Break out step()

This commit is contained in:
Reid 'arrdem' McKenzie 2022-12-23 00:13:19 -07:00
parent 09bb1854bf
commit b7ade42661

569
src/vm.rs
View file

@ -12,6 +12,7 @@ pub enum UxnError {
StackError(StackError), StackError(StackError),
MemoryError(MemoryError), MemoryError(MemoryError),
ExecutionLimit(u16), ExecutionLimit(u16),
Break,
ArithmeticOverflow, ArithmeticOverflow,
ArithmeticUnderflow, ArithmeticUnderflow,
DivisionByZero, DivisionByZero,
@ -111,12 +112,293 @@ impl Uxn {
// Run one clock cycle (instruction) // Run one clock cycle (instruction)
pub fn step(&mut self) -> Result<(), UxnError> { pub fn step(&mut self) -> Result<(), UxnError> {
match self.lda1(self.pc) {
Err(e) => return Err(UxnError::MemoryError(e)),
Ok(opcode) => {
// The value of PC is defined to be the value of the NEXT pc ala Mips
self.pc += 1;
// Extract flags
let sflag: u8 = opcode & 0x20 >> 5;
let rflag: u8 = opcode & 0x40 >> 6;
let kflag: u8 = opcode & 0x80 >> 7;
let icode: u8 = opcode & 0x1F;
// Swizzle the stacks as needed
let [wst, rst] = {
if rflag == 0 {
[self.wst.clone(), self.rst.clone()]
} else {
[self.rst.clone(), self.wst.clone()]
}
};
// Some procedural abstractions over load/store sizes
let pop = |stack: Rc<RefCell<dyn Stack>>| -> Result<u16, StackError> {
if sflag == 1 {
stack.borrow_mut().pop2()
} else {
Ok(stack.borrow_mut().pop1()? as u16)
}
};
let push = |stack: Rc<RefCell<dyn Stack>>, val: u16| {
if sflag == 1 {
stack.borrow_mut().push2(val)
} else {
stack.borrow_mut().push1(val as u8)
}
};
let load = |addr: u16| -> Result<u16, MemoryError> {
if sflag == 1 {
self.memory.borrow_mut().get2(addr)
} else {
Ok(self.memory.borrow_mut().get1(addr)? as u16)
}
};
let store = |addr: u16, value: u16| {
if sflag == 1 {
self.memory.borrow_mut().set2(addr, value)
} else {
self.memory.borrow_mut().set1(addr, value as u8)
}
};
// Just bail out of we get a keep flag, haven't figured out an abstraction for that yet.
if kflag != 0 {
panic!("Got unsupported keep-mode instruction");
}
match (kflag, rflag, sflag, icode) {
(0, 0, 0, 0x00) => {
// BRK
return Err(UxnError::Break);
}
(_, _, _, 0x00) => {
// LIT
push(wst.clone(), load(self.pc)?)?;
self.pc += if sflag == 1 { 2 } else { 1 };
}
(_, _, _, 0x01) => {
// INC
push(wst.clone(), pop(wst.clone())? + 1)?;
}
(_, _, _, 0x02) => {
// POP
pop(wst)?;
}
(_, _, _, 0x03) => {
// NIP a b -- a
let keep = pop(wst.clone())?;
pop(wst.clone())?;
push(wst.clone(), keep)?;
}
(_, _, _, 0x04) => {
// SWP
let a = pop(wst.clone())?;
let b = pop(wst.clone())?;
push(wst.clone(), b)?;
push(wst.clone(), a)?;
}
(_, _, _, 0x05) => {
// ROT
let a = pop(wst.clone())?;
let b = pop(wst.clone())?;
let c = pop(wst.clone())?;
push(wst.clone(), b)?;
push(wst.clone(), c)?;
push(wst.clone(), a)?;
}
(_, _, _, 0x06) => {
// DUP
let a = pop(wst.clone())?;
push(wst.clone(), a)?;
push(wst.clone(), a)?;
}
(_, _, _, 0x07) => {
// OVR a b -- a b a
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a)?;
push(wst.clone(), b)?;
push(wst.clone(), a)?;
}
(_, _, _, 0x08) => {
// EQU
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
wst.borrow_mut().push1(if a == b { 1 } else { 0 })?;
}
(_, _, _, 0x09) => {
// NEQ
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
