95 lines
2.7 KiB
Rust
95 lines
2.7 KiB
Rust
use core::num::Wrapping; // Permet d'autoriser les overflow pour les opérations voulues
|
|
|
|
#[allow(non_snake_case)] // supprimer le warning snake case (quand les noms de variables ont des majuscules)
|
|
#[derive(Debug)]
|
|
pub struct Instruction {
|
|
pub value : u64,
|
|
|
|
pub opcode : u8,
|
|
pub rs1 : u8,
|
|
pub rs2 : u8,
|
|
pub rs3 : u8,
|
|
pub rd : u8,
|
|
pub funct7 : u8,
|
|
pub funct7_smaller : u8,
|
|
pub funct3 : u8,
|
|
pub shamt : u8, // shamt = imm[5:0] or imm[4:0] (depend of opcode)
|
|
|
|
pub imm12_I : u16,
|
|
pub imm12_S : u16,
|
|
|
|
pub imm12_I_signed : i16,
|
|
pub imm12_S_signed : i16,
|
|
pub imm13 : i16,
|
|
pub imm13_signed : i16,
|
|
|
|
pub imm31_12 : u32,
|
|
pub imm21_1 : u32,
|
|
|
|
pub imm31_12_signed : i32,
|
|
pub imm21_1_signed : i32,
|
|
}
|
|
|
|
#[allow(non_snake_case)]
|
|
pub fn decode(val : u64) -> Instruction {
|
|
|
|
let value = val;
|
|
|
|
let opcode = (val & 0x7f) as u8;
|
|
let rs1 = ((val >> 15) & 0x1f) as u8;
|
|
let rs2 = ((val >> 20) & 0x1f) as u8;
|
|
let rs3 = ((val >> 27) & 0x1f) as u8;
|
|
let rd = ((val >> 7) & 0x1f) as u8;
|
|
let funct7 = ((val >> 25) & 0x7f) as u8;
|
|
let funct7_smaller = funct7 & 0x3e;
|
|
|
|
let funct3 = ((val >> 12) & 0x7) as u8;
|
|
let imm12_I = ((val >> 20) & 0xfff) as u16;
|
|
let imm12_S = (((val >> 20) & 0xfe0) + ((val >> 7) & 0x1f)) as u16;
|
|
|
|
let imm12_I_signed = if imm12_I >= 2048 { (Wrapping(imm12_I) - Wrapping(4096)).0 } else { imm12_I } as i16;
|
|
let imm12_S_signed = if imm12_S >= 2048 { (Wrapping(imm12_S) - Wrapping(4096)).0 } else { imm12_S } as i16;
|
|
|
|
let imm13 = (((val >> 19) & 0x1000) + ((val >> 20) & 0x7e0) +
|
|
((val >> 7) & 0x1e) + ((val << 4) & 0x800)) as i16;
|
|
let imm13_signed = if imm13 >= 4096 { imm13 - 8192 } else { imm13 };
|
|
|
|
let imm31_12 = (val & 0xfffff000) as u32;
|
|
let imm31_12_signed = imm31_12 as i32;
|
|
|
|
let imm21_1 = ((val & 0xff000) + ((val >> 9) & 0x800) +
|
|
((val >> 20) & 0x7fe) + ((val >> 11) & 0x100000)) as u32;
|
|
let imm21_1_signed = if imm21_1 >= 1048576 { (Wrapping(imm21_1) - Wrapping(2097152)).0 } else { imm21_1 } as i32;
|
|
|
|
let shamt = ((val >> 20) & 0x3f) as u8;
|
|
|
|
Instruction {
|
|
value,
|
|
|
|
opcode,
|
|
rs1,
|
|
rs2,
|
|
rs3,
|
|
rd,
|
|
funct7,
|
|
funct7_smaller,
|
|
|
|
funct3,
|
|
imm12_I,
|
|
imm12_S,
|
|
|
|
imm12_I_signed,
|
|
imm12_S_signed,
|
|
|
|
imm13,
|
|
imm13_signed,
|
|
|
|
imm31_12,
|
|
imm31_12_signed,
|
|
|
|
imm21_1,
|
|
imm21_1_signed,
|
|
|
|
shamt
|
|
}
|
|
} |