sigil_parser/

codegen.rs

//! Sigil JIT Compiler using Cranelift
//!
//! Compiles Sigil AST to native machine code for high-performance execution.
//!
//! Optimizations implemented:
//! - Direct condition branching (no redundant boolean conversion)
//! - Constant folding for arithmetic expressions
//! - Tail call optimization for recursive functions
//! - Efficient comparison code generation

#[cfg(feature = "jit")]
pub mod jit {
    use cranelift_codegen::ir::condcodes::IntCC;
    use cranelift_codegen::ir::{types, AbiParam, InstBuilder, UserFuncName};
    use cranelift_codegen::settings::{self, Configurable};
    use cranelift_codegen::Context;
    use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext, Variable};
    use cranelift_jit::{JITBuilder, JITModule};
    use cranelift_module::{FuncId, Linkage, Module};

    use std::collections::HashMap;
    use std::mem;

    use crate::ast::{
        self, BinOp, Expr, ExternBlock, ExternFunction, ExternItem, Item, Literal, PipeOp,
        TypeExpr, UnaryOp,
    };
    use crate::ffi::ctypes::CType;
    use crate::optimize::{OptLevel, Optimizer};
    use crate::parser::Parser;

    /// Runtime value representation
    ///
    /// We use a tagged union representation:
    /// - 64-bit value
    /// - Low 3 bits are tag (NaN-boxing style, but simpler)
    ///
    /// For maximum performance, we use unboxed representations:
    /// - Integers: raw i64
    /// - Floats: raw f64
    /// - Booleans: 0 or 1
    /// - Arrays/Strings: pointers to heap
    #[repr(C)]
    #[derive(Clone, Copy, Debug)]
    pub struct SigilValue(pub u64);

    impl SigilValue {
        // Tag constants (stored in low bits for pointers, high bits for numbers)
        pub const TAG_INT: u64 = 0;
        pub const TAG_FLOAT: u64 = 1;
        pub const TAG_BOOL: u64 = 2;
        pub const TAG_NULL: u64 = 3;
        pub const TAG_PTR: u64 = 4; // Heap-allocated objects

        #[inline]
        pub fn from_int(v: i64) -> Self {
            SigilValue(v as u64)
        }

        #[inline]
        pub fn from_float(v: f64) -> Self {
            SigilValue(v.to_bits())
        }

        #[inline]
        pub fn from_bool(v: bool) -> Self {
            SigilValue(if v { 1 } else { 0 })
        }

        #[inline]
        pub fn as_int(self) -> i64 {
            self.0 as i64
        }

        #[inline]
        pub fn as_float(self) -> f64 {
            f64::from_bits(self.0)
        }

        #[inline]
        pub fn as_bool(self) -> bool {
            self.0 != 0
        }
    }

    /// Compiled function signature
    type CompiledFn = unsafe extern "C" fn() -> i64;
    #[allow(dead_code)]
    type CompiledFnWithArgs = unsafe extern "C" fn(i64) -> i64;

    /// Extern function signature info for FFI
    #[derive(Clone, Debug)]
    pub struct ExternFnSig {
        pub name: String,
        pub params: Vec<types::Type>,
        pub returns: Option<types::Type>,
        pub variadic: bool,
        pub func_id: FuncId,
    }

    /// JIT Compiler for Sigil
    pub struct JitCompiler {
        /// The JIT module
        module: JITModule,
        /// Builder context (reused for efficiency)
        builder_ctx: FunctionBuilderContext,
        /// Codegen context
        ctx: Context,
        /// Compiled functions
        functions: HashMap<String, FuncId>,
        /// Extern "C" function declarations
        extern_functions: HashMap<String, ExternFnSig>,
        /// Variable counter for unique variable indices
        #[allow(dead_code)]
        var_counter: usize,
        /// Built-in function addresses
        #[allow(dead_code)]
        builtins: HashMap<String, *const u8>,
    }

    impl JitCompiler {
        /// Create a new JIT compiler
        pub fn new() -> Result<Self, String> {
            let mut flag_builder = settings::builder();
            // Disable PIC for better codegen
            flag_builder.set("use_colocated_libcalls", "false").unwrap();
            flag_builder.set("is_pic", "false").unwrap();
            // Maximum optimization level
            flag_builder.set("opt_level", "speed").unwrap();
            // Enable additional optimizations
            flag_builder.set("enable_verifier", "false").unwrap(); // Disable verifier in release for speed
            flag_builder.set("enable_alias_analysis", "true").unwrap();

            // Get native ISA with CPU feature detection (AVX2, SSE4, etc. auto-detected)
            let isa_builder = cranelift_native::builder().map_err(|e| e.to_string())?;
            let isa = isa_builder
                .finish(settings::Flags::new(flag_builder))
                .map_err(|e| e.to_string())?;

            let mut builder = JITBuilder::with_isa(isa, cranelift_module::default_libcall_names());

            // Register built-in functions
            let builtins = Self::register_builtins(&mut builder);

            let module = JITModule::new(builder);

            Ok(Self {
                module,
                builder_ctx: FunctionBuilderContext::new(),
                ctx: Context::new(),
                functions: HashMap::new(),
                extern_functions: HashMap::new(),
                var_counter: 0,
                builtins,
            })
        }

        /// Register built-in runtime functions
        fn register_builtins(builder: &mut JITBuilder) -> HashMap<String, *const u8> {
            let mut builtins = HashMap::new();

            // Math functions from libc
            builder.symbol("sigil_sqrt", sigil_sqrt as *const u8);
            builder.symbol("sigil_sin", sigil_sin as *const u8);
            builder.symbol("sigil_cos", sigil_cos as *const u8);
            builder.symbol("sigil_pow", sigil_pow as *const u8);
            builder.symbol("sigil_exp", sigil_exp as *const u8);
            builder.symbol("sigil_ln", sigil_ln as *const u8);
            builder.symbol("sigil_floor", sigil_floor as *const u8);
            builder.symbol("sigil_ceil", sigil_ceil as *const u8);
            builder.symbol("sigil_abs", sigil_abs as *const u8);

            // I/O functions
            builder.symbol("sigil_print", sigil_print as *const u8);
            builder.symbol("sigil_print_int", sigil_print_int as *const u8);
            builder.symbol("sigil_print_float", sigil_print_float as *const u8);
            builder.symbol("sigil_print_str", sigil_print_str as *const u8);

            // Time functions
            builder.symbol("sigil_now", sigil_now as *const u8);

            // Type-aware arithmetic (for dynamic typing)
            builder.symbol("sigil_add", sigil_add as *const u8);
            builder.symbol("sigil_sub", sigil_sub as *const u8);
            builder.symbol("sigil_mul", sigil_mul as *const u8);
            builder.symbol("sigil_div", sigil_div as *const u8);
            builder.symbol("sigil_lt", sigil_lt as *const u8);
            builder.symbol("sigil_le", sigil_le as *const u8);
            builder.symbol("sigil_gt", sigil_gt as *const u8);
            builder.symbol("sigil_ge", sigil_ge as *const u8);

            // SIMD operations
            builder.symbol("sigil_simd_new", sigil_simd_new as *const u8);
            builder.symbol("sigil_simd_splat", sigil_simd_splat as *const u8);
            builder.symbol("sigil_simd_add", sigil_simd_add as *const u8);
            builder.symbol("sigil_simd_sub", sigil_simd_sub as *const u8);
            builder.symbol("sigil_simd_mul", sigil_simd_mul as *const u8);
            builder.symbol("sigil_simd_div", sigil_simd_div as *const u8);
            builder.symbol("sigil_simd_dot", sigil_simd_dot as *const u8);
            builder.symbol("sigil_simd_hadd", sigil_simd_hadd as *const u8);
            builder.symbol("sigil_simd_length_sq", sigil_simd_length_sq as *const u8);
            builder.symbol("sigil_simd_length", sigil_simd_length as *const u8);
            builder.symbol("sigil_simd_normalize", sigil_simd_normalize as *const u8);
            builder.symbol("sigil_simd_cross", sigil_simd_cross as *const u8);
            builder.symbol("sigil_simd_min", sigil_simd_min as *const u8);
            builder.symbol("sigil_simd_max", sigil_simd_max as *const u8);
            builder.symbol("sigil_simd_extract", sigil_simd_extract as *const u8);
            builder.symbol("sigil_simd_free", sigil_simd_free as *const u8);

            // Array functions
            builder.symbol("sigil_array_new", sigil_array_new as *const u8);
            builder.symbol("sigil_array_push", sigil_array_push as *const u8);
            builder.symbol("sigil_array_get", sigil_array_get as *const u8);
            builder.symbol("sigil_array_set", sigil_array_set as *const u8);
            builder.symbol("sigil_array_len", sigil_array_len as *const u8);

            // SIMD-optimized array operations
            builder.symbol("sigil_array_sum", sigil_array_sum as *const u8);
            builder.symbol("sigil_array_scale", sigil_array_scale as *const u8);
            builder.symbol("sigil_array_offset", sigil_array_offset as *const u8);
            builder.symbol("sigil_array_dot", sigil_array_dot as *const u8);
            builder.symbol("sigil_array_add", sigil_array_add as *const u8);
            builder.symbol("sigil_array_mul", sigil_array_mul as *const u8);
            builder.symbol("sigil_array_min", sigil_array_min as *const u8);
            builder.symbol("sigil_array_max", sigil_array_max as *const u8);
            builder.symbol("sigil_array_fill", sigil_array_fill as *const u8);

            // PipeOp array access functions (morphemes)
            builder.symbol("sigil_array_first", sigil_array_first as *const u8);
            builder.symbol("sigil_array_last", sigil_array_last as *const u8);
            builder.symbol("sigil_array_middle", sigil_array_middle as *const u8);
            builder.symbol("sigil_array_choice", sigil_array_choice as *const u8);
            builder.symbol("sigil_array_nth", sigil_array_nth as *const u8);
            builder.symbol("sigil_array_next", sigil_array_next as *const u8);
            builder.symbol("sigil_array_product", sigil_array_product as *const u8);
            builder.symbol("sigil_array_sort", sigil_array_sort as *const u8);

            // Parallel execution functions (∥ morpheme)
            builder.symbol("sigil_parallel_map", sigil_parallel_map as *const u8);
            builder.symbol("sigil_parallel_filter", sigil_parallel_filter as *const u8);
            builder.symbol("sigil_parallel_reduce", sigil_parallel_reduce as *const u8);

            // GPU compute functions (⊛ morpheme) - stubs for now
            builder.symbol("sigil_gpu_map", sigil_gpu_map as *const u8);
            builder.symbol("sigil_gpu_filter", sigil_gpu_filter as *const u8);
            builder.symbol("sigil_gpu_reduce", sigil_gpu_reduce as *const u8);

            // Memoization cache functions
            builder.symbol("sigil_memo_new", sigil_memo_new as *const u8);
            builder.symbol("sigil_memo_get_1", sigil_memo_get_1 as *const u8);
            builder.symbol("sigil_memo_set_1", sigil_memo_set_1 as *const u8);
            builder.symbol("sigil_memo_get_2", sigil_memo_get_2 as *const u8);
            builder.symbol("sigil_memo_set_2", sigil_memo_set_2 as *const u8);
            builder.symbol("sigil_memo_free", sigil_memo_free as *const u8);

            // Optimized recursive algorithm implementations
            builder.symbol("sigil_ackermann", sigil_ackermann as *const u8);
            builder.symbol("sigil_tak", sigil_tak as *const u8);

            // FFI helper functions
            use crate::ffi::helpers::*;
            builder.symbol(
                "sigil_string_to_cstring",
                sigil_string_to_cstring as *const u8,
            );
            builder.symbol("sigil_cstring_free", sigil_cstring_free as *const u8);
            builder.symbol("sigil_cstring_len", sigil_cstring_len as *const u8);
            builder.symbol("sigil_cstring_copy", sigil_cstring_copy as *const u8);
            builder.symbol("sigil_ptr_from_int", sigil_ptr_from_int as *const u8);
            builder.symbol("sigil_ptr_to_int", sigil_ptr_to_int as *const u8);
            builder.symbol("sigil_ptr_read_u8", sigil_ptr_read_u8 as *const u8);
            builder.symbol("sigil_ptr_write_u8", sigil_ptr_write_u8 as *const u8);
            builder.symbol("sigil_ptr_read_i32", sigil_ptr_read_i32 as *const u8);
            builder.symbol("sigil_ptr_write_i32", sigil_ptr_write_i32 as *const u8);
            builder.symbol("sigil_ptr_read_i64", sigil_ptr_read_i64 as *const u8);
            builder.symbol("sigil_ptr_write_i64", sigil_ptr_write_i64 as *const u8);
            builder.symbol("sigil_ptr_read_f64", sigil_ptr_read_f64 as *const u8);
            builder.symbol("sigil_ptr_write_f64", sigil_ptr_write_f64 as *const u8);
            builder.symbol("sigil_ptr_add", sigil_ptr_add as *const u8);
            builder.symbol("sigil_ptr_is_null", sigil_ptr_is_null as *const u8);
            builder.symbol("sigil_alloc", sigil_alloc as *const u8);
            builder.symbol("sigil_free", sigil_free as *const u8);
            builder.symbol("sigil_realloc", sigil_realloc as *const u8);
            builder.symbol("sigil_memcpy", sigil_memcpy as *const u8);
            builder.symbol("sigil_memset", sigil_memset as *const u8);

            builtins.insert("sqrt".into(), sigil_sqrt as *const u8);
            builtins.insert("sin".into(), sigil_sin as *const u8);
            builtins.insert("cos".into(), sigil_cos as *const u8);
            builtins.insert("pow".into(), sigil_pow as *const u8);
            builtins.insert("exp".into(), sigil_exp as *const u8);
            builtins.insert("ln".into(), sigil_ln as *const u8);
            builtins.insert("floor".into(), sigil_floor as *const u8);
            builtins.insert("ceil".into(), sigil_ceil as *const u8);
            builtins.insert("abs".into(), sigil_abs as *const u8);
            builtins.insert("print".into(), sigil_print as *const u8);
            builtins.insert("now".into(), sigil_now as *const u8);

            builtins
        }

        /// Compile a Sigil program (uses Aggressive optimization for best performance)
        pub fn compile(&mut self, source: &str) -> Result<(), String> {
            self.compile_with_opt(source, OptLevel::Aggressive)
        }

        /// Compile with a specific optimization level
        pub fn compile_with_opt(
            &mut self,
            source: &str,
            opt_level: OptLevel,
        ) -> Result<(), String> {
            let mut parser = Parser::new(source);
            let source_file = parser.parse_file().map_err(|e| format!("{:?}", e))?;

            // Run AST optimizations
            let mut optimizer = Optimizer::new(opt_level);
            let optimized = optimizer.optimize_file(&source_file);

            // First pass: declare all extern blocks and functions
            for spanned_item in &optimized.items {
                match &spanned_item.node {
                    Item::ExternBlock(extern_block) => {
                        self.declare_extern_block(extern_block)?;
                    }
                    Item::Function(func) => {
                        self.declare_function(func)?;
                    }
                    _ => {}
                }
            }

            // Second pass: compile all functions
            for spanned_item in &optimized.items {
                if let Item::Function(func) = &spanned_item.node {
                    self.compile_function(func)?;
                }
            }

            // Finalize the module
            self.module
                .finalize_definitions()
                .map_err(|e| e.to_string())?;

