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<a href="#705" id="705">705</a></pre></div><pre class="rust"><code><span class="doccomment">//! TinyVm example.
//!
//! This example introduces a simple 16 bit virtual machine the [`TinyVm`]. The VM consists of
//! three registers defined in [`TinyReg`], a separate _data_ and _instruction_ memory and a small
//! set of instructions [`TinyInsn`], sufficient to implement a guest program to compute the
//! Fibonacci sequence.
//!
//! The `TinyVm` implements a simple _just-in-time (JIT)_ compiler to demonstrate the
//! [`juicebox_asm`] crate. Additionally, it implements a reference _interpreter_.
//!
//! ```
//! fn main() {
//! let mut prog = Vec::new();
//! prog.push(TinyInsn::LoadImm(TinyReg::A, 100));
//! prog.push(TinyInsn::Add(TinyReg::B, TinyReg::A));
//! prog.push(TinyInsn::Addi(TinyReg::C, 100));
//! prog.push(TinyInsn::Halt);
//!
//! let mut vm = TinyVm::new(prog);
//! vm.interp();
//!
//! assert_eq!(100, vm.read_reg(TinyReg::A));
//! assert_eq!(100, vm.read_reg(TinyReg::B));
//! assert_eq!(100, vm.read_reg(TinyReg::C));
//! assert_eq!(4, vm.icnt);
//! assert_eq!(4, vm.pc);
//!
//! vm.pc = 0;
//! vm.jit();
//!
//! assert_eq!(100, vm.read_reg(TinyReg::A));
//! assert_eq!(200, vm.read_reg(TinyReg::B));
//! assert_eq!(200, vm.read_reg(TinyReg::C));
//! assert_eq!(8, vm.icnt);
//! assert_eq!(4, vm.pc);
//! }
//! ```
</span><span class="kw">use </span>juicebox_asm::insn::<span class="kw-2">*</span>;
<span class="kw">use </span>juicebox_asm::Runtime;
<span class="kw">use </span>juicebox_asm::{Asm, Imm16, Imm64, Mem16, Reg16, Reg64};
<span class="doccomment">/// A guest physical address.
</span><span class="kw">pub struct </span>PhysAddr(<span class="kw">pub </span>u16);
<span class="kw">impl </span>Into<usize> <span class="kw">for </span>PhysAddr {
<span class="kw">fn </span>into(<span class="self">self</span>) -> usize {
<span class="self">self</span>.<span class="number">0 </span><span class="kw">as </span>usize
}
}
<span class="doccomment">/// The registers for the [`TinyVm`].
</span><span class="attr">#[derive(Debug, PartialEq, Clone, Copy)]
</span><span class="kw">pub enum </span>TinyReg {
A,
B,
C,
}
<span class="kw">impl </span>TinyReg {
<span class="attr">#[inline]
</span><span class="kw">fn </span>idx(<span class="kw-2">&</span><span class="self">self</span>) -> usize {
<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span>usize
}
}
<span class="doccomment">/// The instructions for the [`TinyVm`].
</span><span class="attr">#[derive(Debug, PartialEq, Clone, Copy)]
</span><span class="kw">pub enum </span>TinyInsn {
<span class="doccomment">/// Halt the VM.
</span>Halt,
<span class="doccomment">/// Load the immediate value into the register `reg = imm`.
</span>LoadImm(TinyReg, u16),
<span class="doccomment">/// Load a value from the memory (absolute addressing) into the register `reg = mem[imm]`.
</span>Load(TinyReg, u16),
<span class="doccomment">/// Store a value from the register into the memory (absolute addressing) `mem[imm] = reg`.
</span>Store(TinyReg, u16),
<span class="doccomment">/// Add the register to the register `reg1 += reg2`.
</span>Add(TinyReg, TinyReg),
<span class="doccomment">/// Add the immediate to the register `reg += imm`.
</span>Addi(TinyReg, i16),
<span class="doccomment">/// Jump unconditional (absolute addressing) `pc = disp`.
</span>Branch(usize),
<span class="doccomment">/// Jump if the register is zero (absolute addressing) `pc = (reg == 0) ? disp : pc++`.
</span>BranchZero(TinyReg, usize),
}
<span class="doccomment">/// Value returned from a [`JitFn`].
