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This commit is contained in:
Erin 2023-08-18 01:41:05 +02:00 committed by ondra05
parent bd9b4e0364
commit d4b2a1a266
6 changed files with 483 additions and 462 deletions
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6
hbvm/src/bmc.rs
View file

@ -1,7 +1,7 @@
//! Block memory copier state machine
use {
super::{Memory, MemoryAccessReason, VmRunError},
super::{Memory, mem::MemoryAccessReason, VmRunError},
core::{mem::MaybeUninit, task::Poll},
};
@ -108,7 +108,7 @@ unsafe fn act(
// Load to buffer
memory
.load(src, buf, count)
.map_err(|super::LoadError(addr)| BlkCopyError::Access {
.map_err(|super::mem::LoadError(addr)| BlkCopyError::Access {
access_reason: MemoryAccessReason::Load,
addr,
})?;
@ -116,7 +116,7 @@ unsafe fn act(
// Store from buffer
memory
.store(dst, buf, count)
.map_err(|super::StoreError(addr)| BlkCopyError::Access {
.map_err(|super::mem::StoreError(addr)| BlkCopyError::Access {
access_reason: MemoryAccessReason::Store,
addr,
})?;

459
hbvm/src/lib.rs
View file

@ -14,6 +14,8 @@
#![cfg_attr(feature = "nightly", feature(fn_align))]
#![warn(missing_docs, clippy::missing_docs_in_private_items)]
use mem::Memory;
#[cfg(feature = "alloc")]
extern crate alloc;
@ -21,16 +23,9 @@ pub mod mem;
pub mod value;
mod bmc;
mod vmrun;
use {
bmc::BlockCopier,
core::{cmp::Ordering, mem::size_of, ops},
derive_more::Display,
hbbytecode::{
ParamBB, ParamBBB, ParamBBBB, ParamBBD, ParamBBDH, ParamBBW, ParamBD, ProgramVal,
},
value::{Value, ValueVariant},
};
use {bmc::BlockCopier, value::Value};
/// HoleyBytes Virtual Machine
pub struct Vm<Mem, const TIMER_QUOTIENT: usize> {
@ -70,389 +65,6 @@ where
copier: None,
}
}
/// Execute program
///
/// Program can return [`VmRunError`] if a trap handling failed
#[cfg_attr(feature = "nightly", repr(align(4096)))]
pub fn run(&mut self) -> Result<VmRunOk, VmRunError> {
use hbbytecode::opcode::*;
loop {
// Big match
//
// Contribution guide:
// - Zero register shall never be overwitten. It's value has to always be 0.
// - Prefer `Self::read_reg` and `Self::write_reg` functions
// - Extract parameters using `param!` macro
// - Prioritise speed over code size
// - Memory is cheap, CPUs not that much
// - Do not heap allocate at any cost
// - Yes, user-provided trap handler may allocate,
// but that is not our »fault«.
// - Unsafe is kinda must, but be sure you have validated everything
// - Your contributions have to pass sanitizers and Miri
// - Strictly follow the spec
// - The spec does not specify how you perform actions, in what order,
// just that the observable effects have to be performed in order and
// correctly.
// - Yes, we assume you run 64 bit CPU. Else ?conradluget a better CPU
// sorry 8 bit fans, HBVM won't run on your Speccy :(
unsafe {
match self
.memory
.prog_read::<u8>(self.pc as _)
.ok_or(VmRunError::ProgramFetchLoadEx(self.pc as _))?
