In the beginning was Word

This commit is contained in:
Will Glynn
2022-02-22 18:27:48 -06:00
committed by Ross Andrews
parent 9ea478d6f4
commit 1540cc2e9d
5 changed files with 415 additions and 161 deletions
+5 -4
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@@ -61,6 +61,7 @@ impl<A: Device, B: Device> Device for Bus<A, B> {
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use super::*; use super::*;
use crate::memory::PeekPokeExt;
struct TestDevice(i32); struct TestDevice(i32);
impl Device for TestDevice { impl Device for TestDevice {
@@ -111,8 +112,8 @@ mod tests {
#[test] #[test]
fn test_poke_peek() { fn test_poke_peek() {
let mut bus = Bus::new(5, 10, ArrayDevice([0u8; 10]), ArrayDevice([0u8; 10])); let mut bus = Bus::new(5, 10, ArrayDevice([0u8; 10]), ArrayDevice([0u8; 10]));
bus.poke_u32(2, 2); // Goes into the 2nd device bus.poke8(2, 2); // Goes into the 2nd device
bus.poke_u32(6, 6); // Goes into the first device... bus.poke8(6, 6); // Goes into the first device...
assert_eq!(bus.device.0[1], 6); // At index 1 assert_eq!(bus.device.0[1], 6); // At index 1
assert_eq!(bus.rest.0[2], 2); // Second device gets the other write assert_eq!(bus.rest.0[2], 2); // Second device gets the other write
@@ -120,7 +121,7 @@ mod tests {
assert_eq!(bus.device.0[2], 0); assert_eq!(bus.device.0[2], 0);
assert_eq!(bus.rest.0[1], 0); assert_eq!(bus.rest.0[1], 0);
assert_eq!(bus.peek_u32(2), 2); // Reading from the first device assert_eq!(bus.peek8(2), 2); // Reading from the first device
assert_eq!(bus.peek_u32(6), 6); // And the second assert_eq!(bus.peek8(6), 6); // And the second
} }
} }
+46 -62
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@@ -1,5 +1,5 @@
use crate::memory::Memory;
use crate::memory::PeekPoke; use crate::memory::PeekPoke;
use crate::memory::{Memory, PeekPokeExt};
use crate::opcodes::InvalidOpcode; use crate::opcodes::InvalidOpcode;
use crate::opcodes::Opcode; use crate::opcodes::Opcode;
use crate::word::Word; use crate::word::Word;
@@ -19,7 +19,7 @@ pub struct CPU {
#[derive(Copy, Clone, Eq, PartialEq, Debug)] #[derive(Copy, Clone, Eq, PartialEq, Debug)]
struct Instruction { struct Instruction {
opcode: Opcode, opcode: Opcode,
arg: Option<u32>, arg: Option<Word>,
length: u8, length: u8,
} }
@@ -54,32 +54,32 @@ impl CPU {
self.halted = true; self.halted = true;
} }
fn push_data<A: Into<u32>>(&mut self, word: A) { fn push_data<A: Into<Word>>(&mut self, word: A) {
self.memory.poke24(self.dp, word.into()); self.memory.poke24(self.dp, word);
self.dp += 3; self.dp += 3;
} }
fn push_call<A: Into<u32>>(&mut self, word: A) { fn push_call<A: Into<Word>>(&mut self, word: A) {
self.sp -= 3; self.sp -= 3;
self.memory.poke24(self.sp, word.into()); self.memory.poke24(self.sp, word);
} }
fn pop_data(&mut self) -> u32 { fn pop_data(&mut self) -> Word {
self.dp -= 3; self.dp -= 3;
self.memory.peek24(self.dp) self.memory.peek24(self.dp)
} }
fn pop_call(&mut self) -> u32 { fn pop_call(&mut self) -> Word {
let val = self.memory.peek24(self.sp); let val = self.memory.peek24(self.sp);
self.sp += 3; self.sp += 3;
val val
} }
