oxilean_codegen/wasm_backend/

types.rs

//! Auto-generated module
//!
//! 🤖 Generated with [SplitRS](https://github.com/cool-japan/splitrs)

use crate::lcnf::*;

use super::functions::*;
use std::collections::{HashMap, HashSet, VecDeque};

#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmCacheEntry {
    pub key: String,
    pub data: Vec<u8>,
    pub timestamp: u64,
    pub valid: bool,
}
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmDepGraph {
    pub(super) nodes: Vec<u32>,
    pub(super) edges: Vec<(u32, u32)>,
}
impl WasmDepGraph {
    #[allow(dead_code)]
    pub fn new() -> Self {
        WasmDepGraph {
            nodes: Vec::new(),
            edges: Vec::new(),
        }
    }
    #[allow(dead_code)]
    pub fn add_node(&mut self, id: u32) {
        if !self.nodes.contains(&id) {
            self.nodes.push(id);
        }
    }
    #[allow(dead_code)]
    pub fn add_dep(&mut self, dep: u32, dependent: u32) {
        self.add_node(dep);
        self.add_node(dependent);
        self.edges.push((dep, dependent));
    }
    #[allow(dead_code)]
    pub fn dependents_of(&self, node: u32) -> Vec<u32> {
        self.edges
            .iter()
            .filter(|(d, _)| *d == node)
            .map(|(_, dep)| *dep)
            .collect()
    }
    #[allow(dead_code)]
    pub fn dependencies_of(&self, node: u32) -> Vec<u32> {
        self.edges
            .iter()
            .filter(|(_, dep)| *dep == node)
            .map(|(d, _)| *d)
            .collect()
    }
    #[allow(dead_code)]
    pub fn topological_sort(&self) -> Vec<u32> {
        let mut in_degree: std::collections::HashMap<u32, u32> = std::collections::HashMap::new();
        for &n in &self.nodes {
            in_degree.insert(n, 0);
        }
        for (_, dep) in &self.edges {
            *in_degree.entry(*dep).or_insert(0) += 1;
        }
        let mut queue: std::collections::VecDeque<u32> = self
            .nodes
            .iter()
            .filter(|&&n| in_degree[&n] == 0)
            .copied()
            .collect();
        let mut result = Vec::new();
        while let Some(node) = queue.pop_front() {
            result.push(node);
            for dep in self.dependents_of(node) {
                let cnt = in_degree.entry(dep).or_insert(0);
                *cnt = cnt.saturating_sub(1);
                if *cnt == 0 {
                    queue.push_back(dep);
                }
            }
        }
        result
    }
    #[allow(dead_code)]
    pub fn has_cycle(&self) -> bool {
        self.topological_sort().len() < self.nodes.len()
    }
}
/// Pass registry for WasmX2.
#[allow(dead_code)]
#[derive(Debug, Default)]
pub struct WasmX2PassRegistry {
    pub(super) configs: Vec<WasmX2PassConfig>,
    pub(super) stats: Vec<WasmX2PassStats>,
}
impl WasmX2PassRegistry {
    #[allow(dead_code)]
    pub fn new() -> Self {
        Self::default()
    }
    #[allow(dead_code)]
    pub fn register(&mut self, c: WasmX2PassConfig) {
        self.stats.push(WasmX2PassStats::new());
        self.configs.push(c);
    }
    #[allow(dead_code)]
    pub fn len(&self) -> usize {
        self.configs.len()
    }
    #[allow(dead_code)]
    pub fn is_empty(&self) -> bool {
        self.configs.is_empty()
    }
    #[allow(dead_code)]
    pub fn get(&self, i: usize) -> Option<&WasmX2PassConfig> {
        self.configs.get(i)
    }
    #[allow(dead_code)]
    pub fn get_stats(&self, i: usize) -> Option<&WasmX2PassStats> {
        self.stats.get(i)
    }
    #[allow(dead_code)]
    pub fn enabled_passes(&self) -> Vec<&WasmX2PassConfig> {
        self.configs.iter().filter(|c| c.enabled).collect()
    }
    #[allow(dead_code)]
    pub fn passes_in_phase(&self, ph: &WasmX2PassPhase) -> Vec<&WasmX2PassConfig> {
        self.configs
            .iter()
            .filter(|c| c.enabled && &c.phase == ph)
            .collect()
    }
    #[allow(dead_code)]
    pub fn total_nodes_visited(&self) -> usize {
        self.stats.iter().map(|s| s.nodes_visited).sum()
    }
    #[allow(dead_code)]
    pub fn any_changed(&self) -> bool {
        self.stats.iter().any(|s| s.changed)
    }
}
/// Dominator tree for WasmExt.
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmExtDomTree {
    pub(super) idom: Vec<Option<usize>>,
    pub(super) children: Vec<Vec<usize>>,
    pub(super) depth: Vec<usize>,
}
impl WasmExtDomTree {
    #[allow(dead_code)]
    pub fn new(n: usize) -> Self {
        Self {
            idom: vec![None; n],
            children: vec![Vec::new(); n],
            depth: vec![0; n],
        }
    }
    #[allow(dead_code)]
    pub fn set_idom(&mut self, node: usize, dom: usize) {
        if node < self.idom.len() {
            self.idom[node] = Some(dom);
            if dom < self.children.len() {
                self.children[dom].push(node);
            }
            self.depth[node] = if dom < self.depth.len() {
                self.depth[dom] + 1
            } else {
                1
            };
        }
    }
    #[allow(dead_code)]
    pub fn dominates(&self, a: usize, mut b: usize) -> bool {
        if a == b {
            return true;
        }
        let n = self.idom.len();
        for _ in 0..n {
            match self.idom.get(b).copied().flatten() {
                None => return false,
                Some(p) if p == a => return true,
                Some(p) if p == b => return false,
                Some(p) => b = p,
            }
        }
        false
    }
    #[allow(dead_code)]
    pub fn children_of(&self, n: usize) -> &[usize] {
        self.children.get(n).map(|v| v.as_slice()).unwrap_or(&[])
    }
    #[allow(dead_code)]
    pub fn depth_of(&self, n: usize) -> usize {
        self.depth.get(n).copied().unwrap_or(0)
    }
    #[allow(dead_code)]
    pub fn lca(&self, mut a: usize, mut b: usize) -> usize {
        let n = self.idom.len();
        for _ in 0..(2 * n) {
            if a == b {
                return a;
            }
            if self.depth_of(a) > self.depth_of(b) {
                a = self.idom.get(a).and_then(|x| *x).unwrap_or(a);
            } else {
                b = self.idom.get(b).and_then(|x| *x).unwrap_or(b);
            }
        }
        0
    }
}
/// A complete WebAssembly module.
#[derive(Debug, Clone, Default)]
pub struct WasmModule {
    /// Import declarations.
    pub imports: Vec<WasmImport>,
    /// Function definitions.
    pub functions: Vec<WasmFunc>,
    /// Names of functions to export.
    pub exports: Vec<String>,
    /// Optional memory size in pages (64 KiB each). `None` = no memory.
    pub memory: Option<u32>,
    /// Global variable declarations.
    pub globals: Vec<WasmGlobal>,
}
impl WasmModule {
    /// Create an empty WebAssembly module.
    pub fn new() -> Self {
        Self::default()
    }
    /// Emit this module as WebAssembly text format (WAT).