{
UN => {
self.decode::<()>();
return Err(VmRunError::Unreachable);
}
TX => {
self.decode::<()>();
return Ok(VmRunOk::End);
}
NOP => self.decode::<()>(),
ADD => self.binary_op(u64::wrapping_add),
SUB => self.binary_op(u64::wrapping_sub),
MUL => self.binary_op(u64::wrapping_mul),
AND => self.binary_op::<u64>(ops::BitAnd::bitand),
OR => self.binary_op::<u64>(ops::BitOr::bitor),
XOR => self.binary_op::<u64>(ops::BitXor::bitxor),
SL => self.binary_op(|l, r| u64::wrapping_shl(l, r as u32)),
SR => self.binary_op(|l, r| u64::wrapping_shr(l, r as u32)),
SRS => self.binary_op(|l, r| i64::wrapping_shl(l, r as u32)),
CMP => {
// Compare a0 <=> a1
// < → -1
// > → 1
// = → 0
let ParamBBB(tg, a0, a1) = self.decode();
self.write_reg(
tg,
self.read_reg(a0)
.cast::<i64>()
.cmp(&self.read_reg(a1).cast::<i64>())
as i64,
);
}
CMPU => {
// Unsigned comparsion
let ParamBBB(tg, a0, a1) = self.decode();
self.write_reg(
tg,
self.read_reg(a0)
.cast::<u64>()
.cmp(&self.read_reg(a1).cast::<u64>())
as i64,
);
}
NOT => {
// Logical negation
let ParamBB(tg, a0) = self.decode();
self.write_reg(tg, !self.read_reg(a0).cast::<u64>());
}
NEG => {
// Bitwise negation
let ParamBB(tg, a0) = self.decode();
self.write_reg(
tg,
match self.read_reg(a0).cast::<u64>() {
0 => 1_u64,
_ => 0,
},
);
}
DIR => {
// Fused Division-Remainder
let ParamBBBB(dt, rt, a0, a1) = self.decode();
let a0 = self.read_reg(a0).cast::<u64>();
let a1 = self.read_reg(a1).cast::<u64>();
self.write_reg(dt, a0.checked_div(a1).unwrap_or(u64::MAX));
self.write_reg(rt, a0.checked_rem(a1).unwrap_or(u64::MAX));
}
ADDI => self.binary_op_imm(u64::wrapping_add),
MULI => self.binary_op_imm(u64::wrapping_sub),
ANDI => self.binary_op_imm::<u64>(ops::BitAnd::bitand),
ORI => self.binary_op_imm::<u64>(ops::BitOr::bitor),
XORI => self.binary_op_imm::<u64>(ops::BitXor::bitxor),
SLI => self.binary_op_ims(u64::wrapping_shl),
SRI => self.binary_op_ims(u64::wrapping_shr),
SRSI => self.binary_op_ims(i64::wrapping_shr),
CMPI => {
let ParamBBD(tg, a0, imm) = self.decode();
self.write_reg(
tg,
self.read_reg(a0)
.cast::<i64>()
.cmp(&Value::from(imm).cast::<i64>())
as i64,
);
}
CMPUI => {
let ParamBBD(tg, a0, imm) = self.decode();
self.write_reg(tg, self.read_reg(a0).cast::<u64>().cmp(&imm) as i64);
}
CP => {
let ParamBB(tg, a0) = self.decode();
self.write_reg(tg, self.read_reg(a0));
}
SWA => {
// Swap registers
let ParamBB(r0, r1) = self.decode();
match (r0, r1) {
(0, 0) => (),
(dst, 0) | (0, dst) => self.write_reg(dst, 0_u64),
(r0, r1) => {
core::ptr::swap(
self.registers.get_unchecked_mut(usize::from(r0)),
self.registers.get_unchecked_mut(usize::from(r1)),
);
}
}
}
LI => {
let ParamBD(tg, imm) = self.decode();
self.write_reg(tg, imm);
}
LD => {
// Load. If loading more than register size, continue on adjecent registers
let ParamBBDH(dst, base, off, count) = self.decode();
let n: u8 = match dst {
0 => 1,
_ => 0,
};
self.memory.load(
self.ldst_addr_uber(dst, base, off, count, n)?,
self.registers
.as_mut_ptr()
.add(usize::from(dst) + usize::from(n))
.cast(),
usize::from(count).saturating_sub(n.into()),
)?;
}
ST => {
// Store. Same rules apply as to LD
let ParamBBDH(dst, base, off, count) = self.decode();
self.memory.store(
self.ldst_addr_uber(dst, base, off, count, 0)?,
self.registers.as_ptr().add(usize::from(dst)).cast(),
count.into(),
)?;
}
BMC => {
// Block memory copy
match if let Some(copier) = &mut self.copier {
// There is some copier, poll.
copier.poll(&mut self.memory)
} else {
// There is none, make one!