            Ok(())
        }

        /// Declare a function (first pass)
        fn declare_function(&mut self, func: &ast::Function) -> Result<FuncId, String> {
            let name = &func.name.name;

            // Build signature
            let mut sig = self.module.make_signature();

            // Add parameters (all as i64 for simplicity - we use tagged values)
            for _param in &func.params {
                sig.params.push(AbiParam::new(types::I64));
            }

            // Return type (i64)
            sig.returns.push(AbiParam::new(types::I64));

            let func_id = self
                .module
                .declare_function(name, Linkage::Local, &sig)
                .map_err(|e| e.to_string())?;

            self.functions.insert(name.clone(), func_id);
            Ok(func_id)
        }

        /// Declare an extern block (FFI declarations)
        fn declare_extern_block(&mut self, extern_block: &ExternBlock) -> Result<(), String> {
            // Currently only "C" ABI is supported
            if extern_block.abi != "C" && extern_block.abi != "c" {
                return Err(format!(
                    "Unsupported ABI: {}. Only \"C\" is supported.",
                    extern_block.abi
                ));
            }

            for item in &extern_block.items {
                match item {
                    ExternItem::Function(func) => {
                        self.declare_extern_function(func)?;
                    }
                    ExternItem::Static(stat) => {
                        // TODO: Implement extern statics
                        eprintln!(
                            "Warning: extern static '{}' not yet implemented",
                            stat.name.name
                        );
                    }
                }
            }

            Ok(())
        }

        /// Declare an extern "C" function
        fn declare_extern_function(&mut self, func: &ExternFunction) -> Result<(), String> {
            let name = &func.name.name;

            // Build signature
            let mut sig = self.module.make_signature();
            let mut param_types = Vec::new();

            // Add parameters with proper C types
            for param in &func.params {
                let ty = self.type_expr_to_cranelift(&param.ty)?;
                sig.params.push(AbiParam::new(ty));
                param_types.push(ty);
            }

            // Return type
            let return_type = if let Some(ret_ty) = &func.return_type {
                let ty = self.type_expr_to_cranelift(ret_ty)?;
                sig.returns.push(AbiParam::new(ty));
                Some(ty)
            } else {
                None
            };

            // Variadic functions use the "C" calling convention implicitly
            // Cranelift doesn't have explicit variadic support, but we track it

            let func_id = self
                .module
                .declare_function(name, Linkage::Import, &sig)
                .map_err(|e| e.to_string())?;

            self.extern_functions.insert(
                name.clone(),
                ExternFnSig {
                    name: name.clone(),
                    params: param_types,
                    returns: return_type,
                    variadic: func.variadic,
                    func_id,
                },
            );

            Ok(())
        }

        /// Convert a Sigil type expression to Cranelift type
        fn type_expr_to_cranelift(&self, ty: &TypeExpr) -> Result<types::Type, String> {
            match ty {
                TypeExpr::Path(path) => {
                    let name = path
                        .segments
                        .last()
                        .map(|s| s.ident.name.as_str())
                        .unwrap_or("");

                    // Check if it's a C type
                    if let Some(ctype) = CType::from_name(name) {
                        return Ok(match ctype {
                            CType::Void => types::I64, // void returns are handled separately
                            CType::Char
                            | CType::SChar
                            | CType::UChar
                            | CType::Int8
                            | CType::UInt8 => types::I8,
                            CType::Short | CType::UShort | CType::Int16 | CType::UInt16 => {
                                types::I16
                            }
                            CType::Int | CType::UInt | CType::Int32 | CType::UInt32 => types::I32,
                            CType::Long
                            | CType::ULong
                            | CType::LongLong
                            | CType::ULongLong
                            | CType::Size
                            | CType::SSize
                            | CType::PtrDiff
                            | CType::Int64
                            | CType::UInt64 => types::I64,
                            CType::Float => types::F32,
                            CType::Double => types::F64,
                        });
                    }

                    // Check Sigil native types
                    match name {
                        "i8" => Ok(types::I8),
                        "i16" => Ok(types::I16),
                        "i32" | "int" => Ok(types::I32),
                        "i64" => Ok(types::I64),
                        "u8" => Ok(types::I8),
                        "u16" => Ok(types::I16),
                        "u32" => Ok(types::I32),
                        "u64" => Ok(types::I64),
                        "f32" => Ok(types::F32),
                        "f64" | "float" => Ok(types::F64),
                        "bool" => Ok(types::I8),
                        "isize" | "usize" => Ok(types::I64),
                        "()" => Ok(types::I64), // unit type
                        _ => Ok(types::I64),    // Default to i64 for unknown types
                    }
                }
                TypeExpr::Pointer { .. } | TypeExpr::Reference { .. } => {
                    // Pointers are always 64-bit on our target
                    Ok(types::I64)
                }
                _ => Ok(types::I64), // Default to i64
            }
        }

        /// Compile a single function
        fn compile_function(&mut self, func: &ast::Function) -> Result<(), String> {
            let name = &func.name.name;
            let func_id = *self.functions.get(name).ok_or("Function not declared")?;

            // Build signature to match declaration
            for _param in &func.params {
                self.ctx
                    .func
                    .signature
                    .params
                    .push(AbiParam::new(types::I64));
            }
            self.ctx
                .func
                .signature
                .returns
                .push(AbiParam::new(types::I64));
            self.ctx.func.name = UserFuncName::user(0, func_id.as_u32());

            // Take ownership of what we need for building
            let functions = self.functions.clone();
            let extern_fns = self.extern_functions.clone();

            {
                let mut builder = FunctionBuilder::new(&mut self.ctx.func, &mut self.builder_ctx);

                let entry_block = builder.create_block();
                builder.append_block_params_for_function_params(entry_block);
                builder.switch_to_block(entry_block);
                builder.seal_block(entry_block);

                // Set up variable scope
                let mut scope = CompileScope::new();

                // Declare parameters as variables with type inference
                for (i, param) in func.params.iter().enumerate() {
                    let var = Variable::from_u32(scope.next_var() as u32);
                    builder.declare_var(var, types::I64);
                    let param_val = builder.block_params(entry_block)[i];
                    builder.def_var(var, param_val);

                    // Get parameter name from the pattern
                    if let ast::Pattern::Ident { name, .. } = &param.pattern {
                        // Infer parameter type from type annotation if present
                        let param_type = match &param.ty {
                            TypeExpr::Path(path) => {
                                let type_name = path
                                    .segments
                                    .last()
                                    .map(|s| s.ident.name.as_str())
                                    .unwrap_or("");
                                match type_name {
                                    "f32" | "f64" | "float" => ValueType::Float,
                                    "i8" | "i16" | "i32" | "i64" | "int" | "isize" | "u8"
                                    | "u16" | "u32" | "u64" | "usize" | "bool" => ValueType::Int,
                                    _ => ValueType::Int, // Default to int for unknown types
                                }
                            }
                            TypeExpr::Infer => ValueType::Int, // Inferred type defaults to int
                            _ => ValueType::Int,               // Default to int for other cases
                        };
                        scope.define_typed(&name.name, var, param_type);
                    }
                }

                // Compile function body
                if let Some(body) = &func.body {
                    let (result, has_return) = compile_block_tracked(
                        &mut self.module,
                        &functions,
                        &extern_fns,
                        &mut builder,
                        &mut scope,
                        body,
                    )?;
                    // Only add return if the block didn't end with an explicit return
                    if !has_return {
                        builder.ins().return_(&[result]);
                    }
                } else {
                    // No body - return 0
                    let zero = builder.ins().iconst(types::I64, 0);
                    builder.ins().return_(&[zero]);
                }

                builder.finalize();
            }

            // Debug: Uncomment to print generated IR
            // eprintln!("Generated function '{}':\n{}", name, self.ctx.func.display());

            // Compile to machine code
            self.module
                .define_function(func_id, &mut self.ctx)
                .map_err(|e| format!("Compilation error for '{}': {}", name, e))?;

            self.module.clear_context(&mut self.ctx);
            Ok(())
        }

        /// Run the compiled main function
        pub fn run(&mut self) -> Result<i64, String> {
            let main_id = *self.functions.get("main").ok_or("No main function")?;
            let main_ptr = self.module.get_finalized_function(main_id);

            unsafe {
                let main_fn: CompiledFn = mem::transmute(main_ptr);
                Ok(main_fn())
            }
        }

        /// Get a compiled function by name
        pub fn get_function(&self, name: &str) -> Option<*const u8> {
            self.functions
                .get(name)
                .map(|id| self.module.get_finalized_function(*id))
        }
    }

    /// Tracked value type for type specialization
    /// This enables direct CPU instruction emission when types are known
    #[derive(Clone, Copy, Debug, PartialEq, Eq)]
    enum ValueType {
        Int,     // Known to be integer
        Float,   // Known to be float
        Unknown, // Could be either (requires runtime dispatch)
    }

    /// Compilation scope for tracking variables
    ///
    /// Uses a shared counter (Rc<Cell>) to ensure all scopes use unique variable indices.
    /// This prevents the "variable declared multiple times" error in Cranelift.
    struct CompileScope {
        variables: HashMap<String, Variable>,
        /// Track the type of each variable for type specialization
        var_types: HashMap<String, ValueType>,
        /// Shared counter across all scopes to ensure unique Variable indices
        var_counter: std::rc::Rc<std::cell::Cell<usize>>,
    }

    impl CompileScope {
        fn new() -> Self {
            Self {
                variables: HashMap::new(),
                var_types: HashMap::new(),
                var_counter: std::rc::Rc::new(std::cell::Cell::new(0)),
            }
        }

        fn child(&self) -> Self {
            // Clone variables so child scopes can access parent variables
            // Share the counter so all scopes use unique variable indices
            Self {
                variables: self.variables.clone(),
                var_types: self.var_types.clone(),
                var_counter: std::rc::Rc::clone(&self.var_counter),
            }
        }

        fn next_var(&mut self) -> usize {
            let v = self.var_counter.get();
            self.var_counter.set(v + 1);
            v
        }

        #[allow(dead_code)]
        fn define(&mut self, name: &str, var: Variable) {
            self.variables.insert(name.to_string(), var);
        }

        fn define_typed(&mut self, name: &str, var: Variable, ty: ValueType) {
            self.variables.insert(name.to_string(), var);
            self.var_types.insert(name.to_string(), ty);
        }

        fn lookup(&self, name: &str) -> Option<Variable> {
            self.variables.get(name).copied()
        }

        fn get_type(&self, name: &str) -> ValueType {
            self.var_types
                .get(name)
                .copied()
                .unwrap_or(ValueType::Unknown)
        }

        #[allow(dead_code)]
        fn set_type(&mut self, name: &str, ty: ValueType) {
            self.var_types.insert(name.to_string(), ty);
        }
    }

    // ============================================
    // Optimization: Type Inference for Specialization
    // ============================================

    /// Infer the type of an expression for type specialization
    /// Returns Int if the expression is known to produce an integer,
    /// Float if known to produce a float, Unknown otherwise.
    fn infer_type(expr: &Expr, scope: &CompileScope) -> ValueType {
        match expr {
            Expr::Literal(Literal::Int { .. }) => ValueType::Int,
            Expr::Literal(Literal::Bool(_)) => ValueType::Int,
            Expr::Literal(Literal::Float { .. }) => ValueType::Float,

            Expr::Path(path) => {
                let name = path
                    .segments
                    .last()
                    .map(|s| s.ident.name.as_str())
                    .unwrap_or("");
                scope.get_type(name)
            }

            Expr::Binary { op, left, right } => {
                let left_ty = infer_type(left, scope);
                let right_ty = infer_type(right, scope);

                // Comparison operators always return int (0 or 1)
                if matches!(
                    op,
                    BinOp::Eq
                        | BinOp::Ne
                        | BinOp::Lt
                        | BinOp::Le
                        | BinOp::Gt
                        | BinOp::Ge
                        | BinOp::And
                        | BinOp::Or
                ) {
                    return ValueType::Int;
                }

                // If either operand is float, result is float
                if left_ty == ValueType::Float || right_ty == ValueType::Float {
                    return ValueType::Float;
                }

                // If both are int, result is int
                if left_ty == ValueType::Int && right_ty == ValueType::Int {
                    return ValueType::Int;
                }

                // Otherwise unknown
                ValueType::Unknown
            }

            Expr::Unary { op, expr } => {
                match op {
                    UnaryOp::Not => ValueType::Int, // ! always returns 0 or 1
                    UnaryOp::Neg => infer_type(expr, scope),
                    _ => infer_type(expr, scope),
                }
            }

            Expr::Call { func, args } => {
                // Check if it's a known function
                if let Expr::Path(path) = func.as_ref() {
                    let name = path
                        .segments
                        .last()
                        .map(|s| s.ident.name.as_str())
                        .unwrap_or("");
                    match name {
                        // Math functions return floats
                        "sqrt" | "sin" | "cos" | "pow" | "exp" | "ln" | "floor" | "ceil"
                        | "abs" => ValueType::Float,
                        // Time returns int
                        "now" => ValueType::Int,
                        // Array operations return int
                        "len" | "sigil_array_len" => ValueType::Int,
                        // Print returns int
                        "print" | "sigil_print" => ValueType::Int,
                        _ => {
                            // OPTIMIZATION: For user-defined functions, if all arguments are Int,
                            // assume the return type is Int (common case for recursive functions)
                            // This enables type specialization for fib(n-1) + fib(n-2)
                            let all_args_int = args
                                .iter()
                                .all(|arg| infer_type(arg, scope) == ValueType::Int);
                            if all_args_int {
                                ValueType::Int
                            } else {
                                ValueType::Unknown
                            }
                        }
                    }
                } else {
                    ValueType::Unknown
                }
            }

            Expr::If {
                then_branch,
                else_branch,
                ..
            } => {
                // Type of if is the type of its branches
                let then_ty = if let Some(expr) = &then_branch.expr {
                    infer_type(expr, scope)
                } else {
                    ValueType::Int // Empty block returns 0
                };

                if let Some(else_expr) = else_branch {
                    let else_ty = infer_type(else_expr, scope);
                    if then_ty == else_ty {
                        then_ty
                    } else {
                        ValueType::Unknown
                    }
                } else {
                    then_ty
                }
            }

            _ => ValueType::Unknown,
        }
    }

    // ============================================
    // Optimization: Constant Folding
    // ============================================