    pub fn to_wat(&self) -> String {
        let mut out = String::from("(module\n");
        for import in &self.imports {
            out.push_str(&format!("{}\n", import));
        }
        if let Some(pages) = self.memory {
            out.push_str(&format!("  (memory {})\n", pages));
        }
        for global in &self.globals {
            out.push_str(&format!("{}\n", global));
        }
        for func in &self.functions {
            out.push_str(&format!("{}\n", func));
        }
        for export in &self.exports {
            out.push_str(&format!("  (export \"{}\" (func ${}))\n", export, export));
        }
        out.push(')');
        out
    }
}
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmPassConfig {
    pub phase: WasmPassPhase,
    pub enabled: bool,
    pub max_iterations: u32,
    pub debug_output: bool,
    pub pass_name: String,
}
impl WasmPassConfig {
    #[allow(dead_code)]
    pub fn new(name: impl Into<String>, phase: WasmPassPhase) -> Self {
        WasmPassConfig {
            phase,
            enabled: true,
            max_iterations: 10,
            debug_output: false,
            pass_name: name.into(),
        }
    }
    #[allow(dead_code)]
    pub fn disabled(mut self) -> Self {
        self.enabled = false;
        self
    }
    #[allow(dead_code)]
    pub fn with_debug(mut self) -> Self {
        self.debug_output = true;
        self
    }
    #[allow(dead_code)]
    pub fn max_iter(mut self, n: u32) -> Self {
        self.max_iterations = n;
        self
    }
}
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmWorklist {
    pub(super) items: std::collections::VecDeque<u32>,
    pub(super) in_worklist: std::collections::HashSet<u32>,
}
impl WasmWorklist {
    #[allow(dead_code)]
    pub fn new() -> Self {
        WasmWorklist {
            items: std::collections::VecDeque::new(),
            in_worklist: std::collections::HashSet::new(),
        }
    }
    #[allow(dead_code)]
    pub fn push(&mut self, item: u32) -> bool {
        if self.in_worklist.insert(item) {
            self.items.push_back(item);
            true
        } else {
            false
        }
    }
    #[allow(dead_code)]
    pub fn pop(&mut self) -> Option<u32> {
        let item = self.items.pop_front()?;
        self.in_worklist.remove(&item);
        Some(item)
    }
    #[allow(dead_code)]
    pub fn is_empty(&self) -> bool {
        self.items.is_empty()
    }
    #[allow(dead_code)]
    pub fn len(&self) -> usize {
        self.items.len()
    }
    #[allow(dead_code)]
    pub fn contains(&self, item: u32) -> bool {
        self.in_worklist.contains(&item)
    }
}
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmDominatorTree {
    pub idom: Vec<Option<u32>>,
    pub dom_children: Vec<Vec<u32>>,
    pub dom_depth: Vec<u32>,
}
impl WasmDominatorTree {
    #[allow(dead_code)]
    pub fn new(size: usize) -> Self {
        WasmDominatorTree {
            idom: vec![None; size],
            dom_children: vec![Vec::new(); size],
            dom_depth: vec![0; size],
        }
    }
    #[allow(dead_code)]
    pub fn set_idom(&mut self, node: usize, idom: u32) {
        self.idom[node] = Some(idom);
    }
    #[allow(dead_code)]
    pub fn dominates(&self, a: usize, b: usize) -> bool {
        if a == b {
            return true;
        }
        let mut cur = b;
        loop {
            match self.idom[cur] {
                Some(parent) if parent as usize == a => return true,
                Some(parent) if parent as usize == cur => return false,
                Some(parent) => cur = parent as usize,
                None => return false,
            }
        }
    }
    #[allow(dead_code)]
    pub fn depth(&self, node: usize) -> u32 {
        self.dom_depth.get(node).copied().unwrap_or(0)
    }
}
/// Dependency graph for WasmExt.
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmExtDepGraph {
    pub(super) n: usize,
    pub(super) adj: Vec<Vec<usize>>,
    pub(super) rev: Vec<Vec<usize>>,
    pub(super) edge_count: usize,
}
impl WasmExtDepGraph {
    #[allow(dead_code)]
    pub fn new(n: usize) -> Self {
        Self {
            n,
            adj: vec![Vec::new(); n],
            rev: vec![Vec::new(); n],
            edge_count: 0,
        }
    }
    #[allow(dead_code)]
    pub fn add_edge(&mut self, from: usize, to: usize) {
        if from < self.n && to < self.n {
            if !self.adj[from].contains(&to) {
                self.adj[from].push(to);
                self.rev[to].push(from);
                self.edge_count += 1;
            }
        }
    }
    #[allow(dead_code)]
    pub fn succs(&self, n: usize) -> &[usize] {
        self.adj.get(n).map(|v| v.as_slice()).unwrap_or(&[])
    }
    #[allow(dead_code)]
    pub fn preds(&self, n: usize) -> &[usize] {
        self.rev.get(n).map(|v| v.as_slice()).unwrap_or(&[])
    }
    #[allow(dead_code)]
    pub fn topo_sort(&self) -> Option<Vec<usize>> {
        let mut deg: Vec<usize> = (0..self.n).map(|i| self.rev[i].len()).collect();
        let mut q: std::collections::VecDeque<usize> =
            (0..self.n).filter(|&i| deg[i] == 0).collect();
        let mut out = Vec::with_capacity(self.n);
        while let Some(u) = q.pop_front() {
            out.push(u);
            for &v in &self.adj[u] {
                deg[v] -= 1;
                if deg[v] == 0 {
                    q.push_back(v);
                }
            }
        }
        if out.len() == self.n {
            Some(out)
        } else {
            None
        }
    }
    #[allow(dead_code)]
    pub fn has_cycle(&self) -> bool {
        self.topo_sort().is_none()
    }
    #[allow(dead_code)]
    pub fn reachable(&self, start: usize) -> Vec<usize> {
        let mut vis = vec![false; self.n];
        let mut stk = vec![start];
        let mut out = Vec::new();
        while let Some(u) = stk.pop() {
            if u < self.n && !vis[u] {
                vis[u] = true;
                out.push(u);
                for &v in &self.adj[u] {
                    if !vis[v] {
                        stk.push(v);
                    }
                }
            }
        }
        out
    }
    #[allow(dead_code)]
    pub fn scc(&self) -> Vec<Vec<usize>> {
        let mut visited = vec![false; self.n];
        let mut order = Vec::new();
        for i in 0..self.n {
            if !visited[i] {
                let mut stk = vec![(i, 0usize)];
                while let Some((u, idx)) = stk.last_mut() {
                    if !visited[*u] {
                        visited[*u] = true;
                    }
                    if *idx < self.adj[*u].len() {
                        let v = self.adj[*u][*idx];
                        *idx += 1;
                        if !visited[v] {
                            stk.push((v, 0));
                        }
                    } else {
                        order.push(*u);
                        stk.pop();
                    }
                }
            }
        }
        let mut comp = vec![usize::MAX; self.n];
        let mut components: Vec<Vec<usize>> = Vec::new();
        for &start in order.iter().rev() {
            if comp[start] == usize::MAX {
                let cid = components.len();
                let mut component = Vec::new();
                let mut stk = vec![start];
                while let Some(u) = stk.pop() {
                    if comp[u] == usize::MAX {
                        comp[u] = cid;
                        component.push(u);
                        for &v in &self.rev[u] {
                            if comp[v] == usize::MAX {
                                stk.push(v);
                            }
                        }
                    }
                }
                components.push(component);
            }
        }
        components
    }
    #[allow(dead_code)]
    pub fn node_count(&self) -> usize {
        self.n
    }
    #[allow(dead_code)]
    pub fn edge_count(&self) -> usize {
        self.edge_count
    }
}
/// Statistics for WasmX2 passes.
#[allow(dead_code)]
#[derive(Debug, Clone, Default)]
pub struct WasmX2PassStats {
    pub iterations: usize,
    pub changed: bool,
    pub nodes_visited: usize,
    pub nodes_modified: usize,
    pub time_ms: u64,
    pub memory_bytes: usize,
    pub errors: usize,
}
impl WasmX2PassStats {
    #[allow(dead_code)]
    pub fn new() -> Self {
        Self::default()
    }
    #[allow(dead_code)]
    pub fn visit(&mut self) {
        self.nodes_visited += 1;
    }
    #[allow(dead_code)]
    pub fn modify(&mut self) {
        self.nodes_modified += 1;
        self.changed = true;
    }
    #[allow(dead_code)]
    pub fn iterate(&mut self) {
        self.iterations += 1;
    }
    #[allow(dead_code)]
    pub fn error(&mut self) {
        self.errors += 1;
    }
    #[allow(dead_code)]
    pub fn efficiency(&self) -> f64 {
        if self.nodes_visited == 0 {
            0.0
        } else {
            self.nodes_modified as f64 / self.nodes_visited as f64
        }
    }
    #[allow(dead_code)]
    pub fn merge(&mut self, o: &WasmX2PassStats) {
        self.iterations += o.iterations;
        self.changed |= o.changed;
        self.nodes_visited += o.nodes_visited;
        self.nodes_modified += o.nodes_modified;
        self.time_ms += o.time_ms;
        self.memory_bytes = self.memory_bytes.max(o.memory_bytes);
        self.errors += o.errors;
    }
}
/// Worklist for WasmExt.
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmExtWorklist {
    pub(super) items: std::collections::VecDeque<usize>,
    pub(super) present: Vec<bool>,
}
impl WasmExtWorklist {
    #[allow(dead_code)]
    pub fn new(capacity: usize) -> Self {
        Self {
            items: std::collections::VecDeque::new(),
            present: vec![false; capacity],
        }
    }
    #[allow(dead_code)]
    pub fn push(&mut self, id: usize) {
        if id < self.present.len() && !self.present[id] {
            self.present[id] = true;
            self.items.push_back(id);
        }
    }
    #[allow(dead_code)]
    pub fn push_front(&mut self, id: usize) {
        if id < self.present.len() && !self.present[id] {
            self.present[id] = true;
            self.items.push_front(id);
        }
    }
    #[allow(dead_code)]
    pub fn pop(&mut self) -> Option<usize> {
        let id = self.items.pop_front()?;
        if id < self.present.len() {
            self.present[id] = false;
        }
        Some(id)
    }
    #[allow(dead_code)]
    pub fn is_empty(&self) -> bool {
        self.items.is_empty()
    }
    #[allow(dead_code)]
    pub fn len(&self) -> usize {
        self.items.len()
    }
    #[allow(dead_code)]
    pub fn contains(&self, id: usize) -> bool {
        id < self.present.len() && self.present[id]
    }
    #[allow(dead_code)]
    pub fn drain_all(&mut self) -> Vec<usize> {
        let v: Vec<usize> = self.items.drain(..).collect();
        for &id in &v {
            if id < self.present.len() {
                self.present[id] = false;
            }
        }
        v
    }
}
/// Analysis cache for WasmExt.
