roc/crates/compiler/mono/src/layout/intern.rs

1503 lines
52 KiB
Rust

use std::{
cell::RefCell,
hash::{BuildHasher, Hasher},
marker::PhantomData,
sync::Arc,
};
use bumpalo::Bump;
use parking_lot::{Mutex, RwLock};
use roc_builtins::bitcode::{FloatWidth, IntWidth};
use roc_collections::{default_hasher, BumpMap};
use roc_module::symbol::Symbol;
use roc_target::TargetInfo;
use super::{Builtin, FieldOrderHash, LambdaSet, Layout, SeenRecPtrs, UnionLayout};
macro_rules! cache_interned_layouts {
($($i:literal, $name:ident, $vis:vis, $layout:expr)*; $total_constants:literal) => {
impl<'a> Layout<'a> {
$(
#[allow(unused)] // for now
$vis const $name: InLayout<'static> = unsafe { InLayout::from_index($i) };
)*
}
fn fill_reserved_layouts<'a>(interner: &mut STLayoutInterner<'a>) {
assert!(interner.is_empty());
$(
interner.insert($layout);
)*
}
const fn _are_constants_in_order_non_redundant() -> usize {
let mut total_seen = 0;
$(total_seen += ($i * 0) + 1;)*
match 0usize {
$($i => {})*
_ => {}
}
total_seen
}
const _ASSERT_NON_REDUNDANT_CONSTANTS: () =
assert!(_are_constants_in_order_non_redundant() == $total_constants);
}
}
cache_interned_layouts! {
0, VOID, pub, Layout::VOID_NAKED
1, UNIT, pub, Layout::UNIT_NAKED
2, BOOL, pub, Layout::Builtin(Builtin::Bool)
3, U8, pub, Layout::Builtin(Builtin::Int(IntWidth::U8))
4, U16, pub, Layout::Builtin(Builtin::Int(IntWidth::U16))
5, U32, pub, Layout::Builtin(Builtin::Int(IntWidth::U32))
6, U64, pub, Layout::Builtin(Builtin::Int(IntWidth::U64))
7, U128, pub, Layout::Builtin(Builtin::Int(IntWidth::U128))
8, I8, pub, Layout::Builtin(Builtin::Int(IntWidth::I8))
9, I16, pub, Layout::Builtin(Builtin::Int(IntWidth::I16))
10, I32, pub, Layout::Builtin(Builtin::Int(IntWidth::I32))
11, I64, pub, Layout::Builtin(Builtin::Int(IntWidth::I64))
12, I128, pub, Layout::Builtin(Builtin::Int(IntWidth::I128))
13, F32, pub, Layout::Builtin(Builtin::Float(FloatWidth::F32))
14, F64, pub, Layout::Builtin(Builtin::Float(FloatWidth::F64))
15, DEC, pub, Layout::Builtin(Builtin::Decimal)
16, STR, pub, Layout::Builtin(Builtin::Str)
17, OPAQUE_PTR, pub, Layout::Boxed(Layout::VOID)
18, NAKED_RECURSIVE_PTR, pub(super), Layout::RecursivePointer(Layout::VOID)
; 19
}
macro_rules! impl_to_from_int_width {
($($int_width:path => $layout:path,)*) => {
impl<'a> Layout<'a> {
pub const fn int_width(w: IntWidth) -> InLayout<'static> {
match w {
$($int_width => $layout,)*
}
}
}
impl<'a> InLayout<'a> {
/// # Panics
///
/// Panics if the layout is not an integer
pub fn to_int_width(&self) -> IntWidth {
match self {
$(&$layout => $int_width,)*
_ => roc_error_macros::internal_error!("not an integer layout!")
