Function sign_ext

crates/virtual-machine/src/cpu/decoder.rs:890–893

Sign-extend `val` (a value in the low `bits` bits) to `i64`.

(val: u32, bits: u32)

// Sign-extend `val` (a value in the low `bits` bits) to `i64`.
fn sign_ext(val: u32, bits: u32) -> i64 {
    let shift = 32 - bits;
    ((val << shift) as i32 >> shift) as i64
}

// I-type immediate: bits[31:20], sign-extended to 64 bits.
fn i_imm(word: u32) -> i64 {