wst.borrow_mut().push1(if a == b { 0 } else { 1 })?;
}
(_, _, _, 0x0a) => {
// GTH a b
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
wst.borrow_mut().push1(if a > b { 1 } else { 0 })?;
}
(_, _, _, 0x0b) => {
// LTH a b
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
wst.borrow_mut().push1(if a < b { 1 } else { 0 })?;
}
(_, _, _, 0x0c) => {
// JMP
let delta = wst.borrow_mut().pop1()? as i8;
self.pc = self.pc.wrapping_add(delta as u16);
}
(_, _, 0, 0x0d) => {
// JCN1 cnd8 addr8 (relative)
let delta = wst.borrow_mut().pop1()? as i8;
let cnd = wst.borrow_mut().pop1()?;
if cnd != 0 {
self.pc = self.pc.wrapping_add(delta as u16);
}
}
(_, _, 2, 0x0d) => {
// JCN2 cnd8 addr16 (absolute)
let addr = wst.borrow_mut().pop2()?;
let cnd = wst.borrow_mut().pop1()?;
if cnd != 0 {
self.pc = addr;
}
}
(_, _, 0, 0x0e) => {
// JSR1 addr8 (relative)
rst.borrow_mut().push2(self.pc)?;
let delta = wst.borrow_mut().pop1()? as i8;
self.pc = self.pc.wrapping_add(delta as u16);
}
(_, _, 1, 0x0e) => {
// JSR2 addr16 (absolute)
rst.borrow_mut().push2(self.pc)?;
self.pc = wst.borrow_mut().pop2()?;
}
(_, _, _, 0x0f) => {
// STH a
push(rst, pop(wst)?)?;
}
(_, _, _, 0x10) => {
// LDZ a -- b8
push(wst.clone(), load(wst.borrow_mut().pop1()? as u16)?)?;
}
(_, _, _, 0x11) => {
// STZ val addr8 --
let addr = wst.borrow_mut().pop1()? as u16;
store(addr, pop(wst.clone())?)?;
}
(_, _, _, 0x12) => {
// LDR addr8 -- a8
let delta = wst.borrow_mut().pop1()? as i8;
push(wst.clone(), load(self.pc.wrapping_add(delta as u16))?)?;
}
(_, _, _, 0x13) => {
// STR val8 addr8
let delta = wst.borrow_mut().pop1()?;
store(self.pc.wrapping_add(delta as u16), pop(wst.clone())?)?;
}
(_, _, _, 0x14) => {
// LDA a16
let addr = wst.borrow_mut().pop2()?;
push(wst.clone(), load(addr)?)?;
}
(_, _, _, 0x15) => {
// STA val a16 --
let addr = wst.borrow_mut().pop2()?;
store(addr, pop(wst.clone())?)?;
}
(_, _, 0, 0x16) => {
// DEI port8 -- a8
let mut wst = wst.borrow_mut();
let port = wst.pop1()?;
wst.push1(self.dei1(port))?;
}
(_, _, 1, 0x16) => {
// DEI2 port8 -- a16
let mut wst = wst.borrow_mut();
let port = wst.pop1()?;
wst.push2(self.dei2(port))?;
}
(_, _, 0, 0x17) => {
// DEO1 a8 port8 --
let mut wst = wst.borrow_mut();
let port = wst.pop1()?;
let val = wst.pop1()?;
self.deo1(port, val);
}
(_, _, 1, 0x17) => {
// DEO2 a16 port8 --
let mut wst = wst.borrow_mut();
let port = wst.pop1()?;
let val = wst.pop2()?;
self.deo2(port, val);
}
(_, _, _, 0x18) => {
// ADD a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a + b)?;
}
(_, _, _, 0x19) => {
// SUB a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a - b)?;
}
(_, _, _, 0x1a) => {
// MUL a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a * b)?;
}
(_, _, _, 0x1b) => {
// DIV a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a / b)?;
}
(_, _, _, 0x1c) => {
// AND a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a & b)?;
}
(_, _, _, 0x1d) => {
// OR a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a | b)?;
}
(_, _, _, 0x1e) => {
// XOR a8 b8 -- c8
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a ^ b)?;
}
(_, _, _, 0x1f) => {
// SFT a shift8 -- b
let shift = wst.borrow_mut().pop1()?;
let [left, right] = [shift >> 4, shift & 0xF];
let a = pop(wst.clone())?;