fn peek_call(&self) -> u32 { fn peek_call(&self) -> Word {
self.memory.peek24(self.sp) self.memory.peek24(self.sp)
} }
fn peek_data(&self) -> u32 { fn peek_data(&self) -> Word {
self.memory.peek24(self.dp - 3) self.memory.peek24(self.dp - 3)
} }
@@ -103,7 +103,7 @@ impl CPU {
} }
Ok(Instruction { Ok(Instruction {
opcode, opcode,
arg: Some(arg), arg: Some(Word::from(arg)),
length: arg_length + 1, length: arg_length + 1,
}) })
} }
@@ -130,16 +130,16 @@ impl CPU {
Opcode::And => self.push_data(y & x), Opcode::And => self.push_data(y & x),
Opcode::Or => self.push_data(y | x), Opcode::Or => self.push_data(y | x),
Opcode::Xor => self.push_data(y ^ x), Opcode::Xor => self.push_data(y ^ x),
Opcode::Gt => self.push_data(bool_as_word(y > x)), Opcode::Gt => self.push_data(y > x),
Opcode::Lt => self.push_data(bool_as_word(y < x)), Opcode::Lt => self.push_data(y < x),
Opcode::Agt => self.push_data(bool_as_word(word_as_signed(y) > word_as_signed(x))), Opcode::Agt => self.push_data(i32::from(y) > i32::from(x)),
Opcode::Alt => self.push_data(bool_as_word(word_as_signed(y) < word_as_signed(x))), Opcode::Alt => self.push_data(i32::from(y) < i32::from(x)),
Opcode::Lshift => self.push_data(y << x), Opcode::Lshift => self.push_data(y << x),
Opcode::Rshift => self.push_data(y >> x), Opcode::Rshift => self.push_data(y >> x),
Opcode::Arshift => { Opcode::Arshift => {
if y & 0x800000 != 0 { if y & 0x800000 != 0 {
let mut shifted = y; let mut shifted = y;
for _ in 0..x { for _ in 0..u32::from(x).clamp(0, 24) {
shifted = shifted >> 1 | 0x800000; shifted = shifted >> 1 | 0x800000;
} }
self.push_data(shifted) self.push_data(shifted)
@@ -151,23 +151,23 @@ impl CPU {
self.push_data(x); self.push_data(x);
self.push_data(y) self.push_data(y)
} }
Opcode::Store => self.memory.poke(x.into(), y as u8), Opcode::Store => self.memory.poke8(x, y.to_bytes()[0]),
Opcode::Storew => self.memory.poke24(x.into(), y), Opcode::Storew => self.memory.poke24(x, y),
Opcode::Setsdp => { Opcode::Setsdp => {
self.dp = x.into(); self.dp = x.into();
self.sp = y.into() self.sp = y.into()
} }
Opcode::Brz => { Opcode::Brz => {
if y == 0 { if y == 0 {
return self.pc + word_as_signed(x); return self.pc + i32::from(x);
} }
} }
Opcode::Brnz => { Opcode::Brnz => {
if y != 0 { if y != 0 {
return self.pc + word_as_signed(x); return self.pc + i32::from(x);
} }
} }
_ => {} // This can never happen _ => unreachable!(),
} }
self.pc + instruction.length as i32 self.pc + instruction.length as i32
} else { } else {
@@ -176,7 +176,7 @@ impl CPU {
Opcode::Rand => {} // TODO remove this whole instruction Opcode::Rand => {} // TODO remove this whole instruction
Opcode::Not => { Opcode::Not => {
let x = self.pop_data(); let x = self.pop_data();
self.push_data(bool_as_word(x == 0)) self.push_data(x == 0)
} }
Opcode::Pop => { Opcode::Pop => {
self.pop_data(); self.pop_data();
@@ -184,7 +184,7 @@ impl CPU {
Opcode::Dup => self.push_data(self.peek_data()), Opcode::Dup => self.push_data(self.peek_data()),
Opcode::Pick => { Opcode::Pick => {
let index = self.pop_data(); let index = self.pop_data();