let ParamBBD(src, dst, count) = self.decode();
// So we are still on BMC on next cycle
self.pc -= size_of::<ParamBBD>() + 1;
self.copier = Some(BlockCopier::new(
self.read_reg(src).cast(),
self.read_reg(dst).cast(),
count as _,
));
self.copier
.as_mut()
.unwrap_unchecked() // SAFETY: We just assigned there
.poll(&mut self.memory)
} {
// We are done, shift program counter
core::task::Poll::Ready(Ok(())) => {
self.copier = None;
self.pc += size_of::<ParamBBD>() + 1;
}
// Error, shift program counter (for consistency)
// and yield error
core::task::Poll::Ready(Err(e)) => {
self.pc += size_of::<ParamBBD>() + 1;
return Err(e.into());
}
// Not done yet, proceed to next cycle
core::task::Poll::Pending => (),
}
}
BRC => {
// Block register copy
let ParamBBB(src, dst, count) = self.decode();
if src.checked_add(count).is_none() || dst.checked_add(count).is_none() {
return Err(VmRunError::RegOutOfBounds);
}
core::ptr::copy(
self.registers.get_unchecked(usize::from(src)),
self.registers.get_unchecked_mut(usize::from(dst)),
usize::from(count),
);
}
JAL => {
// Jump and link. Save PC after this instruction to
// specified register and jump to reg + offset.
let ParamBBD(save, reg, offset) = self.decode();
self.write_reg(save, self.pc as u64);
self.pc =
(self.read_reg(reg).cast::<u64>().saturating_add(offset)) as usize;
}
// Conditional jumps, jump only to immediates
JEQ => self.cond_jmp::<u64>(Ordering::Equal),
JNE => {
let ParamBBD(a0, a1, jt) = self.decode();
if self.read_reg(a0).cast::<u64>() != self.read_reg(a1).cast::<u64>() {
self.pc = jt as usize;
}
}
JLT => self.cond_jmp::<u64>(Ordering::Less),
JGT => self.cond_jmp::<u64>(Ordering::Greater),
JLTU => self.cond_jmp::<i64>(Ordering::Less),
JGTU => self.cond_jmp::<i64>(Ordering::Greater),
ECALL => {
self.decode::<()>();
// So we don't get timer interrupt after ECALL
if TIMER_QUOTIENT != 0 {
self.timer = self.timer.wrapping_add(1);
}
return Ok(VmRunOk::Ecall);
}
ADDF => self.binary_op::<f64>(ops::Add::add),
SUBF => self.binary_op::<f64>(ops::Sub::sub),
MULF => self.binary_op::<f64>(ops::Mul::mul),
DIRF => {
let ParamBBBB(dt, rt, a0, a1) = self.decode();
let a0 = self.read_reg(a0).cast::<f64>();
let a1 = self.read_reg(a1).cast::<f64>();
self.write_reg(dt, a0 / a1);
self.write_reg(rt, a0 % a1);
}
FMAF => {
let ParamBBBB(dt, a0, a1, a2) = self.decode();
self.write_reg(
dt,
self.read_reg(a0).cast::<f64>() * self.read_reg(a1).cast::<f64>()
+ self.read_reg(a2).cast::<f64>(),
);
}
NEGF => {
let ParamBB(dt, a0) = self.decode();
self.write_reg(dt, -self.read_reg(a0).cast::<f64>());
}
ITF => {
let ParamBB(dt, a0) = self.decode();
self.write_reg(dt, self.read_reg(a0).cast::<i64>() as f64);
}
FTI => {
let ParamBB(dt, a0) = self.decode();
self.write_reg(dt, self.read_reg(a0).cast::<f64>() as i64);
}
ADDFI => self.binary_op_imm::<f64>(ops::Add::add),
MULFI => self.binary_op_imm::<f64>(ops::Mul::mul),
op => return Err(VmRunError::InvalidOpcode(op)),
}
}
if TIMER_QUOTIENT != 0 {
self.timer = self.timer.wrapping_add(1);
if self.timer % TIMER_QUOTIENT == 0 {
