Struct Cfg 

pub struct Cfg {
    pub blocks: HashMap<BlockId, BasicBlock>,
    pub entry: BlockId,
    pub exit: Option<BlockId>,
    pub loops: Vec<Loop>,
}

Control Flow Graph

Fields

blocks: HashMap<BlockId, BasicBlock>

All basic blocks

entry: BlockId

Entry block ID

exit: Option<BlockId>

Exit block ID (if function has explicit return)

loops: Vec<Loop>

Loop information

Implementations

impl Cfg

pub fn block(&self, id: BlockId) -> Option<&BasicBlock>

Get a basic block by ID

pub fn block_mut(&mut self, id: BlockId) -> Option<&mut BasicBlock>

Get a mutable basic block by ID

pub fn blocks_rpo(&self) -> Vec<BlockId>

Iterate over all blocks in RPO (Reverse Post-Order)

pub fn dominators(&self) -> HashMap<BlockId, BlockId>

Compute dominator tree

pub fn detect_loops(&mut self)

Detect natural loops in the CFG

pub fn reachable_blocks(&self) -> HashSet<BlockId>

Find all blocks reachable from entry (helper for optimization)

pub fn merge_blocks(&mut self) -> usize

Merge basic blocks (CFG optimization) Merge block B into block A if:

• A has only one successor (B)
• B has only one predecessor (A)
• B is not the entry block

Returns the number of blocks merged

pub fn eliminate_unreachable(&mut self) -> usize

Eliminate unreachable blocks (CFG optimization) Removes blocks that cannot be reached from the entry block Returns the number of blocks eliminated

pub fn simplify_branches(&mut self) -> usize

Simplify branches (CFG optimization) Simplifies control flow by:

• Removing branches to the immediate next block (fall-through)
• Collapsing chains of unconditional branches

Returns the number of branches simplified

Trait Implementations

impl Clone for Cfg

fn clone(&self) -> Cfg

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Cfg

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

Formats the value using the given formatter.