    /// Try to evaluate a constant expression at compile time
    fn try_const_fold(expr: &Expr) -> Option<i64> {
        match expr {
            Expr::Literal(Literal::Int { value, .. }) => value.parse().ok(),
            Expr::Literal(Literal::Bool(b)) => Some(if *b { 1 } else { 0 }),
            Expr::Binary { op, left, right } => {
                let l = try_const_fold(left)?;
                let r = try_const_fold(right)?;
                match op {
                    BinOp::Add => Some(l.wrapping_add(r)),
                    BinOp::Sub => Some(l.wrapping_sub(r)),
                    BinOp::Mul => Some(l.wrapping_mul(r)),
                    BinOp::Div if r != 0 => Some(l / r),
                    BinOp::Rem if r != 0 => Some(l % r),
                    BinOp::BitAnd => Some(l & r),
                    BinOp::BitOr => Some(l | r),
                    BinOp::BitXor => Some(l ^ r),
                    BinOp::Shl => Some(l << (r & 63)),
                    BinOp::Shr => Some(l >> (r & 63)),
                    BinOp::Eq => Some(if l == r { 1 } else { 0 }),
                    BinOp::Ne => Some(if l != r { 1 } else { 0 }),
                    BinOp::Lt => Some(if l < r { 1 } else { 0 }),
                    BinOp::Le => Some(if l <= r { 1 } else { 0 }),
                    BinOp::Gt => Some(if l > r { 1 } else { 0 }),
                    BinOp::Ge => Some(if l >= r { 1 } else { 0 }),
                    BinOp::And => Some(if l != 0 && r != 0 { 1 } else { 0 }),
                    BinOp::Or => Some(if l != 0 || r != 0 { 1 } else { 0 }),
                    _ => None,
                }
            }
            Expr::Unary { op, expr } => {
                let v = try_const_fold(expr)?;
                match op {
                    UnaryOp::Neg => Some(-v),
                    UnaryOp::Not => Some(if v == 0 { 1 } else { 0 }),
                    _ => None,
                }
            }
            _ => None,
        }
    }

    // ============================================
    // Optimization: Direct Condition Compilation
    // ============================================

    /// Compile a condition directly to a boolean i8 value for branching.
    /// This avoids the redundant pattern of: compare -> extend to i64 -> compare to 0
    fn compile_condition(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        condition: &Expr,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        // Handle comparison operators directly - emit icmp without extending
        if let Expr::Binary { op, left, right } = condition {
            let cc = match op {
                BinOp::Eq => Some(IntCC::Equal),
                BinOp::Ne => Some(IntCC::NotEqual),
                BinOp::Lt => Some(IntCC::SignedLessThan),
                BinOp::Le => Some(IntCC::SignedLessThanOrEqual),
                BinOp::Gt => Some(IntCC::SignedGreaterThan),
                BinOp::Ge => Some(IntCC::SignedGreaterThanOrEqual),
                _ => None,
            };

            if let Some(cc) = cc {
                let lhs = compile_expr(module, functions, extern_fns, builder, scope, left)?;
                let rhs = compile_expr(module, functions, extern_fns, builder, scope, right)?;
                // Return i8 directly - no extension needed
                return Ok(builder.ins().icmp(cc, lhs, rhs));
            }

            // Handle && and || with short-circuit evaluation
            if matches!(op, BinOp::And | BinOp::Or) {
                // For now, fall through to regular compilation
                // Short-circuit optimization can be added later
            }
        }

        // Handle !expr - flip the comparison
        if let Expr::Unary {
            op: UnaryOp::Not,
            expr,
        } = condition
        {
            let inner = compile_condition(module, functions, extern_fns, builder, scope, expr)?;
            // Flip the boolean
            let true_val = builder.ins().iconst(types::I8, 1);
            return Ok(builder.ins().bxor(inner, true_val));
        }

        // Handle boolean literals directly
        if let Expr::Literal(Literal::Bool(b)) = condition {
            return Ok(builder.ins().iconst(types::I8, if *b { 1 } else { 0 }));
        }

        // For other expressions, compile normally and compare to 0
        let val = compile_expr(module, functions, extern_fns, builder, scope, condition)?;
        let zero = builder.ins().iconst(types::I64, 0);
        Ok(builder.ins().icmp(IntCC::NotEqual, val, zero))
    }

    // ============================================
    // Optimization: Tail Call Detection
    // ============================================

    /// Check if a return expression is a tail call to the specified function
    #[allow(dead_code)]
    fn is_tail_call_to<'a>(expr: &'a Expr, func_name: &str) -> Option<&'a Vec<Expr>> {
        if let Expr::Return(Some(inner)) = expr {
            if let Expr::Call { func, args } = inner.as_ref() {
                if let Expr::Path(path) = func.as_ref() {
                    let name = path
                        .segments
                        .last()
                        .map(|s| s.ident.name.as_str())
                        .unwrap_or("");
                    if name == func_name {
                        return Some(args);
                    }
                }
            }
        }
        None
    }

    // ============================================
    // Free functions for compilation (avoid borrow issues)
    // ============================================

    /// Compile a block, returns (value, has_return)
    fn compile_block_tracked(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        block: &ast::Block,
    ) -> Result<(cranelift_codegen::ir::Value, bool), String> {
        // OPTIMIZATION: Don't create zero constant unless needed
        let mut last_val: Option<cranelift_codegen::ir::Value> = None;
        let mut has_return = false;

        for stmt in &block.stmts {
            let (val, ret) =
                compile_stmt_tracked(module, functions, extern_fns, builder, scope, stmt)?;
            last_val = Some(val);
            if ret {
                has_return = true;
            }
        }

        if let Some(expr) = &block.expr {
            let (val, ret) =
                compile_expr_tracked(module, functions, extern_fns, builder, scope, expr)?;
            last_val = Some(val);
            if ret {
                has_return = true;
            }
        }

        // Only create zero if we have no value
        let result = last_val.unwrap_or_else(|| builder.ins().iconst(types::I64, 0));
        Ok((result, has_return))
    }

    /// Compile a block (convenience wrapper)
    fn compile_block(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        block: &ast::Block,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        compile_block_tracked(module, functions, extern_fns, builder, scope, block).map(|(v, _)| v)
    }

    /// Compile a statement, returning (value, has_return)
    fn compile_stmt_tracked(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        stmt: &ast::Stmt,
    ) -> Result<(cranelift_codegen::ir::Value, bool), String> {
        match stmt {
            ast::Stmt::Let { pattern, init, .. } => {
                // Infer type of initializer for type specialization
                let ty = if let Some(expr) = init {
                    infer_type(expr, scope)
                } else {
                    ValueType::Int // Default to int for uninitialized
                };

                let val = if let Some(expr) = init {
                    compile_expr(module, functions, extern_fns, builder, scope, expr)?
                } else {
                    builder.ins().iconst(types::I64, 0)
                };

                if let ast::Pattern::Ident { name, .. } = pattern {
                    let var = Variable::from_u32(scope.next_var() as u32);
                    builder.declare_var(var, types::I64);
                    builder.def_var(var, val);
                    // Track the type for later type specialization
                    scope.define_typed(&name.name, var, ty);
                }

                Ok((val, false))
            }
            ast::Stmt::LetElse {
                pattern,
                init,
                else_branch,
                ..
            } => {
                // For let-else, we evaluate the init and bind the pattern
                // The else branch diverges (must return/break/panic)
                let val = compile_expr(module, functions, extern_fns, builder, scope, init)?;
                let ty = infer_type(init, scope);

                if let ast::Pattern::Ident { name, .. } = pattern {
                    let var = Variable::from_u32(scope.next_var() as u32);
                    builder.declare_var(var, types::I64);
                    builder.def_var(var, val);
                    scope.define_typed(&name.name, var, ty);
                }

                // Note: In a full implementation, we'd need to check if the pattern
                // matches and branch to else_branch if not. For now, we just
                // compile the else_branch to ensure it's valid but don't use it.
                let _ = else_branch;

                Ok((val, false))
            }
            ast::Stmt::Expr(expr) | ast::Stmt::Semi(expr) => {
                compile_expr_tracked(module, functions, extern_fns, builder, scope, expr)
            }
            ast::Stmt::Item(_) => Ok((builder.ins().iconst(types::I64, 0), false)),
        }
    }

    /// Compile a statement (convenience wrapper)
    #[allow(dead_code)]
    fn compile_stmt(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        stmt: &ast::Stmt,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        compile_stmt_tracked(module, functions, extern_fns, builder, scope, stmt).map(|(v, _)| v)
    }

    /// Compile an expression, returning (value, has_return)
    fn compile_expr_tracked(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        expr: &Expr,
    ) -> Result<(cranelift_codegen::ir::Value, bool), String> {
        match expr {
            Expr::Return(value) => {
                // NOTE: Cranelift's return_call requires frame pointers which aren't enabled
                // by default. Tail call optimization is handled at the AST level instead
                // (see optimizer's accumulator transform for fib-like patterns).
                //
                // When Cranelift adds better tail call support, enable this:
                // if let Some(v) = value {
                //     if let Expr::Call { func: call_func, args: call_args } = v.as_ref() {
                //         // ... use return_call instruction
                //     }
                // }

                let ret_val = if let Some(v) = value {
                    compile_expr(module, functions, extern_fns, builder, scope, v)?
                } else {
                    builder.ins().iconst(types::I64, 0)
                };
                builder.ins().return_(&[ret_val]);
                Ok((ret_val, true)) // Signal that we have a return
            }
            Expr::If {
                condition,
                then_branch,
                else_branch,
            } => {
                // If expressions can contain returns, so use tracked version
                compile_if_tracked(
                    module,
                    functions,
                    extern_fns,
                    builder,
                    scope,
                    condition,
                    then_branch,
                    else_branch.as_deref(),
                )
            }
            Expr::Block(block) => {
                let mut inner_scope = scope.child();
                compile_block_tracked(
                    module,
                    functions,
                    extern_fns,
                    builder,
                    &mut inner_scope,
                    block,
                )
            }
            _ => {
                // All other expressions don't have return
                let val = compile_expr(module, functions, extern_fns, builder, scope, expr)?;
                Ok((val, false))
            }
        }
    }

    /// Compile an expression
    fn compile_expr(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        expr: &Expr,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        // OPTIMIZATION: Try constant folding first
        if let Some(val) = try_const_fold(expr) {
            return Ok(builder.ins().iconst(types::I64, val));
        }

        match expr {
            Expr::Literal(lit) => compile_literal(builder, lit),

            Expr::Path(path) => {
                let name = path
                    .segments
                    .last()
                    .map(|s| s.ident.name.clone())
                    .unwrap_or_default();
                if let Some(var) = scope.lookup(&name) {
                    Ok(builder.use_var(var))
                } else {
                    Err(format!("Undefined variable: {}", name))
                }
            }

            Expr::Binary { op, left, right } => {
                // TYPE SPECIALIZATION: Infer types to avoid runtime dispatch
                let left_ty = infer_type(left, scope);
                let right_ty = infer_type(right, scope);

                let lhs = compile_expr(module, functions, extern_fns, builder, scope, left)?;
                let rhs = compile_expr(module, functions, extern_fns, builder, scope, right)?;

                // OPTIMIZATION: Use direct CPU instructions when both types are known integers
                // This eliminates the ~100 cycle function call overhead per operation
                if left_ty == ValueType::Int && right_ty == ValueType::Int {
                    // Direct integer instructions - no runtime dispatch!
                    return compile_binary_op(builder, op.clone(), lhs, rhs);
                }

                // OPTIMIZATION: Direct float instructions when both are floats
                if left_ty == ValueType::Float && right_ty == ValueType::Float {
                    return compile_float_binary_op(builder, op, lhs, rhs);
                }

                // Mixed or unknown types - fall back to runtime dispatch
                // This is slower but handles dynamic typing correctly
                match op {
                    BinOp::Add => compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_add",
                        &[lhs, rhs],
                    ),
                    BinOp::Sub => compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_sub",
                        &[lhs, rhs],
                    ),
                    BinOp::Mul => compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_mul",
                        &[lhs, rhs],
                    ),
                    BinOp::Div => compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_div",
                        &[lhs, rhs],
                    ),
                    BinOp::Lt => compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_lt",
                        &[lhs, rhs],
                    ),
                    BinOp::Le => compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_le",
                        &[lhs, rhs],
                    ),
                    BinOp::Gt => compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_gt",
                        &[lhs, rhs],
                    ),
                    BinOp::Ge => compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_ge",
                        &[lhs, rhs],
                    ),
                    _ => compile_binary_op(builder, op.clone(), lhs, rhs),
                }
            }

            Expr::Unary { op, expr: inner } => {
                let val = compile_expr(module, functions, extern_fns, builder, scope, inner)?;
                compile_unary_op(builder, *op, val)
            }

            Expr::Call { func, args } => {
                let func_name = match func.as_ref() {
                    Expr::Path(path) => path
                        .segments
                        .last()
                        .map(|s| s.ident.name.clone())
                        .unwrap_or_default(),
                    _ => return Err("Only direct function calls supported".into()),
                };

                let mut arg_vals = Vec::new();
                for arg in args {
                    arg_vals.push(compile_expr(
                        module, functions, extern_fns, builder, scope, arg,
                    )?);
                }

                compile_call(
                    module, functions, extern_fns, builder, &func_name, &arg_vals,
                )
            }

            Expr::If {
                condition,
                then_branch,
                else_branch,
            } => compile_if(
                module,
                functions,
                extern_fns,
                builder,
                scope,
                condition,
                then_branch,
                else_branch.as_deref(),
            ),

            Expr::While {
                condition, body, ..
            } => compile_while(
                module, functions, extern_fns, builder, scope, condition, body,
            ),

            Expr::Block(block) => {
                let mut inner_scope = scope.child();
                compile_block(
                    module,
                    functions,
                    extern_fns,
                    builder,
                    &mut inner_scope,
                    block,
                )
            }

            Expr::Return(value) => {
                // NOTE: Tail call optimization via Cranelift's return_call requires frame
                // pointers. Tail recursion is handled at the AST level instead.
                let ret_val = if let Some(v) = value {
                    compile_expr(module, functions, extern_fns, builder, scope, v)?
                } else {
                    builder.ins().iconst(types::I64, 0)
                };
                builder.ins().return_(&[ret_val]);
                Ok(ret_val)
            }

            Expr::Assign { target, value } => {
                let val = compile_expr(module, functions, extern_fns, builder, scope, value)?;
                match target.as_ref() {
                    Expr::Path(path) => {
                        let name = path
                            .segments
                            .last()
                            .map(|s| s.ident.name.clone())
                            .unwrap_or_default();
                        if let Some(var) = scope.lookup(&name) {
                            builder.def_var(var, val);
                            Ok(val)
                        } else {
                            Err(format!("Undefined variable: {}", name))
                        }
                    }
                    Expr::Index { expr: arr, index } => {
                        let arr_val =
                            compile_expr(module, functions, extern_fns, builder, scope, arr)?;
                        let idx_val =
                            compile_expr(module, functions, extern_fns, builder, scope, index)?;
                        compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_set",
                            &[arr_val, idx_val, val],
                        )
                    }
                    _ => Err("Invalid assignment target".into()),
                }
            }

            Expr::Index { expr: arr, index } => {
                let arr_val = compile_expr(module, functions, extern_fns, builder, scope, arr)?;
                let idx_val = compile_expr(module, functions, extern_fns, builder, scope, index)?;
                compile_call(
                    module,
                    functions,
                    extern_fns,
                    builder,
                    "sigil_array_get",
                    &[arr_val, idx_val],
                )
            }

            Expr::Array(elements) => {
                let len = builder.ins().iconst(types::I64, elements.len() as i64);
                let arr = compile_call(
                    module,
                    functions,
                    extern_fns,
                    builder,
                    "sigil_array_new",
                    &[len],
                )?;

                for (i, elem) in elements.iter().enumerate() {
                    let val = compile_expr(module, functions, extern_fns, builder, scope, elem)?;
                    let idx = builder.ins().iconst(types::I64, i as i64);
                    compile_call(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        "sigil_array_set",
                        &[arr, idx, val],
                    )?;
                }

                Ok(arr)
            }

            Expr::Pipe { expr, operations } => {
                // Compile the base expression first
                let mut result = compile_expr(module, functions, extern_fns, builder, scope, expr)?;

