decode (recquire tests)

This commit is contained in:
Baptiste 2022-10-19 17:23:41 +02:00
parent 9748b0f2dc
commit cfb0a8e176
2 changed files with 78 additions and 45 deletions

View File

@ -1,57 +1,90 @@
pub struct Instruction {
value : u64,
pub value : u64,
opcode : u8,
rs1 : u8,
rs2 : u8,
rs3 : u8,
rd : u8,
funct7 : u8,
funct7_smaller : u8,
funct3 : u8,
shamt : u8,
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,
imm12_I : u16,
imm12_S : u16,
pub imm12_I : u16,
pub imm12_S : u16,
imm12_I_signed : i16,
imm12_S_signed : i16,
imm13 : i16,
imm13_signed : i16,
pub imm12_I_signed : i16,
pub imm12_S_signed : i16,
pub imm13 : i16,
pub imm13_signed : i16,
imm31_12 : u32,
imm21_1 : u32,
pub imm31_12 : u32,
pub imm21_1 : u32,
imm31_12_signed : i32,
imm21_1_signed : i32,
pub imm31_12_signed : i32,
pub imm21_1_signed : i32,
}
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) as u8;
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 { imm12_I - 4096 } else { imm12_I } as i16;
let imm12_S_signed = if imm12_S >= 2048 { imm12_S - 4096 } 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 } as i16;
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 { imm21_1 - 2097152 } else { imm21_1 } as i32;
let shamt = ((val >> 20) & 0x3f) as u8;
Instruction {
value : val,
value : value,
opcode : 0,
rs1 : 0,
rs2 : 0,
rs3 : 0,
rd : 0,
funct7 : 0,
funct7_smaller : 0,
funct3 : 0,
shamt : 0,
opcode : opcode,
rs1 : rs1,
rs2 : rs2,
rs3 : rs3,
rd : rd,
funct7 : funct7,
funct7_smaller : funct7_smaller,
imm12_I : 0,
imm12_S : 0,
funct3 : funct3,
imm12_I : imm12_I,
imm12_S : imm12_S,
imm12_I_signed : 0,
imm12_S_signed : 0,
imm13 : 0,
imm13_signed : 0,
imm12_I_signed : imm12_I_signed,
imm12_S_signed : imm12_S_signed,
imm31_12 : 0,
imm21_1 : 0,
imm13 : imm13,
imm13_signed : imm13_signed,
imm31_12_signed : 0,
imm21_1_signed : 0,
imm31_12 : imm31_12,
imm31_12_signed : imm31_12_signed,
imm21_1 : imm21_1,
imm21_1_signed : imm21_1_signed,
shamt : shamt
}
}

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@ -2,5 +2,5 @@ mod decode;
fn main() {
let instr = decode::decode(98);
println!("Hello, world!");
println!("Hello, world! opcode : {}", instr.opcode);
}