}
}
}
};
}
impl_to_from_int_width! {
IntWidth::U8 => Layout::U8,
IntWidth::U16 => Layout::U16,
IntWidth::U32 => Layout::U32,
IntWidth::U64 => Layout::U64,
IntWidth::U128 => Layout::U128,
IntWidth::I8 => Layout::I8,
IntWidth::I16 => Layout::I16,
IntWidth::I32 => Layout::I32,
IntWidth::I64 => Layout::I64,
IntWidth::I128 => Layout::I128,
}
impl<'a> Layout<'a> {
pub(super) const VOID_NAKED: Self = Layout::Union(UnionLayout::NonRecursive(&[]));
pub(super) const UNIT_NAKED: Self = Layout::Struct {
field_layouts: &[],
field_order_hash: FieldOrderHash::ZERO_FIELD_HASH,
};
pub const fn float_width(w: FloatWidth) -> InLayout<'static> {
match w {
FloatWidth::F32 => Self::F32,
FloatWidth::F64 => Self::F64,
}
}
}
pub trait LayoutInterner<'a>: Sized {
/// Interns a value, returning its interned representation.
/// If the value has been interned before, the old interned representation will be re-used.
///
/// Note that the provided value must be allocated into an arena of your choosing, but which
/// must live at least as long as the interner lives.
// TODO: we should consider maintaining our own arena in the interner, to avoid redundant
// allocations when values already have interned representations.
fn insert(&mut self, value: Layout<'a>) -> InLayout<'a>;
/// Creates a [LambdaSet], including caching the [Layout::LambdaSet] representation of the
/// lambda set onto itself.
fn insert_lambda_set(
&mut self,
arena: &'a Bump,
args: &'a &'a [InLayout<'a>],
ret: InLayout<'a>,
set: &'a &'a [(Symbol, &'a [InLayout<'a>])],
set_may_have_naked_rec_ptr: bool,
representation: InLayout<'a>,
) -> LambdaSet<'a>;
/// Inserts a recursive layout into the interner.
/// Takes a normalized recursive layout with the recursion pointer set to [Layout::VOID].
/// Will update the RecursivePointer as appropriate during insertion.
fn insert_recursive(&mut self, arena: &'a Bump, normalized_layout: Layout<'a>) -> InLayout<'a>;
/// Retrieves a value from the interner.
fn get(&self, key: InLayout<'a>) -> Layout<'a>;
//
// Convenience methods
fn target_info(&self) -> TargetInfo;
fn alignment_bytes(&self, layout: InLayout<'a>) -> u32 {
self.get(layout).alignment_bytes(self, self.target_info())
}
fn allocation_alignment_bytes(&self, layout: InLayout<'a>) -> u32 {
self.get(layout)
.allocation_alignment_bytes(self, self.target_info())
}
fn stack_size(&self, layout: InLayout<'a>) -> u32 {
self.get(layout).stack_size(self, self.target_info())
}
fn stack_size_and_alignment(&self, layout: InLayout<'a>) -> (u32, u32) {
self.get(layout)
.stack_size_and_alignment(self, self.target_info())
}
fn stack_size_without_alignment(&self, layout: InLayout<'a>) -> u32 {
self.get(layout)
.stack_size_without_alignment(self, self.target_info())
}
fn contains_refcounted(&self, layout: InLayout<'a>) -> bool {
self.get(layout).contains_refcounted(self)
}
fn is_refcounted(&self, layout: InLayout<'a>) -> bool {
self.get(layout).is_refcounted()
}
fn is_passed_by_reference(&self, layout: InLayout<'a>) -> bool {
self.get(layout)
.is_passed_by_reference(self, self.target_info())
}
fn runtime_representation(&self, layout: InLayout<'a>) -> Layout<'a> {
self.get(layout).runtime_representation(self)
}
fn runtime_representation_in(&self, layout: InLayout<'a>) -> InLayout<'a> {
Layout::runtime_representation_in(layout, self)
}
fn chase_recursive(&self, mut layout: InLayout<'a>) -> Layout<'a> {
loop {
match self.get(layout) {
Layout::RecursivePointer(l) => layout = l,
other => return other,
}
}
}
fn chase_recursive_in(&self, mut layout: InLayout<'a>) -> InLayout<'a> {
loop {
match self.get(layout) {
Layout::RecursivePointer(l) => layout = l,
_ => return layout,
}
}
}
fn safe_to_memcpy(&self, layout: InLayout<'a>) -> bool {
self.get(layout).safe_to_memcpy(self)
}
/// Checks if two layouts are equivalent up to isomorphism.