push(wst.clone(), (a >> right) << left)?;
}
_ => unreachable!(),
}
}
}
Ok(()) Ok(())
} }
pub fn run(&mut self, limit: u16) -> Result<(), UxnError> { pub fn run(&mut self, limit: u16) -> Result<(), UxnError> {
let mut executed = 0; let mut executed = 0;
'run: loop { loop {
if executed == limit { if executed == limit {
return Err(UxnError::ExecutionLimit(executed)); return Err(UxnError::ExecutionLimit(executed));
} }
@ -127,287 +409,10 @@ impl Uxn {
executed += 1; executed += 1;
match self.lda1(self.pc) { match self.step() {
Err(e) => return Err(UxnError::MemoryError(e)), Err(e) => return Err(e),
Ok(opcode) => { Ok(()) => continue,
// The value of PC is defined to be the value of the NEXT pc ala Mips };
self.pc += 1;
// Extract flags
let sflag: u8 = opcode & 0x20 >> 5;
let rflag: u8 = opcode & 0x40 >> 6;
let kflag: u8 = opcode & 0x80 >> 7;
let icode: u8 = opcode & 0x1F;
// Swizzle the stacks as needed
let [wst, rst] = {
if rflag == 0 {
[self.wst.clone(), self.rst.clone()]
} else {
[self.rst.clone(), self.wst.clone()]
}
};
// Some procedural abstractions over load/store sizes
let pop = |stack: Rc<RefCell<dyn Stack>>| -> Result<u16, StackError> {
if sflag == 1 {
stack.borrow_mut().pop2()
} else {
Ok(stack.borrow_mut().pop1()? as u16)
}
};
let push = |stack: Rc<RefCell<dyn Stack>>, val: u16| {
if sflag == 1 {
stack.borrow_mut().push2(val)
} else {
stack.borrow_mut().push1(val as u8)
}
};
let load = |addr: u16| -> Result<u16, MemoryError> {
if sflag == 1 {
self.memory.borrow_mut().get2(addr)
} else {
Ok(self.memory.borrow_mut().get1(addr)? as u16)
}
};
let store = |addr: u16, value: u16| {
if sflag == 1 {
self.memory.borrow_mut().set2(addr, value)
} else {
self.memory.borrow_mut().set1(addr, value as u8)
}
};
// Just bail out of we get a keep flag, haven't figured out an abstraction for that yet.
if kflag != 0 {
panic!("Got unsupported keep-mode instruction");
}
match (kflag, rflag, sflag, icode) {
(0, 0, 0, 0x00) => {
// BRK
break 'run;
}
(_, _, _, 0x00) => {
// LIT
push(wst.clone(), load(self.pc)?)?;
self.pc += if sflag == 1 { 2 } else { 1 };
}
(_, _, _, 0x01) => {
// INC
push(wst.clone(), pop(wst.clone())? + 1)?;
}
(_, _, _, 0x02) => {
// POP
pop(wst)?;
}
(_, _, _, 0x03) => {
// NIP a b -- a
let keep = pop(wst.clone())?;
pop(wst.clone())?;
push(wst.clone(), keep)?;
}
(_, _, _, 0x04) => {
// SWP
let a = pop(wst.clone())?;
let b = pop(wst.clone())?;
push(wst.clone(), b)?;
push(wst.clone(), a)?;
}
(_, _, _, 0x05) => {
// ROT
let a = pop(wst.clone())?;
let b = pop(wst.clone())?;
let c = pop(wst.clone())?;
push(wst.clone(), b)?;
push(wst.clone(), c)?;
push(wst.clone(), a)?;
}
(_, _, _, 0x06) => {
// DUP
let a = pop(wst.clone())?;
push(wst.clone(), a)?;
push(wst.clone(), a)?;
}
(_, _, _, 0x07) => {
// OVR a b -- a b a
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a)?;
push(wst.clone(), b)?;
push(wst.clone(), a)?;
}
(_, _, _, 0x08) => {
// EQU
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
wst.borrow_mut().push1(if a == b { 1 } else { 0 })?;
}
(_, _, _, 0x09) => {
// NEQ
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
wst.borrow_mut().push1(if a == b { 0 } else { 1 })?;
}
(_, _, _, 0x0a) => {
// GTH a b
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
