Struct UseDefInfo 

pub struct UseDefInfo { /* private fields */ }

Use-def / def-use information for a single function.

Implementations

impl UseDefInfo

pub fn compute(func: &Function) -> Self

Walk all instructions in func and collect definition and use info.

pub fn def_block(&self, id: InstrId) -> Option<BlockId>

The block in which id is defined, or None if not found.

pub fn uses_of(&self, vref: ValueRef) -> &[(BlockId, InstrId)]

All use sites of vref: (block, instruction) pairs.

For phi incoming values the block is the phi’s own block, not the predecessor. Use phi_uses_of when correct predecessor-block semantics are needed (liveness, mem2reg).

Returns an empty slice if the value has no uses.

pub fn phi_uses_of(&self, vref: ValueRef) -> &[(BlockId, InstrId)]

Phi-specific use sites of vref with predecessor-block semantics.

For each phi [vref, %pred] instruction that uses vref, returns a (pred, phi_instr_id) pair. This is the correct view for SSA liveness analysis (the value must be live-out of pred) and for phi elimination (copies are inserted at the end of pred).

Returns an empty slice if vref does not appear in any phi incoming list.

pub fn is_dead(&self, vref: ValueRef) -> bool

true if vref has no recorded uses (dead value).