#[allow(dead_code)]
#[derive(Debug)]
pub struct WasmExtCache {
    pub(super) entries: Vec<(u64, Vec<u8>, bool, u32)>,
    pub(super) cap: usize,
    pub(super) total_hits: u64,
    pub(super) total_misses: u64,
}
impl WasmExtCache {
    #[allow(dead_code)]
    pub fn new(cap: usize) -> Self {
        Self {
            entries: Vec::new(),
            cap,
            total_hits: 0,
            total_misses: 0,
        }
    }
    #[allow(dead_code)]
    pub fn get(&mut self, key: u64) -> Option<&[u8]> {
        for e in self.entries.iter_mut() {
            if e.0 == key && e.2 {
                e.3 += 1;
                self.total_hits += 1;
                return Some(&e.1);
            }
        }
        self.total_misses += 1;
        None
    }
    #[allow(dead_code)]
    pub fn put(&mut self, key: u64, data: Vec<u8>) {
        if self.entries.len() >= self.cap {
            self.entries.retain(|e| e.2);
            if self.entries.len() >= self.cap {
                self.entries.remove(0);
            }
        }
        self.entries.push((key, data, true, 0));
    }
    #[allow(dead_code)]
    pub fn invalidate(&mut self) {
        for e in self.entries.iter_mut() {
            e.2 = false;
        }
    }
    #[allow(dead_code)]
    pub fn hit_rate(&self) -> f64 {
        let t = self.total_hits + self.total_misses;
        if t == 0 {
            0.0
        } else {
            self.total_hits as f64 / t as f64
        }
    }
    #[allow(dead_code)]
    pub fn live_count(&self) -> usize {
        self.entries.iter().filter(|e| e.2).count()
    }
}
/// Dominator tree for WasmX2.
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmX2DomTree {
    pub(super) idom: Vec<Option<usize>>,
    pub(super) children: Vec<Vec<usize>>,
    pub(super) depth: Vec<usize>,
}
impl WasmX2DomTree {
    #[allow(dead_code)]
    pub fn new(n: usize) -> Self {
        Self {
            idom: vec![None; n],
            children: vec![Vec::new(); n],
            depth: vec![0; n],
        }
    }
    #[allow(dead_code)]
    pub fn set_idom(&mut self, node: usize, dom: usize) {
        if node < self.idom.len() {
            self.idom[node] = Some(dom);
            if dom < self.children.len() {
                self.children[dom].push(node);
            }
            self.depth[node] = if dom < self.depth.len() {
                self.depth[dom] + 1
            } else {
                1
            };
        }
    }
    #[allow(dead_code)]
    pub fn dominates(&self, a: usize, mut b: usize) -> bool {
        if a == b {
            return true;
        }
        let n = self.idom.len();
        for _ in 0..n {
            match self.idom.get(b).copied().flatten() {
                None => return false,
                Some(p) if p == a => return true,
                Some(p) if p == b => return false,
                Some(p) => b = p,
            }
        }
        false
    }
    #[allow(dead_code)]
    pub fn children_of(&self, n: usize) -> &[usize] {
        self.children.get(n).map(|v| v.as_slice()).unwrap_or(&[])
    }
    #[allow(dead_code)]
    pub fn depth_of(&self, n: usize) -> usize {
        self.depth.get(n).copied().unwrap_or(0)
    }
    #[allow(dead_code)]
    pub fn lca(&self, mut a: usize, mut b: usize) -> usize {
        let n = self.idom.len();
        for _ in 0..(2 * n) {
            if a == b {
                return a;
            }
            if self.depth_of(a) > self.depth_of(b) {
                a = self.idom.get(a).and_then(|x| *x).unwrap_or(a);
            } else {
                b = self.idom.get(b).and_then(|x| *x).unwrap_or(b);
            }
        }
        0
    }
}
/// The kind of WebAssembly import.
#[derive(Debug, Clone, PartialEq)]
pub enum WasmImportKind {
    /// Imported function with parameter and result types.
    Func {
        params: Vec<WasmType>,
        results: Vec<WasmType>,
    },
    /// Imported memory with minimum pages.
    Memory { min_pages: u32 },
    /// Imported global with type and mutability.
    Global { ty: WasmType, mutable: bool },
}
/// Dependency graph for WasmX2.
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmX2DepGraph {
    pub(super) n: usize,
    pub(super) adj: Vec<Vec<usize>>,
    pub(super) rev: Vec<Vec<usize>>,
    pub(super) edge_count: usize,
}
impl WasmX2DepGraph {
    #[allow(dead_code)]
    pub fn new(n: usize) -> Self {
        Self {
            n,
            adj: vec![Vec::new(); n],
            rev: vec![Vec::new(); n],
            edge_count: 0,
        }
    }
    #[allow(dead_code)]
    pub fn add_edge(&mut self, from: usize, to: usize) {
        if from < self.n && to < self.n {
            if !self.adj[from].contains(&to) {
                self.adj[from].push(to);
                self.rev[to].push(from);
                self.edge_count += 1;
            }
        }
    }
    #[allow(dead_code)]
    pub fn succs(&self, n: usize) -> &[usize] {
        self.adj.get(n).map(|v| v.as_slice()).unwrap_or(&[])
    }
    #[allow(dead_code)]
    pub fn preds(&self, n: usize) -> &[usize] {
        self.rev.get(n).map(|v| v.as_slice()).unwrap_or(&[])
    }
    #[allow(dead_code)]
    pub fn topo_sort(&self) -> Option<Vec<usize>> {
        let mut deg: Vec<usize> = (0..self.n).map(|i| self.rev[i].len()).collect();
        let mut q: std::collections::VecDeque<usize> =
            (0..self.n).filter(|&i| deg[i] == 0).collect();
        let mut out = Vec::with_capacity(self.n);
        while let Some(u) = q.pop_front() {
            out.push(u);
            for &v in &self.adj[u] {
                deg[v] -= 1;
                if deg[v] == 0 {
                    q.push_back(v);
                }
            }
        }
        if out.len() == self.n {
            Some(out)
        } else {
            None
        }
    }
    #[allow(dead_code)]
    pub fn has_cycle(&self) -> bool {
        self.topo_sort().is_none()
    }
    #[allow(dead_code)]
    pub fn reachable(&self, start: usize) -> Vec<usize> {
        let mut vis = vec![false; self.n];
        let mut stk = vec![start];
        let mut out = Vec::new();
        while let Some(u) = stk.pop() {
            if u < self.n && !vis[u] {
                vis[u] = true;
                out.push(u);
                for &v in &self.adj[u] {
                    if !vis[v] {
                        stk.push(v);
                    }
                }
            }
        }
        out
    }
    #[allow(dead_code)]
    pub fn scc(&self) -> Vec<Vec<usize>> {
        let mut visited = vec![false; self.n];
        let mut order = Vec::new();
        for i in 0..self.n {
            if !visited[i] {
                let mut stk = vec![(i, 0usize)];
                while let Some((u, idx)) = stk.last_mut() {
                    if !visited[*u] {
                        visited[*u] = true;
                    }
                    if *idx < self.adj[*u].len() {
                        let v = self.adj[*u][*idx];
                        *idx += 1;
                        if !visited[v] {
                            stk.push((v, 0));
                        }
                    } else {
                        order.push(*u);
                        stk.pop();
                    }
                }
            }
        }
        let mut comp = vec![usize::MAX; self.n];
        let mut components: Vec<Vec<usize>> = Vec::new();
        for &start in order.iter().rev() {
            if comp[start] == usize::MAX {
                let cid = components.len();
                let mut component = Vec::new();
                let mut stk = vec![start];
                while let Some(u) = stk.pop() {
                    if comp[u] == usize::MAX {
                        comp[u] = cid;
                        component.push(u);
                        for &v in &self.rev[u] {
                            if comp[v] == usize::MAX {
                                stk.push(v);
                            }
                        }
                    }
                }
                components.push(component);
            }
        }
        components
    }
    #[allow(dead_code)]
    pub fn node_count(&self) -> usize {
        self.n
    }
    #[allow(dead_code)]
    pub fn edge_count(&self) -> usize {
        self.edge_count
    }
}
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmLivenessInfo {
    pub live_in: Vec<std::collections::HashSet<u32>>,
    pub live_out: Vec<std::collections::HashSet<u32>>,
    pub defs: Vec<std::collections::HashSet<u32>>,
    pub uses: Vec<std::collections::HashSet<u32>>,
}
impl WasmLivenessInfo {
    #[allow(dead_code)]
    pub fn new(block_count: usize) -> Self {
        WasmLivenessInfo {
            live_in: vec![std::collections::HashSet::new(); block_count],
            live_out: vec![std::collections::HashSet::new(); block_count],
            defs: vec![std::collections::HashSet::new(); block_count],
            uses: vec![std::collections::HashSet::new(); block_count],
        }
    }
    #[allow(dead_code)]
    pub fn add_def(&mut self, block: usize, var: u32) {
        if block < self.defs.len() {
            self.defs[block].insert(var);
        }
    }
    #[allow(dead_code)]
    pub fn add_use(&mut self, block: usize, var: u32) {
        if block < self.uses.len() {
            self.uses[block].insert(var);
        }
    }
    #[allow(dead_code)]
    pub fn is_live_in(&self, block: usize, var: u32) -> bool {
        self.live_in
            .get(block)
            .map(|s| s.contains(&var))
            .unwrap_or(false)
    }
    #[allow(dead_code)]
    pub fn is_live_out(&self, block: usize, var: u32) -> bool {
        self.live_out
            .get(block)
            .map(|s| s.contains(&var))
            .unwrap_or(false)
    }
}
/// Pass execution phase for WasmX2.
