diff --git a/hblang/src/codegen.rs b/hblang/src/codegen.rs
index b610399..f16f560 100644
--- a/hblang/src/codegen.rs
+++ b/hblang/src/codegen.rs
@@ -2271,6 +2271,7 @@ enum Loc {
     Imm(u64),
     Stack(Rc<Stack>, u64),
 }
+
 impl Loc {
     fn take_ref(&self) -> Loc {
         match *self {
diff --git a/hblang/src/codegen2.rs b/hblang/src/codegen2.rs
new file mode 100644
index 0000000..b48ec64
--- /dev/null
+++ b/hblang/src/codegen2.rs
@@ -0,0 +1,539 @@
+#![allow(dead_code)]
+
+use std::{collections::hash_map, rc::Rc};
+
+use crate::{
+    ident::Ident,
+    parser::{self, FileId},
+    HashMap,
+};
+
+type Offset = u32;
+type Size = u32;
+
+mod stack {
+    use std::num::NonZeroU32;
+
+    use super::{Offset, Size};
+
+    pub struct Id(NonZeroU32);
+
+    impl Id {
+        fn index(&self) -> usize {
+            self.0.get() as usize - 1
+        }
+    }
+
+    impl Drop for Id {
+        fn drop(&mut self) {
+            if !std::thread::panicking() {
+                unreachable!("stack id leaked: {:?}", self.0);
+            }
+        }
+    }
+
+    #[derive(PartialEq)]
+    struct Meta {
+        size:   Size,
+        offset: Offset,
+        rc:     u32,
+    }
+
+    #[derive(Default)]
+    pub struct Alloc {
+        height:     Size,
+        max_height: Size,
+        meta:       Vec<Meta>,
+    }
+
+    impl Alloc {
+        pub fn alloc(&mut self, size: Size) -> Id {
+            self.meta.push(Meta {
+                size,
+                offset: 0,
+                rc: 1,
+            });
+
+            self.height += size;
+            self.max_height = self.max_height.max(self.height);
+
+            Id(unsafe { NonZeroU32::new_unchecked(self.meta.len() as u32) })
+        }
+
+        pub fn free(&mut self, id: Id) {
+            let meta = &mut self.meta[id.index()];
+            std::mem::forget(id);
+            meta.rc -= 1;
+            if meta.rc != 0 {
+                return;
+            }
+            meta.offset = self.height;
+            self.height -= meta.size;
+        }
+
+        pub fn dup_id(&mut self, id: &Id) -> Id {
+            self.meta[id.index()].rc += 1;
+            Id(id.0)
+        }
+
+        pub fn finalize_leaked(&mut self) {
+            for meta in self.meta.iter_mut().filter(|m| m.rc > u32::MAX / 2) {
+                meta.offset = self.height;
+                self.height -= meta.size;
+            }
+        }
+
+        pub fn clear(&mut self) {
+            self.height = 0;
+            self.max_height = 0;
+            self.meta.clear();
+        }
+
+        pub fn final_offset(&self, id: u32, extra_offset: Offset) -> Offset {
+            (self.max_height - self.meta[id as usize].offset) + extra_offset
+        }
+    }
+}
+
+mod reg {
+    pub const STACK_PTR: Reg = 254;
+    pub const ZERO: Reg = 0;
+    pub const RET_ADDR: Reg = 31;
+
+    type Reg = u8;
+
+    #[derive(Default)]
+    pub struct Id(Reg, bool);
+
+    impl Id {
+        pub fn reg(self) -> Reg {
+            self.0
+        }
+
+        pub fn as_ref(&self) -> Self {
+            Self(self.0, false)
+        }
+    }
+
+    impl Drop for Id {
+        fn drop(&mut self) {
+            if !std::thread::panicking() && self.1 {
+                unreachable!("reg id leaked: {:?}", self.0);
+            }
+        }
+    }
+
+    #[derive(Default, PartialEq, Eq)]
+    pub struct Alloc {
+        free:     Vec<Reg>,
+        max_used: Reg,
+    }
+
+    impl Alloc {
+        fn init(&mut self) {
+            self.free.clear();
+            self.free.extend((32..=253).rev());
+            self.max_used = RET_ADDR;
+        }
+
+        fn allocate(&mut self) -> Id {
+            let reg = self.free.pop().expect("TODO: we need to spill");