let val = self.memory.peek24(self.dp - (index as i32 + 1) * 3); let val = self.memory.peek24(self.dp - (i32::from(index) + 1) * 3);
self.push_data(val) self.push_data(val)
} }
Opcode::Rot => { Opcode::Rot => {
@@ -197,7 +197,7 @@ impl CPU {
} }
Opcode::Jmp => return self.pop_data().into(), Opcode::Jmp => return self.pop_data().into(),
Opcode::Jmpr => { Opcode::Jmpr => {
let x = word_as_signed(self.pop_data()); let x = i32::from(self.pop_data());
return self.pc + x; return self.pc + x;
} }
Opcode::Call => { Opcode::Call => {
@@ -209,11 +209,11 @@ impl CPU {
Opcode::Hlt => self.halted = true, Opcode::Hlt => self.halted = true,
Opcode::Load => { Opcode::Load => {
let x = self.pop_data(); let x = self.pop_data();
self.push_data(self.memory.peek(x.into()) as u32) self.push_data(self.memory.peek8(x))
} }
Opcode::Loadw => { Opcode::Loadw => {
let x = self.pop_data(); let x = self.pop_data();
self.push_data(self.memory.peek24(x.into())) self.push_data(self.memory.peek24(x))
} }
Opcode::Inton => self.int_enabled = true, Opcode::Inton => self.int_enabled = true,
Opcode::Intoff => self.int_enabled = false, Opcode::Intoff => self.int_enabled = false,
@@ -270,29 +270,13 @@ impl Opcode {
} }
} }
fn word_as_signed(word: u32) -> i32 {
if word & 0x800000 != 0 {
-(((word ^ 0xffffff) + 1) as i32)
} else {
word as i32
}
}
fn bool_as_word(flag: bool) -> u32 {
if flag {
1
} else {
0
}
}
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use super::*; use super::*;
use Opcode::*; use Opcode::*;
impl CPU { impl CPU {
fn get_stack(&self) -> Vec<u32> { fn get_stack(&self) -> Vec<Word> {
let mut v = Vec::new(); let mut v = Vec::new();
let mut curr = Word::from(256); let mut curr = Word::from(256);
while curr < self.dp { while curr < self.dp {
@@ -302,7 +286,7 @@ mod tests {
v v
} }
fn get_call(&self) -> Vec<u32> { fn get_call(&self) -> Vec<Word> {
let mut v = Vec::new(); let mut v = Vec::new();
let mut curr = Word::from(1024); let mut curr = Word::from(1024);
while curr > self.sp { while curr > self.sp {
@@ -520,8 +504,8 @@ mod tests {
cpu.push_data(2000u32) cpu.push_data(2000u32)
}, },
|cpu| { |cpu| {
assert_eq!(cpu.sp, 1000.into()); assert_eq!(cpu.sp, 1000);
assert_eq!(cpu.dp, 2000.into()) assert_eq!(cpu.dp, 2000)
}, },
); );
call_stack_opcode_test(vec![123], vec![], Pushr, vec![], vec![123], 1025.into()); call_stack_opcode_test(vec![123], vec![], Pushr, vec![], vec![123], 1025.into());
@@ -532,7 +516,7 @@ mod tests {
#[test] #[test]
fn test_cpu_new() { fn test_cpu_new() {
let cpu = CPU::new(Memory::default()); let cpu = CPU::new(Memory::default());
assert_eq!(cpu.pc, 1024.into()); assert_eq!(cpu.pc, 1024);
assert_eq!(cpu.halted, true); assert_eq!(cpu.halted, true);
} }
@@ -541,7 +525,7 @@ mod tests {
let mut cpu = CPU::new(Memory::default()); let mut cpu = CPU::new(Memory::default());
cpu.iv = 12345.into(); cpu.iv = 12345.into();
cpu.reset(); cpu.reset();
assert_eq!(cpu.iv, 1024.into()); assert_eq!(cpu.iv, 1024);
} }
#[test] #[test]
@@ -549,40 +533,40 @@ mod tests {
let mut cpu = CPU::new(Memory::default()); let mut cpu = CPU::new(Memory::default());
cpu.push_data(37u32); cpu.push_data(37u32);
cpu.push_data(45u32); cpu.push_data(45u32);