</span><span class="attr">#[repr(C)]
</span><span class="kw">struct </span>JitRet(u64, u64);
<span class="doccomment">/// Function signature defining the simple JIT ABI used in this example.
/// A `JitFn` represents the entry point to a jit compiled _basic block_ of the guest software.
///
/// ```text
/// JIT entry:
/// arg0: pointer to guest registers
/// arg1: pointer to guest data memory
///
/// JIT exit:
/// JitRet(0, N): Halt instruction, executed N instructions.
/// JitRet(N, R): N!=0
/// End of basic block, executed N instructions,
/// must re-enter at `pc = R`.
/// ```
</span><span class="kw">type </span>JitFn = <span class="kw">extern </span><span class="string">"C" </span><span class="kw">fn</span>(<span class="kw-2">*mut </span>u16, <span class="kw-2">*mut </span>u8) -> JitRet;
<span class="doccomment">/// The `TinyVm` virtual machine state.
</span><span class="kw">pub struct </span>TinyVm {
<span class="doccomment">/// Data memory, covering full 16 bit guest address space.
///
/// For simplicity add additional trailing 1 byte to support an unaligned access to 0xffff
/// without any special handling.
</span>dmem: [u8; <span class="number">0x1_0000 </span>+ <span class="number">1</span>],
<span class="doccomment">/// Instruction memory.
</span>imem: Vec<TinyInsn>,
<span class="doccomment">/// VM registers.
</span>regs: [u16; <span class="number">3</span>],
<span class="doccomment">/// VM program counter.
</span>pc: usize,
<span class="doccomment">/// VM executed instruction counter (perf counter).
</span>icnt: usize,
<span class="comment">// -- JIT state.
</span><span class="doccomment">/// Mapping of guest PCs to jitted host code (`JitFn`). This mapping is filled when guest
/// _basic blocks_ are jitted.
</span>jit_cache: Vec<<span class="prelude-ty">Option</span><JitFn>>,
<span class="doccomment">/// JIT runtime maintaining the host pages containing the jitted guest code.
</span>rt: Runtime,
}
<span class="kw">impl </span>TinyVm {
<span class="doccomment">/// Create a new [`TinyVm`] and initialize the instruction memory from `code`.
</span><span class="kw">pub fn </span>new(code: Vec<TinyInsn>) -> <span class="self">Self </span>{
<span class="kw">let </span><span class="kw-2">mut </span>jit_cache = Vec::with_capacity(code.len());
jit_cache.resize(code.len(), <span class="prelude-val">None</span>);
TinyVm {
dmem: [<span class="number">0</span>; <span class="number">0x1_0000 </span>+ <span class="number">1</span>],
imem: code,
regs: [<span class="number">0</span>; <span class="number">3</span>],
pc: <span class="number">0</span>,
icnt: <span class="number">0</span>,
<span class="comment">// -- JIT state.
</span>jit_cache,
rt: Runtime::new(),
<span class="comment">// Confifigure the runtime to generates perf meta data.
//rt: Runtime::with_profile(),
</span>}
}
<span class="doccomment">/// Read guest register.
</span><span class="attr">#[inline]
</span><span class="kw">pub fn </span>read_reg(<span class="kw-2">&</span><span class="self">self</span>, reg: TinyReg) -> u16 {
<span class="self">self</span>.regs[reg.idx()]
}
<span class="doccomment">/// Write guest register.
</span><span class="attr">#[inline]
</span><span class="kw">pub fn </span>write_reg(<span class="kw-2">&mut </span><span class="self">self</span>, reg: TinyReg, val: u16) {
<span class="self">self</span>.regs[reg.idx()] = val;
}
<span class="doccomment">/// Read guest data memory.
</span><span class="attr">#[inline]
</span><span class="kw">pub fn </span>read_mem(<span class="kw-2">&</span><span class="self">self</span>, paddr: PhysAddr) -> u16 {
<span class="comment">// dmem covers whole 16 bit address space + 1 byte for unaligned access at 0xffff.
</span><span class="kw">let </span>bytes = <span class="self">self</span>.dmem[paddr.into()..][..<span class="number">2</span>].try_into().unwrap();
u16::from_le_bytes(bytes)
}
<span class="doccomment">/// Write guest data memory.
