WORKING ASM FUNCTION CALLS

src/compiler/elf.rs

@@ -48,6 +48,7 @@ pub struct SectionHeader {
     entry_size: u64,
 }
 
+// this is currently specialized for riscv64; obviously add params later
 pub fn create(program: Vec<u8>, start_offset: u64) -> Vec<u8> {
     let addr_start = 0x1000;
     let page_size = 0x1000;

src/compiler/mod.rs

@@ -5,13 +5,14 @@ use std::{
     process::Command,
 };
 
-mod riscv64;
+mod elf;
 mod program;
+mod riscv64;
 mod target;
 
 pub fn main() {
     use std::io::prelude::*;
-    let dir = Path::new("build");
+    let dir = Path::new("./build");
     create_dir_all(dir).expect("Failed to create or confirm build directory");
     let name = Path::new("test");
     let path = dir.join(name);
@@ -26,9 +27,35 @@ pub fn main() {
     file.write_all(&riscv64::gen())
         .expect("Failed to write to file");
     file.sync_all().expect("Failed to sync file");
-    if let Ok(mut process) = Command::new("qemu-riscv64").arg(path).spawn() {
+    let mut p = Command::new("qemu-riscv64");
+    let run_gdb = std::env::args().nth(1).is_some_and(|a| a == "d");
+    let proc = if run_gdb {
+        p.arg("-g").arg("1234").arg(path).spawn()
+    } else {
+        p.arg(path).spawn()
+    };
+    if let Ok(mut process) = proc {
+        let mut print_exit = true;
+        if run_gdb {
+            match Command::new("gdb")
+                .arg("-q")
+                .arg("-ex")
+                .arg("target remote :1234")
+                .arg(path)
+                .spawn()
+            {
+                Ok(mut gdb) => {
+                    gdb.wait().expect("xd");
+                }
+                Err(e) => {
+                    print_exit = false;
+                    println!("gdb error: {e:?}");
+                    process.kill().expect("uh oh");
+                }
+            }
+        }
         if let Ok(status) = process.wait() {
-            if status.code().is_none_or(|c| c != 0) {
+            if print_exit && status.code().is_none_or(|c| c != 0) {
                 println!("{}", status);
             }
         }
@@ -39,4 +66,3 @@ pub fn main() {
 //     riscv64-linux-gnu-gdb -q \
 //         -ex "target remote :1234" \
 //         test
-

src/compiler/program.rs

@@ -1,53 +1,35 @@
 use std::collections::HashMap;
 
-pub struct Program {
-    data: Vec<u8>,
-    ro_map: HashMap<String, usize>,
-}
-
-impl Program {
-    pub fn new(data: HashMap<String, Vec<u8>>) -> Self {
-        let mut ro_data = Vec::new();
-        let mut ro_map = HashMap::new();
-        for (key, val) in data {
-            ro_map.insert(key, ro_data.len());
-            ro_data.extend(val);
-        }
-        Self {
-            data: ro_data,
-            ro_map,
-        }
-    }
-}
-
 pub fn create_program<I: Instr>(
     ro_data: HashMap<String, Vec<u8>>,
     functions: Vec<Function<I>>,
-) -> Vec<u8> {
+) -> (Vec<u8>, Option<u64>) {
     let mut data = Vec::new();
-    let mut ro_map = HashMap::new();
+    let mut sym_map = HashMap::new();
     for (key, val) in ro_data {
-        ro_map.insert(key, data.len());
+        sym_map.insert(key, data.len() as u64);
         data.extend(val);
     }
-    // let mut fn_map = HashMap::new();
+    let mut start = None;
     for fun in functions {
+        if fun.label == "_start" {
+            start = Some(data.len() as u64);
+        }
+        sym_map.insert(fun.label, data.len() as u64);
         for i in fun.instructions {
-            data.extend(i.to_le_bytes());
+            let pos = data.len() as u64;
+            i.push(&mut data, &sym_map, pos);
         }
     }
-    data
+    (data, start)
 }
 
 pub struct Function<I: Instr> {
-    label: String,
+    pub label: String,
-    instructions: Vec<I>,
+    pub instructions: Vec<I>,
 }
 
 pub trait Instr {
-    fn to_le_bytes(&self) -> impl IntoIterator<Item = u8>;
+    fn push(&self, data: &mut Vec<u8>, ro_map: &HashMap<String, u64>, pos: u64) -> Option<String>;
 }
 