assert_eq!(cpu.memory.peek24_u32(256), 37); assert_eq!(cpu.memory.peek24(256), 37);
assert_eq!(cpu.memory.peek24_u32(259), 45); assert_eq!(cpu.memory.peek24(259), 45);
cpu.push_call(12u32); cpu.push_call(12u32);
cpu.push_call(34u32); cpu.push_call(34u32);
assert_eq!(cpu.memory.peek24(cpu.sp), 34); assert_eq!(cpu.memory.peek24(cpu.sp), 34);
assert_eq!(cpu.memory.peek24(cpu.sp + 3), 12); assert_eq!(cpu.memory.peek24(cpu.sp + 3), 12);
assert_eq!(cpu.sp, (1024 - 6).into()); assert_eq!(cpu.sp, 1024 - 6);
assert_eq!(cpu.dp, (256 + 6).into()); assert_eq!(cpu.dp, 256 + 6);
assert_eq!(cpu.pop_data(), 45); assert_eq!(cpu.pop_data(), 45);
assert_eq!(cpu.pop_data(), 37); assert_eq!(cpu.pop_data(), 37);
assert_eq!(cpu.dp, 256.into()); assert_eq!(cpu.dp, 256);
assert_eq!(cpu.pop_call(), 34); assert_eq!(cpu.pop_call(), 34);
assert_eq!(cpu.pop_call(), 12); assert_eq!(cpu.pop_call(), 12);
assert_eq!(cpu.sp, 1024.into()); assert_eq!(cpu.sp, 1024);
} }
#[test] #[test]
fn test_cpu_fetch() { fn test_cpu_fetch() {
let mut cpu = CPU::new(Memory::default()); let mut cpu = CPU::new(Memory::default());
cpu.memory.poke_u32(0x400, 0x01); // nop 1 arg cpu.memory.poke8(0x400, 0x01); // nop 1 arg
cpu.memory.poke_u32(0x401, 0x02); // 2 cpu.memory.poke8(0x401, 0x02); // 2
cpu.memory.poke_u32(0x402, 0x07); // add 3 arg cpu.memory.poke8(0x402, 0x07); // add 3 arg
cpu.memory.poke24_u32(0x403, 0x123456); // 3-byte arg cpu.memory.poke24(0x403, 0x123456); // 3-byte arg
cpu.memory.poke_u32(0x406, 29 << 2); // hlt cpu.memory.poke8(0x406, 29 << 2); // hlt
cpu.memory.poke_u32(0x407, 0xfc); // gibberish cpu.memory.poke8(0x407, 0xfc); // gibberish
assert_eq!( assert_eq!(
cpu.fetch(), cpu.fetch(),
Ok(Instruction { Ok(Instruction {
opcode: Opcode::Nop, opcode: Opcode::Nop,
arg: Some(2), arg: Some(Word::from(2)),
length: 2 length: 2
}) })
); );
@@ -592,7 +576,7 @@ mod tests {
cpu.fetch(), cpu.fetch(),
Ok(Instruction { Ok(Instruction {
opcode: Opcode::Add, opcode: Opcode::Add,
arg: Some(0x123456), arg: Some(Word::from(0x123456)),
length: 4 length: 4
}) })
); );
+27 -28
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@@ -1,37 +1,36 @@
use crate::memory::PeekPoke; use crate::memory::{PeekPoke, PeekPokeExt};
use crate::Word; use crate::Word;
use std::convert::TryFrom;
#[derive(Copy, Clone, Debug, Eq, PartialEq)] #[derive(Copy, Clone, Debug, Eq, PartialEq)]
struct DisplayRegisters { struct DisplayRegisters {
mode: u8, mode: u8,
screen: u32, screen: Word,
palette: u32, palette: Word,
font: u32, font: Word,
height: u32, height: Word,
width: u32, width: Word,
row_offset: u32, row_offset: Word,
col_offset: u32, col_offset: Word,
} }
impl Default for DisplayRegisters { impl Default for DisplayRegisters {
fn default() -> Self { fn default() -> Self {
Self { Self {
mode: 4, mode: 5,
screen: 0x10000, screen: Word::from(0x10000),
palette: 0x20000 - 0x100, palette: Word::from(0x20000 - 0x100),
font: 0x20000 - 0x100 - 0x2000, font: Word::from(0x20000 - 0x100 - 0x2000),
height: 128, height: Word::from(128),
width: 128, width: Word::from(128),
row_offset: 0, row_offset: Word::from(0),