#[allow(dead_code)]
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum WasmX2PassPhase {
    Early,
    Middle,
    Late,
    Finalize,
}
impl WasmX2PassPhase {
    #[allow(dead_code)]
    pub fn is_early(&self) -> bool {
        matches!(self, Self::Early)
    }
    #[allow(dead_code)]
    pub fn is_middle(&self) -> bool {
        matches!(self, Self::Middle)
    }
    #[allow(dead_code)]
    pub fn is_late(&self) -> bool {
        matches!(self, Self::Late)
    }
    #[allow(dead_code)]
    pub fn is_finalize(&self) -> bool {
        matches!(self, Self::Finalize)
    }
    #[allow(dead_code)]
    pub fn order(&self) -> u32 {
        match self {
            Self::Early => 0,
            Self::Middle => 1,
            Self::Late => 2,
            Self::Finalize => 3,
        }
    }
    #[allow(dead_code)]
    pub fn from_order(n: u32) -> Option<Self> {
        match n {
            0 => Some(Self::Early),
            1 => Some(Self::Middle),
            2 => Some(Self::Late),
            3 => Some(Self::Finalize),
            _ => None,
        }
    }
}
/// Configuration for WasmX2 passes.
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmX2PassConfig {
    pub name: String,
    pub phase: WasmX2PassPhase,
    pub enabled: bool,
    pub max_iterations: usize,
    pub debug: u32,
    pub timeout_ms: Option<u64>,
}
impl WasmX2PassConfig {
    #[allow(dead_code)]
    pub fn new(name: impl Into<String>) -> Self {
        Self {
            name: name.into(),
            phase: WasmX2PassPhase::Middle,
            enabled: true,
            max_iterations: 100,
            debug: 0,
            timeout_ms: None,
        }
    }
    #[allow(dead_code)]
    pub fn with_phase(mut self, phase: WasmX2PassPhase) -> Self {
        self.phase = phase;
        self
    }
    #[allow(dead_code)]
    pub fn with_max_iter(mut self, n: usize) -> Self {
        self.max_iterations = n;
        self
    }
    #[allow(dead_code)]
    pub fn with_debug(mut self, d: u32) -> Self {
        self.debug = d;
        self
    }
    #[allow(dead_code)]
    pub fn disabled(mut self) -> Self {
        self.enabled = false;
        self
    }
    #[allow(dead_code)]
    pub fn with_timeout(mut self, ms: u64) -> Self {
        self.timeout_ms = Some(ms);
        self
    }
    #[allow(dead_code)]
    pub fn is_debug_enabled(&self) -> bool {
        self.debug > 0
    }
}
#[allow(dead_code)]
#[derive(Debug, Clone, Default)]
pub struct WasmPassStats {
    pub total_runs: u32,
    pub successful_runs: u32,
    pub total_changes: u64,
    pub time_ms: u64,
    pub iterations_used: u32,
}
impl WasmPassStats {
    #[allow(dead_code)]
    pub fn new() -> Self {
        Self::default()
    }
    #[allow(dead_code)]
    pub fn record_run(&mut self, changes: u64, time_ms: u64, iterations: u32) {
        self.total_runs += 1;
        self.successful_runs += 1;
        self.total_changes += changes;
        self.time_ms += time_ms;
        self.iterations_used = iterations;
    }
    #[allow(dead_code)]
    pub fn average_changes_per_run(&self) -> f64 {
        if self.total_runs == 0 {
            return 0.0;
        }
        self.total_changes as f64 / self.total_runs as f64
    }
    #[allow(dead_code)]
    pub fn success_rate(&self) -> f64 {
        if self.total_runs == 0 {
            return 0.0;
        }
        self.successful_runs as f64 / self.total_runs as f64
    }
    #[allow(dead_code)]
    pub fn format_summary(&self) -> String {
        format!(
            "Runs: {}/{}, Changes: {}, Time: {}ms",
            self.successful_runs, self.total_runs, self.total_changes, self.time_ms
        )
    }
}
/// A WebAssembly global variable declaration.
#[derive(Debug, Clone, PartialEq)]
pub struct WasmGlobal {
    /// Identifier name of the global.
    pub name: String,
    /// Value type of the global.
    pub ty: WasmType,
    /// Whether the global is mutable.
    pub mutable: bool,
    /// Initial value expression (as a WAT constant expression string).
    pub init_value: String,
}
/// Configuration for WasmExt passes.
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmExtPassConfig {
    pub name: String,
    pub phase: WasmExtPassPhase,
    pub enabled: bool,
    pub max_iterations: usize,
    pub debug: u32,
    pub timeout_ms: Option<u64>,
}
impl WasmExtPassConfig {
    #[allow(dead_code)]
    pub fn new(name: impl Into<String>) -> Self {
        Self {
            name: name.into(),
            phase: WasmExtPassPhase::Middle,
            enabled: true,
            max_iterations: 100,
            debug: 0,
            timeout_ms: None,
        }
    }
    #[allow(dead_code)]
    pub fn with_phase(mut self, phase: WasmExtPassPhase) -> Self {
        self.phase = phase;
        self
    }
    #[allow(dead_code)]
    pub fn with_max_iter(mut self, n: usize) -> Self {
        self.max_iterations = n;
        self
    }
    #[allow(dead_code)]
    pub fn with_debug(mut self, d: u32) -> Self {
        self.debug = d;
        self
    }
    #[allow(dead_code)]
    pub fn disabled(mut self) -> Self {
        self.enabled = false;
        self
    }
    #[allow(dead_code)]
    pub fn with_timeout(mut self, ms: u64) -> Self {
        self.timeout_ms = Some(ms);
        self
    }
    #[allow(dead_code)]
    pub fn is_debug_enabled(&self) -> bool {
        self.debug > 0
    }
}
/// Statistics for WasmExt passes.