</span><span class="attr">#[inline]
</span><span class="kw">pub fn </span>write_mem(<span class="kw-2">&mut </span><span class="self">self</span>, paddr: PhysAddr, val: u16) {
<span class="kw">let </span>bytes = val.to_le_bytes();
<span class="self">self</span>.dmem[paddr.into()..][..<span class="number">2</span>].copy_from_slice(<span class="kw-2">&</span>bytes);
}
<span class="doccomment">/// Dump the VM state to stdout.
</span><span class="kw">pub fn </span>dump(<span class="kw-2">&</span><span class="self">self</span>) {
<span class="macro">println!</span>(<span class="string">"-- TinyVm state --"</span>);
<span class="macro">println!</span>(<span class="string">" ICNT: {}"</span>, <span class="self">self</span>.icnt);
<span class="macro">println!</span>(<span class="string">" PC : {:02x}"</span>, <span class="self">self</span>.pc - <span class="number">1</span>);
<span class="macro">println!</span>(
<span class="string">" A:{:04x} B:{:04x} C:{:04x}"</span>,
<span class="self">self</span>.read_reg(TinyReg::A),
<span class="self">self</span>.read_reg(TinyReg::B),
<span class="self">self</span>.read_reg(TinyReg::C),
);
}
<span class="doccomment">/// Run in interpreter mode until the next [`TinyInsn::Halt`] instruction is hit.
</span><span class="kw">pub fn </span>interp(<span class="kw-2">&mut </span><span class="self">self</span>) {
<span class="lifetime">'outer</span>: <span class="kw">loop </span>{
<span class="kw">let </span>insn = <span class="self">self</span>.imem[<span class="self">self</span>.pc];
<span class="comment">//println!("[0x{:02x}] {:?}", self.pc, insn);
</span><span class="self">self</span>.pc = <span class="self">self</span>.pc.wrapping_add(<span class="number">1</span>);
<span class="self">self</span>.icnt += <span class="number">1</span>;
<span class="kw">match </span>insn {
TinyInsn::Halt => {
<span class="kw">break </span><span class="lifetime">'outer</span>;
}
TinyInsn::LoadImm(a, imm) => {
<span class="self">self</span>.write_reg(a, imm);
}
TinyInsn::Load(a, addr) => {
<span class="kw">let </span>val = <span class="self">self</span>.read_mem(PhysAddr(addr));
<span class="self">self</span>.write_reg(a, val);
}
TinyInsn::Store(a, addr) => {
<span class="kw">let </span>val = <span class="self">self</span>.read_reg(a);
<span class="self">self</span>.write_mem(PhysAddr(addr), val);
}
TinyInsn::Add(a, b) => {
<span class="kw">let </span>res = <span class="self">self</span>.read_reg(a).wrapping_add(<span class="self">self</span>.read_reg(b));
<span class="self">self</span>.write_reg(a, res);
}
TinyInsn::Addi(a, imm) => {
<span class="kw">let </span>res = <span class="self">self</span>.read_reg(a).wrapping_add(imm <span class="kw">as </span>u16);
<span class="self">self</span>.write_reg(a, res);
}
TinyInsn::Branch(disp) => {
<span class="self">self</span>.pc = disp;
}
TinyInsn::BranchZero(a, disp) => {
<span class="kw">if </span><span class="self">self</span>.read_reg(a) == <span class="number">0 </span>{
<span class="self">self</span>.pc = disp;
}
}
}
}
}
<span class="doccomment">/// Run in JIT mode until the next [`TinyInsn::Halt`] instruction is hit. Translate guest
/// _basic blocks_ on demand.
</span><span class="kw">pub fn </span>jit(<span class="kw-2">&mut </span><span class="self">self</span>) {
<span class="lifetime">'outer</span>: <span class="kw">loop </span>{
<span class="kw">let </span>bb_fn = <span class="kw">if let </span><span class="prelude-val">Some</span>(bb_fn) = <span class="self">self</span>.jit_cache[<span class="self">self</span>.pc] {
bb_fn
} <span class="kw">else </span>{
<span class="kw">let </span>bb_fn = <span class="self">self</span>.translate_next_bb();
<span class="self">self</span>.jit_cache[<span class="self">self</span>.pc] = <span class="prelude-val">Some</span>(bb_fn);
<span class="comment">//println!("[0x{:02x}] translated bb at {:p}", self.pc, bb_fn);
</span>bb_fn
};
<span class="kw">match </span>bb_fn(<span class="self">self</span>.regs.as_mut_ptr(), <span class="self">self</span>.dmem.as_mut_ptr()) {
<span class="comment">// HALT instruction hit.