return Ok(VmRunOk::Timer);
}
}
}
}
/// Decode instruction operands
#[inline(always)]
unsafe fn decode<T: ProgramVal>(&mut self) -> T {
let pc1 = self.pc + 1;
let data = self.memory.prog_read_unchecked::<T>(pc1 as _);
self.pc += 1 + size_of::<T>();
data
}
/// Perform binary operating over two registers
#[inline(always)]
unsafe fn binary_op<T: ValueVariant>(&mut self, op: impl Fn(T, T) -> T) {
let ParamBBB(tg, a0, a1) = self.decode();
self.write_reg(
tg,
op(self.read_reg(a0).cast::<T>(), self.read_reg(a1).cast::<T>()),
);
}
/// Perform binary operation over register and immediate
#[inline(always)]
unsafe fn binary_op_imm<T: ValueVariant>(&mut self, op: impl Fn(T, T) -> T) {
let ParamBBD(tg, reg, imm) = self.decode();
self.write_reg(
tg,
op(self.read_reg(reg).cast::<T>(), Value::from(imm).cast::<T>()),
);
}
/// Perform binary operation over register and shift immediate
#[inline(always)]
unsafe fn binary_op_ims<T: ValueVariant>(&mut self, op: impl Fn(T, u32) -> T) {
let ParamBBW(tg, reg, imm) = self.decode();
self.write_reg(tg, op(self.read_reg(reg).cast::<T>(), imm));
}
/// Jump at `#3` if ordering on `#0 <=> #1` is equal to expected
#[inline(always)]
unsafe fn cond_jmp<T: ValueVariant + Ord>(&mut self, expected: Ordering) {
let ParamBBD(a0, a1, ja) = self.decode();
if self
.read_reg(a0)
.cast::<T>()
.cmp(&self.read_reg(a1).cast::<T>())
== expected
{
self.pc = ja as usize;
}
}
/// Read register
#[inline(always)]
unsafe fn read_reg(&self, n: u8) -> Value {
*self.registers.get_unchecked(n as usize)
}
/// Write a register.
/// Writing to register 0 is no-op.
#[inline(always)]
unsafe fn write_reg(&mut self, n: u8, value: impl Into<Value>) {
if n != 0 {
*self.registers.get_unchecked_mut(n as usize) = value.into();
}
}
/// Load / Store Address check-computation überfunction
#[inline(always)]
unsafe fn ldst_addr_uber(
&self,
dst: u8,
base: u8,
offset: u64,
size: u16,
adder: u8,
) -> Result<u64, VmRunError> {
let reg = dst.checked_add(adder).ok_or(VmRunError::RegOutOfBounds)?;
if usize::from(reg) * 8 + usize::from(size) > 2048 {
Err(VmRunError::RegOutOfBounds)
} else {
self.read_reg(base)
.cast::<u64>()
.checked_add(offset)
.and_then(|x| x.checked_add(adder.into()))
.ok_or(VmRunError::AddrOutOfBounds)
}
}
}
/// Virtual machine halt error
@ -493,66 +105,3 @@ pub enum VmRunOk {
/// Environment call
Ecall,
}
/// Load-store memory access
pub trait Memory {
/// Load data from memory on address
///
/// # Safety
/// - Shall not overrun the buffer
unsafe fn load(&mut self, addr: u64, target: *mut u8, count: usize) -> Result<(), LoadError>;
/// Store data to memory on address
///
/// # Safety
/// - Shall not overrun the buffer
unsafe fn store(
&mut self,
addr: u64,
source: *const u8,
count: usize,
) -> Result<(), StoreError>;
/// Read from program memory to execute
///
/// # Safety
/// - Data read have to be valid
unsafe fn prog_read<T: ProgramVal>(&mut self, addr: u64) -> Option<T>;
/// Read from program memory to exectue
///
/// # Safety
/// - You have to be really sure that these bytes are there, understand?