///
/// This is only to be used when layouts need to be compared across statements and depths,
/// for example
/// - when looking up a layout index in a lambda set
/// - in the [checker][crate::debug::check_procs], where `x = UnionAtIndex(f, 0)` may have
/// that the recorded layout of `x` is at a different depth than that determined when we
/// index the recorded layout of `f` at 0. Hence the two layouts may have different
/// interned representations, even if they are in fact isomorphic.
fn equiv(&self, l1: InLayout<'a>, l2: InLayout<'a>) -> bool {
std::thread_local! {
static SCRATCHPAD: RefCell<Option<Vec<(InLayout<'static>, InLayout<'static>)>>> = RefCell::new(Some(Vec::with_capacity(64)));
}
SCRATCHPAD.with(|f| {
// SAFETY: the promotion to lifetime 'a only lasts during equivalence-checking; the
// scratchpad stack is cleared after every use.
let mut stack: Vec<(InLayout<'a>, InLayout<'a>)> =
unsafe { std::mem::transmute(f.take().unwrap()) };
let answer = equiv::equivalent(&mut stack, self, l1, l2);
stack.clear();
let stack: Vec<(InLayout<'static>, InLayout<'static>)> =
unsafe { std::mem::transmute(stack) };
f.replace(Some(stack));
answer
})
}
fn to_doc<'b, D, A>(
&self,
layout: InLayout<'a>,
alloc: &'b D,
seen_rec: &mut SeenRecPtrs<'a>,
parens: crate::ir::Parens,
) -> ven_pretty::DocBuilder<'b, D, A>
where
D: ven_pretty::DocAllocator<'b, A>,
D::Doc: Clone,
A: Clone,
{
use Layout::*;
match self.get(layout) {
Builtin(builtin) => builtin.to_doc(alloc, self, seen_rec, parens),
Struct { field_layouts, .. } => {
let fields_doc = field_layouts
.iter()
.map(|x| self.to_doc(*x, alloc, seen_rec, parens));
alloc
.text("{")
.append(alloc.intersperse(fields_doc, ", "))
.append(alloc.text("}"))
}
Union(union_layout) => {
let is_recursive = !matches!(union_layout, UnionLayout::NonRecursive(..));
if is_recursive {
seen_rec.insert(layout);
}
let doc = union_layout.to_doc(alloc, self, seen_rec, parens);
if is_recursive {
seen_rec.remove(&layout);
}
doc
}
LambdaSet(lambda_set) => {
self.to_doc(lambda_set.runtime_representation(), alloc, seen_rec, parens)
}
RecursivePointer(rec_layout) => {
if seen_rec.contains(&rec_layout) {
alloc.text("*self")
} else {
self.to_doc(rec_layout, alloc, seen_rec, parens)
}
}
Boxed(inner) => alloc
.text("Boxed(")
.append(self.to_doc(inner, alloc, seen_rec, parens))
.append(")"),
}
}
fn to_doc_top<'b, D, A>(
&self,
layout: InLayout<'a>,
alloc: &'b D,
) -> ven_pretty::DocBuilder<'b, D, A>
where
D: ven_pretty::DocAllocator<'b, A>,
D::Doc: Clone,
A: Clone,
{
self.to_doc(
layout,
alloc,
&mut Default::default(),
crate::ir::Parens::NotNeeded,
)
}
fn dbg(&self, layout: InLayout<'a>) -> String {
let alloc: ven_pretty::Arena<()> = ven_pretty::Arena::new();
let doc = self.to_doc_top(layout, &alloc);
doc.1.pretty(80).to_string()
}
}
/// An interned layout.
///
/// When possible, prefer comparing/hashing on the [InLayout] representation of a value, rather
/// than the value itself.
#[derive(PartialEq, Eq, Hash, PartialOrd, Ord)]
pub struct InLayout<'a>(usize, std::marker::PhantomData<&'a ()>);
impl<'a> Clone for InLayout<'a> {
fn clone(&self) -> Self {
Self(self.0, Default::default())
}
}
impl<'a> Copy for InLayout<'a> {}
impl std::fmt::Debug for InLayout<'_> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_tuple("InLayout").field(&self.0).finish()
}
}
impl<'a> InLayout<'a> {
/// # Safety
///
/// The index is not guaranteed to exist. Use this only when creating an interner with constant
/// indices, with the variant that `insert` returns a monotonically increasing index.