</span>JitRet(<span class="number">0</span>, insn) => {
<span class="self">self</span>.pc += insn <span class="kw">as </span>usize;
<span class="self">self</span>.icnt += insn <span class="kw">as </span>usize;
<span class="kw">break </span><span class="lifetime">'outer</span>;
}
<span class="comment">// End of basic block, re-enter.
</span>JitRet(insn, reenter_pc) => {
<span class="self">self</span>.pc = reenter_pc <span class="kw">as </span>usize;
<span class="self">self</span>.icnt += insn <span class="kw">as </span>usize;
}
}
}
}
<span class="attr">#[cfg(all(any(target_arch = <span class="string">"x86_64"</span>, target_os = <span class="string">"linux"</span>)))]
</span><span class="doccomment">/// Translate the bb at the current pc and return a JitFn pointer to it.
</span><span class="kw">fn </span>translate_next_bb(<span class="kw-2">&mut </span><span class="self">self</span>) -> JitFn {
<span class="kw">let </span><span class="kw-2">mut </span>bb = Asm::new();
<span class="kw">let </span><span class="kw-2">mut </span>pc = <span class="self">self</span>.pc;
<span class="lifetime">'outer</span>: <span class="kw">loop </span>{
<span class="kw">let </span>insn = <span class="self">self</span>.imem[pc];
pc = pc.wrapping_add(<span class="number">1</span>);
<span class="comment">// JIT abi: JitFn -> JitRet
//
// According to SystemV abi:
// enter
// rdi => regs
// rsi => dmem
// exit
// rax => JitRet.0
// rdx => JitRet.1
// Generate memory operand into regs for guest register.
</span><span class="kw">let </span>reg_op = |r: TinyReg| {
Mem16::indirect_disp(Reg64::rdi, (r.idx() * <span class="number">2</span>).try_into().expect(<span class="string">"only 3 regs"</span>))
};
<span class="comment">// Generate memory operand into dmem for guest phys address.
</span><span class="kw">let </span>mem_op = |paddr: u16| Mem16::indirect_disp(Reg64::rsi, paddr.into());
<span class="comment">// Compute instructions in translated basic block.
</span><span class="kw">let </span>bb_icnt = || -> u64 { (pc - <span class="self">self</span>.pc).try_into().unwrap() };
<span class="kw">let </span>reenter_pc = |pc: usize| -> u64 { pc.try_into().unwrap() };
<span class="kw">match </span>insn {
TinyInsn::Halt => {
bb.mov(Reg64::rax, Imm64::from(<span class="number">0</span>));
bb.mov(Reg64::rdx, Imm64::from(bb_icnt()));
bb.ret();
<span class="kw">break </span><span class="lifetime">'outer</span>;
}
TinyInsn::LoadImm(a, imm) => {
bb.mov(reg_op(a), Imm16::from(imm));
}
TinyInsn::Load(a, addr) => {
bb.mov(Reg16::ax, mem_op(addr));
bb.mov(reg_op(a), Reg16::ax);
}
TinyInsn::Store(a, addr) => {
bb.mov(Reg16::ax, reg_op(a));
bb.mov(mem_op(addr), Reg16::ax);
}
TinyInsn::Add(a, b) => {
bb.mov(Reg16::ax, reg_op(b));
bb.add(reg_op(a), Reg16::ax);
}
TinyInsn::Addi(a, imm) => {
bb.add(reg_op(a), Imm16::from(imm));
}
TinyInsn::Branch(disp) => {
bb.mov(Reg64::rax, Imm64::from(bb_icnt()));
bb.mov(Reg64::rdx, Imm64::from(reenter_pc(disp)));
bb.ret();
<span class="kw">break </span><span class="lifetime">'outer</span>;
}
TinyInsn::BranchZero(a, disp) => {
bb.cmp(reg_op(a), Imm16::from(<span class="number">0u16</span>));
bb.mov(Reg64::rax, Imm64::from(bb_icnt()));
<span class="comment">// Default fall-through PC (branch not taken).
</span>bb.mov(Reg64::rdx, Imm64::from(reenter_pc(pc)));
<span class="comment">// Conditionally update PC if condition is ZERO (branch taken).