-struct SymbolInstr {
-    i: usize
-}

src/compiler/riscv64/asm.rs

@@ -1,2 +1,57 @@
-pub enum Instruction {
+use crate::compiler::program::Instr;
+
+use super::*;
+
+pub enum AsmInstruction {
+    Addi(Reg, Reg, i32),
+    La(Reg, String),
+    Jal(Reg, i32),
+    Jala(String),
+    Ja(String),
+    Ret,
+    Ecall,
+}
+
+impl Instr for AsmInstruction {
+    fn push(
+        &self,
+        data: &mut Vec<u8>,
+        sym_map: &std::collections::HashMap<String, u64>,
+        pos: u64,
+    ) -> Option<String> {
+        match self {
+            Self::Addi(dest, src, imm) => {
+                data.extend(addi(*dest, *src, BitsI32::new(*imm)).to_le_bytes());
+            }
+            Self::La(dest, sym) => {
+                if let Some(addr) = sym_map.get(sym) {
+                    let offset = *addr as i32 - pos as i32;
+                    data.extend(auipc(*dest, BitsI32::new(0)).to_le_bytes());
+                    data.extend(addi(*dest, *dest, BitsI32::new(offset)).to_le_bytes());
+                } else {
+                    return Some(sym.to_string());
+                }
+            }
+            Self::Jal(dest, offset) => data.extend(jal(*dest, BitsI32::new(*offset)).to_le_bytes()),
+            Self::Ja(sym) => {
+                if let Some(addr) = sym_map.get(sym) {
+                    let offset = *addr as i32 - pos as i32;
+                    data.extend(j(BitsI32::new(offset)).to_le_bytes());
+                } else {
+                    return Some(sym.to_string());
+                }
+            }
+            Self::Jala(sym) => {
+                if let Some(addr) = sym_map.get(sym) {
+                    let offset = *addr as i32 - pos as i32;
+                    data.extend(jal(ra, BitsI32::new(offset)).to_le_bytes());
+                } else {
+                    return Some(sym.to_string());
+                }
+            }
+            Self::Ret => data.extend(ret().to_le_bytes()),
+            Self::Ecall => data.extend(ecall().to_le_bytes()),
+        }
+        None
+    }
 }

src/compiler/riscv64/base.rs

@@ -0,0 +1,78 @@
+use crate::util::Bits32;
+
+use super::Reg;
+
+pub struct Instruction(u32);
+
+use Instruction as I;
+
+impl Instruction {
+    pub fn to_le_bytes(&self) -> impl IntoIterator<Item = u8> {
+        self.0.to_le_bytes().into_iter()
+    }
+    pub fn to_be_bytes(&self) -> impl IntoIterator<Item = u8> {
+        self.0.to_be_bytes().into_iter()
+    }
+}
+
+pub type Funct3 = Bits32<2, 0>;
+
+pub const fn r_type(
+    funct7: u32,
+    rs2: Reg,
+    rs1: Reg,
+    funct3: Bits32<2, 0>,
+    rd: Reg,
+    opcode: u32,
+) -> I {
+    I((funct7 << 25)
+        + (rs2.val() << 20)
+        + (rs1.val() << 15)
+        + (funct3.val() << 12)
+        + (rd.val() << 7)
+        + opcode)
+}
+pub const fn i_type(imm: Bits32<11, 0>, rs1: Reg, funct: Funct3, rd: Reg, opcode: u32) -> I {
+    I((imm.val() << 20) + (rs1.val() << 15) + (funct.val() << 12) + (rd.val() << 7) + opcode)
+}
+pub const fn s_type(
+    rs2: Reg,
+    rs1: Reg,
+    funct3: Funct3,
+    imm: Bits32<11, 0>,
+    opcode: u32,
+) -> I {
+    I((imm.bits(11, 5) << 25)
+        + (rs2.val() << 20)
+        + (rs1.val() << 15)
+        + (funct3.val() << 12)
+        + (imm.bits(4, 0) << 7)
+        + opcode)
+}
+pub const fn b_type(
+    rs2: Reg,
+    rs1: Reg,
+    funct3: Funct3,
+    imm: Bits32<12, 1>,
+    opcode: u32,
+) -> I {
+    I((imm.bit(12) << 31)
+        + (imm.bits(10, 5) << 25)
+        + (rs2.val() << 20)
+        + (rs1.val() << 15)
+        + (funct3.val() << 8)
+        + (imm.bits(4, 1) << 8)
+        + (imm.bit(11) << 7)
+        + opcode)
+}
+pub const fn u_type(imm: Bits32<31, 12>, rd: Reg, opcode: u32) -> I {
+    I((imm.bits(31, 12) << 12) + (rd.val() << 7) + opcode)
+}
+pub const fn j_type(imm: Bits32<20, 1>, rd: Reg, opcode: u32) -> I {
+    I((imm.bit(20) << 31)
+        + (imm.bits(10, 1) << 21)
+        + (imm.bit(11) << 20)
+        + (imm.bits(19, 12) << 12)
+        + (rd.val() << 7)
+        + opcode)
+}