#[allow(dead_code)]
#[derive(Debug, Clone, Default)]
pub struct WasmExtPassStats {
    pub iterations: usize,
    pub changed: bool,
    pub nodes_visited: usize,
    pub nodes_modified: usize,
    pub time_ms: u64,
    pub memory_bytes: usize,
    pub errors: usize,
}
impl WasmExtPassStats {
    #[allow(dead_code)]
    pub fn new() -> Self {
        Self::default()
    }
    #[allow(dead_code)]
    pub fn visit(&mut self) {
        self.nodes_visited += 1;
    }
    #[allow(dead_code)]
    pub fn modify(&mut self) {
        self.nodes_modified += 1;
        self.changed = true;
    }
    #[allow(dead_code)]
    pub fn iterate(&mut self) {
        self.iterations += 1;
    }
    #[allow(dead_code)]
    pub fn error(&mut self) {
        self.errors += 1;
    }
    #[allow(dead_code)]
    pub fn efficiency(&self) -> f64 {
        if self.nodes_visited == 0 {
            0.0
        } else {
            self.nodes_modified as f64 / self.nodes_visited as f64
        }
    }
    #[allow(dead_code)]
    pub fn merge(&mut self, o: &WasmExtPassStats) {
        self.iterations += o.iterations;
        self.changed |= o.changed;
        self.nodes_visited += o.nodes_visited;
        self.nodes_modified += o.nodes_modified;
        self.time_ms += o.time_ms;
        self.memory_bytes = self.memory_bytes.max(o.memory_bytes);
        self.errors += o.errors;
    }
}
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmAnalysisCache {
    pub(super) entries: std::collections::HashMap<String, WasmCacheEntry>,
    pub(super) max_size: usize,
    pub(super) hits: u64,
    pub(super) misses: u64,
}
impl WasmAnalysisCache {
    #[allow(dead_code)]
    pub fn new(max_size: usize) -> Self {
        WasmAnalysisCache {
            entries: std::collections::HashMap::new(),
            max_size,
            hits: 0,
            misses: 0,
        }
    }
    #[allow(dead_code)]
    pub fn get(&mut self, key: &str) -> Option<&WasmCacheEntry> {
        if self.entries.contains_key(key) {
            self.hits += 1;
            self.entries.get(key)
        } else {
            self.misses += 1;
            None
        }
    }
    #[allow(dead_code)]
    pub fn insert(&mut self, key: String, data: Vec<u8>) {
        if self.entries.len() >= self.max_size {
            if let Some(oldest) = self.entries.keys().next().cloned() {
                self.entries.remove(&oldest);
            }
        }
        self.entries.insert(
            key.clone(),
            WasmCacheEntry {
                key,
                data,
                timestamp: 0,
                valid: true,
            },
        );
    }
    #[allow(dead_code)]
    pub fn invalidate(&mut self, key: &str) {
        if let Some(entry) = self.entries.get_mut(key) {
            entry.valid = false;
        }
    }
    #[allow(dead_code)]
    pub fn clear(&mut self) {
        self.entries.clear();
    }
    #[allow(dead_code)]
    pub fn hit_rate(&self) -> f64 {
        let total = self.hits + self.misses;
        if total == 0 {
            return 0.0;
        }
        self.hits as f64 / total as f64
    }
    #[allow(dead_code)]
    pub fn size(&self) -> usize {
        self.entries.len()
    }
}
/// Pass registry for WasmExt.
#[allow(dead_code)]
#[derive(Debug, Default)]
pub struct WasmExtPassRegistry {
    pub(super) configs: Vec<WasmExtPassConfig>,
    pub(super) stats: Vec<WasmExtPassStats>,
}
impl WasmExtPassRegistry {
    #[allow(dead_code)]
    pub fn new() -> Self {
        Self::default()
    }
    #[allow(dead_code)]
    pub fn register(&mut self, c: WasmExtPassConfig) {
        self.stats.push(WasmExtPassStats::new());
        self.configs.push(c);
    }
    #[allow(dead_code)]
    pub fn len(&self) -> usize {
        self.configs.len()
    }
    #[allow(dead_code)]
    pub fn is_empty(&self) -> bool {
        self.configs.is_empty()
    }
    #[allow(dead_code)]
    pub fn get(&self, i: usize) -> Option<&WasmExtPassConfig> {
        self.configs.get(i)
    }
    #[allow(dead_code)]
    pub fn get_stats(&self, i: usize) -> Option<&WasmExtPassStats> {
        self.stats.get(i)
    }
    #[allow(dead_code)]
    pub fn enabled_passes(&self) -> Vec<&WasmExtPassConfig> {
        self.configs.iter().filter(|c| c.enabled).collect()
    }
    #[allow(dead_code)]
    pub fn passes_in_phase(&self, ph: &WasmExtPassPhase) -> Vec<&WasmExtPassConfig> {
        self.configs
            .iter()
            .filter(|c| c.enabled && &c.phase == ph)
            .collect()
    }
    #[allow(dead_code)]
    pub fn total_nodes_visited(&self) -> usize {
        self.stats.iter().map(|s| s.nodes_visited).sum()
    }
    #[allow(dead_code)]
    pub fn any_changed(&self) -> bool {
        self.stats.iter().any(|s| s.changed)
    }
}
/// WebAssembly value types.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum WasmType {
    /// 32-bit integer
    I32,
    /// 64-bit integer
    I64,
    /// 32-bit float
    F32,
    /// 64-bit float
    F64,
    /// Function reference
    FuncRef,
    /// External reference
    ExternRef,
    /// 128-bit SIMD vector
    V128,
}
#[allow(dead_code)]
pub struct WasmPassRegistry {
    pub(super) configs: Vec<WasmPassConfig>,
    pub(super) stats: std::collections::HashMap<String, WasmPassStats>,
}
impl WasmPassRegistry {
    #[allow(dead_code)]
    pub fn new() -> Self {
        WasmPassRegistry {
            configs: Vec::new(),
            stats: std::collections::HashMap::new(),
        }
    }
    #[allow(dead_code)]
    pub fn register(&mut self, config: WasmPassConfig) {
        self.stats
            .insert(config.pass_name.clone(), WasmPassStats::new());
        self.configs.push(config);
    }
    #[allow(dead_code)]
    pub fn enabled_passes(&self) -> Vec<&WasmPassConfig> {
        self.configs.iter().filter(|c| c.enabled).collect()
    }
    #[allow(dead_code)]
    pub fn get_stats(&self, name: &str) -> Option<&WasmPassStats> {
        self.stats.get(name)
    }
    #[allow(dead_code)]
    pub fn total_passes(&self) -> usize {
        self.configs.len()
    }
    #[allow(dead_code)]
    pub fn enabled_count(&self) -> usize {
        self.enabled_passes().len()
    }
    #[allow(dead_code)]
    pub fn update_stats(&mut self, name: &str, changes: u64, time_ms: u64, iter: u32) {
        if let Some(stats) = self.stats.get_mut(name) {
            stats.record_run(changes, time_ms, iter);
        }
    }
}
/// Worklist for WasmX2.
#[allow(dead_code)]
#[derive(Debug, Clone)]
pub struct WasmX2Worklist {
    pub(super) items: std::collections::VecDeque<usize>,
    pub(super) present: Vec<bool>,
}
impl WasmX2Worklist {
    #[allow(dead_code)]
    pub fn new(capacity: usize) -> Self {
        Self {
            items: std::collections::VecDeque::new(),
            present: vec![false; capacity],
        }
    }
    #[allow(dead_code)]
    pub fn push(&mut self, id: usize) {
        if id < self.present.len() && !self.present[id] {
            self.present[id] = true;
            self.items.push_back(id);
        }
    }
    #[allow(dead_code)]
    pub fn push_front(&mut self, id: usize) {
        if id < self.present.len() && !self.present[id] {
            self.present[id] = true;
            self.items.push_front(id);
        }
    }
    #[allow(dead_code)]
    pub fn pop(&mut self) -> Option<usize> {
        let id = self.items.pop_front()?;
        if id < self.present.len() {
            self.present[id] = false;
        }
        Some(id)
    }
    #[allow(dead_code)]
    pub fn is_empty(&self) -> bool {
        self.items.is_empty()
    }
    #[allow(dead_code)]
    pub fn len(&self) -> usize {
        self.items.len()
    }
    #[allow(dead_code)]
    pub fn contains(&self, id: usize) -> bool {
        id < self.present.len() && self.present[id]
    }
    #[allow(dead_code)]
    pub fn drain_all(&mut self) -> Vec<usize> {
        let v: Vec<usize> = self.items.drain(..).collect();
        for &id in &v {
            if id < self.present.len() {
                self.present[id] = false;
            }
        }
        v
    }
}
/// Constant folding helper for WasmX2.