wst.borrow_mut().push1(if a > b { 1 } else { 0 })?;
}
(_, _, _, 0x0b) => {
// LTH a b
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
wst.borrow_mut().push1(if a < b { 1 } else { 0 })?;
}
(_, _, _, 0x0c) => {
// JMP
let delta = wst.borrow_mut().pop1()? as i8;
self.pc = self.pc.wrapping_add(delta as u16);
}
(_, _, 0, 0x0d) => {
// JCN1 cnd8 addr8 (relative)
let delta = wst.borrow_mut().pop1()? as i8;
let cnd = wst.borrow_mut().pop1()?;
if cnd != 0 {
self.pc = self.pc.wrapping_add(delta as u16);
}
}
(_, _, 2, 0x0d) => {
// JCN2 cnd8 addr16 (absolute)
let addr = wst.borrow_mut().pop2()?;
let cnd = wst.borrow_mut().pop1()?;
if cnd != 0 {
self.pc = addr;
}
}
(_, _, 0, 0x0e) => {
// JSR1 addr8 (relative)
rst.borrow_mut().push2(self.pc)?;
let delta = wst.borrow_mut().pop1()? as i8;
self.pc = self.pc.wrapping_add(delta as u16);
}
(_, _, 1, 0x0e) => {
// JSR2 addr16 (absolute)
rst.borrow_mut().push2(self.pc)?;
self.pc = wst.borrow_mut().pop2()?;
}
(_, _, _, 0x0f) => {
// STH a
push(rst, pop(wst)?)?;
}
(_, _, _, 0x10) => {
// LDZ a -- b8
push(wst.clone(), load(wst.borrow_mut().pop1()? as u16)?)?;
}
(_, _, _, 0x11) => {
// STZ val addr8 --
let addr = wst.borrow_mut().pop1()? as u16;
store(addr, pop(wst.clone())?)?;
}
(_, _, _, 0x12) => {
// LDR addr8 -- a8
let delta = wst.borrow_mut().pop1()? as i8;
push(wst.clone(), load(self.pc.wrapping_add(delta as u16))?)?;
}
(_, _, _, 0x13) => {
// STR val8 addr8
let delta = wst.borrow_mut().pop1()?;
store(self.pc.wrapping_add(delta as u16), pop(wst.clone())?)?;
}
(_, _, _, 0x14) => {
// LDA a16
let addr = wst.borrow_mut().pop2()?;
push(wst.clone(), load(addr)?)?;
}
(_, _, _, 0x15) => {
// STA val a16 --
let addr = wst.borrow_mut().pop2()?;
store(addr, pop(wst.clone())?)?;
}
(_, _, 0, 0x16) => {
// DEI port8 -- a8
let mut wst = wst.borrow_mut();
let port = wst.pop1()?;
wst.push1(self.dei1(port))?;
}
(_, _, 1, 0x16) => {
// DEI2 port8 -- a16
let mut wst = wst.borrow_mut();
let port = wst.pop1()?;
wst.push2(self.dei2(port))?;
}
(_, _, 0, 0x17) => {
// DEO1 a8 port8 --
let mut wst = wst.borrow_mut();
let port = wst.pop1()?;
let val = wst.pop1()?;
self.deo1(port, val);
}
(_, _, 1, 0x17) => {
// DEO2 a16 port8 --
let mut wst = wst.borrow_mut();
let port = wst.pop1()?;
let val = wst.pop2()?;
self.deo2(port, val);
}
(_, _, _, 0x18) => {
// ADD a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a + b)?;
}
(_, _, _, 0x19) => {
// SUB a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a - b)?;
}
(_, _, _, 0x1a) => {
// MUL a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a * b)?;
}
(_, _, _, 0x1b) => {
// DIV a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a / b)?;
}
(_, _, _, 0x1c) => {
// AND a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a & b)?;
}
(_, _, _, 0x1d) => {
// OR a b -- c
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a | b)?;
}
(_, _, _, 0x1e) => {
// XOR a8 b8 -- c8
let b = pop(wst.clone())?;
let a = pop(wst.clone())?;
push(wst.clone(), a ^ b)?;
}
(_, _, _, 0x1f) => {
// SFT a shift8 -- b
let shift = wst.borrow_mut().pop1()?;
let [left, right] = [shift >> 4, shift & 0xF];
let a = pop(wst.clone())?;
push(wst.clone(), (a >> right) << left)?;
}
_ => unreachable!(),
}
}
}
} }
Ok(()) Ok(())
} }