src/compiler/riscv64/funct.rs

@@ -0,0 +1,24 @@
+use super::Funct3;
+
+pub mod op {
+    use super::*;
+    pub const ADD : Funct3 = Funct3::new(0b000);
+    pub const SLL : Funct3 = Funct3::new(0b001);
+    pub const SLT : Funct3 = Funct3::new(0b010);
+    pub const SLTU: Funct3 = Funct3::new(0b011);
+    pub const XOR : Funct3 = Funct3::new(0b100);
+    pub const SR  : Funct3 = Funct3::new(0b101);
+    pub const OR  : Funct3 = Funct3::new(0b110);
+    pub const AND : Funct3 = Funct3::new(0b111);
+}
+
+pub mod width {
+    use super::*;
+    pub const B : Funct3 = Funct3::new(0b000);
+    pub const H : Funct3 = Funct3::new(0b001);
+    pub const W : Funct3 = Funct3::new(0b010);
+    pub const D : Funct3 = Funct3::new(0b011);
+    pub const BU: Funct3 = Funct3::new(0b100);
+    pub const HU: Funct3 = Funct3::new(0b101);
+    pub const WU: Funct3 = Funct3::new(0b110);
+}

src/compiler/riscv64/instruction/base.rs

@@ -1,58 +0,0 @@
-use super::{Reg, OPCODE_MASK};
-use crate::{compiler::program::Instr, util::{bit, bits, in_bit_range}};
-
-pub struct Instruction(u32);
-
-use Instruction as I;
-
-impl Instr for Instruction {
-    fn to_le_bytes(&self) -> impl IntoIterator<Item = u8> {
-        self.0.to_le_bytes().into_iter()
-    }
-}
-
-pub const fn r_type(funct7: u32, rs2: Reg, rs1: Reg, funct3: u32, rd: Reg, opcode: u32) -> I {
-    I((funct7 << 25)
-        + (rs2.val() << 20)
-        + (rs1.val() << 15)
-        + (funct3 << 12)
-        + (rd.val() << 7)
-        + opcode)
-}
-pub const fn i_type(imm: i32, rs1: Reg, funct3: u32, rd: Reg, opcode: u32) -> I {
-    debug_assert!(in_bit_range(imm, 11, 0));
-    I((bits(imm, 11, 0) << 20) + (rs1.val() << 15) + (funct3 << 12) + (rd.val() << 7) + opcode)
-}
-pub const fn s_type(rs2: Reg, rs1: Reg, funct3: u32, imm: i32, opcode: u32) -> I {
-    debug_assert!(in_bit_range(imm, 11, 0));
-    I((bits(imm, 11, 5) << 25)
-        + (rs2.val() << 20)
-        + (rs1.val() << 15)
-        + (funct3 << 12)
-        + (bits(imm, 4, 0) << 7)
-        + opcode)
-}
-pub const fn b_type(rs2: Reg, rs1: Reg, funct3: u32, imm: i32, opcode: u32) -> I {
-    debug_assert!(in_bit_range(imm, 12, 1));
-    I((bit(imm, 12) << 31)
-        + (bits(imm, 10, 5) << 25)
-        + (rs2.val() << 20)
-        + (rs1.val() << 15)
-        + (funct3 << 8)
-        + (bits(imm, 4, 1) << 8)
-        + (bit(imm, 11) << 7)
-        + opcode)
-}
-pub const fn u_type(imm: i32, rd: Reg, opcode: u32) -> I {
-    debug_assert!(in_bit_range(imm, 31, 12));
-    I((bits(imm, 31, 12) << 12) + (rd.val() << 7) + opcode)
-}
-pub const fn j_type(imm: i32, rd: Reg, opcode: u32) -> I {
-    debug_assert!(in_bit_range(imm, 20, 1));
-    I((bit(imm, 20) << 31)
-        + (bits(imm, 10, 1) << 21)
-        + (bit(imm, 11) << 20)
-        + (bits(imm, 19, 12) << 12)
-        + (rd.val() << 7)
-        + opcode)
-}