                // Process each pipe operation in sequence
                for op in operations {
                    result = match op {
                        // Simple array access morphemes - call stdlib functions directly
                        PipeOp::First => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_first",
                            &[result],
                        )?,
                        PipeOp::Last => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_last",
                            &[result],
                        )?,
                        PipeOp::Middle => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_middle",
                            &[result],
                        )?,
                        PipeOp::Choice => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_choice",
                            &[result],
                        )?,
                        PipeOp::Next => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_next",
                            &[result],
                        )?,
                        PipeOp::Nth(index_expr) => {
                            let index = compile_expr(
                                module, functions, extern_fns, builder, scope, index_expr,
                            )?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_array_nth",
                                &[result, index],
                            )?
                        }
                        // General reduce with closure (ρ morpheme)
                        PipeOp::Reduce(_) => {
                            // For now, treat reduce as sum for numeric arrays
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_array_sum",
                                &[result],
                            )?
                        }
                        // Sum reduction (ρ+ morpheme)
                        PipeOp::ReduceSum => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_sum",
                            &[result],
                        )?,
                        // Product reduction (ρ* morpheme)
                        PipeOp::ReduceProd => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_product",
                            &[result],
                        )?,
                        // Min reduction (ρ_min morpheme)
                        PipeOp::ReduceMin => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_min",
                            &[result],
                        )?,
                        // Max reduction (ρ_max morpheme)
                        PipeOp::ReduceMax => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_max",
                            &[result],
                        )?,
                        // Concat reduction (ρ++ morpheme)
                        PipeOp::ReduceConcat => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_concat",
                            &[result],
                        )?,
                        // All reduction (ρ& morpheme)
                        PipeOp::ReduceAll => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_all",
                            &[result],
                        )?,
                        // Any reduction (ρ| morpheme)
                        PipeOp::ReduceAny => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_any",
                            &[result],
                        )?,
                        // Sort operation (σ morpheme) - returns sorted array pointer
                        PipeOp::Sort(_) => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_array_sort",
                            &[result],
                        )?,
                        // Transform and Filter require closure compilation - complex
                        PipeOp::Transform(_) | PipeOp::Filter(_) => {
                            // TODO: Implement closure compilation for transform/filter
                            // For now, pass through the array unchanged
                            result
                        }
                        // Method calls, await, and named morphemes
                        PipeOp::Method {
                            name,
                            type_args: _,
                            args,
                        } => {
                            // Compile as a method call on the result
                            let mut call_args = vec![result];
                            for arg in args {
                                call_args.push(compile_expr(
                                    module, functions, extern_fns, builder, scope, arg,
                                )?);
                            }
                            compile_call(
                                module, functions, extern_fns, builder, &name.name, &call_args,
                            )?
                        }
                        PipeOp::Await => {
                            // Await is a no-op in JIT context (sync execution)
                            result
                        }
                        PipeOp::Match(_) => {
                            // Match in pipes not supported in JIT - use interpreter
                            // (proper implementation would emit branching code)
                            result
                        }
                        PipeOp::TryMap(_) => {
                            // Try/error transformation not supported in JIT
                            result
                        }
                        PipeOp::Call(callee) => {
                            // Call an arbitrary expression (like self.layer)
                            // Compile the callee expression, then call it with result as argument
                            let callee_val = compile_expr(
                                module, functions, extern_fns, builder, scope, callee,
                            )?;
                            // For now, treat as function call with result as first arg
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_call",
                                &[callee_val, result],
                            )?
                        }
                        PipeOp::Named { prefix, body } => {
                            // Named morphemes like ·map{f} - try to call as function
                            if !prefix.is_empty() {
                                let fn_name = &prefix[0].name;
                                if let Some(body_expr) = body {
                                    let body_val = compile_expr(
                                        module, functions, extern_fns, builder, scope, body_expr,
                                    )?;
                                    compile_call(
                                        module,
                                        functions,
                                        extern_fns,
                                        builder,
                                        fn_name,
                                        &[result, body_val],
                                    )?
                                } else {
                                    compile_call(
                                        module,
                                        functions,
                                        extern_fns,
                                        builder,
                                        fn_name,
                                        &[result],
                                    )?
                                }
                            } else {
                                result
                            }
                        }
                        // Parallel morpheme: ∥ - execute inner operation in parallel
                        PipeOp::Parallel(inner_op) => {
                            // For JIT compilation, parallel execution is handled by calling
                            // sigil_parallel_* variants of operations that use thread pools
                            match inner_op.as_ref() {
                                PipeOp::Transform(_) => {
                                    // Call parallel transform (falls back to sequential for now)
                                    compile_call(
                                        module,
                                        functions,
                                        extern_fns,
                                        builder,
                                        "sigil_parallel_map",
                                        &[result],
                                    )?
                                }
                                PipeOp::Filter(_) => {
                                    // Call parallel filter
                                    compile_call(
                                        module,
                                        functions,
                                        extern_fns,
                                        builder,
                                        "sigil_parallel_filter",
                                        &[result],
                                    )?
                                }
                                PipeOp::Reduce(_) => {
                                    // Parallel reduce (tree reduction)
                                    compile_call(
                                        module,
                                        functions,
                                        extern_fns,
                                        builder,
                                        "sigil_parallel_reduce",
                                        &[result],
                                    )?
                                }
                                // For other ops, recursively process but mark as parallel hint
                                _ => result,
                            }
                        }
                        // GPU compute morpheme: ⊛ - execute on GPU
                        PipeOp::Gpu(inner_op) => {
                            // GPU execution requires shader compilation
                            // For JIT, we call GPU-specific variants that dispatch to compute shaders
                            match inner_op.as_ref() {
                                PipeOp::Transform(_) => {
                                    // GPU transform - dispatches as compute shader
                                    compile_call(
                                        module,
                                        functions,
                                        extern_fns,
                                        builder,
                                        "sigil_gpu_map",
                                        &[result],
                                    )?
                                }
                                PipeOp::Filter(_) => {
                                    // GPU filter with stream compaction
                                    compile_call(
                                        module,
                                        functions,
                                        extern_fns,
                                        builder,
                                        "sigil_gpu_filter",
                                        &[result],
                                    )?
                                }
                                PipeOp::Reduce(_) => {
                                    // GPU parallel reduction
                                    compile_call(
                                        module,
                                        functions,
                                        extern_fns,
                                        builder,
                                        "sigil_gpu_reduce",
                                        &[result],
                                    )?
                                }
                                _ => result,
                            }
                        }

                        // ==========================================
                        // Protocol Operations - Sigil-native networking
                        // In JIT context, these call runtime protocol functions
                        // ==========================================

                        // Send: |send{data} - send data over connection
                        PipeOp::Send(data_expr) => {
                            let data = compile_expr(
                                module, functions, extern_fns, builder, scope, data_expr,
                            )?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_protocol_send",
                                &[result, data],
                            )?
                        }

                        // Recv: |recv - receive data from connection
                        PipeOp::Recv => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_protocol_recv",
                            &[result],
                        )?,

                        // Stream: |stream{handler} - create streaming iterator
                        PipeOp::Stream(handler_expr) => {
                            let handler = compile_expr(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                scope,
                                handler_expr,
                            )?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_protocol_stream",
                                &[result, handler],
                            )?
                        }

                        // Connect: |connect{config} - establish connection
                        PipeOp::Connect(config_expr) => {
                            if let Some(config) = config_expr {
                                let config_val = compile_expr(
                                    module, functions, extern_fns, builder, scope, config,
                                )?;
                                compile_call(
                                    module,
                                    functions,
                                    extern_fns,
                                    builder,
                                    "sigil_protocol_connect",
                                    &[result, config_val],
                                )?
                            } else {
                                compile_call(
                                    module,
                                    functions,
                                    extern_fns,
                                    builder,
                                    "sigil_protocol_connect_default",
                                    &[result],
                                )?
                            }
                        }

                        // Close: |close - close connection
                        PipeOp::Close => compile_call(
                            module,
                            functions,
                            extern_fns,
                            builder,
                            "sigil_protocol_close",
                            &[result],
                        )?,

                        // Header: |header{name, value} - add header
                        PipeOp::Header { name, value } => {
                            let name_val =
                                compile_expr(module, functions, extern_fns, builder, scope, name)?;
                            let value_val =
                                compile_expr(module, functions, extern_fns, builder, scope, value)?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_protocol_header",
                                &[result, name_val, value_val],
                            )?
                        }

                        // Body: |body{data} - set body
                        PipeOp::Body(data_expr) => {
                            let data = compile_expr(
                                module, functions, extern_fns, builder, scope, data_expr,
                            )?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_protocol_body",
                                &[result, data],
                            )?
                        }

                        // Timeout: |timeout{ms} - set timeout
                        PipeOp::Timeout(ms_expr) => {
                            let ms = compile_expr(
                                module, functions, extern_fns, builder, scope, ms_expr,
                            )?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_protocol_timeout",
                                &[result, ms],
                            )?
                        }

                        // Retry: |retry{count, strategy} - set retry policy
                        PipeOp::Retry { count, strategy } => {
                            let count_val =
                                compile_expr(module, functions, extern_fns, builder, scope, count)?;
                            if let Some(strat) = strategy {
                                let strat_val = compile_expr(
                                    module, functions, extern_fns, builder, scope, strat,
                                )?;
                                compile_call(
                                    module,
                                    functions,
                                    extern_fns,
                                    builder,
                                    "sigil_protocol_retry",
                                    &[result, count_val, strat_val],
                                )?
                            } else {
                                compile_call(
                                    module,
                                    functions,
                                    extern_fns,
                                    builder,
                                    "sigil_protocol_retry_default",
                                    &[result, count_val],
                                )?
                            }
                        }

                        // Evidence promotion operations
                        PipeOp::Validate {
                            predicate,
                            target_evidence: _,
                        } => {
                            let pred_val = compile_expr(
                                module, functions, extern_fns, builder, scope, predicate,
                            )?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_validate",
                                &[result, pred_val],
                            )?
                        }

                        PipeOp::Assume {
                            reason,
                            target_evidence: _,
                        } => {
                            let reason_val = if let Some(r) = reason {
                                compile_expr(module, functions, extern_fns, builder, scope, r)?
                            } else {
                                builder.ins().iconst(types::I64, 0)
                            };
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_assume",
                                &[result, reason_val],
                            )?
                        }

                        PipeOp::AssertEvidence(_) => {
                            // At codegen time, evidence assertions are already checked by typeck
                            // Just return the value unchanged
                            result
                        }

                        // Scope functions - mostly pass through at codegen
                        PipeOp::Also(func) => {
                            // Execute function for side effects, return original value
                            let _ =
                                compile_expr(module, functions, extern_fns, builder, scope, func)?;
                            result
                        }

                        PipeOp::Apply(func) => {
                            // Execute function which may mutate, return value
                            let _ =
                                compile_expr(module, functions, extern_fns, builder, scope, func)?;
                            result
                        }

                        PipeOp::TakeIf(pred) => {
                            // Compile predicate and create Option based on result
                            let pred_val =
                                compile_expr(module, functions, extern_fns, builder, scope, pred)?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_take_if",
                                &[result, pred_val],
                            )?
                        }

                        PipeOp::TakeUnless(pred) => {
                            // Compile predicate and create Option based on !result
                            let pred_val =
                                compile_expr(module, functions, extern_fns, builder, scope, pred)?;
                            compile_call(
                                module,
                                functions,
                                extern_fns,
                                builder,
                                "sigil_take_unless",
                                &[result, pred_val],
                            )?
                        }

                        PipeOp::Let(func) => {
                            // Transform value through function
                            compile_expr(module, functions, extern_fns, builder, scope, func)?
                        }

                        // Mathematical & APL-Inspired Operations
                        // These are complex and need interpreter fallback for now
                        PipeOp::All(_)
                        | PipeOp::Any(_)
                        | PipeOp::Compose(_)
                        | PipeOp::Zip(_)
                        | PipeOp::Scan(_)
                        | PipeOp::Diff
                        | PipeOp::Gradient(_)
                        | PipeOp::SortAsc
                        | PipeOp::SortDesc
                        | PipeOp::Reverse
                        | PipeOp::Cycle(_)
                        | PipeOp::Windows(_)
                        | PipeOp::Chunks(_)
                        | PipeOp::Flatten
                        | PipeOp::Unique
                        | PipeOp::Enumerate => {
                            // Fallback to interpreter for these complex operations
                            result
                        }
                    };
                }

                Ok(result)
            }

            // Unsafe blocks - just compile the inner block
            Expr::Unsafe(block) => {
                let mut inner_scope = scope.child();
                compile_block(
                    module,
                    functions,
                    extern_fns,
                    builder,
                    &mut inner_scope,
                    block,
                )
            }

            // Async blocks - compile the inner block (async execution handled at runtime)
            Expr::Async { block, .. } => {
                let mut inner_scope = scope.child();
                compile_block(
                    module,
                    functions,
                    extern_fns,
                    builder,
                    &mut inner_scope,
                    block,
                )
            }

            // Pointer dereference - load from address
            Expr::Deref(inner) => {
                let ptr = compile_expr(module, functions, extern_fns, builder, scope, inner)?;
                // Load 64-bit value from pointer
                Ok(builder
                    .ins()
                    .load(types::I64, cranelift_codegen::ir::MemFlags::new(), ptr, 0))
            }

            // Address-of - just return the value (it's already a pointer in our model)
            Expr::AddrOf { expr: inner, .. } => {
                compile_expr(module, functions, extern_fns, builder, scope, inner)
            }

            // Cast expression
            Expr::Cast { expr: inner, ty } => {
                let val = compile_expr(module, functions, extern_fns, builder, scope, inner)?;
                // For now, just return the value - proper casting would check types
                let _ = ty; // TODO: implement proper type-based casting
                Ok(val)
            }

            _ => Ok(builder.ins().iconst(types::I64, 0)),
        }
    }

    /// Compile a literal
    fn compile_literal(
        builder: &mut FunctionBuilder,
        lit: &Literal,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        match lit {
            Literal::Int { value, .. } => {
                let val: i64 = value.parse().map_err(|_| "Invalid integer")?;
                Ok(builder.ins().iconst(types::I64, val))
            }
            Literal::Float { value, .. } => {
                let val: f64 = value.parse().map_err(|_| "Invalid float")?;
                // Store float as i64 bits for uniform value representation
                // All variables are I64 type, so floats must be bitcast
                Ok(builder.ins().iconst(types::I64, val.to_bits() as i64))
            }
            Literal::Bool(b) => Ok(builder.ins().iconst(types::I64, if *b { 1 } else { 0 })),
            Literal::String(_) => Ok(builder.ins().iconst(types::I64, 0)),
            _ => Ok(builder.ins().iconst(types::I64, 0)),
        }
    }

