add forwarding bit to all heap cells (#1384)

This commit is contained in:
Mark Thom
2022-04-05 20:13:17 -06:00
parent 8c99d748e2
commit f3167f6b5f
9 changed files with 91 additions and 110 deletions

View File

@@ -808,16 +808,16 @@ mod tests {
_ => { unreachable!() }
);
let fixnum_b_cell = fixnum_as_cell!(Fixnum::build_with(1 << 55));
let fixnum_b_cell = fixnum_as_cell!(Fixnum::build_with(1 << 54));
assert_eq!(fixnum_b_cell.get_tag(), HeapCellValueTag::Fixnum);
match fixnum_b_cell.to_fixnum() {
Some(n) => assert_eq!(n.get_num(), 1 << 55),
Some(n) => assert_eq!(n.get_num(), 1 << 54),
None => assert!(false),
}
match Fixnum::build_with_checked(1 << 57) {
match Fixnum::build_with_checked(1 << 56) {
Ok(_) => assert!(false),
_ => assert!(true),
}
@@ -837,17 +837,17 @@ mod tests {
_ => assert!(false),
}
match Fixnum::build_with_checked((1 << 56) - 1) {
Ok(n) => assert_eq!(n.get_num(), (1 << 56) - 1),
match Fixnum::build_with_checked((1 << 55) - 1) {
Ok(n) => assert_eq!(n.get_num(), (1 << 55) - 1),
_ => assert!(false),
}
match Fixnum::build_with_checked(-(1 << 56)) {
Ok(n) => assert_eq!(n.get_num(), -(1 << 56)),
match Fixnum::build_with_checked(-(1 << 55)) {
Ok(n) => assert_eq!(n.get_num(), -(1 << 55)),
_ => assert!(false),
}
match Fixnum::build_with_checked(-(1 << 56) - 1) {
match Fixnum::build_with_checked(-(1 << 55) - 1) {
Ok(_n) => assert!(false),
_ => assert!(true),
}

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@@ -1,4 +1,3 @@
#[cfg(test)]
pub(crate) use crate::machine::gc::{IteratorUMP, StacklessPreOrderHeapIter};
use crate::machine::heap::*;
@@ -91,7 +90,7 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
let h = h.value() as usize;
let cell = self.heap[h];
if cell.get_forwarding_bit() == Some(true) {
if cell.get_forwarding_bit() {
return Some(h);
} else if cell.get_mark_bit() && !is_readable_marked {
continue;
@@ -122,7 +121,7 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
let cell = &mut self.heap[h];
if cell.get_forwarding_bit() == Some(true) {
if cell.get_forwarding_bit() {
cell.set_forwarding_bit(false);
} else if cell.get_mark_bit() && !is_readable_marked {
cell.set_mark_bit(false);
@@ -150,7 +149,7 @@ impl<'a> StackfulPreOrderHeapIter<'a> {
self.h = h;
let cell = &mut self.heap[h];
if cell.get_forwarding_bit() == Some(true) {
if cell.get_forwarding_bit() {
let copy = *cell;
cell.set_forwarding_bit(false);
return Some(copy);
@@ -225,7 +224,6 @@ impl<'a> Iterator for StackfulPreOrderHeapIter<'a> {
}
#[inline(always)]
#[cfg(test)]
pub(crate) fn stackless_preorder_iter(
heap: &mut Vec<HeapCellValue>,
cell: HeapCellValue,
@@ -337,12 +335,10 @@ pub(crate) fn stackful_post_order_iter<'a>(
PostOrderIterator::new(StackfulPreOrderHeapIter::new(heap, cell))
}
#[cfg(test)]
pub(crate) type RightistPostOrderHeapIter<'a> =
PostOrderIterator<StacklessPreOrderHeapIter<'a, IteratorUMP>>;
#[inline]
#[cfg(test)]
pub(crate) fn stackless_post_order_iter<'a>(
heap: &'a mut Heap,
cell: HeapCellValue,