src/compiler/riscv64/instruction/func.rs

@@ -1,20 +0,0 @@
-pub mod op {
-    pub const ADD : u32 = 0b000;
-    pub const SLL : u32 = 0b001;
-    pub const SLT : u32 = 0b010;
-    pub const SLTU: u32 = 0b011;
-    pub const XOR : u32 = 0b100;
-    pub const SR  : u32 = 0b101;
-    pub const OR  : u32 = 0b110;
-    pub const AND : u32 = 0b111;
-}
-
-pub mod width {
-    pub const B : u32 = 0b000;
-    pub const H : u32 = 0b001;
-    pub const W : u32 = 0b010;
-    pub const D : u32 = 0b011;
-    pub const BU: u32 = 0b100;
-    pub const HU: u32 = 0b101;
-    pub const WU: u32 = 0b110;
-}

src/compiler/riscv64/instruction/mod.rs

@@ -1,53 +0,0 @@
-mod base;
-mod reg;
-mod opcode;
-mod func;
-
-use base::*;
-pub use reg::*;
-use Instruction as I;
-use opcode::*;
-use func::{op::*, width};
-
-pub const fn ecall() -> I {
-    i_type(0, zero, 0, zero, SYSTEM)
-}
-pub const fn ebreak() -> I {
-    i_type(1, zero, 0, zero, SYSTEM)
-}
-pub const fn auipc(dest: Reg, imm: i32) -> I {
-    u_type(imm, dest, AUIPC)
-}
-pub const fn ld(dest: Reg, offset: i32, base: Reg) -> I {
-    i_type(offset, base, width::D, dest, LOAD)
-}
-pub const fn lw(dest: Reg, offset: i32, base: Reg) -> I {
-    i_type(offset, base, width::W, dest, LOAD)
-}
-pub const fn lb(dest: Reg, offset: i32, base: Reg) -> I {
-    i_type(offset, base, width::B, dest, LOAD)
-}
-pub const fn sb(src: Reg, offset: i32, base: Reg) -> I {
-    s_type(src, base, width::B, offset, STORE)
-}
-pub const fn sw(src: Reg, offset: i32, base: Reg) -> I {
-    s_type(src, base, width::W, offset, STORE)
-}
-pub const fn sd(src: Reg, offset: i32, base: Reg) -> I {
-    s_type(src, base, width::D, offset, STORE)
-}
-pub const fn addi(dest: Reg, src: Reg, imm: i32) -> I {
-    i_type(imm, src, ADD, dest, IMM_OP)
-}
-pub const fn jal(offset: i32, dest: Reg) -> I {
-    j_type(offset, dest, JAL)
-}
-
-// pseudo instructions that map to a single instruction
-
-pub const fn j(offset: i32) -> I {
-    jal(offset, zero)
-}
-pub const fn mv(dest: Reg, src: Reg) -> I {
-    addi(dest, src, 0)
-}

src/compiler/riscv64/mod.rs

@@ -1,33 +1,81 @@
-use crate::compiler::program::Instr;
-mod elf;
-mod instruction;
 mod asm;
+mod base;
+mod funct;
+mod opcode;
+mod reg;
+mod single;
 
