61 lines
1.4 KiB
Rust
61 lines
1.4 KiB
Rust
// 128k, the amount of memory in a standard Vulcan machine
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pub const MEM_SIZE: u32 = 128 * 1024;
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#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
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pub struct Word(u32);
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impl From<u32> for Word {
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fn from(a: u32) -> Self { Self(a & 0xffffff) }
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}
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impl From<Word> for u32 {
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fn from(word: Word) -> Self { word.0 }
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}
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impl std::ops::Add<i32> for Word {
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type Output = Word;
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fn add(self, rhs: i32) -> Self::Output {
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Word::from((self.0 as i32).overflowing_add(rhs).0 as u32)
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}
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}
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impl std::ops::Sub<i32> for Word {
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type Output = Word;
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fn sub(self, rhs: i32) -> Self::Output { self + -rhs }
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}
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impl std::ops::Sub<Word> for Word {
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type Output = Word;
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fn sub(self, rhs: Word) -> Self::Output { Word(self.0 - rhs.0) }
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}
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impl std::ops::SubAssign<i32> for Word {
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fn sub_assign(&mut self, rhs: i32) { *self = *self - rhs; }
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}
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impl std::ops::AddAssign<i32> for Word {
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fn add_assign(&mut self, rhs: i32) { *self = *self + rhs; }
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}
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#[test]
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fn test_address_truncation() {
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let a: Word = 0x11223344.into();
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assert_eq!(a, 0x00223344.into());
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}
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#[test]
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fn test_address_overflows() {
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let a = Word::from(0xfffffa);
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assert_eq!(a + 10, Word(4));
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let b = Word::from(3);
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assert_eq!(b - 10, Word(0xfffff9));
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let mut c = Word::from(5);
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c += 3;
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assert_eq!(c, Word(8));
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let mut d = Word::from(5);
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d -= 3;
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assert_eq!(d, Word(2));
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} |