View File

@@ -833,7 +833,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
fn check_for_seen(&mut self) -> Option<HeapCellValue> {
if let Some(addr) = self.iter.next() {
let is_cyclic = addr.is_forwarded();
let is_cyclic = addr.get_forwarding_bit();
let addr = heap_bound_store(
self.iter.heap,

View File

@@ -1098,10 +1098,10 @@ impl MachineState {
pub(crate) fn arith_eval_by_metacall(&mut self, value: HeapCellValue) -> Result<Number, MachineStub> {
let stub_gen = || functor_stub(atom!("is"), 2);
let mut iter = stackful_post_order_iter(&mut self.heap, value);
let mut iter = stackless_post_order_iter(&mut self.heap, value);
while let Some(value) = iter.next() {
if value.is_forwarded() {
if value.get_forwarding_bit() {
let (name, arity) = read_heap_cell!(value,
(HeapCellValueTag::Atom, (name, arity)) => {
(name, arity)
@@ -1125,8 +1125,8 @@ impl MachineState {
read_heap_cell!(value,
(HeapCellValueTag::Atom, (name, arity)) => {
if arity == 2 {
let a2 = self.interms.pop().unwrap();
let a1 = self.interms.pop().unwrap();
let a2 = self.interms.pop().unwrap();
match name {
atom!("+") => self.interms.push(drop_iter_on_err!(