unsafe fn prog_read_unchecked<T: ProgramVal>(&mut self, addr: u64) -> T;
}
/// Unhandled load access trap
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
#[display(fmt = "Load access error at address {_0:#x}")]
pub struct LoadError(pub u64);
/// Unhandled store access trap
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
#[display(fmt = "Store access error at address {_0:#x}")]
pub struct StoreError(pub u64);
/// Reason to access memory
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
pub enum MemoryAccessReason {
/// Memory was accessed for load (read)
Load,
/// Memory was accessed for store (write)
Store,
}
impl From<LoadError> for VmRunError {
fn from(value: LoadError) -> Self {
Self::LoadAccessEx(value.0)
}
}
impl From<StoreError> for VmRunError {
fn from(value: StoreError) -> Self {
Self::StoreAccessEx(value.0)
}
}

7
hbvm/src/main.rs
View file

@ -1,8 +1,11 @@
use {
hbbytecode::valider::validate,
hbvm::{
mem::softpaging::{paging::PageTable, HandlePageFault, PageSize, SoftPagedMem},
MemoryAccessReason, Vm,
mem::{
softpaging::{paging::PageTable, HandlePageFault, PageSize, SoftPagedMem},
MemoryAccessReason,
},
Vm,
},
std::io::{stdin, Read},
};

65
hbvm/src/mem/mod.rs
View file

@ -1,3 +1,68 @@
//! Memory implementations
use {derive_more::Display, hbbytecode::ProgramVal};
pub mod softpaging;
/// Load-store memory access
pub trait Memory {
/// Load data from memory on address
///
/// # Safety
/// - Shall not overrun the buffer
unsafe fn load(&mut self, addr: u64, target: *mut u8, count: usize) -> Result<(), LoadError>;
/// Store data to memory on address
///
/// # Safety
/// - Shall not overrun the buffer
unsafe fn store(
&mut self,
addr: u64,
source: *const u8,
count: usize,
) -> Result<(), StoreError>;
/// Read from program memory to execute
///
/// # Safety
/// - Data read have to be valid
unsafe fn prog_read<T: ProgramVal>(&mut self, addr: u64) -> Option<T>;
/// Read from program memory to exectue
///
/// # Safety
/// - You have to be really sure that these bytes are there, understand?
unsafe fn prog_read_unchecked<T: ProgramVal>(&mut self, addr: u64) -> T;
}
/// Unhandled load access trap
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
#[display(fmt = "Load access error at address {_0:#x}")]
pub struct LoadError(pub u64);
/// Unhandled store access trap
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
#[display(fmt = "Store access error at address {_0:#x}")]
pub struct StoreError(pub u64);
/// Reason to access memory
#[derive(Clone, Copy, Display, Debug, PartialEq, Eq)]
pub enum MemoryAccessReason {
/// Memory was accessed for load (read)
Load,
/// Memory was accessed for store (write)
Store,
}
impl From<LoadError> for crate::VmRunError {
fn from(value: LoadError) -> Self {
Self::LoadAccessEx(value.0)
}
}
impl From<StoreError> for crate::VmRunError {
fn from(value: StoreError) -> Self {
Self::StoreAccessEx(value.0)
}
}

4
hbvm/src/mem/softpaging/mod.rs
View file

@ -12,13 +12,13 @@ pub mod paging;
pub mod mapping;
use {
crate::{LoadError, Memory, MemoryAccessReason, StoreError},
super::{LoadError, Memory, MemoryAccessReason, StoreError},
lookup::{AddrPageLookupError, AddrPageLookupOk, AddrPageLookuper},
paging::{PageTable, Permission},
};
/// HoleyBytes software paged memory
///
///
/// - `OUT_PROG_EXEC`: set to `false` to disable executing program
/// not contained in initially provided program, even the pages
/// are executable

404
hbvm/src/vmrun.rs Normal file
View file

@ -0,0 +1,404 @@
//! Welcome to the land of The Great Dispatch Loop
//!
//! Have fun
use {
super::{
bmc::BlockCopier,
mem::Memory,
value::{Value, ValueVariant},
Vm, VmRunError, VmRunOk,
},
core::{cmp::Ordering, mem::size_of, ops},
hbbytecode::{
ParamBB, ParamBBB, ParamBBBB, ParamBBD, ParamBBDH, ParamBBW, ParamBD, ProgramVal,
},
};
impl<Mem, const TIMER_QUOTIENT: usize> Vm<Mem, TIMER_QUOTIENT>
where
Mem: Memory,
{
/// Execute program
///
/// Program can return [`VmRunError`] if a trap handling failed
#[cfg_attr(feature = "nightly", repr(align(4096)))]
pub fn run(&mut self) -> Result<VmRunOk, VmRunError> {
use hbbytecode::opcode::*;
loop {
// Big match
//
// Contribution guide:
// - Zero register shall never be overwitten. It's value has to always be 0.