#[allow(dead_code)]
#[derive(Debug, Clone, Default)]
pub struct WasmX2ConstFolder {
    pub(super) folds: usize,
    pub(super) failures: usize,
    pub(super) enabled: bool,
}
impl WasmX2ConstFolder {
    #[allow(dead_code)]
    pub fn new() -> Self {
        Self {
            folds: 0,
            failures: 0,
            enabled: true,
        }
    }
    #[allow(dead_code)]
    pub fn add_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        self.folds += 1;
        a.checked_add(b)
    }
    #[allow(dead_code)]
    pub fn sub_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        self.folds += 1;
        a.checked_sub(b)
    }
    #[allow(dead_code)]
    pub fn mul_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        self.folds += 1;
        a.checked_mul(b)
    }
    #[allow(dead_code)]
    pub fn div_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        if b == 0 {
            self.failures += 1;
            None
        } else {
            self.folds += 1;
            a.checked_div(b)
        }
    }
    #[allow(dead_code)]
    pub fn rem_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        if b == 0 {
            self.failures += 1;
            None
        } else {
            self.folds += 1;
            a.checked_rem(b)
        }
    }
    #[allow(dead_code)]
    pub fn neg_i64(&mut self, a: i64) -> Option<i64> {
        self.folds += 1;
        a.checked_neg()
    }
    #[allow(dead_code)]
    pub fn shl_i64(&mut self, a: i64, s: u32) -> Option<i64> {
        if s >= 64 {
            self.failures += 1;
            None
        } else {
            self.folds += 1;
            a.checked_shl(s)
        }
    }
    #[allow(dead_code)]
    pub fn shr_i64(&mut self, a: i64, s: u32) -> Option<i64> {
        if s >= 64 {
            self.failures += 1;
            None
        } else {
            self.folds += 1;
            a.checked_shr(s)
        }
    }
    #[allow(dead_code)]
    pub fn and_i64(&mut self, a: i64, b: i64) -> i64 {
        self.folds += 1;
        a & b
    }
    #[allow(dead_code)]
    pub fn or_i64(&mut self, a: i64, b: i64) -> i64 {
        self.folds += 1;
        a | b
    }
    #[allow(dead_code)]
    pub fn xor_i64(&mut self, a: i64, b: i64) -> i64 {
        self.folds += 1;
        a ^ b
    }
    #[allow(dead_code)]
    pub fn not_i64(&mut self, a: i64) -> i64 {
        self.folds += 1;
        !a
    }
    #[allow(dead_code)]
    pub fn fold_count(&self) -> usize {
        self.folds
    }
    #[allow(dead_code)]
    pub fn failure_count(&self) -> usize {
        self.failures
    }
    #[allow(dead_code)]
    pub fn enable(&mut self) {
        self.enabled = true;
    }
    #[allow(dead_code)]
    pub fn disable(&mut self) {
        self.enabled = false;
    }
    #[allow(dead_code)]
    pub fn is_enabled(&self) -> bool {
        self.enabled
    }
}
/// The WebAssembly code generation backend.
///
/// Compiles LCNF function declarations to WebAssembly text format (WAT).
#[derive(Debug, Default)]
pub struct WasmBackend {
    /// Counter for generating unique local variable names.
    pub(super) local_counter: u64,
}
impl WasmBackend {
    /// Create a new WasmBackend instance.
    pub fn new() -> Self {
        Self::default()
    }
    /// Generate a fresh local variable name.
    pub(super) fn fresh_local(&mut self) -> String {
        let n = self.local_counter;
        self.local_counter += 1;
        format!("_t{}", n)
    }
    /// Map an LCNF type to a WebAssembly value type.
    pub(super) fn lcnf_type_to_wasm(ty: &LcnfType) -> WasmType {
        match ty {
            LcnfType::Nat => WasmType::I64,
            LcnfType::Erased | LcnfType::Irrelevant | LcnfType::Unit => WasmType::I32,
            LcnfType::LcnfString => WasmType::I32,
            LcnfType::Fun(_, _) => WasmType::I32,
            LcnfType::Ctor(_, _) => WasmType::I32,
            LcnfType::Object => WasmType::I32,
            LcnfType::Var(_) => WasmType::I32,
        }
    }
    /// Compile a single LCNF expression to a list of WASM instructions.
    /// The value is left on the stack.
    pub(super) fn compile_expr(
        &mut self,
        expr: &LcnfExpr,
        locals: &mut Vec<(String, WasmType)>,
    ) -> Vec<WasmInstr> {
        match expr {
            LcnfExpr::Let {
                id,
                ty,
                value,
                body,
                ..
            } => {
                let local_name = format!("x{}", id.0);
                let val_type = Self::lcnf_type_to_wasm(ty);
                locals.push((local_name.clone(), val_type));
                let mut instrs = self.compile_let_value(value, locals);
                instrs.push(WasmInstr::LocalSet(local_name));
                instrs.extend(self.compile_expr(body, locals));
                instrs
            }
            LcnfExpr::Case {
                scrutinee,
                alts,
                default,
                ..
            } => self.compile_case(scrutinee, alts, default.as_deref(), locals),
            LcnfExpr::Return(arg) => self.compile_arg(arg),
            LcnfExpr::Unreachable => vec![WasmInstr::Unreachable],
            LcnfExpr::TailCall(func, args) => {
                let mut instrs = Vec::new();
                for arg in args {
                    instrs.extend(self.compile_arg(arg));
                }
                match func {
                    LcnfArg::Var(_) => {
                        instrs.extend(self.compile_arg(func));
                        instrs.push(WasmInstr::CallIndirect);
                    }
                    _ => {
                        instrs.push(WasmInstr::CallIndirect);
                    }
                }
                instrs
            }
        }
    }
    /// Compile an LCNF argument to WASM instructions.
    pub(super) fn compile_arg(&self, arg: &LcnfArg) -> Vec<WasmInstr> {
        match arg {
            LcnfArg::Var(id) => vec![WasmInstr::LocalGet(format!("x{}", id.0))],
            LcnfArg::Lit(LcnfLit::Nat(n)) => vec![WasmInstr::I64Const(*n as i64)],
            LcnfArg::Lit(LcnfLit::Str(_)) => vec![WasmInstr::I32Const(0)],
            LcnfArg::Erased => vec![WasmInstr::I32Const(0)],
            LcnfArg::Type(_) => vec![WasmInstr::I32Const(0)],
        }
    }
    /// Compile an LCNF let-value binding.
    pub(super) fn compile_let_value(
        &mut self,
        val: &LcnfLetValue,
        _locals: &mut Vec<(String, WasmType)>,
    ) -> Vec<WasmInstr> {
        match val {
            LcnfLetValue::Lit(lit) => match lit {
                LcnfLit::Nat(n) => vec![WasmInstr::I64Const(*n as i64)],
                LcnfLit::Str(_) => vec![WasmInstr::I32Const(0)],
            },
            LcnfLetValue::FVar(id) => vec![WasmInstr::LocalGet(format!("x{}", id.0))],
            LcnfLetValue::App(func, args) => {
                let mut instrs = Vec::new();
                for arg in args {
                    instrs.extend(self.compile_arg(arg));
                }
                match func {
                    LcnfArg::Var(_) => {
                        instrs.extend(self.compile_arg(func));
                        instrs.push(WasmInstr::CallIndirect);
                    }
                    _ => {
                        instrs.push(WasmInstr::CallIndirect);
                    }
                }
                instrs
            }
            LcnfLetValue::Ctor(name, _tag, args) => {
                let mut instrs = Vec::new();
                for arg in args {
                    instrs.extend(self.compile_arg(arg));
                }
                instrs.push(WasmInstr::Call(mangle_wasm_name(name)));
                instrs
            }
            LcnfLetValue::Proj(_name, _idx, var) => {
                vec![WasmInstr::LocalGet(format!("x{}", var.0))]
            }
            LcnfLetValue::Erased => vec![WasmInstr::I32Const(0)],
            LcnfLetValue::Reset(var) => vec![WasmInstr::LocalGet(format!("x{}", var.0))],
            LcnfLetValue::Reuse(_slot, name, _tag, args) => {
                let mut instrs = Vec::new();
                for arg in args {
                    instrs.extend(self.compile_arg(arg));
                }
                instrs.push(WasmInstr::Call(mangle_wasm_name(name)));
                instrs
            }
        }
    }
    /// Compile a case expression to WASM instructions.
    pub(super) fn compile_case(
        &mut self,
        scrutinee: &LcnfVarId,
        alts: &[LcnfAlt],
        default: Option<&LcnfExpr>,
        locals: &mut Vec<(String, WasmType)>,
    ) -> Vec<WasmInstr> {
        let mut instrs = Vec::new();
        if alts.is_empty() {
            if let Some(def) = default {
                instrs.extend(self.compile_expr(def, locals));
            } else {
                instrs.push(WasmInstr::Unreachable);
            }
            return instrs;
        }
        instrs.push(WasmInstr::LocalGet(format!("x{}", scrutinee.0)));
        instrs.push(WasmInstr::Drop);
        let body_instrs = if let Some(first_alt) = alts.first() {
            self.compile_expr(&first_alt.body, locals)
        } else if let Some(def) = default {
            self.compile_expr(def, locals)
        } else {
            vec![WasmInstr::Unreachable]
        };
        instrs.extend(body_instrs);
        instrs
    }
    /// Compile a single LCNF function declaration to a `WasmFunc`.
    pub fn compile_decl(&mut self, decl: &LcnfFunDecl) -> WasmFunc {
        let name = mangle_wasm_name(&decl.name);
        let params: Vec<(String, WasmType)> = decl
            .params
            .iter()
            .map(|p| {
                let pname = format!("x{}", p.id.0);
                let pty = Self::lcnf_type_to_wasm(&p.ty);
                (pname, pty)
            })
            .collect();
        let results = vec![Self::lcnf_type_to_wasm(&decl.ret_type)];
        let mut locals: Vec<(String, WasmType)> = Vec::new();
        let body = self.compile_expr(&decl.body, &mut locals);
        WasmFunc {
            name,
            params,
            results,
            locals,
            body,
        }
    }
    /// Compile a slice of LCNF function declarations and emit a WAT string.
    pub fn emit_module(decls: &[LcnfFunDecl]) -> Result<String, String> {
        let mut backend = WasmBackend::new();
        let mut module = WasmModule::new();
        module.memory = Some(1);
        module.imports.push(WasmImport {
            module: "env".to_string(),
            name: "memory".to_string(),
            kind: WasmImportKind::Memory { min_pages: 1 },
        });
        module.imports.push(WasmImport {
            module: "oxilean".to_string(),
            name: "alloc".to_string(),
            kind: WasmImportKind::Func {
                params: vec![WasmType::I32],
                results: vec![WasmType::I32],
            },
        });
        for decl in decls {
            let func = backend.compile_decl(decl);
            let func_name = func.name.clone();
            module.functions.push(func);
            module.exports.push(func_name);
        }
        Ok(module.to_wat())
    }
}
/// Analysis cache for WasmX2.