View File

@@ -12,10 +12,8 @@ pub(crate) trait UnmarkPolicy {
Self: Sized;
}
#[cfg(test)]
pub(crate) struct IteratorUMP;
#[cfg(test)]
impl UnmarkPolicy for IteratorUMP {
#[inline(always)]
fn unmark(heap: &mut [HeapCellValue], current: usize) {
@@ -44,7 +42,7 @@ impl UnmarkPolicy for MarkerUMP {
#[inline(always)]
fn forward_attr_var(iter: &mut StacklessPreOrderHeapIter<Self>) -> Option<HeapCellValue> {
if iter.heap[iter.current + 1].get_forwarding_bit() == Some(true) {
if iter.heap[iter.current + 1].get_forwarding_bit() {
return iter.forward_var();
}
@@ -87,10 +85,9 @@ impl<'a, UMP: UnmarkPolicy> Drop for StacklessPreOrderHeapIter<'a, UMP> {
impl<'a> StacklessPreOrderHeapIter<'a, MarkerUMP> {
pub(crate) fn new(heap: &'a mut Vec<HeapCellValue>, cell: HeapCellValue) -> Self {
let orig_heap_len = heap.len();
let start = orig_heap_len; // + 1;
let start = orig_heap_len;
heap.push(cell);
// heap.push(heap_loc_as_cell!(orig_heap_len));
heap[start].set_forwarding_bit(true);
let next = heap[start].get_value();
@@ -106,7 +103,6 @@ impl<'a> StacklessPreOrderHeapIter<'a, MarkerUMP> {
}
}
#[cfg(test)]
impl<'a> StacklessPreOrderHeapIter<'a, IteratorUMP> {
pub(crate) fn new(heap: &'a mut Vec<HeapCellValue>, cell: HeapCellValue) -> Self {
let orig_heap_len = heap.len();
@@ -145,7 +141,7 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
}
fn forward_var(&mut self) -> Option<HeapCellValue> {
if self.heap[self.next].get_forwarding_bit() == Some(true) {
if self.heap[self.next].get_forwarding_bit() {
return self.backward_and_return();
}
@@ -167,19 +163,19 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
HeapCellValueTag::AttrVar => {
if let Some(cell) = UMP::forward_attr_var(self) { return Some(cell); }
if self.heap[self.next].get_mark_bit() { //self.current == self.next {
if self.heap[self.next].get_mark_bit() {
return Some(attr_var_as_cell!(self.current));
}
}
HeapCellValueTag::Var => {
if let Some(cell) = self.forward_var() { return Some(cell); }
if self.heap[self.next].get_mark_bit() { //self.current == self.next {
if self.heap[self.next].get_mark_bit() {
return Some(heap_loc_as_cell!(self.current));
}
}
HeapCellValueTag::Str => {
if self.heap[self.next + 1].get_forwarding_bit() == Some(true) {
if self.heap[self.next + 1].get_forwarding_bit() {
return self.backward_and_return();
}
@@ -203,7 +199,7 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
HeapCellValueTag::Lis => {
let last_cell_loc = self.next + 1;
if self.heap[last_cell_loc].get_forwarding_bit() == Some(true) {
if self.heap[last_cell_loc].get_forwarding_bit() {
return self.backward_and_return();
}
@@ -219,7 +215,7 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
let h = self.next;
let cell = self.heap[h];
if self.heap[h+1].get_forwarding_bit() == Some(true) {
if self.heap[h+1].get_forwarding_bit() {
return self.backward_and_return();
}
@@ -253,7 +249,7 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
let last_cell_loc = h+1;
if self.heap[last_cell_loc].get_forwarding_bit() == Some(true) {
if self.heap[last_cell_loc].get_forwarding_bit() {
return self.backward_and_return();
}
@@ -301,7 +297,7 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
}
fn backward(&mut self) -> bool {
while !self.heap[self.current].get_forwarding_bit().unwrap_or(false) {
while !self.heap[self.current].get_forwarding_bit() {
let temp = self.heap[self.current].get_value();
UMP::unmark(self.heap, self.current);
@@ -724,7 +720,7 @@ mod tests {
assert!(wam.machine_st.heap[8].get_mark_bit());
for cell in &wam.machine_st.heap {
assert!(cell.get_forwarding_bit() != Some(true));
assert!(!cell.get_forwarding_bit());
}
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[0]), atom_as_cell!(atom!("irrelevant stuff")));
@@ -754,7 +750,7 @@ mod tests {
assert!(wam.machine_st.heap[8].get_mark_bit());
for cell in &wam.machine_st.heap {
assert!(cell.get_forwarding_bit() != Some(true));
assert!(!cell.get_forwarding_bit());
}
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[0]), atom_as_cell!(atom!("irrelevant stuff")));
@@ -784,7 +780,7 @@ mod tests {
assert!(wam.machine_st.heap[8].get_mark_bit());
for cell in &wam.machine_st.heap {
assert!(cell.get_forwarding_bit() != Some(true));
assert!(!cell.get_forwarding_bit());
}
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[0]), atom_as_cell!(atom!("irrelevant stuff")));
@@ -814,7 +810,7 @@ mod tests {
assert!(wam.machine_st.heap[8].get_mark_bit());
for cell in &wam.machine_st.heap {
assert!(cell.get_forwarding_bit() != Some(true));
assert!(!cell.get_forwarding_bit());
}
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[0]), atom_as_cell!(atom!("irrelevant stuff")));
@@ -1175,9 +1171,7 @@ mod tests {
wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(3)));
wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(4)));
mark_cells(&mut wam.machine_st.heap, str_loc_as_cell!(1));
print_heap_terms(wam.machine_st.heap[1 ..].iter(), 0);
mark_cells(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
all_cells_marked_and_unforwarded(&wam.machine_st.heap);

View File

@@ -2056,7 +2056,7 @@ impl MachineState {
let mut iter = stackful_preorder_iter(&mut self.heap, addr);
while let Some(value) = iter.next() {
if value.is_forwarded() {
if value.get_forwarding_bit() {
let value = heap_bound_store(iter.heap, heap_bound_deref(iter.heap, value));
if value.is_compound() {

View File

@@ -168,7 +168,7 @@ pub fn all_cells_marked_and_unforwarded(heap: &[HeapCellValue]) {
idx
);
assert!(
cell.get_forwarding_bit() != Some(true),
!cell.get_forwarding_bit(),
"cell {:?} at index {} is forwarded",
cell,
idx
@@ -187,7 +187,7 @@ pub fn all_cells_unmarked(heap: &Heap) {
);
assert!(
cell.get_forwarding_bit() != Some(true),
!cell.get_forwarding_bit(),
"cell {:?} at index {} is still forwarded",
cell,
idx

