Method sext8

pulley/src/interp.rs:2127–2131

(&mut self, dst: XReg, src: XReg)

    }

    fn sext8(&mut self, dst: XReg, src: XReg) -> ControlFlow<Done> {
        let src = self.state[src].get_i64() as i8;
        self.state[dst].set_i64(src.into());
        ControlFlow::Continue(())
    }

    fn sext16(&mut self, dst: XReg, src: XReg) -> ControlFlow<Done> {
        let src = self.state[src].get_i64() as i16;