</span>bb.mov(Reg64::r11, Imm64::from(reenter_pc(disp)));
bb.cmovz(Reg64::rdx, Reg64::r11);
bb.ret();
<span class="kw">break </span><span class="lifetime">'outer</span>;
}
}
}
<span class="kw">unsafe </span>{ <span class="self">self</span>.rt.add_code::<JitFn>(bb.into_code()) }
}
}
<span class="doccomment">/// A minial fixup utility to implement jump labels when constructing guest programs.
</span><span class="kw">pub struct </span>Fixup {
pc: usize,
}
<span class="kw">impl </span>Fixup {
<span class="doccomment">/// Create a new `Fixup` at the current pc.
</span><span class="kw">pub fn </span>new(pc: usize) -> <span class="self">Self </span>{
Fixup { pc }
}
<span class="doccomment">/// Bind the `Fixup` to the current location of `prog` and resolve the `Fixup`.
</span><span class="kw">pub fn </span>bind(<span class="self">self</span>, prog: <span class="kw-2">&mut </span>Vec<TinyInsn>) {
<span class="kw">let </span>plen = prog.len();
<span class="kw">let </span>insn = prog.get_mut(<span class="self">self</span>.pc).expect(<span class="kw-2">&</span><span class="macro">format!</span>(
<span class="string">"Trying to apply Fixup, but Fixup is out of range pc={} prog.len={}"</span>,
<span class="self">self</span>.pc, plen
));
<span class="kw">match </span>insn {
TinyInsn::Branch(disp) | TinyInsn::BranchZero(<span class="kw">_</span>, disp) => {
<span class="kw-2">*</span>disp = plen;
}
<span class="kw">_ </span>=> {
<span class="macro">unimplemented!</span>(<span class="string">"Trying to fixup non-branch instruction '{:?}'"</span>, <span class="kw-2">*</span>insn);
}
}
}
}
<span class="doccomment">/// Generate a guest program to compute the fiibonacci sequence for `n`.
</span><span class="kw">pub fn </span>make_tinyvm_fib(start_n: u16) -> Vec<TinyInsn> {
<span class="comment">// Reference implementation:
//
// int fib(int n)
// int tmp = 0;
// int prv = 1;
// int sum = 0;
// loop:
// if (n == 0) goto end;
// tmp = sum;
// sum += prv;
// prv = tmp;
// --n;
// goto loop;
// end:
// return sum;
// Variables live in memory, bin to fixed addresses.
</span><span class="kw">let </span>tmp = <span class="number">0u16</span>;
<span class="kw">let </span>prv = <span class="number">2u16</span>;
<span class="kw">let </span>sum = <span class="number">4u16</span>;
<span class="comment">// Loop counter mapped to register.
</span><span class="kw">let </span>n = TinyReg::C;
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::with_capacity(<span class="number">32</span>);
<span class="comment">// n = start_n
</span>prog.push(TinyInsn::LoadImm(n, start_n));
<span class="comment">// tmp = sum = 0
</span>prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">0</span>));
prog.push(TinyInsn::Store(TinyReg::A, tmp));
prog.push(TinyInsn::Store(TinyReg::A, sum));
<span class="comment">// prv = 1
</span>prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">1</span>));
prog.push(TinyInsn::Store(TinyReg::A, prv));
<span class="comment">// Create loop_start label.
</span><span class="kw">let </span>loop_start = prog.len();
<span class="comment">// Create fixup to capture PC that need to be patched later.
</span><span class="kw">let </span>end_fixup = Fixup::new(prog.len());
<span class="comment">// if (n == 0) goto end
</span>prog.push(TinyInsn::BranchZero(n, <span class="number">0xdead</span>));
<span class="comment">// tmp = sum
</span>prog.push(TinyInsn::Load(TinyReg::A, sum));
prog.push(TinyInsn::Store(TinyReg::A, tmp));
<span class="comment">// sum += prv
</span>prog.push(TinyInsn::Load(TinyReg::B, prv));
prog.push(TinyInsn::Add(TinyReg::A, TinyReg::B));
prog.push(TinyInsn::Store(TinyReg::A, sum));
<span class="comment">// prv = tmp
</span>prog.push(TinyInsn::Load(TinyReg::A, tmp));
prog.push(TinyInsn::Store(TinyReg::A, prv));
<span class="comment">// --n
</span>prog.push(TinyInsn::Addi(n, -<span class="number">1</span>));
<span class="comment">// goto loop_start
</span>prog.push(TinyInsn::Branch(loop_start));
<span class="comment">// Bind end fixup to current PC, to patch branch to jump to here.