-use instruction::*;
+use std::collections::HashMap;
+
+use super::{elf, program::{create_program, Function}};
+use crate::util::BitsI32;
+use base::*;
+use funct::{op::*, width};
+use opcode::*;
+pub use reg::*;
+
+use single::*;
 
 pub fn gen() -> Vec<u8> {
-    let mut program = Vec::new();
+    use asm::AsmInstruction as I;
+    // let mut program = Vec::new();
+    // let msg = b"Hello world!\n";
+    // program.extend(msg);
+    // program.resize(((program.len() - 1) / 4 + 1) * 4, 0);
+    // let start = program.len() as u64;
+    // let instructions = [
+    //     auipc(t0, BitsI32::new(0)),
+    //     addi(t0, t0, BitsI32::new(-(start as i32))),
+    //     addi(a0, zero, BitsI32::new(1)),
+    //     mv(a1, t0),
+    //     addi(a2, zero, BitsI32::new(msg.len() as i32)),
+    //     addi(a7, zero, BitsI32::new(64)),
+    //     addi(t0, zero, const { BitsI32::new(-10) }),
+    //     ecall(),
+    //     // exit
+    //     addi(a0, zero, BitsI32::new(0)),
+    //     addi(a7, zero, BitsI32::new(93)),
+    //     ecall(),
+    //     j(BitsI32::new(0)),
+    // ];
+    // for i in instructions {
+    //     program.extend(i.to_le_bytes());
+    // }
     let msg = b"Hello world!\n";
-    program.extend(msg);
+    let msg2 = b"IT WORKS!!!!\n";
-    program.resize(((program.len() - 1) / 4 + 1) * 4, 0);
+    let ro_data = HashMap::from([
-    let start = program.len() as u64;
+        ("msg".to_string(), msg.to_vec()),
-    let instructions = [
+        ("msg2".to_string(), msg2.to_vec()),
-        auipc(t0, 0),
+    ]);
-        addi(t0, t0, -(start as i32)),
+    let functions = vec![
-        addi(a0, zero, 1),
+        Function {
-        mv(a1, t0),
+            label: "print_stuff".to_string(),
-        addi(a2, zero, msg.len() as i32),
+            instructions: vec![
-        addi(a7, zero, 64),
+                I::Addi(a0, zero, 1),
-        addi(t0, zero, 200),
+                I::La(a1, "msg".to_string()),
-        ecall(),
+                I::Addi(a2, zero, msg.len() as i32),
-        // exit
+                I::Addi(a7, zero, 64),
-        addi(a0, zero, 0),
+                I::Ecall,
-        addi(a7, zero, 93),
+                I::Addi(a0, zero, 1),
-        ecall(),
+                I::La(a1, "msg2".to_string()),
-        j(0),
+                I::Addi(a2, zero, msg2.len() as i32),
+                I::Addi(a7, zero, 64),
+                I::Ecall,
+                I::Ret,
+            ]
+        },
+        Function {
+            label: "_start".to_string(),
+            instructions: vec![
+                I::Jala("print_stuff".to_string()),
+                I::Ecall,
+                I::Addi(a0, zero, 0),
+                I::Addi(a7, zero, 93),
+                I::Ecall,
+                I::Jal(zero, 0),
+            ]
+        },
     ];
-    for i in instructions {
+    let (program, start) = create_program(ro_data, functions);
-        program.extend(i.to_le_bytes());
+    elf::create(program, start.expect("no start!"))
-    }
-    elf::create(program, start)
 }

src/compiler/riscv64/opcode.rs

@@ -7,3 +7,4 @@ pub const AUIPC : u32 = 0b0010111;
 pub const IMM_OP: u32 = 0b0010011;
 pub const OP    : u32 = 0b0110011;
 pub const JAL   : u32 = 0b1101111;
+pub const JALR  : u32 = 0b1100111;

src/compiler/riscv64/reg.rs

@@ -1,5 +1,6 @@
 #![allow(non_upper_case_globals)]
 
+#[derive(Debug, Clone, Copy)]
 pub struct Reg(u8);
 