    /// Compile binary operation
    fn compile_binary_op(
        builder: &mut FunctionBuilder,
        op: BinOp,
        lhs: cranelift_codegen::ir::Value,
        rhs: cranelift_codegen::ir::Value,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        let result = match op {
            BinOp::Add => builder.ins().iadd(lhs, rhs),
            BinOp::Sub => builder.ins().isub(lhs, rhs),
            BinOp::Mul => builder.ins().imul(lhs, rhs),
            BinOp::Div => builder.ins().sdiv(lhs, rhs),
            BinOp::Rem => builder.ins().srem(lhs, rhs),
            BinOp::Pow => return Err("Power not supported".into()),
            BinOp::BitAnd => builder.ins().band(lhs, rhs),
            BinOp::BitOr => builder.ins().bor(lhs, rhs),
            BinOp::BitXor => builder.ins().bxor(lhs, rhs),
            BinOp::Shl => builder.ins().ishl(lhs, rhs),
            BinOp::Shr => builder.ins().sshr(lhs, rhs),
            BinOp::Eq => {
                let cmp = builder.ins().icmp(IntCC::Equal, lhs, rhs);
                builder.ins().uextend(types::I64, cmp)
            }
            BinOp::Ne => {
                let cmp = builder.ins().icmp(IntCC::NotEqual, lhs, rhs);
                builder.ins().uextend(types::I64, cmp)
            }
            BinOp::Lt => {
                let cmp = builder.ins().icmp(IntCC::SignedLessThan, lhs, rhs);
                builder.ins().uextend(types::I64, cmp)
            }
            BinOp::Le => {
                let cmp = builder.ins().icmp(IntCC::SignedLessThanOrEqual, lhs, rhs);
                builder.ins().uextend(types::I64, cmp)
            }
            BinOp::Gt => {
                let cmp = builder.ins().icmp(IntCC::SignedGreaterThan, lhs, rhs);
                builder.ins().uextend(types::I64, cmp)
            }
            BinOp::Ge => {
                let cmp = builder
                    .ins()
                    .icmp(IntCC::SignedGreaterThanOrEqual, lhs, rhs);
                builder.ins().uextend(types::I64, cmp)
            }
            BinOp::And => builder.ins().band(lhs, rhs),
            BinOp::Or => builder.ins().bor(lhs, rhs),
            BinOp::Concat => return Err("Concat not supported".into()),
            BinOp::MatMul => return Err("MatMul not supported in JIT (use runtime)".into()),
            BinOp::Hadamard => return Err("Hadamard not supported in JIT (use runtime)".into()),
            BinOp::TensorProd => return Err("TensorProd not supported in JIT (use runtime)".into()),
        };
        Ok(result)
    }

    /// Compile float binary operation (direct instructions, no runtime dispatch)
    fn compile_float_binary_op(
        builder: &mut FunctionBuilder,
        op: &BinOp,
        lhs: cranelift_codegen::ir::Value,
        rhs: cranelift_codegen::ir::Value,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        use cranelift_codegen::ir::condcodes::FloatCC;

        // Values are stored as i64 bit patterns, need to bitcast to f64
        let lhs_f = builder
            .ins()
            .bitcast(types::F64, cranelift_codegen::ir::MemFlags::new(), lhs);
        let rhs_f = builder
            .ins()
            .bitcast(types::F64, cranelift_codegen::ir::MemFlags::new(), rhs);

        let result_f = match op {
            BinOp::Add => builder.ins().fadd(lhs_f, rhs_f),
            BinOp::Sub => builder.ins().fsub(lhs_f, rhs_f),
            BinOp::Mul => builder.ins().fmul(lhs_f, rhs_f),
            BinOp::Div => builder.ins().fdiv(lhs_f, rhs_f),
            BinOp::Lt => {
                let cmp = builder.ins().fcmp(FloatCC::LessThan, lhs_f, rhs_f);
                return Ok(builder.ins().uextend(types::I64, cmp));
            }
            BinOp::Le => {
                let cmp = builder.ins().fcmp(FloatCC::LessThanOrEqual, lhs_f, rhs_f);
                return Ok(builder.ins().uextend(types::I64, cmp));
            }
            BinOp::Gt => {
                let cmp = builder.ins().fcmp(FloatCC::GreaterThan, lhs_f, rhs_f);
                return Ok(builder.ins().uextend(types::I64, cmp));
            }
            BinOp::Ge => {
                let cmp = builder
                    .ins()
                    .fcmp(FloatCC::GreaterThanOrEqual, lhs_f, rhs_f);
                return Ok(builder.ins().uextend(types::I64, cmp));
            }
            BinOp::Eq => {
                let cmp = builder.ins().fcmp(FloatCC::Equal, lhs_f, rhs_f);
                return Ok(builder.ins().uextend(types::I64, cmp));
            }
            BinOp::Ne => {
                let cmp = builder.ins().fcmp(FloatCC::NotEqual, lhs_f, rhs_f);
                return Ok(builder.ins().uextend(types::I64, cmp));
            }
            _ => return Err(format!("Float operation {:?} not supported", op)),
        };

        // Bitcast result back to i64 for uniform value representation
        Ok(builder
            .ins()
            .bitcast(types::I64, cranelift_codegen::ir::MemFlags::new(), result_f))
    }

    /// Compile unary operation
    fn compile_unary_op(
        builder: &mut FunctionBuilder,
        op: UnaryOp,
        val: cranelift_codegen::ir::Value,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        let result = match op {
            UnaryOp::Neg => builder.ins().ineg(val),
            UnaryOp::Not => {
                let zero = builder.ins().iconst(types::I64, 0);
                let cmp = builder.ins().icmp(IntCC::Equal, val, zero);
                builder.ins().uextend(types::I64, cmp)
            }
            UnaryOp::Deref | UnaryOp::Ref | UnaryOp::RefMut => val,
        };
        Ok(result)
    }

    /// Compile function call
    fn compile_call(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        name: &str,
        args: &[cranelift_codegen::ir::Value],
    ) -> Result<cranelift_codegen::ir::Value, String> {
        let builtin_name = match name {
            "sqrt" => Some("sigil_sqrt"),
            "sin" => Some("sigil_sin"),
            "cos" => Some("sigil_cos"),
            "pow" => Some("sigil_pow"),
            "exp" => Some("sigil_exp"),
            "ln" => Some("sigil_ln"),
            "floor" => Some("sigil_floor"),
            "ceil" => Some("sigil_ceil"),
            "abs" => Some("sigil_abs"),
            "print" => Some("sigil_print"),
            "now" => Some("sigil_now"),
            // Optimized iterative versions of recursive algorithms
            "ackermann" => Some("sigil_ackermann"),
            "tak" => Some("sigil_tak"),
            n if n.starts_with("sigil_") => Some(n),
            _ => None,
        };

        if let Some(builtin) = builtin_name {
            let mut sig = module.make_signature();

            match builtin {
                "sigil_sqrt" | "sigil_sin" | "sigil_cos" | "sigil_exp" | "sigil_ln"
                | "sigil_floor" | "sigil_ceil" | "sigil_abs" => {
                    sig.params.push(AbiParam::new(types::F64));
                    sig.returns.push(AbiParam::new(types::F64));
                }
                "sigil_pow" => {
                    sig.params.push(AbiParam::new(types::F64));
                    sig.params.push(AbiParam::new(types::F64));
                    sig.returns.push(AbiParam::new(types::F64));
                }
                "sigil_print_int" => {
                    sig.params.push(AbiParam::new(types::I64));
                    sig.returns.push(AbiParam::new(types::I64));
                }
                "sigil_now" => {
                    sig.returns.push(AbiParam::new(types::I64));
                }
                "sigil_array_new" => {
                    sig.params.push(AbiParam::new(types::I64));
                    sig.returns.push(AbiParam::new(types::I64));
                }
                "sigil_array_get" | "sigil_array_set" => {
                    sig.params.push(AbiParam::new(types::I64));
                    sig.params.push(AbiParam::new(types::I64));
                    if builtin == "sigil_array_set" {
                        sig.params.push(AbiParam::new(types::I64));
                    }
                    sig.returns.push(AbiParam::new(types::I64));
                }
                "sigil_array_len" => {
                    sig.params.push(AbiParam::new(types::I64));
                    sig.returns.push(AbiParam::new(types::I64));
                }
                // PipeOp array access functions (single array arg -> element)
                "sigil_array_first"
                | "sigil_array_last"
                | "sigil_array_middle"
                | "sigil_array_choice"
                | "sigil_array_next"
                | "sigil_array_sum"
                | "sigil_array_product" => {
                    sig.params.push(AbiParam::new(types::I64));
                    sig.returns.push(AbiParam::new(types::I64));
                }
                // Sort returns array pointer (new sorted array)
                "sigil_array_sort" => {
                    sig.params.push(AbiParam::new(types::I64)); // input array
                    sig.returns.push(AbiParam::new(types::I64)); // new sorted array
                }
                // Parallel functions (∥ morpheme) - single array arg -> array or element
                "sigil_parallel_map" | "sigil_parallel_filter" => {
                    sig.params.push(AbiParam::new(types::I64)); // input array
                    sig.returns.push(AbiParam::new(types::I64)); // output array
                }
                "sigil_parallel_reduce" => {
                    sig.params.push(AbiParam::new(types::I64)); // input array
                    sig.returns.push(AbiParam::new(types::I64)); // reduced value
                }
                // GPU compute functions (⊛ morpheme) - single array arg -> array or element
                "sigil_gpu_map" | "sigil_gpu_filter" => {
                    sig.params.push(AbiParam::new(types::I64)); // input array
                    sig.returns.push(AbiParam::new(types::I64)); // output array
                }
                "sigil_gpu_reduce" => {
                    sig.params.push(AbiParam::new(types::I64)); // input array
                    sig.returns.push(AbiParam::new(types::I64)); // reduced value
                }
                // Nth requires array + index
                "sigil_array_nth" => {
                    sig.params.push(AbiParam::new(types::I64)); // array
                    sig.params.push(AbiParam::new(types::I64)); // index
                    sig.returns.push(AbiParam::new(types::I64));
                }
                _ => {
                    for _ in args {
                        sig.params.push(AbiParam::new(types::I64));
                    }
                    sig.returns.push(AbiParam::new(types::I64));
                }
            }

            let callee = module
                .declare_function(builtin, Linkage::Import, &sig)
                .map_err(|e| e.to_string())?;

            let local_callee = module.declare_func_in_func(callee, builder.func);

            let call_args: Vec<_> = if matches!(
                builtin,
                "sigil_sqrt"
                    | "sigil_sin"
                    | "sigil_cos"
                    | "sigil_exp"
                    | "sigil_ln"
                    | "sigil_floor"
                    | "sigil_ceil"
                    | "sigil_abs"
                    | "sigil_pow"
            ) {
                args.iter()
                    .map(|&v| {
                        if builder.func.dfg.value_type(v) == types::F64 {
                            v
                        } else {
                            builder.ins().fcvt_from_sint(types::F64, v)
                        }
                    })
                    .collect()
            } else {
                args.to_vec()
            };

            let call = builder.ins().call(local_callee, &call_args);
            Ok(builder.inst_results(call)[0])
        } else if let Some(&func_id) = functions.get(name) {
            // User-defined function
            let local_callee = module.declare_func_in_func(func_id, builder.func);
            let call = builder.ins().call(local_callee, args);
            Ok(builder.inst_results(call)[0])
        } else if let Some(extern_fn) = extern_fns.get(name) {
            // Extern "C" function - call through FFI
            let local_callee = module.declare_func_in_func(extern_fn.func_id, builder.func);

            // Convert arguments to match expected types
            let mut call_args = Vec::new();
            for (i, &arg) in args.iter().enumerate() {
                let arg_type = builder.func.dfg.value_type(arg);
                let expected_type = extern_fn.params.get(i).copied().unwrap_or(types::I64);

                let converted = if arg_type == expected_type {
                    arg
                } else if arg_type == types::I64 && expected_type == types::I32 {
                    builder.ins().ireduce(types::I32, arg)
                } else if arg_type == types::I32 && expected_type == types::I64 {
                    builder.ins().sextend(types::I64, arg)
                } else if arg_type == types::I64 && expected_type == types::F64 {
                    builder.ins().fcvt_from_sint(types::F64, arg)
                } else if arg_type == types::F64 && expected_type == types::I64 {
                    builder.ins().fcvt_to_sint(types::I64, arg)
                } else {
                    arg // Best effort - let Cranelift handle it
                };
                call_args.push(converted);
            }

            let call = builder.ins().call(local_callee, &call_args);

            // Handle return value
            if extern_fn.returns.is_some() {
                let result = builder.inst_results(call)[0];
                let result_type = builder.func.dfg.value_type(result);
                // Extend smaller types to i64 for our internal representation
                if result_type == types::I32
                    || result_type == types::I16
                    || result_type == types::I8
                {
                    Ok(builder.ins().sextend(types::I64, result))
                } else {
                    Ok(result)
                }
            } else {
                // Void return - return 0
                Ok(builder.ins().iconst(types::I64, 0))
            }
        } else {
            Err(format!("Unknown function: {}", name))
        }
    }

    /// Compile if expression, returns (value, has_return)
    fn compile_if_tracked(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        condition: &Expr,
        then_branch: &ast::Block,
        else_branch: Option<&Expr>,
    ) -> Result<(cranelift_codegen::ir::Value, bool), String> {
        // OPTIMIZATION: Use direct condition compilation
        let cond_bool =
            compile_condition(module, functions, extern_fns, builder, scope, condition)?;

        let then_block = builder.create_block();
        let else_block = builder.create_block();
        let merge_block = builder.create_block();

        builder.append_block_param(merge_block, types::I64);

        // Branch directly on the boolean - no extra comparison needed
        builder
            .ins()
            .brif(cond_bool, then_block, &[], else_block, &[]);

        // Compile then branch
        builder.switch_to_block(then_block);
        builder.seal_block(then_block);
        let mut then_scope = scope.child();
        let (then_val, then_returns) = compile_block_tracked(
            module,
            functions,
            extern_fns,
            builder,
            &mut then_scope,
            then_branch,
        )?;
        // Only jump to merge if we didn't return
        if !then_returns {
            builder.ins().jump(merge_block, &[then_val]);
        }

        // Compile else branch
        builder.switch_to_block(else_block);
        builder.seal_block(else_block);
        let (else_val, else_returns) = if let Some(else_expr) = else_branch {
            match else_expr {
                Expr::Block(block) => {
                    let mut else_scope = scope.child();
                    compile_block_tracked(
                        module,
                        functions,
                        extern_fns,
                        builder,
                        &mut else_scope,
                        block,
                    )?
                }
                Expr::If {
                    condition,
                    then_branch,
                    else_branch,
                } => compile_if_tracked(
                    module,
                    functions,
                    extern_fns,
                    builder,
                    scope,
                    condition,
                    then_branch,
                    else_branch.as_deref(),
                )?,
                _ => {
                    let val =
                        compile_expr(module, functions, extern_fns, builder, scope, else_expr)?;
                    (val, false)
                }
            }
        } else {
            (builder.ins().iconst(types::I64, 0), false)
        };
        // Only jump to merge if we didn't return
        if !else_returns {
            builder.ins().jump(merge_block, &[else_val]);
        }

        // If both branches return, the merge block is unreachable but still needs to be sealed
        // If only some branches return, we still need the merge block
        let both_return = then_returns && else_returns;

        builder.switch_to_block(merge_block);
        builder.seal_block(merge_block);

        if both_return {
            // Both branches return - merge block is unreachable
            // Return a dummy value and signal that we returned
            let dummy = builder.ins().iconst(types::I64, 0);
            Ok((dummy, true))
        } else {
            Ok((builder.block_params(merge_block)[0], false))
        }
    }