+            self.max_used = self.max_used.max(reg);
+            Id(reg, true)
+        }
+
+        fn free(&mut self, reg: Id) {
+            assert!(reg.1);
+            self.free.push(reg.0);
+            std::mem::forget(reg);
+        }
+
+        fn pushed_size(&self) -> usize {
+            ((self.max_used as usize).saturating_sub(RET_ADDR as usize) + 1) * 8
+        }
+    }
+}
+
+mod ty {
+    use crate::{
+        ident,
+        lexer::TokenKind,
+        parser::{self, Expr},
+    };
+
+    pub type Builtin = u32;
+    pub type Struct = u32;
+    pub type Ptr = u32;
+    pub type Func = u32;
+    pub type Global = u32;
+    pub type Module = u32;
+
+    #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Default)]
+    pub struct Id(pub u32);
+
+    impl Id {
+        pub fn is_signed(self) -> bool {
+            (I8..=INT).contains(&self.0)
+        }
+
+        pub fn is_unsigned(self) -> bool {
+            (U8..=UINT).contains(&self.0)
+        }
+
+        fn strip_pointer(self) -> Self {
+            match self.expand() {
+                Kind::Ptr(_) => Id(INT),
+                _ => self,
+            }
+        }
+
+        pub fn is_pointer(self) -> bool {
+            matches!(Kind::from_ty(self), Kind::Ptr(_))
+        }
+
+        pub fn try_upcast(self, ob: Self) -> Option<Self> {
+            let (oa, ob) = (Self(self.0.min(ob.0)), Self(self.0.max(ob.0)));
+            let (a, b) = (oa.strip_pointer(), ob.strip_pointer());
+            Some(match () {
+                _ if oa == ob => oa,
+                _ if a.is_signed() && b.is_signed() || a.is_unsigned() && b.is_unsigned() => ob,
+                _ if a.is_unsigned() && b.is_signed() && a.0 - U8 < b.0 - I8 => ob,
+                _ => return None,
+            })
+        }
+
+        pub fn expand(self) -> Kind {
+            Kind::from_ty(self)
+        }
+    }
+
+    const fn array_to_lower_case<const N: usize>(array: [u8; N]) -> [u8; N] {
+        let mut result = [0; N];
+        let mut i = 0;
+        while i < N {
+            result[i] = array[i].to_ascii_lowercase();
+            i += 1;
+        }
+        result
+    }
+    // const string to lower case
+
+    macro_rules! builtin_type {
+        ($($name:ident;)*) => {
+            $(pub const $name: Builtin = ${index(0)};)*
+
+            mod __lc_names {
+                use super::*;
+                $(pub const $name: &[u8] = &array_to_lower_case(unsafe {
+                    *(stringify!($name).as_ptr() as *const [u8; stringify!($name).len()]) });)*
+            }
+
+            pub fn from_str(name: &str) -> Option<Builtin> {
+                match name.as_bytes() {
+                    $(__lc_names::$name => Some($name),)*
+                    _ => None,
+                }
+            }
+
+            pub fn to_str(ty: Builtin) -> &'static str {
+                match ty {
+                    $(${index(0)} => unsafe { std::str::from_utf8_unchecked(__lc_names::$name) },)*
+                    v => unreachable!("invalid type: {}", v),
+                }
+            }
+        };
+    }
+
+    builtin_type! {
+        UNDECLARED;
+        NEVER;
+        VOID;
+        TYPE;
+        BOOL;
+        U8;
+        U16;
+        U32;
+        UINT;
+        I8;
+        I16;
+        I32;
+        INT;
+    }
+
+    macro_rules! type_kind {
+        ($(#[$meta:meta])* $vis:vis enum $name:ident {$( $variant:ident, )*}) => {
+            $(#[$meta])*
+            $vis enum $name {
+                $($variant($variant),)*
+            }
+
+            impl $name {
+                const FLAG_BITS: u32 = (${count($variant)} as u32).next_power_of_two().ilog2();
+                const FLAG_OFFSET: u32 = std::mem::size_of::<Id>() as u32 * 8 - Self::FLAG_BITS;
