Struct rustc_mir::transform::match_branches::MatchBranchSimplification

pub struct MatchBranchSimplification;

Trait Implementations

impl<'tcx> MirPass<'tcx> for MatchBranchSimplification

If a source block is found that switches between two blocks that are exactly the same modulo const bool assignments (e.g., one assigns true another false to the same place), merge a target block statements into the source block, using Eq / Ne comparison with switch value where const bools value differ.

For example:

bb0: {
    switchInt(move _3) -> [42_isize: bb1, otherwise: bb2];
}

bb1: {
    _2 = const true;
    goto -> bb3;
}

bb2: {
    _2 = const false;
    goto -> bb3;
}

into:

bb0: {
   _2 = Eq(move _3, const 42_isize);
   goto -> bb3;
}

pub fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>)

pub fn name(&self) -> Cow<'_, str>