gen/
gen.rs

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//! Add example.
//!
//! Jit compile a function at runtime (generate native host code) which calls a function defined in
//! the example based on the SystemV abi to demonstrate the [`juicebox_asm`] crate.

#[cfg(not(any(target_arch = "x86_64", target_os = "linux")))]
compile_error!("Only supported on x86_64 with SystemV abi");

use juicebox_asm::insn::*;
use juicebox_asm::{Asm, Imm16, Imm64, Imm8, Label, Reg16, Reg64::*, Runtime};
use juicebox_asm::{MemOp, MemOp16, MemOp32, MemOp64, MemOp8};

extern "C" fn add(a: u32, b: u32) -> u32 {
    a + b
}

fn main() {
    let mut asm1 = Asm::new();
    asm1.xor(r11, r11);

    assert!(0x7fu8 <= i8::MAX as u8);

    asm1.add(MemOp::IndirectBaseIndex(rdi, r11), Imm8::from(0x10u8));
    asm1.ret();

    let code = asm1.into_code();
    std::fs::write("jit.asm", &code).unwrap();

    let mut asm2 = Asm::new();
    asm2.mov(Reg16::cx, Imm16::from(1u16));
    asm2.mov(MemOp::Indirect(rdi), Reg16::cx);
    asm2.ret();

    let mut rt = Runtime::new();
    let fn1 = unsafe { rt.add_code::<extern "C" fn(*mut u64)>(code) };
    let fn2 = unsafe { rt.add_code::<extern "C" fn(*mut u64)>(asm2.into_code()) };

    let mut data = 0xffff_ffff_ffff_ff00u64;
    fn1(&mut data as *mut u64);
    println!("data={:x}", data);

    let mut data = 0xffff_ffff_ffff_ffffu64;
    fn2(&mut data as *mut u64);
    println!("data={:x}", data);
}