// - Prefer `Self::read_reg` and `Self::write_reg` functions
// - Extract parameters using `param!` macro
// - Prioritise speed over code size
// - Memory is cheap, CPUs not that much
// - Do not heap allocate at any cost
// - Yes, user-provided trap handler may allocate,
// but that is not our »fault«.
// - Unsafe is kinda must, but be sure you have validated everything
// - Your contributions have to pass sanitizers and Miri
// - Strictly follow the spec
// - The spec does not specify how you perform actions, in what order,
// just that the observable effects have to be performed in order and
// correctly.
// - Yes, we assume you run 64 bit CPU. Else ?conradluget a better CPU
// sorry 8 bit fans, HBVM won't run on your Speccy :(
unsafe {
match self
.memory
.prog_read::<u8>(self.pc as _)
.ok_or(VmRunError::ProgramFetchLoadEx(self.pc as _))?
{
UN => {
self.decode::<()>();
return Err(VmRunError::Unreachable);
}
TX => {
self.decode::<()>();
return Ok(VmRunOk::End);
}
NOP => self.decode::<()>(),
ADD => self.binary_op(u64::wrapping_add),
SUB => self.binary_op(u64::wrapping_sub),
MUL => self.binary_op(u64::wrapping_mul),
AND => self.binary_op::<u64>(ops::BitAnd::bitand),
OR => self.binary_op::<u64>(ops::BitOr::bitor),
XOR => self.binary_op::<u64>(ops::BitXor::bitxor),
SL => self.binary_op(|l, r| u64::wrapping_shl(l, r as u32)),
SR => self.binary_op(|l, r| u64::wrapping_shr(l, r as u32)),
SRS => self.binary_op(|l, r| i64::wrapping_shl(l, r as u32)),
CMP => {
// Compare a0 <=> a1
// < → -1
// > → 1
// = → 0
let ParamBBB(tg, a0, a1) = self.decode();
self.write_reg(
tg,
self.read_reg(a0)
.cast::<i64>()
.cmp(&self.read_reg(a1).cast::<i64>())
as i64,
);
}
CMPU => {
// Unsigned comparsion
let ParamBBB(tg, a0, a1) = self.decode();
self.write_reg(
tg,
self.read_reg(a0)
.cast::<u64>()
.cmp(&self.read_reg(a1).cast::<u64>())
as i64,
);
}
NOT => {
// Logical negation
let ParamBB(tg, a0) = self.decode();
self.write_reg(tg, !self.read_reg(a0).cast::<u64>());
}
NEG => {
// Bitwise negation
let ParamBB(tg, a0) = self.decode();
self.write_reg(
tg,
match self.read_reg(a0).cast::<u64>() {
0 => 1_u64,
_ => 0,
},
);
}
DIR => {
// Fused Division-Remainder
let ParamBBBB(dt, rt, a0, a1) = self.decode();
let a0 = self.read_reg(a0).cast::<u64>();
let a1 = self.read_reg(a1).cast::<u64>();
self.write_reg(dt, a0.checked_div(a1).unwrap_or(u64::MAX));
self.write_reg(rt, a0.checked_rem(a1).unwrap_or(u64::MAX));
}
ADDI => self.binary_op_imm(u64::wrapping_add),
MULI => self.binary_op_imm(u64::wrapping_sub),
ANDI => self.binary_op_imm::<u64>(ops::BitAnd::bitand),
ORI => self.binary_op_imm::<u64>(ops::BitOr::bitor),
XORI => self.binary_op_imm::<u64>(ops::BitXor::bitxor),
SLI => self.binary_op_ims(u64::wrapping_shl),
SRI => self.binary_op_ims(u64::wrapping_shr),
SRSI => self.binary_op_ims(i64::wrapping_shr),
CMPI => {
let ParamBBD(tg, a0, imm) = self.decode();
self.write_reg(
tg,
self.read_reg(a0)
.cast::<i64>()
.cmp(&Value::from(imm).cast::<i64>())
as i64,
);
}
CMPUI => {
let ParamBBD(tg, a0, imm) = self.decode();
self.write_reg(tg, self.read_reg(a0).cast::<u64>().cmp(&imm) as i64);
}
CP => {
let ParamBB(tg, a0) = self.decode();
self.write_reg(tg, self.read_reg(a0));
}
SWA => {
