Struct Loop 

pub struct Loop {
    pub header: BlockId,
    pub blocks: HashSet<BlockId, FxBuildHasher>,
    pub back_edges: SmallVec<[BlockId; 2]>,
    pub exit_blocks: SmallVec<[BlockId; 2]>,
    pub preheader: Option<BlockId>,
    pub induction_vars: Vec<InductionVariable>,
    pub invariant_insts: HashSet<InstId, FxBuildHasher>,
    pub trip_count: Option<u64>,
    pub trip_guard_is_header: bool,
}

A natural loop in the control flow graph.

Fields

header: BlockId

The header block (entry point with back edge).

blocks: HashSet<BlockId, FxBuildHasher>

All blocks in the loop body (including header).

back_edges: SmallVec<[BlockId; 2]>

Back edges: blocks that jump back to the header.

exit_blocks: SmallVec<[BlockId; 2]>

Exit blocks: blocks outside the loop that are successors of loop blocks.

preheader: Option<BlockId>

Preheader block (if exists): unique predecessor of header outside the loop.

induction_vars: Vec<InductionVariable>

Loop induction variables.

invariant_insts: HashSet<InstId, FxBuildHasher>

Instructions that are invariant (don’t change within the loop).

trip_count: Option<u64>

Optional: constant trip count if statically known.

trip_guard_is_header: bool

Whether the guard that produced Self::trip_count is the header’s terminator. Control enters every iteration at the header, so when this holds, non-header blocks only execute after that iteration’s bound check passed and observe the induction variable strictly below the bound; header instructions (and any guard placed deeper in the body) still run once more in the exiting partial iteration.

Trait Implementations

impl Clone for Loop

fn clone(&self) -> Loop

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Loop

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.