View File

@@ -466,7 +466,8 @@ pub enum Fixity {
#[repr(u64)]
#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
pub struct Fixnum {
num: B57,
num: B56,
#[allow(unused)] f: bool,
#[allow(unused)] m: bool,
#[allow(unused)] tag: B6,
}
@@ -475,7 +476,7 @@ impl Fixnum {
#[inline]
pub fn build_with(num: i64) -> Self {
Fixnum::new()
.with_num(u64::from_ne_bytes(num.to_ne_bytes()) & ((1 << 57) - 1))
.with_num(u64::from_ne_bytes(num.to_ne_bytes()) & ((1 << 56) - 1))
.with_tag(HeapCellValueTag::Fixnum as u8)
.with_m(false)
//num as u64).with__m(false)
@@ -483,14 +484,14 @@ impl Fixnum {
#[inline]
pub fn build_with_checked(num: i64) -> Result<Self, OutOfBounds> {
const UPPER_BOUND: i64 = (1 << 56) - 1;
const LOWER_BOUND: i64 = -(1 << 56);
const UPPER_BOUND: i64 = (1 << 55) - 1;
const LOWER_BOUND: i64 = -(1 << 55);
if LOWER_BOUND <= num && num <= UPPER_BOUND {
Ok(Fixnum::new()
.with_m(false)
.with_tag(HeapCellValueTag::Fixnum as u8)
.with_num(u64::from_ne_bytes(num.to_ne_bytes()) & ((1 << 57) - 1))) //num as u64 & ((1 << 57) - 1)))
.with_num(u64::from_ne_bytes(num.to_ne_bytes()) & ((1 << 56) - 1)))
} else {
Err(OutOfBounds {})
}
@@ -499,7 +500,7 @@ impl Fixnum {
#[inline]
pub fn get_num(self) -> i64 {
let n = self.num() as i64;
let (n, overflowed) = (n << 7).overflowing_shr(7); // sign-extend the 57-bit signed fixnum.
let (n, overflowed) = (n << 8).overflowing_shr(8);
debug_assert_eq!(overflowed, false);
n
}