col_offset: 0, col_offset: Word::from(0),
} }
} }
} }
fn read_display_registers<P: PeekPoke>(machine: &P, start: Word) -> DisplayRegisters { fn read_display_registers<P: PeekPoke>(machine: &P, start: Word) -> DisplayRegisters {
DisplayRegisters { DisplayRegisters {
mode: machine.peek(start), mode: machine.peek8(start),
screen: machine.peek24(start + 1), screen: machine.peek24(start + 1),
palette: machine.peek24(start + 4), palette: machine.peek24(start + 4),
font: machine.peek24(start + 7), font: machine.peek24(start + 7),
@@ -45,13 +44,13 @@ fn read_display_registers<P: PeekPoke>(machine: &P, start: Word) -> DisplayRegis
fn init_display_registers<P: PeekPoke>(machine: &mut P, start: Word) { fn init_display_registers<P: PeekPoke>(machine: &mut P, start: Word) {
let dr = DisplayRegisters::default(); let dr = DisplayRegisters::default();
machine.poke(start, dr.mode); machine.poke(start, dr.mode);
machine.poke24(start + 1, dr.screen.into()); machine.poke24(start + 1, dr.screen);
machine.poke24(start + 4, dr.palette.into()); machine.poke24(start + 4, dr.palette);
machine.poke24(start + 7, dr.font.into()); machine.poke24(start + 7, dr.font);
machine.poke24(start + 10, dr.height.into()); machine.poke24(start + 10, dr.height);
machine.poke24(start + 13, dr.width.into()); machine.poke24(start + 13, dr.width);
machine.poke24(start + 16, dr.row_offset.into()); machine.poke24(start + 16, dr.row_offset);
machine.poke24(start + 19, dr.col_offset.into()); machine.poke24(start + 19, dr.col_offset);
} }
fn init_font<P: PeekPoke>(machine: &mut P) { fn init_font<P: PeekPoke>(machine: &mut P) {
@@ -96,9 +95,9 @@ fn init_palette<P: PeekPoke>(machine: &mut P) {
} }
} }
fn to_byte_address((x, y): (u32, u32), reg: DisplayRegisters) -> u32 { fn to_byte_address((x, y): (u32, u32), reg: DisplayRegisters) -> Word {
let row_start = (y + reg.row_offset % reg.height) * reg.width + reg.screen; let row_start = (Word::from(y) + reg.row_offset % reg.height) * reg.width + reg.screen;
((x + reg.col_offset) % reg.width) + row_start ((Word::from(x) + reg.col_offset) % reg.width) + row_start
} }
fn draw_direct_high_gfx<P: PeekPoke>(machine: &P, reg: DisplayRegisters, frame: &mut [u8]) { fn draw_direct_high_gfx<P: PeekPoke>(machine: &P, reg: DisplayRegisters, frame: &mut [u8]) {
+47 -38
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@@ -10,13 +10,6 @@ impl Default for Memory {
} }
} }
impl From<Word> for usize {
fn from(w: Word) -> Self {
let w: u32 = w.into();
(w & (MEM_SIZE - 1)) as usize
}
}
impl<R: Rng> From<R> for Memory { impl<R: Rng> From<R> for Memory {
fn from(mut rng: R) -> Self { fn from(mut rng: R) -> Self {
let mut mem = Memory::default(); let mut mem = Memory::default();
@@ -41,32 +34,54 @@ impl std::ops::IndexMut<Word> for Memory {
} }
pub trait PeekPoke { pub trait PeekPoke {
/// Read a byte from a given address.
fn peek(&self, addr: Word) -> u8; fn peek(&self, addr: Word) -> u8;
/// Write a byte to a given address.
fn poke(&mut self, addr: Word, val: u8); fn poke(&mut self, addr: Word, val: u8);
fn peek24(&self, addr: Word) -> u32 { /// Read a slice, starting from a given address.
