Rativel/BurritOS
1
1
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix decode to allow overflow in certains cases, add a case in test for riscv_lui where imm is negative

Browse Source
This commit is contained in:
Quentin Legot 2022-11-09 17:31:14 +01:00
parent 2a708ce335
commit 2a3f0b3bb3
2 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/decode.rs
View File

@ -1,3 +1,5 @@
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) #[allow(non_snake_case)] // supprimer le warning snake case (quand les noms de variables ont des majuscules)
#[derive(Debug)] #[derive(Debug)]
pub struct Instruction { pub struct Instruction {
@ -45,8 +47,8 @@ pub fn decode(val : u32) -> Instruction {
let imm12_I = ((val >> 20) & 0xfff) as u16; let imm12_I = ((val >> 20) & 0xfff) as u16;
let imm12_S = (((val >> 20) & 0xfe0) + ((val >> 7) & 0x1f)) 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_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 { imm12_S - 4096 } else { imm12_S } 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) + let imm13 = (((val >> 19) & 0x1000) + ((val >> 20) & 0x7e0) +
((val >> 7) & 0x1e) + ((val << 4) & 0x800)) as i16; ((val >> 7) & 0x1e) + ((val << 4) & 0x800)) as i16;
@ -57,7 +59,7 @@ pub fn decode(val : u32) -> Instruction {
let imm21_1 = ((val & 0xff000) + ((val >> 9) & 0x800) + let imm21_1 = ((val & 0xff000) + ((val >> 9) & 0x800) +
((val >> 20) & 0x7fe) + ((val >> 11) & 0x100000)) as u32; ((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 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; let shamt = ((val >> 20) & 0x3f) as u8;

2
src/print.rs
View File

@ -299,7 +299,9 @@ mod test {
#[test] #[test]
fn test_lui() { fn test_lui() {
let lui = decode::decode(0b01110001000011111000_11100_0110111); let lui = decode::decode(0b01110001000011111000_11100_0110111);
let lui_negatif = decode::decode(0b11110001000011111000_11100_0110111);
assert_eq!("lui x28, 0x710F8000", print::print(lui, 0)); assert_eq!("lui x28, 0x710F8000", print::print(lui, 0));
assert_eq!("lui x28, 0xF10F8000", print::print(lui_negatif, 0));
} }
#[test] #[test]