#[allow(dead_code)]
#[derive(Debug)]
pub struct WasmX2Cache {
    pub(super) entries: Vec<(u64, Vec<u8>, bool, u32)>,
    pub(super) cap: usize,
    pub(super) total_hits: u64,
    pub(super) total_misses: u64,
}
impl WasmX2Cache {
    #[allow(dead_code)]
    pub fn new(cap: usize) -> Self {
        Self {
            entries: Vec::new(),
            cap,
            total_hits: 0,
            total_misses: 0,
        }
    }
    #[allow(dead_code)]
    pub fn get(&mut self, key: u64) -> Option<&[u8]> {
        for e in self.entries.iter_mut() {
            if e.0 == key && e.2 {
                e.3 += 1;
                self.total_hits += 1;
                return Some(&e.1);
            }
        }
        self.total_misses += 1;
        None
    }
    #[allow(dead_code)]
    pub fn put(&mut self, key: u64, data: Vec<u8>) {
        if self.entries.len() >= self.cap {
            self.entries.retain(|e| e.2);
            if self.entries.len() >= self.cap {
                self.entries.remove(0);
            }
        }
        self.entries.push((key, data, true, 0));
    }
    #[allow(dead_code)]
    pub fn invalidate(&mut self) {
        for e in self.entries.iter_mut() {
            e.2 = false;
        }
    }
    #[allow(dead_code)]
    pub fn hit_rate(&self) -> f64 {
        let t = self.total_hits + self.total_misses;
        if t == 0 {
            0.0
        } else {
            self.total_hits as f64 / t as f64
        }
    }
    #[allow(dead_code)]
    pub fn live_count(&self) -> usize {
        self.entries.iter().filter(|e| e.2).count()
    }
}
/// Pass execution phase for WasmExt.
#[allow(dead_code)]
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum WasmExtPassPhase {
    Early,
    Middle,
    Late,
    Finalize,
}
impl WasmExtPassPhase {
    #[allow(dead_code)]
    pub fn is_early(&self) -> bool {
        matches!(self, Self::Early)
    }
    #[allow(dead_code)]
    pub fn is_middle(&self) -> bool {
        matches!(self, Self::Middle)
    }
    #[allow(dead_code)]
    pub fn is_late(&self) -> bool {
        matches!(self, Self::Late)
    }
    #[allow(dead_code)]
    pub fn is_finalize(&self) -> bool {
        matches!(self, Self::Finalize)
    }
    #[allow(dead_code)]
    pub fn order(&self) -> u32 {
        match self {
            Self::Early => 0,
            Self::Middle => 1,
            Self::Late => 2,
            Self::Finalize => 3,
        }
    }
    #[allow(dead_code)]
    pub fn from_order(n: u32) -> Option<Self> {
        match n {
            0 => Some(Self::Early),
            1 => Some(Self::Middle),
            2 => Some(Self::Late),
            3 => Some(Self::Finalize),
            _ => None,
        }
    }
}
/// WebAssembly instructions for the WAT text format.
#[derive(Debug, Clone, PartialEq)]
pub enum WasmInstr {
    /// Get local variable: `local.get $name`
    LocalGet(String),
    /// Set local variable: `local.set $name`
    LocalSet(String),
    /// 32-bit integer constant: `i32.const N`
    I32Const(i32),
    /// 64-bit integer constant: `i64.const N`
    I64Const(i64),
    /// 64-bit float constant: `f64.const N`
    F64Const(f64),
    /// Direct function call: `call $name`
    Call(String),
    /// Indirect function call via table: `call_indirect`
    CallIndirect,
    /// Return from function: `return`
    Return,
    /// Branch if condition is true: `br_if N`
    BrIf(u32),
    /// Begin a block: `block`
    Block,
    /// Begin a loop: `loop`
    Loop,
    /// End a block/loop/function: `end`
    End,
    /// Drop top of stack: `drop`
    Drop,
    /// Select one of two values based on condition: `select`
    Select,
    /// No-op: `nop`
    Nop,
    /// Trap unconditionally: `unreachable`
    Unreachable,
    /// `i32.add`
    I32Add,
    /// `i32.sub`
    I32Sub,
    /// `i32.mul`
    I32Mul,
    /// `i32.div_s`
    I32DivS,
    /// `i64.add`
    I64Add,
    /// `i64.mul`
    I64Mul,
    /// `f64.add`
    F64Add,
    /// `f64.mul`
    F64Mul,
    /// `f64.div`
    F64Div,
    /// `f64.sqrt`
    F64Sqrt,
    /// Load from linear memory with alignment: `i32.load align=N`
    MemLoad(u32),
    /// Store to linear memory with alignment: `i32.store align=N`
    MemStore(u32),
    /// `i32.eqz`
    I32Eqz,
    /// `i32.eq`
    I32Eq,
    /// `i32.ne`
    I32Ne,
    /// `i32.lt_s`
    I32LtS,
    /// `i32.gt_s`
    I32GtS,
    /// `i32.le_s`
    I32LeS,
    /// `i32.ge_s`
    I32GeS,
    /// Null reference: `ref.null funcref`
    RefNull,
    /// Test if reference is null: `ref.is_null`
    RefIsNull,
    /// Get element from table: `table.get N`
    TableGet(u32),
    /// Set element in table: `table.set N`
    TableSet(u32),
}
/// Constant folding helper for WasmExt.
#[allow(dead_code)]
#[derive(Debug, Clone, Default)]
pub struct WasmExtConstFolder {
    pub(super) folds: usize,
    pub(super) failures: usize,
    pub(super) enabled: bool,
}
impl WasmExtConstFolder {
    #[allow(dead_code)]
    pub fn new() -> Self {
        Self {
            folds: 0,
            failures: 0,
            enabled: true,
        }
    }
    #[allow(dead_code)]
    pub fn add_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        self.folds += 1;
        a.checked_add(b)
    }
    #[allow(dead_code)]
    pub fn sub_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        self.folds += 1;
        a.checked_sub(b)
    }
    #[allow(dead_code)]
    pub fn mul_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        self.folds += 1;
        a.checked_mul(b)
    }
    #[allow(dead_code)]
    pub fn div_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        if b == 0 {
            self.failures += 1;
            None
        } else {
            self.folds += 1;
            a.checked_div(b)
        }
    }
    #[allow(dead_code)]
    pub fn rem_i64(&mut self, a: i64, b: i64) -> Option<i64> {
        if b == 0 {
            self.failures += 1;
            None
        } else {
            self.folds += 1;
            a.checked_rem(b)
        }
    }
    #[allow(dead_code)]
    pub fn neg_i64(&mut self, a: i64) -> Option<i64> {
        self.folds += 1;
        a.checked_neg()
    }
    #[allow(dead_code)]
    pub fn shl_i64(&mut self, a: i64, s: u32) -> Option<i64> {
        if s >= 64 {
            self.failures += 1;
            None
        } else {
            self.folds += 1;
            a.checked_shl(s)
        }
    }
    #[allow(dead_code)]
    pub fn shr_i64(&mut self, a: i64, s: u32) -> Option<i64> {
        if s >= 64 {
            self.failures += 1;
            None
        } else {
            self.folds += 1;
            a.checked_shr(s)
        }
    }
    #[allow(dead_code)]
    pub fn and_i64(&mut self, a: i64, b: i64) -> i64 {
        self.folds += 1;
        a & b
    }
    #[allow(dead_code)]
    pub fn or_i64(&mut self, a: i64, b: i64) -> i64 {
        self.folds += 1;
        a | b
    }
    #[allow(dead_code)]
    pub fn xor_i64(&mut self, a: i64, b: i64) -> i64 {
        self.folds += 1;
        a ^ b
    }
    #[allow(dead_code)]
    pub fn not_i64(&mut self, a: i64) -> i64 {
        self.folds += 1;
        !a
    }
    #[allow(dead_code)]
    pub fn fold_count(&self) -> usize {
        self.folds
    }
    #[allow(dead_code)]
    pub fn failure_count(&self) -> usize {
        self.failures
    }
    #[allow(dead_code)]
    pub fn enable(&mut self) {
        self.enabled = true;
    }
    #[allow(dead_code)]
    pub fn disable(&mut self) {
        self.enabled = false;
    }
    #[allow(dead_code)]
    pub fn is_enabled(&self) -> bool {
        self.enabled
    }
}
/// A WebAssembly function definition.