</span>end_fixup.bind(<span class="kw-2">&mut </span>prog);
<span class="comment">// TinyReg::A = sum
</span>prog.push(TinyInsn::Load(TinyReg::A, sum));
<span class="comment">// Halt the VM.
</span>prog.push(TinyInsn::Halt);
prog
}
<span class="doccomment">/// Generate a test program for the jit.
</span><span class="kw">pub fn </span>make_tinyvm_jit_test() -> Vec<TinyInsn> {
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::with_capacity(<span class="number">32</span>);
prog.push(TinyInsn::Branch(<span class="number">1</span>));
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">0x0010</span>));
prog.push(TinyInsn::LoadImm(TinyReg::B, <span class="number">0x0</span>));
<span class="kw">let </span>start = prog.len();
<span class="kw">let </span>end = Fixup::new(prog.len());
prog.push(TinyInsn::BranchZero(TinyReg::A, <span class="number">0xdead</span>));
prog.push(TinyInsn::LoadImm(TinyReg::C, <span class="number">0x1</span>));
prog.push(TinyInsn::Add(TinyReg::B, TinyReg::C));
prog.push(TinyInsn::Addi(TinyReg::A, -<span class="number">1</span>));
prog.push(TinyInsn::Branch(start));
end.bind(<span class="kw-2">&mut </span>prog);
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">0xabcd</span>));
prog.push(TinyInsn::Store(TinyReg::A, <span class="number">0xffff</span>));
prog.push(TinyInsn::Load(TinyReg::C, <span class="number">0xffff</span>));
prog.push(TinyInsn::Halt);
prog.push(TinyInsn::Halt);
prog.push(TinyInsn::Halt);
prog.push(TinyInsn::Halt);
prog
}
<span class="doccomment">/// Generate a simple count down loop to crunch some instructions.
</span><span class="kw">pub fn </span>make_tinyvm_jit_perf() -> Vec<TinyInsn> {
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::with_capacity(<span class="number">32</span>);
prog.push(TinyInsn::Halt);
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">0xffff</span>));
prog.push(TinyInsn::LoadImm(TinyReg::B, <span class="number">1</span>));
prog.push(TinyInsn::LoadImm(TinyReg::C, <span class="number">2</span>));
prog.push(TinyInsn::Addi(TinyReg::A, -<span class="number">1</span>));
prog.push(TinyInsn::BranchZero(TinyReg::A, <span class="number">0</span>));
prog.push(TinyInsn::Branch(<span class="number">2</span>));
prog
}
<span class="kw">fn </span>main() {
<span class="kw">let </span>use_jit = <span class="kw">match </span>std::env::args().nth(<span class="number">1</span>) {
<span class="prelude-val">Some</span>(a) <span class="kw">if </span>a == <span class="string">"-h" </span>|| a == <span class="string">"--help" </span>=> {
<span class="macro">println!</span>(<span class="string">"Usage: tiny_vm [mode]"</span>);
<span class="macro">println!</span>(<span class="string">""</span>);
<span class="macro">println!</span>(<span class="string">"Options:"</span>);
<span class="macro">println!</span>(<span class="string">" mode if mode is 'jit' then run in jit mode, else in interpreter mode"</span>);
std::process::exit(<span class="number">0</span>);
}
<span class="prelude-val">Some</span>(a) <span class="kw">if </span>a == <span class="string">"jit" </span>=> <span class="bool-val">true</span>,
<span class="kw">_ </span>=> <span class="bool-val">false</span>,
};
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(make_tinyvm_fib(<span class="number">42</span>));
<span class="kw">if </span>use_jit {
<span class="macro">println!</span>(<span class="string">"Run in jit mode.."</span>);
vm.jit();
} <span class="kw">else </span>{
<span class="macro">println!</span>(<span class="string">"Run in interpreter mode.."</span>);
vm.interp();
}
vm.dump();
}
<span class="attr">#[cfg(test)]
</span><span class="kw">mod </span>test {
<span class="kw">use super</span>::<span class="kw-2">*</span>;
<span class="kw">fn </span>fib_rs(n: u64) -> u64 {
<span class="kw">if </span>n < <span class="number">2 </span>{
n
} <span class="kw">else </span>{
<span class="kw">let </span><span class="kw-2">mut </span>fib_n_m1 = <span class="number">0</span>;
<span class="kw">let </span><span class="kw-2">mut </span>fib_n = <span class="number">1</span>;