// Swap registers
let ParamBB(r0, r1) = self.decode();
match (r0, r1) {
(0, 0) => (),
(dst, 0) | (0, dst) => self.write_reg(dst, 0_u64),
(r0, r1) => {
core::ptr::swap(
self.registers.get_unchecked_mut(usize::from(r0)),
self.registers.get_unchecked_mut(usize::from(r1)),
);
}
}
}
LI => {
let ParamBD(tg, imm) = self.decode();
self.write_reg(tg, imm);
}
LD => {
// Load. If loading more than register size, continue on adjecent registers
let ParamBBDH(dst, base, off, count) = self.decode();
let n: u8 = match dst {
0 => 1,
_ => 0,
};
self.memory.load(
self.ldst_addr_uber(dst, base, off, count, n)?,
self.registers
.as_mut_ptr()
.add(usize::from(dst) + usize::from(n))
.cast(),
usize::from(count).saturating_sub(n.into()),
)?;
}
ST => {
// Store. Same rules apply as to LD
let ParamBBDH(dst, base, off, count) = self.decode();
self.memory.store(
self.ldst_addr_uber(dst, base, off, count, 0)?,
self.registers.as_ptr().add(usize::from(dst)).cast(),
count.into(),
)?;
}
BMC => {
// Block memory copy
match if let Some(copier) = &mut self.copier {
// There is some copier, poll.
copier.poll(&mut self.memory)
} else {
// There is none, make one!
let ParamBBD(src, dst, count) = self.decode();
// So we are still on BMC on next cycle
self.pc -= size_of::<ParamBBD>() + 1;
self.copier = Some(BlockCopier::new(
self.read_reg(src).cast(),
self.read_reg(dst).cast(),
count as _,
));
self.copier
.as_mut()
.unwrap_unchecked() // SAFETY: We just assigned there
.poll(&mut self.memory)
} {
// We are done, shift program counter
core::task::Poll::Ready(Ok(())) => {
self.copier = None;
self.pc += size_of::<ParamBBD>() + 1;
}
// Error, shift program counter (for consistency)
// and yield error
core::task::Poll::Ready(Err(e)) => {
self.pc += size_of::<ParamBBD>() + 1;
return Err(e.into());
}
// Not done yet, proceed to next cycle
core::task::Poll::Pending => (),
}
}
BRC => {
// Block register copy
let ParamBBB(src, dst, count) = self.decode();
if src.checked_add(count).is_none() || dst.checked_add(count).is_none() {
return Err(VmRunError::RegOutOfBounds);
}
core::ptr::copy(
self.registers.get_unchecked(usize::from(src)),
self.registers.get_unchecked_mut(usize::from(dst)),
usize::from(count),
);
}
JAL => {
// Jump and link. Save PC after this instruction to
// specified register and jump to reg + offset.
let ParamBBD(save, reg, offset) = self.decode();
self.write_reg(save, self.pc as u64);
self.pc =
(self.read_reg(reg).cast::<u64>().saturating_add(offset)) as usize;
}
// Conditional jumps, jump only to immediates
JEQ => self.cond_jmp::<u64>(Ordering::Equal),
JNE => {
let ParamBBD(a0, a1, jt) = self.decode();
if self.read_reg(a0).cast::<u64>() != self.read_reg(a1).cast::<u64>() {
self.pc = jt as usize;
}
}
JLT => self.cond_jmp::<u64>(Ordering::Less),
JGT => self.cond_jmp::<u64>(Ordering::Greater),
JLTU => self.cond_jmp::<i64>(Ordering::Less),
JGTU => self.cond_jmp::<i64>(Ordering::Greater),
ECALL => {
self.decode::<()>();
// So we don't get timer interrupt after ECALL
if TIMER_QUOTIENT != 0 {
self.timer = self.timer.wrapping_add(1);
}
return Ok(VmRunOk::Ecall);
}
ADDF => self.binary_op::<f64>(ops::Add::add),
SUBF => self.binary_op::<f64>(ops::Sub::sub),
MULF => self.binary_op::<f64>(ops::Mul::mul),