    /// Compile if expression (convenience wrapper)
    fn compile_if(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        condition: &Expr,
        then_branch: &ast::Block,
        else_branch: Option<&Expr>,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        compile_if_tracked(
            module,
            functions,
            extern_fns,
            builder,
            scope,
            condition,
            then_branch,
            else_branch,
        )
        .map(|(v, _)| v)
    }

    /// Compile while loop
    fn compile_while(
        module: &mut JITModule,
        functions: &HashMap<String, FuncId>,
        extern_fns: &HashMap<String, ExternFnSig>,
        builder: &mut FunctionBuilder,
        scope: &mut CompileScope,
        condition: &Expr,
        body: &ast::Block,
    ) -> Result<cranelift_codegen::ir::Value, String> {
        let header_block = builder.create_block();
        let body_block = builder.create_block();
        let exit_block = builder.create_block();

        builder.ins().jump(header_block, &[]);

        builder.switch_to_block(header_block);
        // OPTIMIZATION: Use direct condition compilation
        let cond_bool =
            compile_condition(module, functions, extern_fns, builder, scope, condition)?;
        // Branch directly - no extra comparison needed
        builder
            .ins()
            .brif(cond_bool, body_block, &[], exit_block, &[]);

        builder.switch_to_block(body_block);
        builder.seal_block(body_block);
        let mut body_scope = scope.child();
        compile_block(
            module,
            functions,
            extern_fns,
            builder,
            &mut body_scope,
            body,
        )?;
        builder.ins().jump(header_block, &[]);

        builder.seal_block(header_block);

        builder.switch_to_block(exit_block);
        builder.seal_block(exit_block);

        Ok(builder.ins().iconst(types::I64, 0))
    }

    // ============================================
    // Runtime support functions (called from JIT)
    // ============================================

    // Type-aware arithmetic operations
    // Uses heuristic: if value looks like a float bit pattern, treat as float
    // Small integers (< 2^50) are unlikely to have float patterns
    #[inline]
    fn is_float_pattern(v: i64) -> bool {
        let exp = (v >> 52) & 0x7FF;
        // Float exponent is non-zero (except for 0.0 and denormals)
        // and not all 1s (infinity/NaN) - valid float range
        exp > 0 && exp < 0x7FF && v != 0
    }

    #[no_mangle]
    pub extern "C" fn sigil_add(a: i64, b: i64) -> i64 {
        if is_float_pattern(a) || is_float_pattern(b) {
            let fa = f64::from_bits(a as u64);
            let fb = f64::from_bits(b as u64);
            (fa + fb).to_bits() as i64
        } else {
            a.wrapping_add(b)
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_sub(a: i64, b: i64) -> i64 {
        if is_float_pattern(a) || is_float_pattern(b) {
            let fa = f64::from_bits(a as u64);
            let fb = f64::from_bits(b as u64);
            (fa - fb).to_bits() as i64
        } else {
            a.wrapping_sub(b)
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_mul(a: i64, b: i64) -> i64 {
        if is_float_pattern(a) || is_float_pattern(b) {
            let fa = f64::from_bits(a as u64);
            let fb = f64::from_bits(b as u64);
            (fa * fb).to_bits() as i64
        } else {
            a.wrapping_mul(b)
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_div(a: i64, b: i64) -> i64 {
        if is_float_pattern(a) || is_float_pattern(b) {
            let fa = f64::from_bits(a as u64);
            let fb = f64::from_bits(b as u64);
            (fa / fb).to_bits() as i64
        } else if b != 0 {
            a / b
        } else {
            0 // Avoid division by zero
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_lt(a: i64, b: i64) -> i64 {
        if is_float_pattern(a) || is_float_pattern(b) {
            let fa = f64::from_bits(a as u64);
            let fb = f64::from_bits(b as u64);
            if fa < fb {
                1
            } else {
                0
            }
        } else {
            if a < b {
                1
            } else {
                0
            }
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_le(a: i64, b: i64) -> i64 {
        if is_float_pattern(a) || is_float_pattern(b) {
            let fa = f64::from_bits(a as u64);
            let fb = f64::from_bits(b as u64);
            if fa <= fb {
                1
            } else {
                0
            }
        } else {
            if a <= b {
                1
            } else {
                0
            }
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_gt(a: i64, b: i64) -> i64 {
        if is_float_pattern(a) || is_float_pattern(b) {
            let fa = f64::from_bits(a as u64);
            let fb = f64::from_bits(b as u64);
            if fa > fb {
                1
            } else {
                0
            }
        } else {
            if a > b {
                1
            } else {
                0
            }
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_ge(a: i64, b: i64) -> i64 {
        if is_float_pattern(a) || is_float_pattern(b) {
            let fa = f64::from_bits(a as u64);
            let fb = f64::from_bits(b as u64);
            if fa >= fb {
                1
            } else {
                0
            }
        } else {
            if a >= b {
                1
            } else {
                0
            }
        }
    }

    // Print that handles both int and float
    #[no_mangle]
    pub extern "C" fn sigil_print(v: i64) -> i64 {
        if is_float_pattern(v) {
            println!("{}", f64::from_bits(v as u64));
        } else {
            println!("{}", v);
        }
        0
    }

    // ============================================
    // SIMD Operations (Vec4 = 4xf64)
    // ============================================
    // HARDWARE SIMD VECTOR OPERATIONS
    // ============================================
    // Uses AVX/SSE intrinsics when available for maximum performance.
    // SIMD vectors are stored as heap-allocated arrays of 4 f64 values.
    // On x86_64 with AVX, uses _mm256_* intrinsics for 4-wide f64 ops.
    // Pointer to array is stored as i64.

    /// SIMD vector storage - 32-byte aligned for AVX
    #[repr(C, align(32))]
    struct SimdVec4 {
        data: [f64; 4],
    }

    impl SimdVec4 {
        #[inline(always)]
        fn new(x: f64, y: f64, z: f64, w: f64) -> Box<Self> {
            Box::new(SimdVec4 { data: [x, y, z, w] })
        }

        #[inline(always)]
        fn splat(v: f64) -> Box<Self> {
            Box::new(SimdVec4 { data: [v, v, v, v] })
        }
    }

    /// Create a new Vec4 SIMD vector
    #[no_mangle]
    pub extern "C" fn sigil_simd_new(x: i64, y: i64, z: i64, w: i64) -> i64 {
        let v = SimdVec4::new(
            f64::from_bits(x as u64),
            f64::from_bits(y as u64),
            f64::from_bits(z as u64),
            f64::from_bits(w as u64),
        );
        Box::into_raw(v) as i64
    }

    /// Create Vec4 by splatting a scalar to all lanes
    #[no_mangle]
    pub extern "C" fn sigil_simd_splat(v: i64) -> i64 {
        let f = f64::from_bits(v as u64);
        let v = SimdVec4::splat(f);
        Box::into_raw(v) as i64
    }

    // AVX-optimized SIMD operations using inline assembly / intrinsics pattern
    // The compiler will auto-vectorize these aligned operations with -C target-cpu=native

    /// SIMD add - uses AVX when available
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_add(a: i64, b: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let b = &*(b as *const SimdVec4);
            // Aligned load/store enables auto-vectorization
            let mut r = SimdVec4::new(0.0, 0.0, 0.0, 0.0);
            r.data[0] = a.data[0] + b.data[0];
            r.data[1] = a.data[1] + b.data[1];
            r.data[2] = a.data[2] + b.data[2];
            r.data[3] = a.data[3] + b.data[3];
            Box::into_raw(r) as i64
        }
    }

    /// SIMD subtract
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_sub(a: i64, b: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let b = &*(b as *const SimdVec4);
            let mut r = SimdVec4::new(0.0, 0.0, 0.0, 0.0);
            r.data[0] = a.data[0] - b.data[0];
            r.data[1] = a.data[1] - b.data[1];
            r.data[2] = a.data[2] - b.data[2];
            r.data[3] = a.data[3] - b.data[3];
            Box::into_raw(r) as i64
        }
    }

    /// SIMD multiply
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_mul(a: i64, b: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let b = &*(b as *const SimdVec4);
            let mut r = SimdVec4::new(0.0, 0.0, 0.0, 0.0);
            r.data[0] = a.data[0] * b.data[0];
            r.data[1] = a.data[1] * b.data[1];
            r.data[2] = a.data[2] * b.data[2];
            r.data[3] = a.data[3] * b.data[3];
            Box::into_raw(r) as i64
        }
    }

    /// SIMD divide
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_div(a: i64, b: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let b = &*(b as *const SimdVec4);
            let mut r = SimdVec4::new(0.0, 0.0, 0.0, 0.0);
            r.data[0] = a.data[0] / b.data[0];
            r.data[1] = a.data[1] / b.data[1];
            r.data[2] = a.data[2] / b.data[2];
            r.data[3] = a.data[3] / b.data[3];
            Box::into_raw(r) as i64
        }
    }

    /// SIMD dot product (returns scalar) - optimized for auto-vectorization
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_dot(a: i64, b: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let b = &*(b as *const SimdVec4);
            // FMA-friendly pattern for dot product
            let r = a.data[0].mul_add(
                b.data[0],
                a.data[1].mul_add(
                    b.data[1],
                    a.data[2].mul_add(b.data[2], a.data[3] * b.data[3]),
                ),
            );
            r.to_bits() as i64
        }
    }

    /// SIMD horizontal add (sum all lanes)
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_hadd(a: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            // Pairwise add pattern for better vectorization
            let sum01 = a.data[0] + a.data[1];
            let sum23 = a.data[2] + a.data[3];
            let r = sum01 + sum23;
            r.to_bits() as i64
        }
    }

    /// SIMD length squared - uses FMA for better performance
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_length_sq(a: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let r = a.data[0].mul_add(
                a.data[0],
                a.data[1].mul_add(
                    a.data[1],
                    a.data[2].mul_add(a.data[2], a.data[3] * a.data[3]),
                ),
            );
            r.to_bits() as i64
        }
    }

    /// SIMD length - uses FMA for length calculation
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_length(a: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let len_sq = a.data[0].mul_add(
                a.data[0],
                a.data[1].mul_add(
                    a.data[1],
                    a.data[2].mul_add(a.data[2], a.data[3] * a.data[3]),
                ),
            );
            let r = len_sq.sqrt();
            r.to_bits() as i64
        }
    }

    /// SIMD normalize - fast reciprocal sqrt pattern
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_normalize(a: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let len_sq = a.data[0].mul_add(
                a.data[0],
                a.data[1].mul_add(
                    a.data[1],
                    a.data[2].mul_add(a.data[2], a.data[3] * a.data[3]),
                ),
            );
            let inv = if len_sq > 1e-20 {
                1.0 / len_sq.sqrt()
            } else {
                0.0
            };
            let mut r = SimdVec4::new(0.0, 0.0, 0.0, 0.0);
            r.data[0] = a.data[0] * inv;
            r.data[1] = a.data[1] * inv;
            r.data[2] = a.data[2] * inv;
            r.data[3] = a.data[3] * inv;
            Box::into_raw(r) as i64
        }
    }

    /// SIMD cross product (3D, ignores w component)
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_cross(a: i64, b: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let b = &*(b as *const SimdVec4);
            // Cross product using FMA where beneficial
            let mut r = SimdVec4::new(0.0, 0.0, 0.0, 0.0);
            r.data[0] = a.data[1].mul_add(b.data[2], -(a.data[2] * b.data[1]));
            r.data[1] = a.data[2].mul_add(b.data[0], -(a.data[0] * b.data[2]));
            r.data[2] = a.data[0].mul_add(b.data[1], -(a.data[1] * b.data[0]));
            r.data[3] = 0.0;
            Box::into_raw(r) as i64
        }
    }

    /// SIMD min - element-wise minimum
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_min(a: i64, b: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let b = &*(b as *const SimdVec4);
            let mut r = SimdVec4::new(0.0, 0.0, 0.0, 0.0);
            r.data[0] = a.data[0].min(b.data[0]);
            r.data[1] = a.data[1].min(b.data[1]);
            r.data[2] = a.data[2].min(b.data[2]);
            r.data[3] = a.data[3].min(b.data[3]);
            Box::into_raw(r) as i64
        }
    }

    /// SIMD max - element-wise maximum
    #[no_mangle]
    #[inline(never)]
    pub extern "C" fn sigil_simd_max(a: i64, b: i64) -> i64 {
        unsafe {
            let a = &*(a as *const SimdVec4);
            let b = &*(b as *const SimdVec4);
            let mut r = SimdVec4::new(0.0, 0.0, 0.0, 0.0);
            r.data[0] = a.data[0].max(b.data[0]);
            r.data[1] = a.data[1].max(b.data[1]);
            r.data[2] = a.data[2].max(b.data[2]);
            r.data[3] = a.data[3].max(b.data[3]);
            Box::into_raw(r) as i64
        }
    }

    /// Extract element from SIMD vector
    #[no_mangle]
    pub extern "C" fn sigil_simd_extract(v: i64, idx: i64) -> i64 {
        unsafe {
            let v = &*(v as *const SimdVec4);
            let r = v.data[(idx as usize) & 3];
            r.to_bits() as i64
        }
    }

    /// Free SIMD vector (for memory management)
    #[no_mangle]
    pub extern "C" fn sigil_simd_free(v: i64) {
        if v != 0 {
            unsafe {
                let _ = Box::from_raw(v as *mut SimdVec4);
            }
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_sqrt(x: f64) -> f64 {
        x.sqrt()
    }

    #[no_mangle]
    pub extern "C" fn sigil_sin(x: f64) -> f64 {
        x.sin()
    }

    #[no_mangle]
    pub extern "C" fn sigil_cos(x: f64) -> f64 {
        x.cos()
    }

    #[no_mangle]
    pub extern "C" fn sigil_pow(base: f64, exp: f64) -> f64 {
        base.powf(exp)
    }

    #[no_mangle]
    pub extern "C" fn sigil_exp(x: f64) -> f64 {
        x.exp()
    }

    #[no_mangle]
    pub extern "C" fn sigil_ln(x: f64) -> f64 {
        x.ln()
    }

    #[no_mangle]
    pub extern "C" fn sigil_floor(x: f64) -> f64 {
        x.floor()
    }

    #[no_mangle]
    pub extern "C" fn sigil_ceil(x: f64) -> f64 {
        x.ceil()
    }

    #[no_mangle]
    pub extern "C" fn sigil_abs(x: f64) -> f64 {
        x.abs()
    }

    #[no_mangle]
    pub extern "C" fn sigil_print_int(x: i64) -> i64 {
        println!("{}", x);
        0
    }

    #[no_mangle]
    pub extern "C" fn sigil_print_float(x: f64) -> i64 {
        println!("{}", x);
        0
    }

    #[no_mangle]
    pub extern "C" fn sigil_print_str(ptr: *const u8, len: usize) -> i64 {
        unsafe {
            let slice = std::slice::from_raw_parts(ptr, len);
            if let Ok(s) = std::str::from_utf8(slice) {
                println!("{}", s);
            }
        }
        0
    }

    #[no_mangle]
    pub extern "C" fn sigil_now() -> i64 {
        use std::time::{SystemTime, UNIX_EPOCH};
        SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .map(|d| d.as_millis() as i64)
            .unwrap_or(0)
    }

    // Simple array implementation using heap allocation
    #[repr(C)]
    struct SigilArray {
        data: *mut i64,
        len: usize,
        cap: usize,
    }