+                const INDEX_MASK: u32 = (1 << (32 - Self::FLAG_BITS)) - 1;
+
+                $vis const fn from_ty(ty: Id) -> Self {
+                    let (flag, index) = (ty.0 >> Self::FLAG_OFFSET, ty.0 & Self::INDEX_MASK);
+                    match flag {
+                        $(${index(0)} => Self::$variant(index),)*
+                        _ => unreachable!(),
+                    }
+                }
+
+                $vis const fn compress(self) -> Id {
+                    let (index, flag) = match self {
+                        $(Self::$variant(index) => (index, ${index(0)}),)*
+                    };
+                   Id((flag << Self::FLAG_OFFSET) | index)
+                }
+            }
+        };
+    }
+
+    type_kind! {
+        #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+        pub enum Kind {
+            Builtin,
+            Struct,
+            Ptr,
+            Func,
+            Global,
+            Module,
+        }
+    }
+
+    impl Default for Kind {
+        fn default() -> Self {
+            Self::Builtin(UNDECLARED)
+        }
+    }
+
+    pub struct Display<'a> {
+        tys:   &'a super::Types,
+        files: &'a [parser::Ast],
+        ty:    Id,
+    }
+
+    impl<'a> Display<'a> {
+        pub fn new(tys: &'a super::Types, files: &'a [parser::Ast], ty: Id) -> Self {
+            Self { tys, files, ty }
+        }
+
+        fn rety(&self, ty: Id) -> Self {
+            Self::new(self.tys, self.files, ty)
+        }
+    }
+
+    impl<'a> std::fmt::Display for Display<'a> {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            use Kind as TK;
+            match TK::from_ty(self.ty) {
+                TK::Module(idx) => write!(f, "module{}", idx),
+                TK::Builtin(ty) => write!(f, "{}", to_str(ty)),
+                TK::Ptr(ty) => {
+                    write!(f, "^{}", self.rety(self.tys.pointers[ty as usize].base))
+                }
+                _ if let Some((key, _)) = self
+                    .tys
+                    .symbols
+                    .iter()
+                    .find(|(sym, &ty)| sym.file != u32::MAX && ty == self.ty.0)
+                    && let Some(name) = self.files[key.file as usize].exprs().iter().find_map(
+                        |expr| match expr {
+                            Expr::BinOp {
+                                left: &Expr::Ident { name, id, .. },
+                                op: TokenKind::Decl,
+                                ..
+                            } if id == key.ident => Some(name),
+                            _ => None,
+                        },
+                    ) =>
+                {
+                    write!(f, "{name}")
+                }
+                TK::Struct(idx) => {
+                    let record = &self.tys.structs[idx as usize];
+                    write!(f, "{{")?;
+                    for (i, &super::Field { name, ty }) in record.fields.iter().enumerate() {
+                        if i != 0 {
+                            write!(f, ", ")?;
+                        }
+                        let name = &self.tys.names[ident::range(name)];
+                        write!(f, "{name}: {}", self.rety(ty))?;
+                    }
+                    write!(f, "}}")
+                }
+                TK::Func(idx) => write!(f, "fn{idx}"),
+                TK::Global(idx) => write!(f, "global{idx}"),
+            }
+        }
+    }
+}
+
+struct Reloc {
+    code_offset: Offset,
+    /// code_offset - sub_offset = instr_offset
+    sub_offset:  u8,
+    width:       u8,
+}
+
+impl Reloc {
+    fn new(code_offset: u32, sub_offset: u8, width: u8) -> Self {