<span class="kw">for _ in </span><span class="number">1</span>..n {
<span class="kw">let </span>tmp = fib_n + fib_n_m1;
fib_n_m1 = fib_n;
fib_n = tmp;
}
fib_n
}
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_fib_interp() {
<span class="kw">for </span>n <span class="kw">in </span><span class="number">0</span>..<span class="number">92 </span>{
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(make_tinyvm_fib(n));
vm.interp();
<span class="macro">assert_eq!</span>((fib_rs(n <span class="kw">as </span>u64) & <span class="number">0xffff</span>) <span class="kw">as </span>u16, vm.read_reg(TinyReg::A));
}
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_fib_jit() {
<span class="kw">for </span>n <span class="kw">in </span><span class="number">0</span>..<span class="number">92 </span>{
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(make_tinyvm_fib(n));
vm.jit();
<span class="macro">assert_eq!</span>((fib_rs(n <span class="kw">as </span>u64) & <span class="number">0xffff</span>) <span class="kw">as </span>u16, vm.read_reg(TinyReg::A));
}
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_fib_icnt() {
<span class="kw">let </span><span class="kw-2">mut </span>vm1 = TinyVm::new(make_tinyvm_fib(<span class="number">91</span>));
vm1.interp();
<span class="kw">let </span><span class="kw-2">mut </span>vm2 = TinyVm::new(make_tinyvm_fib(<span class="number">91</span>));
vm2.jit();
<span class="macro">assert_eq!</span>(vm1.icnt, vm2.icnt);
<span class="macro">assert_eq!</span>(vm1.pc, vm2.pc);
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_jit_load_imm() {
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::new();
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">0x1111</span>));
prog.push(TinyInsn::LoadImm(TinyReg::B, <span class="number">0x2222</span>));
prog.push(TinyInsn::LoadImm(TinyReg::C, <span class="number">0x3333</span>));
prog.push(TinyInsn::Halt);
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(prog);
vm.jit();
<span class="macro">assert_eq!</span>(<span class="number">0x1111</span>, vm.read_reg(TinyReg::A));
<span class="macro">assert_eq!</span>(<span class="number">0x2222</span>, vm.read_reg(TinyReg::B));
<span class="macro">assert_eq!</span>(<span class="number">0x3333</span>, vm.read_reg(TinyReg::C));
<span class="macro">assert_eq!</span>(<span class="number">4</span>, vm.icnt);
<span class="macro">assert_eq!</span>(<span class="number">4</span>, vm.pc);
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_jit_add() {
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::new();
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">0</span>));
prog.push(TinyInsn::Addi(TinyReg::A, <span class="number">123</span>));
prog.push(TinyInsn::LoadImm(TinyReg::B, <span class="number">100</span>));
prog.push(TinyInsn::LoadImm(TinyReg::C, <span class="number">200</span>));
prog.push(TinyInsn::Add(TinyReg::B, TinyReg::C));
prog.push(TinyInsn::Halt);
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(prog);
vm.jit();
<span class="macro">assert_eq!</span>(<span class="number">123</span>, vm.read_reg(TinyReg::A));
<span class="macro">assert_eq!</span>(<span class="number">300</span>, vm.read_reg(TinyReg::B));
<span class="macro">assert_eq!</span>(<span class="number">200</span>, vm.read_reg(TinyReg::C));
<span class="macro">assert_eq!</span>(<span class="number">6</span>, vm.icnt);
<span class="macro">assert_eq!</span>(<span class="number">6</span>, vm.pc);
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_jit_load_store() {
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::new();
prog.push(TinyInsn::Load(TinyReg::A, <span class="number">0xffff</span>));
prog.push(TinyInsn::LoadImm(TinyReg::B, <span class="number">0xf00d</span>));
prog.push(TinyInsn::Store(TinyReg::B, <span class="number">0x8000</span>));
prog.push(TinyInsn::Halt);
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(prog);
vm.write_mem(PhysAddr(<span class="number">0xffff</span>), <span class="number">0xaabb</span>);
