Struct PredicateGVN 

pub struct PredicateGVN {
    pub equalities_derived: usize,
    /* private fields */
}

GVN pass that uses branch predicates to derive additional equalities.

When we enter a case branch where the scrutinee matches tag t, we know the scrutinee is a specific constructor. This lets us refine value numbers for projection expressions.

Fields

equalities_derived: usize

Number of additional equalities derived from predicates.

Implementations

impl PredicateGVN

pub fn new() -> Self

pub fn enter_branch(&mut self, scrutinee: LcnfVarId, ctor_tag: u32)

Enter a case branch where scrutinee has constructor tag ctor_tag.

pub fn exit_branch(&mut self)

Exit the current branch, restoring the predicate environment.

pub fn knows_eq_lit(&self, var: LcnfVarId, lit: &LcnfLit) -> bool

Check if var == lit is known from active predicates.

pub fn run(&mut self, decl: &mut LcnfFunDecl, base_pass: &mut GVNPass)

Run predicate-based GVN on decl, augmenting an existing GVNPass.

Trait Implementations

impl Debug for PredicateGVN

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

Formats the value using the given formatter.

impl Default for PredicateGVN

fn default() -> PredicateGVN

Returns the “default value” for a type.