 /// hard wired 0

src/compiler/riscv64/single.rs

@@ -0,0 +1,51 @@
+use crate::util::{Bits32, BitsI32};
+
+use super::*;
+
+use Instruction as I;
+
+pub const fn ecall() -> I {
+    i_type(Bits32::new(0), zero, Bits32::new(0), zero, SYSTEM)
+}
+pub const fn ebreak() -> I {
+    i_type(Bits32::new(1), zero, Bits32::new(0), zero, SYSTEM)
+}
+pub const fn auipc(dest: Reg, imm: BitsI32<31, 12>) -> I {
+    u_type(imm.to_u(), dest, AUIPC)
+}
+pub const fn ld(dest: Reg, offset: BitsI32<11, 0>, base: Reg) -> I {
+    i_type(offset.to_u(), base, width::D, dest, LOAD)
+}
+pub const fn lw(dest: Reg, offset: BitsI32<11, 0>, base: Reg) -> I {
+    i_type(offset.to_u(), base, width::W, dest, LOAD)
+}
+pub const fn lb(dest: Reg, offset: BitsI32<11, 0>, base: Reg) -> I {
+    i_type(offset.to_u(), base, width::B, dest, LOAD)
+}
+pub const fn sb(src: Reg, offset: BitsI32<11, 0>, base: Reg) -> I {
+    s_type(src, base, width::B, offset.to_u(), STORE)
+}
+pub const fn sw(src: Reg, offset: BitsI32<11, 0>, base: Reg) -> I {
+    s_type(src, base, width::W, offset.to_u(), STORE)
+}
+pub const fn sd(src: Reg, offset: BitsI32<11, 0>, base: Reg) -> I {
+    s_type(src, base, width::D, offset.to_u(), STORE)
+}
+pub const fn addi(dest: Reg, src: Reg, imm: BitsI32<11, 0>) -> I {
+    i_type(imm.to_u(), src, ADD, dest, IMM_OP)
+}
+pub const fn jal(dest: Reg, offset: BitsI32<20, 1>) -> I {
+    j_type(offset.to_u(), dest, JAL)
+}
+pub const fn jalr(dest: Reg, offset: BitsI32<11, 0>, base: Reg) -> I {
+    i_type(offset.to_u(), base, Bits32::new(0), dest, JALR)
+}
+
+// pseudoinstructions that map to a single instruction
+
+pub const fn j(offset: BitsI32<20, 1>) -> I {
+    jal(zero, offset)
+}
+pub const fn ret() -> I {
+    jalr(zero, BitsI32::new(0), ra)
+}

src/util/bits.rs

@@ -2,74 +2,59 @@ pub const fn u(x: i32) -> u32 {
     unsafe { std::mem::transmute(x) }
 }
 
-pub const fn low_mask(high: u32, low: u32) -> u32 {
+pub const fn base_mask(len: u8) -> u32 {
-    (2u32.unbounded_shl(high - low)).wrapping_sub(1)
+    (2 << len) - 1
 }
 
-pub const fn mask(high: u32, low: u32) -> u32 {
+pub const fn mask(h: u8, l: u8) -> u32 {
-    low_mask(high, low).unbounded_shl(low)
+    base_mask(h - l) << l
 }
 
-pub const fn bits(x: i32, high: u32, low: u32) -> u32 {
+#[derive(Debug, Clone, Copy)]
-    let x = u(x);
+pub struct Bits32<const H: u8, const L: u8>(u32);
-    x.unbounded_shr(low) & low_mask(high, low)
+#[derive(Debug, Clone, Copy)]
+pub struct BitsI32<const H: u8, const L: u8>(u32);
+
+impl<const H: u8, const L: u8> Bits32<H, L> {
+    pub const fn new(val: u32) -> Self {
+        let lsh = 31 - H;
+        let rsh = lsh + L;
+        debug_assert!(((val << lsh) >> rsh) == (val >> L));
+        Self(val)
+    }
+    pub const fn val(&self) -> u32 {
+        self.0
+    }
+    pub const fn bit(&self, i: u8) -> u32 {
+        (self.0 >> i) & 1
+    }
+    pub const fn bits(&self, h: u8, l: u8) -> u32 {
+        (self.0 >> l) & base_mask(h - l)
+    }
 }
 