(self.peek(addr) as u32) fn peek_slice(&self, addr: Word, buffer: &mut [u8]) {
| ((self.peek(addr + 1) as u32) << 8) for (i, byte) in buffer.iter_mut().enumerate() {
| ((self.peek(addr + 2) as u32) << 16) *byte = self.peek(addr + i);
}
} }
fn poke24(&mut self, addr: Word, val: u32) { /// Write a slice, starting at a given address.
self.poke(addr, val as u8); fn poke_slice(&mut self, addr: Word, buffer: &[u8]) {
self.poke(addr + 1, (val >> 8) as u8); for (i, byte) in buffer.iter().enumerate() {
self.poke(addr + 2, (val >> 16) as u8); self.poke(addr + i, *byte);
}
}
} }
fn peek_u32(&self, addr: u32) -> u8 { pub trait PeekPokeExt {
fn peek8<A: Into<Word>>(&self, addr: A) -> u8;
fn poke8<A: Into<Word>, V: Into<u8>>(&mut self, addr: A, val: V);
fn peek24<A: Into<Word>>(&self, addr: A) -> Word;
fn poke24<A: Into<Word>, V: Into<Word>>(&mut self, addr: A, val: V);
}
impl<T: PeekPoke> PeekPokeExt for T {
fn peek8<A: Into<Word>>(&self, addr: A) -> u8 {
self.peek(addr.into()) self.peek(addr.into())
} }
fn poke_u32(&mut self, addr: u32, val: u8) {
self.poke(addr.into(), val) fn poke8<A: Into<Word>, V: Into<u8>>(&mut self, addr: A, val: V) {
self.poke(addr.into(), val.into());
} }
fn peek24_u32(&mut self, addr: u32) -> u32 {
self.peek24(addr.into()) fn peek24<A: Into<Word>>(&self, addr: A) -> Word {
let mut bytes = [0u8; 3];
self.peek_slice(addr.into(), &mut bytes);
bytes.into()
} }
fn poke24_u32(&mut self, addr: u32, val: u32) {
self.poke24(addr.into(), val) fn poke24<A: Into<Word>, V: Into<Word>>(&mut self, addr: A, val: V) {
let addr = addr.into();
let val = val.into();
self.poke_slice(addr, &val.to_bytes());
} }
} }
@@ -86,26 +101,20 @@ mod tests {
#[test] #[test]
fn test_mem_peek_poke() { fn test_mem_peek_poke() {
let mut mem = Memory::default(); let mut mem = Memory::default();
assert_eq!(mem.peek_u32(35), 0); assert_eq!(mem.peek24(35), 0);
mem.poke_u32(35, 45); mem.poke24(35, 45);
assert_eq!(mem.peek_u32(35), 45); assert_eq!(mem.peek24(35), 45);
assert_eq!(mem.peek_u32(36), 0); assert_eq!(mem.peek24(36), 0);
} }
#[test] #[test]
fn test_mem_word_fns() { fn test_mem_word_fns() {
let mut mem = Memory::default(); let mut mem = Memory::default();
mem.poke24(10.into(), 0x123456); mem.poke24(10, 0x123456);
assert_eq!(mem.peek_u32(10), 0x56); assert_eq!(mem.peek8(10), 0x56);
assert_eq!(mem.peek_u32(11), 0x34); assert_eq!(mem.peek8(11), 0x34);
assert_eq!(mem.peek_u32(12), 0x12); assert_eq!(mem.peek8(12), 0x12);
assert_eq!(mem.peek24(10.into()), 0x123456); assert_eq!(mem.peek24(10), 0x123456);
assert_eq!(mem.peek24(11.into()), 0x001234); assert_eq!(mem.peek24(11), 0x001234);
}
#[test]
fn test_addressing_arrays() {
let a: usize = Word::from(0xffffff).into();
assert_eq!(a, 0x01ffff as usize);
} }
} }
+289 -28
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@@ -1,58 +1,319 @@
// 128k, the amount of memory in a standard Vulcan machine // 128k, the amount of memory in a standard Vulcan machine
pub const MEM_SIZE: u32 = 128 * 1024; pub const MEM_SIZE: u32 = 128 * 1024;
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)] #[derive(Debug, Copy, Clone, Eq, Ord)]
pub struct Word(u32); pub struct Word(u32);
impl Word {
/// Create a `Word` from three bytes.
///
/// # Example
///
/// ```
/// use vulcan_emu::Word;
///
/// assert_eq!(Word::from_bytes([0x01, 0x02, 0x03]) == 0x010203);
/// ```
pub fn from_bytes(bytes: [u8; 3]) -> Self {
let [a, b, c] = bytes;
Self(u32::from_le_bytes([a, b, c, 0]))
}
/// Convert a `Word` into three bytes.
