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pub mod opcodes;
pub mod funct3;
pub mod funct7;
pub type Word = u32;
pub type SignedWord = i32;
pub type HalfWord = u16;
pub type SignedHalfWord = i16;
pub type Byte = u8;
pub type SignedByte = i8;
pub type Address = u32;
#[derive(Debug, PartialEq)]
pub enum Register {
X0 = 0,
X1 = 1,
X2 = 2,
X3 = 3,
X4 = 4,
X5 = 5,
X6 = 6,
X7 = 7,
X8 = 8,
X9 = 9,
X10 = 10,
X11 = 11,
X12 = 12,
X13 = 13,
X14 = 14,
X15 = 15,
X16 = 16,
X17 = 17,
X18 = 18,
X19 = 19,
X20 = 20,
X21 = 21,
X22 = 22,
X23 = 23,
X24 = 24,
X25 = 25,
X26 = 26,
X27 = 27,
X28 = 28,
X29 = 29,
X30 = 30,
X31 = 31,
}
impl Register {
pub fn as_num(self) -> usize {
self as usize
}
pub fn from_num(num: u32) -> Register {
match num {
0 => Register::X0,
1 => Register::X1,
2 => Register::X2,
3 => Register::X3,
4 => Register::X4,
5 => Register::X5,
6 => Register::X6,
7 => Register::X7,
8 => Register::X8,
9 => Register::X9,
10 => Register::X10,
11 => Register::X11,
12 => Register::X12,
13 => Register::X13,
14 => Register::X14,
15 => Register::X15,
16 => Register::X16,
17 => Register::X17,
18 => Register::X18,
19 => Register::X19,
20 => Register::X20,
21 => Register::X21,
22 => Register::X22,
23 => Register::X23,
24 => Register::X24,
25 => Register::X25,
26 => Register::X26,
27 => Register::X27,
28 => Register::X28,
29 => Register::X29,
30 => Register::X30,
31 => Register::X31,
_ => panic!("Invalid register number: {}", num),
}
}
}
#[derive(Copy, Clone, Debug)]
pub struct Instruction {
// TODO: rename word to something correct - instructions are not always a
// word
word: u32,
}
impl Instruction {
pub fn new(word: u32) -> Instruction {
Instruction {
word: word,
}
}
pub fn opcode(&self) -> u32 {
self.word & 0x7F
}
pub fn rd(&self) -> Register {
Register::from_num((self.word >> 7) & 0x1F)
}
pub fn funct3(&self) -> u32 {
(self.word >> 12) & 0x3
}
pub fn funct7(&self) -> u32 {
(self.word >> 25) & 0x7F
}
pub fn shamt(&self) -> u32 {
(self.word >> 20) & 0x1F
}
pub fn rs1(&self) -> Register {
Register::from_num((self.word >> 15) & 0x1F)
}
pub fn rs2(&self) -> Register {
Register::from_num((self.word >> 20) & 0x1F)
}
pub fn i_imm(&self) -> SignedWord {
(self.word as SignedWord) >> 20
}
pub fn s_imm(&self) -> SignedWord {
let low = (self.word >> 7) & 0x1F;
let high = (((self.word as SignedWord) >> 25) & 0x7F) as Word;
((high << 7) | low) as SignedWord
}
pub fn uj_imm(&self) -> SignedWord {
// Want zero-extension
let low1 = (self.word >> 21) & 0x3FF;
let low11 = (self.word >> 20) & 0x1;
let low12 = (self.word >> 12) & 0xFF;
// Want sign-extension
let low20 = ((self.word as SignedWord) >> 30) as Word;
((low20 << 20) | (low12 << 12) | (low11 << 11) | (low1 << 1)) as SignedWord
}
pub fn sb_imm(&self) -> SignedWord {
let low1 = (self.word >> 8) & 0xF;
let low5 = (self.word >> 25) & 0x3F;
let low11 = (self.word >> 7) & 0x1;
let low12 = ((self.word as SignedWord) >> 31) as Word;
((low12 << 12) | (low11 << 11) | (low5 << 5) | (low1 << 1)) as SignedWord
}
}
|