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@@ -15,55 +15,55 @@ use std::ops::{Add, Sub, SubAssign};
#[derive(BitfieldSpecifier, Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
#[bits = 6]
pub enum HeapCellValueTag {
Str = 0b000010,
Lis = 0b000011,
Var = 0b000110,
StackVar = 0b000111,
AttrVar = 0b010011,
PStrLoc = 0b111111,
PStrOffset = 0b001110,
Str = 0b000011,
Lis = 0b000101,
Var = 0b000111,
StackVar = 0b001001,
AttrVar = 0b001011,
PStrLoc = 0b001101,
PStrOffset = 0b001111,
// constants.
Cons = 0b0,
F64 = 0b000001,
Fixnum = 0b010010,
Char = 0b011011,
Atom = 0b001010,
PStr = 0b001011,
CStr = 0b010110, // a complete string.
F64 = 0b010001,
Fixnum = 0b010011,
Char = 0b010101,
Atom = 0b010111,
PStr = 0b011001,
CStr = 0b011011,
}
#[derive(BitfieldSpecifier, Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
#[bits = 6]
pub enum HeapCellValueView {
Str = 0b000010,
Lis = 0b000011,
Var = 0b000110,
StackVar = 0b000111,
AttrVar = 0b010011,
PStrLoc = 0b111111,
PStrOffset = 0b001110,
Str = 0b000011,
Lis = 0b000101,
Var = 0b000111,
StackVar = 0b001001,
AttrVar = 0b001011,
PStrLoc = 0b001101,
PStrOffset = 0b001111,
// constants.
Cons = 0b00,
F64 = 0b000001,
Fixnum = 0b010010,
Char = 0b011011,
Atom = 0b001010,
PStr = 0b001011,
CStr = 0b010110,
Cons = 0b0,
F64 = 0b010001,
Fixnum = 0b010011,
Char = 0b010101,
Atom = 0b010111,
PStr = 0b011001,
CStr = 0b011011,
// trail elements.
TrailedHeapVar = 0b011110,
TrailedHeapVar = 0b011101,
TrailedStackVar = 0b011111,
TrailedAttrVarHeapLink = 0b101110,
TrailedAttrVarListLink = 0b100010,
TrailedAttachedValue = 0b101010,
TrailedBlackboardEntry = 0b100110,
TrailedBlackboardOffset = 0b100111,
TrailedAttrVarHeapLink = 0b100001,
TrailedAttrVarListLink = 0b100011,
TrailedAttachedValue = 0b100101,
TrailedBlackboardEntry = 0b100111,
TrailedBlackboardOffset = 0b101001,
}
#[derive(BitfieldSpecifier, Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
#[bits = 2]
#[bits = 1]
pub enum ConsPtrMaskTag {
Cons = 0b00,
Cons = 0b0,
}
#[bitfield]
@@ -71,6 +71,7 @@ pub enum ConsPtrMaskTag {
#[derive(Copy, Clone, Debug)]
pub struct ConsPtr {
ptr: B61,
f: bool,
m: bool,
tag: ConsPtrMaskTag,
}
@@ -80,6 +81,7 @@ impl ConsPtr {
pub fn build_with(ptr: *const ArenaHeader, tag: ConsPtrMaskTag) -> Self {
ConsPtr::new()
.with_ptr(ptr as *const u8 as u64)
.with_f(false)
.with_m(false)
.with_tag(tag)
}
@@ -98,9 +100,9 @@ impl ConsPtr {
#[derive(BitfieldSpecifier, Copy, Clone, Debug)]
#[bits = 6]
pub(crate) enum RefTag {
HeapCell = 0b0110,
StackCell = 0b111,
AttrVar = 0b10011,
HeapCell = 0b000111,
StackCell = 0b001001,
AttrVar = 0b001011,
}
#[bitfield]
@@ -379,11 +381,6 @@ impl HeapCellValue {
}
}
#[inline(always)]
pub fn is_forwarded(self) -> bool {
self.get_forwarding_bit().unwrap_or(false)
}
#[inline]
pub fn is_ref(self) -> bool {
match self.get_tag() {
@@ -536,33 +533,26 @@ impl HeapCellValue {
}
}
#[inline]
pub fn get_forwarding_bit(self) -> Option<bool> {
#[inline(always)]
pub fn get_forwarding_bit(self) -> bool {
match self.get_tag() {
HeapCellValueTag::Cons // the list of non-forwardable cell tags.
| HeapCellValueTag::F64
// | HeapCellValueTag::Atom
// | HeapCellValueTag::PStr
| HeapCellValueTag::Fixnum
| HeapCellValueTag::Char => None,
_ => Some(self.f()),
HeapCellValueTag::Cons => ConsPtr::from_bytes(self.into_bytes()).f(),
_ => self.f()
}
}
#[inline]
#[inline(always)]
pub fn set_forwarding_bit(&mut self, f: bool) {
match self.get_tag() {
HeapCellValueTag::Cons // the list of non-forwardable cell tags.
| HeapCellValueTag::F64
// | HeapCellValueTag::Atom
// | HeapCellValueTag::PStr
| HeapCellValueTag::Fixnum
| HeapCellValueTag::Char => {}
HeapCellValueTag::Cons => {
let value = ConsPtr::from_bytes(self.into_bytes()).with_f(f);
*self = HeapCellValue::from_bytes(value.into_bytes());
}
_ => self.set_f(f),
}
}
#[inline]
#[inline(always)]
pub fn get_mark_bit(self) -> bool {
match self.get_tag() {
HeapCellValueTag::Cons => {
@@ -572,7 +562,7 @@ impl HeapCellValue {
}
}
#[inline]
#[inline(always)]
pub fn set_mark_bit(&mut self, m: bool) {
match self.get_tag() {
HeapCellValueTag::Cons => {