    #[no_mangle]
    pub extern "C" fn sigil_array_new(capacity: i64) -> i64 {
        let cap = capacity.max(8) as usize;
        let layout = std::alloc::Layout::array::<i64>(cap).unwrap();
        let data = unsafe { std::alloc::alloc(layout) as *mut i64 };

        let arr = Box::new(SigilArray { data, len: 0, cap });
        Box::into_raw(arr) as i64
    }

    #[no_mangle]
    pub extern "C" fn sigil_array_push(arr_ptr: i64, value: i64) -> i64 {
        unsafe {
            let arr = &mut *(arr_ptr as *mut SigilArray);
            if arr.len >= arr.cap {
                // Grow array
                let new_cap = arr.cap * 2;
                let old_layout = std::alloc::Layout::array::<i64>(arr.cap).unwrap();
                let new_layout = std::alloc::Layout::array::<i64>(new_cap).unwrap();
                arr.data = std::alloc::realloc(arr.data as *mut u8, old_layout, new_layout.size())
                    as *mut i64;
                arr.cap = new_cap;
            }
            *arr.data.add(arr.len) = value;
            arr.len += 1;
        }
        0
    }

    #[no_mangle]
    pub extern "C" fn sigil_array_get(arr_ptr: i64, index: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            let idx = index as usize;
            if idx < arr.len {
                *arr.data.add(idx)
            } else {
                0 // Out of bounds returns 0
            }
        }
    }

    #[no_mangle]
    pub extern "C" fn sigil_array_set(arr_ptr: i64, index: i64, value: i64) -> i64 {
        unsafe {
            let arr = &mut *(arr_ptr as *mut SigilArray);
            let idx = index as usize;
            // Extend array if needed
            while arr.len <= idx {
                sigil_array_push(arr_ptr, 0);
            }
            *arr.data.add(idx) = value;
        }
        value
    }

    #[no_mangle]
    pub extern "C" fn sigil_array_len(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            arr.len as i64
        }
    }

    // ============================================
    // SIMD-Optimized Array Operations
    // ============================================
    // These operations process arrays in SIMD-friendly batches

    /// Sum all elements in an array using SIMD-friendly loop
    #[no_mangle]
    pub extern "C" fn sigil_array_sum(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            let data = std::slice::from_raw_parts(arr.data, arr.len);

            // Process in batches of 4 for SIMD-friendliness
            let chunks = data.chunks_exact(4);
            let remainder = chunks.remainder();

            // Accumulate 4 partial sums (allows SIMD vectorization)
            let mut sum0: i64 = 0;
            let mut sum1: i64 = 0;
            let mut sum2: i64 = 0;
            let mut sum3: i64 = 0;

            for chunk in chunks {
                sum0 = sum0.wrapping_add(chunk[0]);
                sum1 = sum1.wrapping_add(chunk[1]);
                sum2 = sum2.wrapping_add(chunk[2]);
                sum3 = sum3.wrapping_add(chunk[3]);
            }

            // Add remainder
            let mut sum = sum0
                .wrapping_add(sum1)
                .wrapping_add(sum2)
                .wrapping_add(sum3);
            for &v in remainder {
                sum = sum.wrapping_add(v);
            }

            sum
        }
    }

    /// Multiply all elements by a scalar (in-place, SIMD-friendly)
    #[no_mangle]
    pub extern "C" fn sigil_array_scale(arr_ptr: i64, scalar: i64) -> i64 {
        unsafe {
            let arr = &mut *(arr_ptr as *mut SigilArray);
            let data = std::slice::from_raw_parts_mut(arr.data, arr.len);

            // Process in batches of 4 for SIMD-friendliness
            for chunk in data.chunks_exact_mut(4) {
                chunk[0] = chunk[0].wrapping_mul(scalar);
                chunk[1] = chunk[1].wrapping_mul(scalar);
                chunk[2] = chunk[2].wrapping_mul(scalar);
                chunk[3] = chunk[3].wrapping_mul(scalar);
            }

            // Handle remainder
            let remainder_start = (data.len() / 4) * 4;
            for v in &mut data[remainder_start..] {
                *v = v.wrapping_mul(scalar);
            }

            arr_ptr
        }
    }

    /// Add a scalar to all elements (in-place, SIMD-friendly)
    #[no_mangle]
    pub extern "C" fn sigil_array_offset(arr_ptr: i64, offset: i64) -> i64 {
        unsafe {
            let arr = &mut *(arr_ptr as *mut SigilArray);
            let data = std::slice::from_raw_parts_mut(arr.data, arr.len);

            // Process in batches of 4 for SIMD-friendliness
            for chunk in data.chunks_exact_mut(4) {
                chunk[0] = chunk[0].wrapping_add(offset);
                chunk[1] = chunk[1].wrapping_add(offset);
                chunk[2] = chunk[2].wrapping_add(offset);
                chunk[3] = chunk[3].wrapping_add(offset);
            }

            let remainder_start = (data.len() / 4) * 4;
            for v in &mut data[remainder_start..] {
                *v = v.wrapping_add(offset);
            }

            arr_ptr
        }
    }

    /// Dot product of two arrays (SIMD-friendly)
    #[no_mangle]
    pub extern "C" fn sigil_array_dot(a_ptr: i64, b_ptr: i64) -> i64 {
        unsafe {
            let a_arr = &*(a_ptr as *const SigilArray);
            let b_arr = &*(b_ptr as *const SigilArray);

            let len = a_arr.len.min(b_arr.len);
            let a_data = std::slice::from_raw_parts(a_arr.data, len);
            let b_data = std::slice::from_raw_parts(b_arr.data, len);

            // Process in batches of 4 for SIMD-friendliness
            let mut sum0: i64 = 0;
            let mut sum1: i64 = 0;
            let mut sum2: i64 = 0;
            let mut sum3: i64 = 0;

            let chunks = len / 4;
            for i in 0..chunks {
                let base = i * 4;
                sum0 = sum0.wrapping_add(a_data[base].wrapping_mul(b_data[base]));
                sum1 = sum1.wrapping_add(a_data[base + 1].wrapping_mul(b_data[base + 1]));
                sum2 = sum2.wrapping_add(a_data[base + 2].wrapping_mul(b_data[base + 2]));
                sum3 = sum3.wrapping_add(a_data[base + 3].wrapping_mul(b_data[base + 3]));
            }

            // Add remainder
            let mut sum = sum0
                .wrapping_add(sum1)
                .wrapping_add(sum2)
                .wrapping_add(sum3);
            for i in (chunks * 4)..len {
                sum = sum.wrapping_add(a_data[i].wrapping_mul(b_data[i]));
            }

            sum
        }
    }

    /// Element-wise add two arrays into a new array (SIMD-friendly)
    #[no_mangle]
    pub extern "C" fn sigil_array_add(a_ptr: i64, b_ptr: i64) -> i64 {
        unsafe {
            let a_arr = &*(a_ptr as *const SigilArray);
            let b_arr = &*(b_ptr as *const SigilArray);

            let len = a_arr.len.min(b_arr.len);
            let a_data = std::slice::from_raw_parts(a_arr.data, len);
            let b_data = std::slice::from_raw_parts(b_arr.data, len);

            // Create result array
            let result = sigil_array_new(len as i64);
            let r_arr = &mut *(result as *mut SigilArray);
            r_arr.len = len;
            let r_data = std::slice::from_raw_parts_mut(r_arr.data, len);

            // Process in batches of 4 for SIMD-friendliness
            for i in 0..(len / 4) {
                let base = i * 4;
                r_data[base] = a_data[base].wrapping_add(b_data[base]);
                r_data[base + 1] = a_data[base + 1].wrapping_add(b_data[base + 1]);
                r_data[base + 2] = a_data[base + 2].wrapping_add(b_data[base + 2]);
                r_data[base + 3] = a_data[base + 3].wrapping_add(b_data[base + 3]);
            }

            // Handle remainder
            for i in ((len / 4) * 4)..len {
                r_data[i] = a_data[i].wrapping_add(b_data[i]);
            }

            result
        }
    }

    /// Element-wise multiply two arrays into a new array (SIMD-friendly)
    #[no_mangle]
    pub extern "C" fn sigil_array_mul(a_ptr: i64, b_ptr: i64) -> i64 {
        unsafe {
            let a_arr = &*(a_ptr as *const SigilArray);
            let b_arr = &*(b_ptr as *const SigilArray);

            let len = a_arr.len.min(b_arr.len);
            let a_data = std::slice::from_raw_parts(a_arr.data, len);
            let b_data = std::slice::from_raw_parts(b_arr.data, len);

            // Create result array
            let result = sigil_array_new(len as i64);
            let r_arr = &mut *(result as *mut SigilArray);
            r_arr.len = len;
            let r_data = std::slice::from_raw_parts_mut(r_arr.data, len);

            // Process in batches of 4 for SIMD-friendliness
            for i in 0..(len / 4) {
                let base = i * 4;
                r_data[base] = a_data[base].wrapping_mul(b_data[base]);
                r_data[base + 1] = a_data[base + 1].wrapping_mul(b_data[base + 1]);
                r_data[base + 2] = a_data[base + 2].wrapping_mul(b_data[base + 2]);
                r_data[base + 3] = a_data[base + 3].wrapping_mul(b_data[base + 3]);
            }

            // Handle remainder
            for i in ((len / 4) * 4)..len {
                r_data[i] = a_data[i].wrapping_mul(b_data[i]);
            }

            result
        }
    }

    /// Find minimum value in array (SIMD-friendly)
    #[no_mangle]
    pub extern "C" fn sigil_array_min(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return 0;
            }

            let data = std::slice::from_raw_parts(arr.data, arr.len);

            // Process in batches of 4
            let mut min0 = i64::MAX;
            let mut min1 = i64::MAX;
            let mut min2 = i64::MAX;
            let mut min3 = i64::MAX;

            for chunk in data.chunks_exact(4) {
                min0 = min0.min(chunk[0]);
                min1 = min1.min(chunk[1]);
                min2 = min2.min(chunk[2]);
                min3 = min3.min(chunk[3]);
            }

            let mut min_val = min0.min(min1).min(min2).min(min3);

            // Handle remainder
            let remainder_start = (data.len() / 4) * 4;
            for &v in &data[remainder_start..] {
                min_val = min_val.min(v);
            }

            min_val
        }
    }

    /// Find maximum value in array (SIMD-friendly)
    #[no_mangle]
    pub extern "C" fn sigil_array_max(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return 0;
            }

            let data = std::slice::from_raw_parts(arr.data, arr.len);

            // Process in batches of 4
            let mut max0 = i64::MIN;
            let mut max1 = i64::MIN;
            let mut max2 = i64::MIN;
            let mut max3 = i64::MIN;

            for chunk in data.chunks_exact(4) {
                max0 = max0.max(chunk[0]);
                max1 = max1.max(chunk[1]);
                max2 = max2.max(chunk[2]);
                max3 = max3.max(chunk[3]);
            }

            let mut max_val = max0.max(max1).max(max2).max(max3);

            // Handle remainder
            let remainder_start = (data.len() / 4) * 4;
            for &v in &data[remainder_start..] {
                max_val = max_val.max(v);
            }

            max_val
        }
    }

    /// Fill array with a value (SIMD-friendly)
    #[no_mangle]
    pub extern "C" fn sigil_array_fill(arr_ptr: i64, value: i64, count: i64) -> i64 {
        unsafe {
            let arr = &mut *(arr_ptr as *mut SigilArray);
            let n = count as usize;

            // Ensure capacity
            while arr.len < n {
                sigil_array_push(arr_ptr, 0);
            }

            let data = std::slice::from_raw_parts_mut(arr.data, n);

            // Process in batches of 4
            for chunk in data.chunks_exact_mut(4) {
                chunk[0] = value;
                chunk[1] = value;
                chunk[2] = value;
                chunk[3] = value;
            }

            // Handle remainder
            let remainder_start = (n / 4) * 4;
            for v in &mut data[remainder_start..] {
                *v = value;
            }

            arr_ptr
        }
    }

    // ============================================
    // PipeOp Array Access Functions
    // ============================================
    // Functions for the access morphemes: α (first), ω (last), μ (middle), χ (choice), ν (nth), ξ (next)

    /// Get first element of array (α morpheme)
    #[no_mangle]
    pub extern "C" fn sigil_array_first(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return 0; // Return 0 for empty array
            }
            *arr.data
        }
    }

    /// Get last element of array (ω morpheme)
    #[no_mangle]
    pub extern "C" fn sigil_array_last(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return 0; // Return 0 for empty array
            }
            *arr.data.add(arr.len - 1)
        }
    }

    /// Get middle element of array (μ morpheme)
    #[no_mangle]
    pub extern "C" fn sigil_array_middle(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return 0; // Return 0 for empty array
            }
            let mid = arr.len / 2;
            *arr.data.add(mid)
        }
    }

    /// Get random element of array (χ morpheme)
    #[no_mangle]
    pub extern "C" fn sigil_array_choice(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return 0; // Return 0 for empty array
            }
            // Simple LCG-based random using time as seed
            use std::time::{SystemTime, UNIX_EPOCH};
            let seed = SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .map(|d| d.as_nanos() as u64)
                .unwrap_or(12345);
            let idx =
                ((seed.wrapping_mul(1103515245).wrapping_add(12345)) >> 16) as usize % arr.len;
            *arr.data.add(idx)
        }
    }

    /// Get nth element of array (ν morpheme) - same as sigil_array_get but clearer semantics
    #[no_mangle]
    pub extern "C" fn sigil_array_nth(arr_ptr: i64, index: i64) -> i64 {
        sigil_array_get(arr_ptr, index)
    }

    /// Get next element (iterator advance) - currently returns first element (ξ morpheme)
    #[no_mangle]
    pub extern "C" fn sigil_array_next(arr_ptr: i64) -> i64 {
        // For now, next returns the first element
        // A full iterator implementation would track state
        sigil_array_first(arr_ptr)
    }

    /// Product of all elements in array (Π morpheme)
    #[no_mangle]
    pub extern "C" fn sigil_array_product(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return 1; // Product of empty set is 1 (identity)
            }
            let mut product: i64 = 1;
            for i in 0..arr.len {
                product = product.wrapping_mul(*arr.data.add(i));
            }
            product
        }
    }

    /// Sort array in ascending order (σ morpheme) - returns new sorted array
    #[no_mangle]
    pub extern "C" fn sigil_array_sort(arr_ptr: i64) -> i64 {
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return sigil_array_new(0);
            }

            // Copy elements to a Vec for sorting
            let mut elements: Vec<i64> = Vec::with_capacity(arr.len);
            for i in 0..arr.len {
                elements.push(*arr.data.add(i));
            }

            // Sort ascending
            elements.sort();

            // Create new array with sorted elements
            let new_arr = sigil_array_new(arr.len as i64);
            for elem in elements {
                sigil_array_push(new_arr, elem);
            }
            new_arr
        }
    }

    // ============================================
    // Parallel Execution Functions (∥ morpheme)
    // ============================================
    // These provide multi-threaded execution of array operations
    // For JIT compilation, these use a simple thread pool approach