///
/// For example:
///
/// ```ignore(illustrative)
/// let reserved_interned = InLayout::from_reserved_index(0);
/// let interner = GlobalLayoutInterner::with_capacity(1);
/// let inserted = interner.insert("something");
/// assert_eq!(reserved_interned, inserted);
/// ```
pub(crate) const unsafe fn from_index(index: usize) -> Self {
Self(index, PhantomData)
}
}
/// A concurrent interner, suitable for usage between threads.
///
/// The interner does not currently maintain its own arena; you will have to supply
/// values-to-be-interned as allocated in an independent arena.
///
/// If you need a concurrent global interner, you'll likely want each thread to take a
/// [TLLayoutInterner] via [GlobalLayoutInterner::fork], for caching purposes.
///
/// Originally derived from https://gist.github.com/matklad/44ba1a5a6168bc0c26c995131c007907;
/// thank you, Aleksey!
#[derive(Debug)]
pub struct GlobalLayoutInterner<'a>(Arc<GlobalLayoutInternerInner<'a>>);
#[derive(Debug)]
struct GlobalLayoutInternerInner<'a> {
map: Mutex<BumpMap<Layout<'a>, InLayout<'a>>>,
normalized_lambda_set_map: Mutex<BumpMap<LambdaSet<'a>, LambdaSet<'a>>>,
vec: RwLock<Vec<Layout<'a>>>,
target_info: TargetInfo,
}
/// A derivative of a [GlobalLayoutInterner] interner that provides caching desirable for
/// thread-local workloads. The only way to get a [TLLayoutInterner] is via
/// [GlobalLayoutInterner::fork].
///
/// All values interned into a [TLLayoutInterner] are made available in its parent
/// [GlobalLayoutInterner], making this suitable for global sharing of interned values.
///
/// Originally derived from https://gist.github.com/matklad/44ba1a5a6168bc0c26c995131c007907;
/// thank you, Aleksey!
#[derive(Debug)]
pub struct TLLayoutInterner<'a> {
parent: GlobalLayoutInterner<'a>,
map: BumpMap<Layout<'a>, InLayout<'a>>,
normalized_lambda_set_map: BumpMap<LambdaSet<'a>, LambdaSet<'a>>,
/// Cache of interned values from the parent for local access.
vec: RefCell<Vec<Option<Layout<'a>>>>,
target_info: TargetInfo,
}
/// A single-threaded interner, with no concurrency properties.
///
/// The only way to construct such an interner is to collapse a shared [GlobalLayoutInterner] into
/// a [STLayoutInterner], via [GlobalLayoutInterner::unwrap].
#[derive(Debug)]
pub struct STLayoutInterner<'a> {
map: BumpMap<Layout<'a>, InLayout<'a>>,
normalized_lambda_set_map: BumpMap<LambdaSet<'a>, LambdaSet<'a>>,
vec: Vec<Layout<'a>>,
target_info: TargetInfo,
}
/// Interner constructed with an exclusive lock over [GlobalLayoutInterner]
struct LockedGlobalInterner<'a, 'r> {
map: &'r mut BumpMap<Layout<'a>, InLayout<'a>>,
normalized_lambda_set_map: &'r mut BumpMap<LambdaSet<'a>, LambdaSet<'a>>,
vec: &'r mut Vec<Layout<'a>>,
target_info: TargetInfo,
}
/// Generic hasher for a value, to be used by all interners.
///
/// This uses the [default_hasher], so interner maps should also rely on [default_hasher].
fn hash<V: std::hash::Hash>(val: V) -> u64 {
let mut state = roc_collections::all::BuildHasher::default().build_hasher();
val.hash(&mut state);
state.finish()
}
#[inline(always)]
fn make_normalized_lamdba_set<'a>(
args: &'a &'a [InLayout<'a>],
ret: InLayout<'a>,
set: &'a &'a [(Symbol, &'a [InLayout<'a>])],
representation: InLayout<'a>,
) -> LambdaSet<'a> {
LambdaSet {
args,
ret,
set,
representation,
full_layout: Layout::VOID,
}
}
impl<'a> GlobalLayoutInterner<'a> {
/// Creates a new global interner with the given capacity.
pub fn with_capacity(cap: usize, target_info: TargetInfo) -> Self {
STLayoutInterner::with_capacity(cap, target_info).into_global()
}
/// Creates a derivative [TLLayoutInterner] pointing back to this global interner.
pub fn fork(&self) -> TLLayoutInterner<'a> {
TLLayoutInterner {
parent: Self(Arc::clone(&self.0)),
map: Default::default(),
normalized_lambda_set_map: Default::default(),
vec: Default::default(),
target_info: self.0.target_info,
}
}
/// Collapses a shared [GlobalLayoutInterner] into a [STLayoutInterner].
