Method process_elab_stack

cranelift/codegen/src/egraph/elaborate.rs:451–747

(&mut self)

    }

    fn process_elab_stack(&mut self) {
        while let Some(entry) = self.elab_stack.pop() {
            match entry {
                ElabStackEntry::Start { value, before } => {
                    debug_assert!(self.func.dfg.value_is_real(value));

                    self.stats.elaborate_visit_node += 1;

                    // Get the best option; we use `value` (latest
                    // value) here so we have a full view of the
                    // eclass.
                    trace!("looking up best value for {}", value);
                    let BestEntry(_, best_value) = self.value_to_best_value[value];
                    trace!("elaborate: value {} -> best {}", value, best_value);
                    debug_assert_ne!(best_value, Value::reserved_value());

                    if let Some(elab_val) =
                        self.value_to_elaborated_value.get(&NullCtx, &best_value)
                    {
                        // Value is available; use it.
                        trace!("elaborate: value {} -> {:?}", value, elab_val);
                        self.stats.elaborate_memoize_hit += 1;
                        self.elab_result_stack.push(*elab_val);
                        continue;
                    }

                    self.stats.elaborate_memoize_miss += 1;

                    // Now resolve the value to its definition to see
                    // how we can compute it.
                    let (inst, result_idx) = match self.func.dfg.value_def(best_value) {
                        ValueDef::Result(inst, result_idx) => {
                            trace!(
                                " -> value {} is result {} of {}",
                                best_value, result_idx, inst
                            );
                            (inst, result_idx)
                        }
                        ValueDef::Param(in_block, _) => {
                            // We don't need to do anything to compute
                            // this value; just push its result on the
                            // result stack (blockparams are already
                            // available).
                            trace!(" -> value {} is a blockparam", best_value);
                            self.elab_result_stack.push(ElaboratedValue {
                                in_block,
                                value: best_value,
                            });
                            continue;
                        }
                        ValueDef::Union(_, _) => {
                            panic!("Should never have a Union value as the best value");
                        }
                    };

                    trace!(
                        " -> result {} of inst {:?}",
                        result_idx, self.func.dfg.insts[inst]