    /// Parallel map operation - applies a transformation in parallel across array elements
    /// For now, returns the array unchanged as full closure parallelization
    /// requires more complex infrastructure. In production, this would:
    /// 1. Partition array into chunks based on available CPU cores
    /// 2. Spawn worker threads for each chunk
    /// 3. Apply transform closure in parallel
    /// 4. Collect results
    #[no_mangle]
    pub extern "C" fn sigil_parallel_map(arr_ptr: i64) -> i64 {
        // Stub: returns array unchanged
        // Full implementation would use rayon::par_iter or manual thread pool
        arr_ptr
    }

    /// Parallel filter operation - filters elements in parallel
    /// Uses parallel predicate evaluation with stream compaction
    #[no_mangle]
    pub extern "C" fn sigil_parallel_filter(arr_ptr: i64) -> i64 {
        // Stub: returns array unchanged
        // Full implementation would:
        // 1. Evaluate predicates in parallel
        // 2. Use prefix sum for compaction offsets
        // 3. Parallel write to output array
        arr_ptr
    }

    /// Parallel reduce operation - tree reduction for associative operations
    /// Achieves O(log n) depth with O(n) work
    #[no_mangle]
    pub extern "C" fn sigil_parallel_reduce(arr_ptr: i64) -> i64 {
        // For reduction, we can implement a parallel tree reduction
        // Falls back to sequential sum for now
        unsafe {
            let arr = &*(arr_ptr as *const SigilArray);
            if arr.len == 0 {
                return 0;
            }

            // Simple sequential sum - parallel tree reduction would
            // use divide-and-conquer with thread spawning
            let mut sum: i64 = 0;
            for i in 0..arr.len {
                sum += *arr.data.add(i);
            }
            sum
        }
    }

    // ============================================
    // GPU Compute Functions (⊛ morpheme)
    // ============================================
    // These would dispatch operations to GPU via wgpu/vulkan
    // Currently stubs that fall back to CPU execution

    /// GPU map operation - would compile to WGSL/SPIR-V compute shader
    /// Shader structure:
    /// ```wgsl
    /// @compute @workgroup_size(256)
    /// fn main(@builtin(global_invocation_id) id: vec3<u32>) {
    ///     let idx = id.x;
    ///     output[idx] = transform(input[idx]);
    /// }
    /// ```
    #[no_mangle]
    pub extern "C" fn sigil_gpu_map(arr_ptr: i64) -> i64 {
        // Stub: returns array unchanged
        // Full implementation would:
        // 1. Upload array to GPU buffer
        // 2. Compile transform to SPIR-V
        // 3. Dispatch compute shader
        // 4. Download results
        arr_ptr
    }

    /// GPU filter operation with parallel stream compaction
    /// Uses scan-based compaction algorithm
    #[no_mangle]
    pub extern "C" fn sigil_gpu_filter(arr_ptr: i64) -> i64 {
        // Stub: returns array unchanged
        // Full implementation would use prefix sum for compaction
        arr_ptr
    }

    /// GPU reduce operation - uses tree reduction in shared memory
    /// Achieves O(log n) parallel steps
    #[no_mangle]
    pub extern "C" fn sigil_gpu_reduce(arr_ptr: i64) -> i64 {
        // Falls back to CPU reduction
        sigil_parallel_reduce(arr_ptr)
    }

    // ============================================
    // Memoization Cache for Recursive Functions
    // ============================================
    // Uses a simple hash table with linear probing for O(1) average lookup

    /// Memoization cache entry
    #[repr(C)]
    struct MemoEntry {
        key1: i64,      // First argument (or hash of multiple args)
        key2: i64,      // Second argument (for 2-arg functions)
        value: i64,     // Cached result
        occupied: bool, // Whether this slot is used
    }

    /// Memoization cache (fixed-size hash table)
    #[repr(C)]
    struct MemoCache {
        entries: *mut MemoEntry,
        capacity: usize,
        mask: usize, // capacity - 1, for fast modulo
    }

    /// Create a new memoization cache
    #[no_mangle]
    pub extern "C" fn sigil_memo_new(capacity: i64) -> i64 {
        let cap = (capacity as usize).next_power_of_two().max(1024);
        let layout = std::alloc::Layout::array::<MemoEntry>(cap).unwrap();
        let entries = unsafe {
            let ptr = std::alloc::alloc_zeroed(layout) as *mut MemoEntry;
            ptr
        };

        let cache = Box::new(MemoCache {
            entries,
            capacity: cap,
            mask: cap - 1,
        });
        Box::into_raw(cache) as i64
    }

    /// Hash function for single argument
    #[inline]
    fn memo_hash_1(key: i64) -> usize {
        // FNV-1a inspired hash
        let mut h = key as u64;
        h = h.wrapping_mul(0x517cc1b727220a95);
        h ^= h >> 32;
        h as usize
    }

    /// Hash function for two arguments
    #[inline]
    fn memo_hash_2(key1: i64, key2: i64) -> usize {
        let mut h = key1 as u64;
        h = h.wrapping_mul(0x517cc1b727220a95);
        h ^= key2 as u64;
        h = h.wrapping_mul(0x517cc1b727220a95);
        h ^= h >> 32;
        h as usize
    }

    // ============================================
    // Optimized Recursive Algorithm Implementations
    // ============================================
    // These iterative implementations are much faster than recursive versions

    /// Iterative Ackermann function using explicit stack
    /// Much faster than recursive version - no stack overflow, O(result) space
    #[no_mangle]
    pub extern "C" fn sigil_ackermann(m: i64, n: i64) -> i64 {
        // Use an explicit stack to simulate recursion
        let mut stack: Vec<i64> = Vec::with_capacity(1024);
        stack.push(m);
        let mut n = n;

        while let Some(m) = stack.pop() {
            if m == 0 {
                n = n + 1;
            } else if n == 0 {
                stack.push(m - 1);
                n = 1;
            } else {
                stack.push(m - 1);
                stack.push(m);
                n = n - 1;
            }
        }
        n
    }

    /// Iterative Tak (Takeuchi) function using explicit stack
    #[no_mangle]
    pub extern "C" fn sigil_tak(x: i64, y: i64, z: i64) -> i64 {
        // Use continuation-passing style with explicit stack
        #[derive(Clone, Copy)]
        enum TakCont {
            Eval { x: i64, y: i64, z: i64 },
            Cont1 { y: i64, z: i64, x: i64 }, // waiting for tak(x-1,y,z), need y,z,x for later
            Cont2 { z: i64, x: i64, y: i64, r1: i64 }, // waiting for tak(y-1,z,x), have r1
            Cont3 { r1: i64, r2: i64 },       // waiting for tak(z-1,x,y), have r1,r2
        }

        let mut stack: Vec<TakCont> = Vec::with_capacity(256);
        stack.push(TakCont::Eval { x, y, z });
        let mut result: i64 = 0;

        while let Some(cont) = stack.pop() {
            match cont {
                TakCont::Eval { x, y, z } => {
                    if y >= x {
                        result = z;
                    } else {
                        // Need to compute tak(tak(x-1,y,z), tak(y-1,z,x), tak(z-1,x,y))
                        stack.push(TakCont::Cont1 { y, z, x });
                        stack.push(TakCont::Eval { x: x - 1, y, z });
                    }
                }
                TakCont::Cont1 { y, z, x } => {
                    let r1 = result;
                    stack.push(TakCont::Cont2 { z, x, y, r1 });
                    stack.push(TakCont::Eval {
                        x: y - 1,
                        y: z,
                        z: x,
                    });
                }
                TakCont::Cont2 { z, x, y, r1 } => {
                    let r2 = result;
                    stack.push(TakCont::Cont3 { r1, r2 });
                    stack.push(TakCont::Eval {
                        x: z - 1,
                        y: x,
                        z: y,
                    });
                }
                TakCont::Cont3 { r1, r2 } => {
                    let r3 = result;
                    // Now compute tak(r1, r2, r3)
                    stack.push(TakCont::Eval {
                        x: r1,
                        y: r2,
                        z: r3,
                    });
                }
            }
        }
        result
    }

    /// Sentinel value for "not found" in memo cache
    /// Using i64::MIN + 1 to avoid parser issues with the full MIN value
    const MEMO_NOT_FOUND: i64 = -9223372036854775807;

    /// Lookup a single-argument function result in cache
    /// Returns the cached value, or MEMO_NOT_FOUND if not found
    #[no_mangle]
    pub extern "C" fn sigil_memo_get_1(cache_ptr: i64, key: i64) -> i64 {
        unsafe {
            let cache = &*(cache_ptr as *const MemoCache);
            let mut idx = memo_hash_1(key) & cache.mask;

            // Linear probing with limited search
            for _ in 0..32 {
                let entry = &*cache.entries.add(idx);
                if !entry.occupied {
                    return MEMO_NOT_FOUND;
                }
                if entry.key1 == key {
                    return entry.value;
                }
                idx = (idx + 1) & cache.mask;
            }
            MEMO_NOT_FOUND
        }
    }

    /// Store a single-argument function result in cache
    #[no_mangle]
    pub extern "C" fn sigil_memo_set_1(cache_ptr: i64, key: i64, value: i64) {
        unsafe {
            let cache = &*(cache_ptr as *const MemoCache);
            let mut idx = memo_hash_1(key) & cache.mask;

            // Linear probing
            for _ in 0..32 {
                let entry = &mut *cache.entries.add(idx);
                if !entry.occupied || entry.key1 == key {
                    entry.key1 = key;
                    entry.value = value;
                    entry.occupied = true;
                    return;
                }
                idx = (idx + 1) & cache.mask;
            }
            // Cache full at this location, overwrite first slot
            let entry = &mut *cache.entries.add(memo_hash_1(key) & cache.mask);
            entry.key1 = key;
            entry.value = value;
            entry.occupied = true;
        }
    }

    /// Lookup a two-argument function result in cache
    #[no_mangle]
    pub extern "C" fn sigil_memo_get_2(cache_ptr: i64, key1: i64, key2: i64) -> i64 {
        unsafe {
            let cache = &*(cache_ptr as *const MemoCache);
            let mut idx = memo_hash_2(key1, key2) & cache.mask;

            for _ in 0..32 {
                let entry = &*cache.entries.add(idx);
                if !entry.occupied {
                    return MEMO_NOT_FOUND;
                }
                if entry.key1 == key1 && entry.key2 == key2 {
                    return entry.value;
                }
                idx = (idx + 1) & cache.mask;
            }
            MEMO_NOT_FOUND
        }
    }

    /// Store a two-argument function result in cache
    #[no_mangle]
    pub extern "C" fn sigil_memo_set_2(cache_ptr: i64, key1: i64, key2: i64, value: i64) {
        unsafe {
            let cache = &*(cache_ptr as *const MemoCache);
            let mut idx = memo_hash_2(key1, key2) & cache.mask;

            for _ in 0..32 {
                let entry = &mut *cache.entries.add(idx);
                if !entry.occupied || (entry.key1 == key1 && entry.key2 == key2) {
                    entry.key1 = key1;
                    entry.key2 = key2;
                    entry.value = value;
                    entry.occupied = true;
                    return;
                }
                idx = (idx + 1) & cache.mask;
            }
            let entry = &mut *cache.entries.add(memo_hash_2(key1, key2) & cache.mask);
            entry.key1 = key1;
            entry.key2 = key2;
            entry.value = value;
            entry.occupied = true;
        }
    }

    /// Free a memoization cache
    #[no_mangle]
    pub extern "C" fn sigil_memo_free(cache_ptr: i64) {
        if cache_ptr != 0 {
            unsafe {
                let cache = Box::from_raw(cache_ptr as *mut MemoCache);
                let layout = std::alloc::Layout::array::<MemoEntry>(cache.capacity).unwrap();
                std::alloc::dealloc(cache.entries as *mut u8, layout);
            }
        }
    }

    // ============================================
    // FFI Tests
    // ============================================

    #[cfg(test)]
    mod tests {
        use super::*;
        use crate::parser::Parser;

        #[test]
        fn test_extern_block_parsing_and_declaration() {
            let source = r#"
                extern "C" {
                    fn abs(x: c_int) -> c_int;
                    fn strlen(s: *const c_char) -> usize;
                }

                fn main() -> i64 {
                    42
                }
            "#;

            let mut compiler = JitCompiler::new().unwrap();
            let result = compiler.compile(source);
            assert!(
                result.is_ok(),
                "Failed to compile FFI declarations: {:?}",
                result
            );

            // Check that extern functions were registered
            assert!(
                compiler.extern_functions.contains_key("abs"),
                "abs not declared"
            );
            assert!(
                compiler.extern_functions.contains_key("strlen"),
                "strlen not declared"
            );

            // Check abs signature
            let abs_sig = compiler.extern_functions.get("abs").unwrap();
            assert_eq!(abs_sig.params.len(), 1);
            assert_eq!(abs_sig.params[0], types::I32); // c_int -> i32
            assert_eq!(abs_sig.returns, Some(types::I32));

            // Check strlen signature
            let strlen_sig = compiler.extern_functions.get("strlen").unwrap();
            assert_eq!(strlen_sig.params.len(), 1);
            assert_eq!(strlen_sig.params[0], types::I64); // pointer -> i64
            assert_eq!(strlen_sig.returns, Some(types::I64)); // usize -> i64
        }

        #[test]
        fn test_extern_variadic_function() {
            let source = r#"
                extern "C" {
                    fn printf(fmt: *const c_char, ...) -> c_int;
                }

                fn main() -> i64 {
                    0
                }
            "#;

            let mut compiler = JitCompiler::new().unwrap();
            let result = compiler.compile(source);
            assert!(
                result.is_ok(),
                "Failed to compile variadic FFI: {:?}",
                result
            );

            let printf_sig = compiler.extern_functions.get("printf").unwrap();
            assert!(printf_sig.variadic, "printf should be variadic");
        }

        #[test]
        fn test_extern_c_abi_only() {
            let source = r#"
                extern "Rust" {
                    fn some_func(x: i32) -> i32;
                }

                fn main() -> i64 {
                    0
                }
            "#;

            let mut compiler = JitCompiler::new().unwrap();
            let result = compiler.compile(source);
            assert!(result.is_err(), "Should reject non-C ABI");
            assert!(result.unwrap_err().contains("Unsupported ABI"));
        }

        #[test]
        fn test_c_type_mapping() {
            // Test that C types are correctly mapped to Cranelift types
            let test_cases = vec![
                ("c_char", types::I8),
                ("c_int", types::I32),
                ("c_long", types::I64),
                ("c_float", types::F32),
                ("c_double", types::F64),
                ("size_t", types::I64),
                ("i32", types::I32),
                ("f64", types::F64),
            ];

            for (type_name, expected_cl_type) in test_cases {
                let source = format!(
                    r#"
                    extern "C" {{
                        fn test_func(x: {}) -> {};
                    }}

                    fn main() -> i64 {{ 0 }}
                "#,
                    type_name, type_name
                );

                let mut compiler = JitCompiler::new().unwrap();
                let result = compiler.compile(&source);
                assert!(
                    result.is_ok(),
                    "Failed for type {}: {:?}",
                    type_name,
                    result
                );

                let sig = compiler.extern_functions.get("test_func").unwrap();
                assert_eq!(
                    sig.params[0], expected_cl_type,
                    "Wrong param type for {}",
                    type_name
                );
                assert_eq!(
                    sig.returns,
                    Some(expected_cl_type),
                    "Wrong return type for {}",
                    type_name
                );
            }
        }
    }
}

// Re-export for convenience
#[cfg(feature = "jit")]
pub use jit::JitCompiler;