///
/// Returns an [Err] with `self` if there are outstanding references to the [GlobalLayoutInterner].
pub fn unwrap(self) -> Result<STLayoutInterner<'a>, Self> {
let GlobalLayoutInternerInner {
map,
normalized_lambda_set_map,
vec,
target_info,
} = match Arc::try_unwrap(self.0) {
Ok(inner) => inner,
Err(li) => return Err(Self(li)),
};
let map = Mutex::into_inner(map);
let normalized_lambda_set_map = Mutex::into_inner(normalized_lambda_set_map);
let vec = RwLock::into_inner(vec);
Ok(STLayoutInterner {
map,
normalized_lambda_set_map,
vec,
target_info,
})
}
/// Interns a value with a pre-computed hash.
/// Prefer calling this when possible, especially from [TLLayoutInterner], to avoid
/// re-computing hashes.
fn insert_hashed(&self, value: Layout<'a>, hash: u64) -> InLayout<'a> {
let mut map = self.0.map.lock();
let (_, interned) = map
.raw_entry_mut()
.from_key_hashed_nocheck(hash, &value)
.or_insert_with(|| {
let mut vec = self.0.vec.write();
let interned = InLayout(vec.len(), Default::default());
vec.push(value);
(value, interned)
});
*interned
}
fn get_or_insert_hashed_normalized_lambda_set(
&self,
arena: &'a Bump,
normalized: LambdaSet<'a>,
set_may_have_naked_rec_ptr: bool,
normalized_hash: u64,
) -> WrittenGlobalLambdaSet<'a> {
let mut normalized_lambda_set_map = self.0.normalized_lambda_set_map.lock();
if let Some((_, &full_lambda_set)) = normalized_lambda_set_map
.raw_entry()
.from_key_hashed_nocheck(normalized_hash, &normalized)
{
let full_layout = self.0.vec.read()[full_lambda_set.full_layout.0];
return WrittenGlobalLambdaSet {
full_lambda_set,
full_layout,
};
}
// We don't already have an entry for the lambda set, which means it must be new to
// the world. Reserve a slot, insert the lambda set, and that should fill the slot
// in.
let mut map = self.0.map.lock();
let mut vec = self.0.vec.write();
let slot = unsafe { InLayout::from_index(vec.len()) };
vec.push(Layout::VOID_NAKED);
let set = if set_may_have_naked_rec_ptr {
let mut interner = LockedGlobalInterner {
map: &mut map,
normalized_lambda_set_map: &mut normalized_lambda_set_map,
vec: &mut vec,
target_info: self.0.target_info,
};
reify::reify_lambda_set_captures(arena, &mut interner, slot, normalized.set)
} else {
normalized.set
};
let full_lambda_set = LambdaSet {
full_layout: slot,
set,
..normalized
};
let lambda_set_layout = Layout::LambdaSet(full_lambda_set);
vec[slot.0] = lambda_set_layout;
// TODO: Is it helpful to persist the hash and give it back to the thread-local
// interner?