+        Self {
+            code_offset,
+            sub_offset,
+            width,
+        }
+    }
+
+    fn apply_stack_offset(&self, code: &mut [u8], stack: &stack::Alloc) {
+        let bytes = &code[self.code_offset as usize..][..self.width as usize];
+        let id = u32::from_ne_bytes(bytes[..4].try_into().unwrap());
+        let extra_offset = u32::from_ne_bytes(bytes[4..].try_into().unwrap());
+        self.write_offset(code, stack.final_offset(id, extra_offset) as i64);
+    }
+
+    fn apply_jump(&self, code: &mut [u8], to: u32) {
+        let offset = to as i64 - (self.code_offset as i64 - self.sub_offset as i64);
+        self.write_offset(code, offset);
+    }
+
+    fn write_offset(&self, code: &mut [u8], offset: i64) {
+        let bytes = offset.to_ne_bytes();
+        code[self.code_offset as usize..][..self.width as usize]
+            .copy_from_slice(&bytes[..self.width as usize]);
+    }
+}
+
+struct Value {
+    ty:  ty::Id,
+    loc: Loc,
+}
+
+struct Loc {
+    reg:     reg::Id,
+    derefed: bool,
+    stack:   Option<stack::Id>,
+    offset:  Offset,
+}
+
+struct Loop {
+    var_count:  u32,
+    offset:     u32,
+    reloc_base: u32,
+}
+
+struct Variable {
+    id:    Ident,
+    value: Value,
+}
+
+#[derive(Default)]
+struct ItemCtx {
+    id:      ty::Kind,
+    ret:     ty::Id,
+    ret_reg: reg::Id,
+
+    stack: stack::Alloc,
+    regs:  reg::Alloc,
+
+    stack_relocs: Vec<Reloc>,
+    ret_relocs:   Vec<Reloc>,
+    loop_relocs:  Vec<Reloc>,
+    loops:        Vec<Loop>,
+    variables:    Vec<Variable>,
+}
+
+impl ItemCtx {
+    pub fn dup_loc(&mut self, loc: &Loc) -> Loc {
+        Loc {
+            reg:     loc.reg.as_ref(),
+            derefed: loc.derefed,
+            stack:   loc.stack.as_ref().map(|s| self.stack.dup_id(s)),
+            offset:  loc.offset,
+        }
+    }
+}
+
+#[derive(PartialEq, Eq, Hash)]
+struct SymKey {
+    file:  FileId,
+    ident: Ident,
+}
+
+struct Func {
+    offset: Offset,
+    args:   Rc<[ty::Id]>,
+    ret:    ty::Id,
+}
+
+struct Global {
+    code:   Offset,
+    offset: Offset,
+    dep:    ty::Global,
+    ty:     ty::Id,
+}
+
+struct Field {
+    name: Ident,
+    ty:   ty::Id,
+}
+
+struct Struct {
+    fields: Rc<[Field]>,
+    ast:    parser::ExprRef,
+}
+
+struct Ptr {
+    base: ty::Id,
+}
+
+#[derive(Default)]
+struct Types {
+    symbols: HashMap<SymKey, u32>,
+    names:   String,
+
+    funcs:    Vec<Func>,
+    globals:  Vec<Global>,
+    structs:  Vec<Struct>,
+    pointers: Vec<Ptr>,
+}
+
+impl Types {
+    pub fn make_ptr(&mut self, base: ty::Id) -> ty::Ptr {
+        let id = SymKey {
+            file:  u32::MAX,
+            ident: base.0,
+        };
+
+        match self.symbols.entry(id) {
+            hash_map::Entry::Occupied(occ) => *occ.get(),
+            hash_map::Entry::Vacant(vac) => {
+                self.pointers.push(Ptr { base });
+                *vac.insert(self.pointers.len() as u32 - 1)
+            }
+        }
+    }
+}
+
+#[derive(Default)]
+struct Output {
+    code: Vec<u8>,
+    func_relocs: Vec<(ty::Func, Reloc)>,
+    global_relocs: Vec<(ty::Global, Reloc)>,
+    tasks: Vec<ty::Func>,
+}
+
+#[derive(Default)]
+pub struct Codegen {
+    pub files: Vec<parser::Ast>,
+    tys:       Types,
+    ci:        ItemCtx,
+    output:    Output,
+}
+
+impl Codegen {
+    fn ty_display(&self, ty: ty::Id) -> ty::Display {
+        ty::Display::new(&self.tys, &self.files, ty)
+    }
+}
diff --git a/hblang/src/lib.rs b/hblang/src/lib.rs
index 0abc4db..ec81f13 100644
--- a/hblang/src/lib.rs
+++ b/hblang/src/lib.rs
@@ -32,6 +32,7 @@ macro_rules! run_tests {
 }
 
 pub mod codegen;
+pub mod codegen2;
 mod ident;
 mod instrs;
 mod lexer;