-pub const fn bit(x: i32, i: u32) -> u32 {
+impl<const H: u8, const L: u8> BitsI32<H, L> {
-    let x = u(x);
+    pub const fn new(val: i32) -> Self {
-    x.unbounded_shr(i) & 2u32 << i
+        let lsh = 31 - H;
+        let rsh = lsh + L;
+        assert!(((val << lsh) >> rsh) == (val >> L));
+        Self(u(val) & mask(H, L))
     }
-
+    pub const fn tryy(val: i32) -> Option<Self> {
-pub const fn in_bit_range(x: i32, high: u32, low: u32) -> bool {
+        let lsh = 31 - H;
-    if x < 0 {
+        let rsh = lsh + L;
-        if high == low {
+        if ((val << lsh) >> rsh) == (val >> L) {
-            return false;
+            Some(Self(u(val) & mask(H, L)))
-        }
-        (bits(x, high - 1, low) | !mask(high - 1, low)) == u(x)
         } else {
-        bits(x, high, low) << low == u(x)
+            None
+        }
+    }
+    pub const fn to_u(self) -> Bits32<H, L> {
+        Bits32(self.0)
     }
 }
 
-// use std::ops::{Add, Shl, Shr};
+// I hate (love) rust https://github.com/rust-lang/rust-project-goals/issues/106
-//
-// pub const fn u(x: i32) -> u32 {
-//     unsafe { std::mem::transmute(x) }
-// }
-//
-// pub const fn low_mask(high: u8, low: u8) -> u32 {
-//     (2u32.unbounded_shl(high - low)).wrapping_sub(1)
-// }
-//
-// pub const fn mask(high: u8, low: u8) -> u32 {
-//     low_mask(high, low).unbounded_shl(low)
-// }
-//
-// pub const fn bits(x: i32, high: u8, low: u8) -> u32 {
-//     let x = u(x);
-//     x.unbounded_shr(low) & low_mask(high, low)
-// }
-//
-// pub const fn bit(x: i32, i: u32) -> u32 {
-//     let x = u(x);
-//     x.unbounded_shr(i) & 2u32 << i
-// }
-//
-// pub const fn in_bit_range<T: Shl<u8, Output = T> + Shr<u8, Output = T>>(
-//     x: T,
-//     high: u8,
-//     low: u8,
-// ) -> bool {
-//     if x < 0 {
-//         if high == low {
-//             return false;
-//         }
-//         (bits(x, high - 1, low) | !mask(high - 1, low)) == u(x)
-//     } else {
-//         bits(x, high, low) << low == u(x)
-//     }
-// }
-
 // pub struct Bits<
 //     T: Shl<u8, Output = T> + Shr<u8, Output = T>,
 //     const S: bool,
@@ -78,7 +63,7 @@ pub const fn in_bit_range(x: i32, high: u32, low: u32) -> bool {
 // >(T);
 // pub struct U32Bits<const H: u32, const L: u32>(u32);
 //
-// impl<T: Shl<u8, Output = T> + Shr<u8, Output = T> + Add<u8, Output = T>, const S: bool, const H: u8, const L: u8>
+// impl<T: const Shl<u8, Output = T> + const Shr<u8, Output = T>, const S: bool, const H: u8, const L: u8>
 //     Bits<T, S, H, L>
 // {
 //     pub const fn new(val: T) -> Self {
@@ -86,35 +71,3 @@ pub const fn in_bit_range(x: i32, high: u32, low: u32) -> bool {
 //         Self(val + L)
 //     }
 // }
-
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn get_bits() {
-        assert_eq!(bits(0b10111010, 5, 3), 0b111);
-        assert_eq!(bits(0b10111010, 7, 5), 0b101);
-        assert_eq!(bits(0b10111010, 2, 0), 0b010);
-        assert_eq!(bits(0b10111010, 7, 7), 0b1);
-        assert_eq!(bits(0b1, 0, 0), 0b1);
-        assert_eq!(bits(0b1, 1, 1), 0b0);
-    }
-
-    #[test]
-    fn range() {
-        assert!(!in_bit_range(0b00111100, 5, 3));
-        assert!(!in_bit_range(0b00111100, 4, 2));
-        assert!(in_bit_range(0b000111100, 5, 2));
-        assert!(in_bit_range(0b000000001, 0, 0));
-        assert!(in_bit_range(0b000001000, 3, 3));
-
-        assert!(!in_bit_range(-3, 1, 0));
-        assert!(!in_bit_range(-5, 2, 2));
-        assert!(!in_bit_range(-5, 4, 3));
-        assert!(in_bit_range(-1, 1, 0));
-        assert!(in_bit_range(-4, 2, 0));
-        assert!(in_bit_range(-5, 3, 2));
-    }
-}