vm.jit();
<span class="macro">assert_eq!</span>(<span class="number">0xaabb</span>, vm.read_reg(TinyReg::A));
<span class="macro">assert_eq!</span>(<span class="number">0xf00d</span>, vm.read_mem(PhysAddr(<span class="number">0x8000</span>)));
<span class="macro">assert_eq!</span>(<span class="number">4</span>, vm.icnt);
<span class="macro">assert_eq!</span>(<span class="number">4</span>, vm.pc);
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_jit_branch() {
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::new();
prog.push(TinyInsn::Branch(<span class="number">2</span>));
prog.push(TinyInsn::Halt);
prog.push(TinyInsn::Branch(<span class="number">6</span>));
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">1</span>));
prog.push(TinyInsn::LoadImm(TinyReg::B, <span class="number">2</span>));
prog.push(TinyInsn::LoadImm(TinyReg::C, <span class="number">3</span>));
prog.push(TinyInsn::Branch(<span class="number">1</span>));
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(prog);
vm.jit();
<span class="macro">assert_eq!</span>(<span class="number">0</span>, vm.read_reg(TinyReg::A));
<span class="macro">assert_eq!</span>(<span class="number">0</span>, vm.read_reg(TinyReg::B));
<span class="macro">assert_eq!</span>(<span class="number">0</span>, vm.read_reg(TinyReg::C));
<span class="macro">assert_eq!</span>(<span class="number">4</span>, vm.icnt);
<span class="macro">assert_eq!</span>(<span class="number">2</span>, vm.pc);
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_jit_branch_zero() {
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::new();
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">1</span>));
prog.push(TinyInsn::BranchZero(TinyReg::A, <span class="number">5</span>));
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">0</span>));
prog.push(TinyInsn::BranchZero(TinyReg::A, <span class="number">5</span>));
prog.push(TinyInsn::LoadImm(TinyReg::B, <span class="number">22</span>));
prog.push(TinyInsn::Halt);
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(prog);
vm.jit();
<span class="macro">assert_eq!</span>(<span class="number">0</span>, vm.read_reg(TinyReg::A));
<span class="macro">assert_eq!</span>(<span class="number">0</span>, vm.read_reg(TinyReg::B));
<span class="macro">assert_eq!</span>(<span class="number">0</span>, vm.read_reg(TinyReg::C));
<span class="macro">assert_eq!</span>(<span class="number">5</span>, vm.icnt);
<span class="macro">assert_eq!</span>(<span class="number">6</span>, vm.pc);
}
<span class="attr">#[test]
</span><span class="kw">fn </span>test_mixed() {
<span class="kw">let </span><span class="kw-2">mut </span>prog = Vec::new();
prog.push(TinyInsn::LoadImm(TinyReg::A, <span class="number">100</span>));
prog.push(TinyInsn::Add(TinyReg::B, TinyReg::A));
prog.push(TinyInsn::Addi(TinyReg::C, <span class="number">100</span>));
prog.push(TinyInsn::Halt);
<span class="kw">let </span><span class="kw-2">mut </span>vm = TinyVm::new(prog);
vm.interp();
<span class="macro">assert_eq!</span>(<span class="number">100</span>, vm.read_reg(TinyReg::A));
<span class="macro">assert_eq!</span>(<span class="number">100</span>, vm.read_reg(TinyReg::B));
<span class="macro">assert_eq!</span>(<span class="number">100</span>, vm.read_reg(TinyReg::C));
<span class="macro">assert_eq!</span>(<span class="number">4</span>, vm.icnt);
<span class="macro">assert_eq!</span>(<span class="number">4</span>, vm.pc);
vm.pc = <span class="number">0</span>;
vm.jit();
<span class="macro">assert_eq!</span>(<span class="number">100</span>, vm.read_reg(TinyReg::A));
<span class="macro">assert_eq!</span>(<span class="number">200</span>, vm.read_reg(TinyReg::B));
<span class="macro">assert_eq!</span>(<span class="number">200</span>, vm.read_reg(TinyReg::C));
<span class="macro">assert_eq!</span>(<span class="number">8</span>, vm.icnt);
<span class="macro">assert_eq!</span>(<span class="number">4</span>, vm.pc);
}
}
</code></pre></div></section></main></body></html>