DIRF => {
let ParamBBBB(dt, rt, a0, a1) = self.decode();
let a0 = self.read_reg(a0).cast::<f64>();
let a1 = self.read_reg(a1).cast::<f64>();
self.write_reg(dt, a0 / a1);
self.write_reg(rt, a0 % a1);
}
FMAF => {
let ParamBBBB(dt, a0, a1, a2) = self.decode();
self.write_reg(
dt,
self.read_reg(a0).cast::<f64>() * self.read_reg(a1).cast::<f64>()
+ self.read_reg(a2).cast::<f64>(),
);
}
NEGF => {
let ParamBB(dt, a0) = self.decode();
self.write_reg(dt, -self.read_reg(a0).cast::<f64>());
}
ITF => {
let ParamBB(dt, a0) = self.decode();
self.write_reg(dt, self.read_reg(a0).cast::<i64>() as f64);
}
FTI => {
let ParamBB(dt, a0) = self.decode();
self.write_reg(dt, self.read_reg(a0).cast::<f64>() as i64);
}
ADDFI => self.binary_op_imm::<f64>(ops::Add::add),
MULFI => self.binary_op_imm::<f64>(ops::Mul::mul),
op => return Err(VmRunError::InvalidOpcode(op)),
}
}
if TIMER_QUOTIENT != 0 {
self.timer = self.timer.wrapping_add(1);
if self.timer % TIMER_QUOTIENT == 0 {
return Ok(VmRunOk::Timer);
}
}
}
}
/// Decode instruction operands
#[inline(always)]
unsafe fn decode<T: ProgramVal>(&mut self) -> T {
let pc1 = self.pc + 1;
let data = self.memory.prog_read_unchecked::<T>(pc1 as _);
self.pc += 1 + size_of::<T>();
data
}
/// Perform binary operating over two registers
#[inline(always)]
unsafe fn binary_op<T: ValueVariant>(&mut self, op: impl Fn(T, T) -> T) {
let ParamBBB(tg, a0, a1) = self.decode();
self.write_reg(
tg,
op(self.read_reg(a0).cast::<T>(), self.read_reg(a1).cast::<T>()),
);
}
/// Perform binary operation over register and immediate
#[inline(always)]
unsafe fn binary_op_imm<T: ValueVariant>(&mut self, op: impl Fn(T, T) -> T) {
let ParamBBD(tg, reg, imm) = self.decode();
self.write_reg(
tg,
op(self.read_reg(reg).cast::<T>(), Value::from(imm).cast::<T>()),
);
}
/// Perform binary operation over register and shift immediate
#[inline(always)]
unsafe fn binary_op_ims<T: ValueVariant>(&mut self, op: impl Fn(T, u32) -> T) {
let ParamBBW(tg, reg, imm) = self.decode();
self.write_reg(tg, op(self.read_reg(reg).cast::<T>(), imm));
}
/// Jump at `#3` if ordering on `#0 <=> #1` is equal to expected
#[inline(always)]
unsafe fn cond_jmp<T: ValueVariant + Ord>(&mut self, expected: Ordering) {
let ParamBBD(a0, a1, ja) = self.decode();
if self
.read_reg(a0)
.cast::<T>()
.cmp(&self.read_reg(a1).cast::<T>())
== expected
{
self.pc = ja as usize;
}
}
/// Read register
#[inline(always)]
unsafe fn read_reg(&self, n: u8) -> Value {
*self.registers.get_unchecked(n as usize)
}
/// Write a register.
/// Writing to register 0 is no-op.
#[inline(always)]
unsafe fn write_reg(&mut self, n: u8, value: impl Into<Value>) {
if n != 0 {
*self.registers.get_unchecked_mut(n as usize) = value.into();
}
}
/// Load / Store Address check-computation überfunction
#[inline(always)]
unsafe fn ldst_addr_uber(
&self,
dst: u8,
base: u8,
offset: u64,
size: u16,
adder: u8,
) -> Result<u64, VmRunError> {
let reg = dst.checked_add(adder).ok_or(VmRunError::RegOutOfBounds)?;
if usize::from(reg) * 8 + usize::from(size) > 2048 {
Err(VmRunError::RegOutOfBounds)
} else {
self.read_reg(base)
.cast::<u64>()
.checked_add(offset)
.and_then(|x| x.checked_add(adder.into()))
.ok_or(VmRunError::AddrOutOfBounds)
}
}
}