#[derive(Debug, Clone, PartialEq)]
pub struct WasmFunc {
    /// Function name (used as `$name` in WAT).
    pub name: String,
    /// Named parameters with their types: `(param $name type)`.
    pub params: Vec<(String, WasmType)>,
    /// Result types: `(result type)`.
    pub results: Vec<WasmType>,
    /// Named local variables: `(local $name type)`.
    pub locals: Vec<(String, WasmType)>,
    /// Function body instructions.
    pub body: Vec<WasmInstr>,
}
/// Liveness analysis for WasmExt.
#[allow(dead_code)]
#[derive(Debug, Clone, Default)]
pub struct WasmExtLiveness {
    pub live_in: Vec<Vec<usize>>,
    pub live_out: Vec<Vec<usize>>,
    pub defs: Vec<Vec<usize>>,
    pub uses: Vec<Vec<usize>>,
}
impl WasmExtLiveness {
    #[allow(dead_code)]
    pub fn new(n: usize) -> Self {
        Self {
            live_in: vec![Vec::new(); n],
            live_out: vec![Vec::new(); n],
            defs: vec![Vec::new(); n],
            uses: vec![Vec::new(); n],
        }
    }
    #[allow(dead_code)]
    pub fn live_in(&self, b: usize, v: usize) -> bool {
        self.live_in.get(b).map(|s| s.contains(&v)).unwrap_or(false)
    }
    #[allow(dead_code)]
    pub fn live_out(&self, b: usize, v: usize) -> bool {
        self.live_out
            .get(b)
            .map(|s| s.contains(&v))
            .unwrap_or(false)
    }
    #[allow(dead_code)]
    pub fn add_def(&mut self, b: usize, v: usize) {
        if let Some(s) = self.defs.get_mut(b) {
            if !s.contains(&v) {
                s.push(v);
            }
        }
    }
    #[allow(dead_code)]
    pub fn add_use(&mut self, b: usize, v: usize) {
        if let Some(s) = self.uses.get_mut(b) {
            if !s.contains(&v) {
                s.push(v);
            }
        }
    }
    #[allow(dead_code)]
    pub fn var_is_used_in_block(&self, b: usize, v: usize) -> bool {
        self.uses.get(b).map(|s| s.contains(&v)).unwrap_or(false)
    }
    #[allow(dead_code)]
    pub fn var_is_def_in_block(&self, b: usize, v: usize) -> bool {
        self.defs.get(b).map(|s| s.contains(&v)).unwrap_or(false)
    }
}
/// A WebAssembly import declaration.
#[derive(Debug, Clone, PartialEq)]
pub struct WasmImport {
    /// The external module name (e.g. `"env"`)
    pub module: String,
    /// The name of the imported item (e.g. `"memory"`)
    pub name: String,
    /// The kind of the import (func/memory/global)
    pub kind: WasmImportKind,
}
#[allow(dead_code)]
pub struct WasmConstantFoldingHelper;
impl WasmConstantFoldingHelper {
    #[allow(dead_code)]
    pub fn fold_add_i64(a: i64, b: i64) -> Option<i64> {
        a.checked_add(b)
    }
    #[allow(dead_code)]
    pub fn fold_sub_i64(a: i64, b: i64) -> Option<i64> {
        a.checked_sub(b)
    }
    #[allow(dead_code)]
    pub fn fold_mul_i64(a: i64, b: i64) -> Option<i64> {
        a.checked_mul(b)
    }
    #[allow(dead_code)]
    pub fn fold_div_i64(a: i64, b: i64) -> Option<i64> {
        if b == 0 {
            None
        } else {
            a.checked_div(b)
        }
    }
    #[allow(dead_code)]
    pub fn fold_add_f64(a: f64, b: f64) -> f64 {
        a + b
    }
    #[allow(dead_code)]
    pub fn fold_mul_f64(a: f64, b: f64) -> f64 {
        a * b
    }
    #[allow(dead_code)]
    pub fn fold_neg_i64(a: i64) -> Option<i64> {
        a.checked_neg()
    }
    #[allow(dead_code)]
    pub fn fold_not_bool(a: bool) -> bool {
        !a
    }
    #[allow(dead_code)]
    pub fn fold_and_bool(a: bool, b: bool) -> bool {
        a && b
    }
    #[allow(dead_code)]
    pub fn fold_or_bool(a: bool, b: bool) -> bool {
        a || b
    }
    #[allow(dead_code)]
    pub fn fold_shl_i64(a: i64, b: u32) -> Option<i64> {
        a.checked_shl(b)
    }
    #[allow(dead_code)]
    pub fn fold_shr_i64(a: i64, b: u32) -> Option<i64> {
        a.checked_shr(b)
    }
    #[allow(dead_code)]
    pub fn fold_rem_i64(a: i64, b: i64) -> Option<i64> {
        if b == 0 {
            None
        } else {
            Some(a % b)
        }
    }
    #[allow(dead_code)]
    pub fn fold_bitand_i64(a: i64, b: i64) -> i64 {
        a & b
    }
    #[allow(dead_code)]
    pub fn fold_bitor_i64(a: i64, b: i64) -> i64 {
        a | b
    }
    #[allow(dead_code)]
    pub fn fold_bitxor_i64(a: i64, b: i64) -> i64 {
        a ^ b
    }
    #[allow(dead_code)]
    pub fn fold_bitnot_i64(a: i64) -> i64 {
        !a
    }
}
#[allow(dead_code)]
#[derive(Debug, Clone, PartialEq)]
pub enum WasmPassPhase {
    Analysis,
    Transformation,
    Verification,
    Cleanup,
}
impl WasmPassPhase {
    #[allow(dead_code)]
    pub fn name(&self) -> &str {
        match self {
            WasmPassPhase::Analysis => "analysis",
            WasmPassPhase::Transformation => "transformation",
            WasmPassPhase::Verification => "verification",
            WasmPassPhase::Cleanup => "cleanup",
        }
    }
    #[allow(dead_code)]
    pub fn is_modifying(&self) -> bool {
        matches!(self, WasmPassPhase::Transformation | WasmPassPhase::Cleanup)
    }
}
/// Liveness analysis for WasmX2.
#[allow(dead_code)]
#[derive(Debug, Clone, Default)]
pub struct WasmX2Liveness {
    pub live_in: Vec<Vec<usize>>,
    pub live_out: Vec<Vec<usize>>,
    pub defs: Vec<Vec<usize>>,
    pub uses: Vec<Vec<usize>>,
}
impl WasmX2Liveness {
    #[allow(dead_code)]
    pub fn new(n: usize) -> Self {
        Self {
            live_in: vec![Vec::new(); n],
            live_out: vec![Vec::new(); n],
            defs: vec![Vec::new(); n],
            uses: vec![Vec::new(); n],
        }
    }
    #[allow(dead_code)]
    pub fn live_in(&self, b: usize, v: usize) -> bool {
        self.live_in.get(b).map(|s| s.contains(&v)).unwrap_or(false)
    }
    #[allow(dead_code)]
    pub fn live_out(&self, b: usize, v: usize) -> bool {
        self.live_out
            .get(b)
            .map(|s| s.contains(&v))
            .unwrap_or(false)
    }
    #[allow(dead_code)]
    pub fn add_def(&mut self, b: usize, v: usize) {
        if let Some(s) = self.defs.get_mut(b) {
            if !s.contains(&v) {
                s.push(v);
            }
        }
    }
    #[allow(dead_code)]
    pub fn add_use(&mut self, b: usize, v: usize) {
        if let Some(s) = self.uses.get_mut(b) {
            if !s.contains(&v) {
                s.push(v);
            }
        }
    }
    #[allow(dead_code)]
    pub fn var_is_used_in_block(&self, b: usize, v: usize) -> bool {
        self.uses.get(b).map(|s| s.contains(&v)).unwrap_or(false)
    }
    #[allow(dead_code)]
    pub fn var_is_def_in_block(&self, b: usize, v: usize) -> bool {
        self.defs.get(b).map(|s| s.contains(&v)).unwrap_or(false)
    }
}