///
/// # Example
///
/// ```
/// use vulcan_emu::Word;
///
/// assert_eq!(Word::from(0x010203).to_bytes(), [0x01, 0x02, 0x03]);
/// ```
pub fn to_bytes(self) -> [u8; 3] {
let [a, b, c, _] = self.0.to_le_bytes();
[a, b, c]
}
}
impl From<u32> for Word { impl From<u32> for Word {
fn from(a: u32) -> Self { fn from(a: u32) -> Self {
Self(a & 0xffffff) Self(a & 0xffffff)
} }
} }
impl From<Word> for u32 { impl From<Word> for u32 {
fn from(word: Word) -> Self { fn from(word: Word) -> Self {
word.0 word.0
} }
} }
impl std::ops::Add<i32> for Word { #[test]
type Output = Word; fn to_from_u32() {
fn add(self, rhs: i32) -> Self::Output { assert_eq!(u32::from(Word::from(0x123456u32)), 0x123456u32);
Word::from((self.0 as i32).overflowing_add(rhs).0 as u32) assert_eq!(u32::from(Word::from(0x12345678u32)), 0x345678u32);
}
} }
impl std::ops::Sub<i32> for Word { impl From<Word> for i32 {
type Output = Word; fn from(word: Word) -> Self {
fn sub(self, rhs: i32) -> Self::Output { if word.0 & 0x800000 != 0 {
self + -rhs -(((word.0 ^ 0xffffff) + 1) as i32)
} else {
word.0 as i32
} }
} }
impl std::ops::Sub<Word> for Word {
type Output = Word;
fn sub(self, rhs: Word) -> Self::Output {
Word(self.0 - rhs.0)
} }
} impl From<i32> for Word {
fn from(value: i32) -> Self {
impl std::ops::SubAssign<i32> for Word { (value as u32).into()
fn sub_assign(&mut self, rhs: i32) {
*self = *self - rhs;
}
}
impl std::ops::AddAssign<i32> for Word {
fn add_assign(&mut self, rhs: i32) {
*self = *self + rhs;
} }
} }
#[test]
fn to_from_i32() {
assert_eq!(i32::from(Word::from(0x123456i32)), 0x123456i32);
assert_eq!(i32::from(Word::from(-555i32)), -555i32);
}
// Perform various conversions using the conversions above
macro_rules! convert_via {
($big:ty => $little:ty) => {
impl From<$big> for Word {
fn from(value: $big) -> Self {
(value as $little).into()
}
}
impl From<Word> for $big {
fn from(value: Word) -> Self {
<$little>::from(value) as $big
}
}
};
}
convert_via!(u8 => u32);
convert_via!(i8 => i32);
#[test]
fn to_from_u8() {
assert_eq!(u8::from(Word::from(0x7fu8)), 0x7fu8);
assert_eq!(u8::from(Word::from_bytes([1, 2, 3])), 1u8);
}
#[test]
fn to_from_i8() {
assert_eq!(i8::from(Word::from(-1i8)), -1i8);
assert_eq!(i8::from(Word::from_bytes([1, 2, 3])), 1i8);
assert_eq!(i8::from(Word::from_bytes([0xff, 0, 0])), -1i8);
}
convert_via!(u16 => u32);
convert_via!(i16 => i32);
convert_via!(u64 => u32);
convert_via!(i64 => i32);
convert_via!(usize => u32);
convert_via!(isize => i32);
impl From<bool> for Word {
fn from(value: bool) -> Self {
if value {
Word::from(1)
} else {
Word::from(0)
}
}
}
impl From<Word> for bool {
fn from(word: Word) -> Self {
word.0 != 0
}
}
#[test]
fn to_from_bool() {
assert_eq!(bool::from(Word::from(0)), false);
assert_eq!(bool::from(Word::from(1)), true);
assert_eq!(bool::from(Word::from(0x123456)), true);
assert_eq!(Word::from(false), Word::from(0));
assert_eq!(Word::from(true), Word::from(1));
}
impl From<[u8; 3]> for Word {
fn from(value: [u8; 3]) -> Self {
Word::from_bytes(value)
}
}
impl From<Word> for [u8; 3] {
fn from(value: Word) -> Self {
value.to_bytes()
}
}
#[test]
fn to_from_u8_3() {
assert_eq!(Word::from([0, 0, 0]), Word::from(0));
assert_eq!(Word::from([1, 0, 0]), Word::from(1));
assert_eq!(Word::from([0xff, 0xff, 0xff]), Word::from(0xffffff));
