statement/terminator will correctly report locals that are read in the statement/terminator to be live. We are additionally conservative by treating all written to locals as also being read from.

fn internal_filter_liveness(&mut self)

fn apply_conflicts(&mut self)

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 56 bytes