assert_eq!(<[u8; 3]>::from(Word::from(0)), [0, 0, 0]);
assert_eq!(<[u8; 3]>::from(Word::from(1)), [1, 0, 0]);
assert_eq!(<[u8; 3]>::from(Word::from(0xffffff)), [0xff, 0xff, 0xff]);
}
// Implement negation via i32
impl std::ops::Neg for Word {
type Output = Word;
fn neg(self) -> Self::Output {
Self::from(-i32::from(self))
}
}
macro_rules! ops {
// Implement operations for $target by converting both Word and $target to $target
($target:ty) => {
ops!($target, $target);
};
// Implement operations for $target by converting both Word and $target to $intermediate
($target:ty, $intermediate:ty) => {
impl std::ops::Add<$target> for Word {
type Output = Word;
fn add(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.overflowing_add(<$intermediate>::from(rhs))
.0
.into()
}
}
impl std::ops::Sub<$target> for Word {
type Output = Word;
fn sub(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.overflowing_sub(<$intermediate>::from(rhs))
.0
.into()
}
}
impl std::ops::Mul<$target> for Word {
type Output = Word;
fn mul(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.overflowing_mul(<$intermediate>::from(rhs))
.0
.into()
}
}
impl std::ops::Div<$target> for Word {
type Output = Word;
fn div(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.overflowing_div(<$intermediate>::from(rhs))
.0
.into()
}
}
impl std::ops::Rem<$target> for Word {
type Output = Word;
fn rem(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.rem(<$intermediate>::from(rhs))
.into()
}
}
impl std::ops::BitAnd<$target> for Word {
type Output = Word;
fn bitand(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.bitand(<$intermediate>::from(rhs))
.into()
}
}
impl std::ops::BitOr<$target> for Word {
type Output = Word;
fn bitor(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.bitor(<$intermediate>::from(rhs))
.into()
}
}
impl std::ops::BitXor<$target> for Word {
type Output = Word;
fn bitxor(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.bitxor(<$intermediate>::from(rhs))
.into()
}
}
impl std::ops::Shl<$target> for Word {
type Output = Word;
fn shl(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.shl(<$intermediate>::from(rhs))
.into()
}
}
impl std::ops::Shr<$target> for Word {
type Output = Word;
fn shr(self, rhs: $target) -> Self::Output {
<$intermediate>::from(self)
.shr(<$intermediate>::from(rhs))
.into()
}
}
impl std::ops::SubAssign<$target> for Word {
fn sub_assign(&mut self, rhs: $target) {
*self = *self - rhs;
}
}
impl std::ops::AddAssign<$target> for Word {
fn add_assign(&mut self, rhs: $target) {
*self = *self + rhs;
}
}
impl std::cmp::PartialOrd<$target> for Word {
fn partial_cmp(&self, rhs: &$target) -> Option<std::cmp::Ordering> {
<$intermediate>::from(*self).partial_cmp(&<$intermediate>::from(*rhs))
}
}
impl std::cmp::PartialEq<$target> for Word {
fn eq(&self, rhs: &$target) -> bool {
<$intermediate>::from(*self).eq(&<$intermediate>::from(*rhs))
}
}
};
}
ops!(Word, u32);
ops!(u8);
ops!(u16);
ops!(u32);
ops!(u64);
ops!(usize);
ops!(i8);
ops!(i16);
ops!(i32);
ops!(i64);
ops!(isize);
#[test] #[test]
fn test_address_truncation() { fn test_address_truncation() {
let a: Word = 0x11223344.into(); let a: Word = 0x11223344.into();
assert_eq!(a, 0x00223344.into()); assert_eq!(a, 0x00223344);
} }
#[test] #[test]