let _old = map.insert(lambda_set_layout, slot);
debug_assert!(_old.is_none());
let _old_normalized = normalized_lambda_set_map.insert(normalized, full_lambda_set);
debug_assert!(_old_normalized.is_none());
let full_layout = vec[full_lambda_set.full_layout.0];
WrittenGlobalLambdaSet {
full_lambda_set,
full_layout,
}
}
fn get_or_insert_hashed_normalized_recursive(
&self,
arena: &'a Bump,
normalized: Layout<'a>,
normalized_hash: u64,
) -> WrittenGlobalRecursive<'a> {
let mut map = self.0.map.lock();
if let Some((_, &interned)) = map
.raw_entry()
.from_key_hashed_nocheck(normalized_hash, &normalized)
{
let full_layout = self.0.vec.read()[interned.0];
return WrittenGlobalRecursive {
interned_layout: interned,
full_layout,
};
}
let mut vec = self.0.vec.write();
let mut normalized_lambda_set_map = self.0.normalized_lambda_set_map.lock();
let slot = unsafe { InLayout::from_index(vec.len()) };
vec.push(Layout::VOID_NAKED);
let mut interner = LockedGlobalInterner {
map: &mut map,
normalized_lambda_set_map: &mut normalized_lambda_set_map,
vec: &mut vec,
target_info: self.0.target_info,
};
let full_layout = reify::reify_recursive_layout(arena, &mut interner, slot, normalized);
vec[slot.0] = full_layout;
let _old = map.insert(normalized, slot);
debug_assert!(_old.is_none());
let _old_full_layout = map.insert(full_layout, slot);
debug_assert!(_old_full_layout.is_none());
WrittenGlobalRecursive {
interned_layout: slot,
full_layout,
}
}
fn get(&self, interned: InLayout<'a>) -> Layout<'a> {
let InLayout(index, _) = interned;
self.0.vec.read()[index]
}
pub fn is_empty(&self) -> bool {
self.0.vec.read().is_empty()
}
}
struct WrittenGlobalLambdaSet<'a> {
full_lambda_set: LambdaSet<'a>,
full_layout: Layout<'a>,
}
struct WrittenGlobalRecursive<'a> {
interned_layout: InLayout<'a>,
full_layout: Layout<'a>,
}
impl<'a> TLLayoutInterner<'a> {
/// Records an interned value in thread-specific storage, for faster access on lookups.
fn record(&self, key: Layout<'a>, interned: InLayout<'a>) {
let mut vec = self.vec.borrow_mut();
let len = vec.len().max(interned.0 + 1);
vec.resize(len, None);
vec[interned.0] = Some(key);
}
}
impl<'a> LayoutInterner<'a> for TLLayoutInterner<'a> {
fn insert(&mut self, value: Layout<'a>) -> InLayout<'a> {
let global = &self.parent;
let hash = hash(value);
let (&mut value, &mut interned) = self
.map
.raw_entry_mut()
.from_key_hashed_nocheck(hash, &value)
.or_insert_with(|| {
let interned = global.insert_hashed(value, hash);
(value, interned)
});
self.record(value, interned);
interned
}
fn insert_lambda_set(
&mut self,
arena: &'a Bump,
args: &'a &'a [InLayout<'a>],
ret: InLayout<'a>,
set: &'a &'a [(Symbol, &'a [InLayout<'a>])],
set_may_have_naked_rec_ptr: bool,
representation: InLayout<'a>,
) -> LambdaSet<'a> {
// The tricky bit of inserting a lambda set is we need to fill in the `full_layout` only
// after the lambda set is inserted, but we don't want to allocate a new interned slot if
// the same lambda set layout has already been inserted with a different `full_layout`
// slot.
//
// So,
// - check if the "normalized" lambda set (with a void full_layout slot) maps to an
// inserted lambda set in
// - in our thread-local cache, or globally
// - if so, use that one immediately
// - otherwise, allocate a new (global) slot, intern the lambda set, and then fill the slot in
let global = &self.parent;
let normalized = make_normalized_lamdba_set(args, ret, set, representation);
let normalized_hash = hash(normalized);
let mut new_interned_layout = None;
let (_, &mut full_lambda_set) = self
.normalized_lambda_set_map
.raw_entry_mut()
.from_key_hashed_nocheck(normalized_hash, &normalized)
.or_insert_with(|| {
let WrittenGlobalLambdaSet {
full_lambda_set,
full_layout,
} = global.get_or_insert_hashed_normalized_lambda_set(
arena,
normalized,
set_may_have_naked_rec_ptr,
normalized_hash,
);
// The Layout(lambda_set) isn't present in our thread; make sure it is for future
// reference.
new_interned_layout = Some((full_layout, full_lambda_set.full_layout));
(normalized, full_lambda_set)
});
if let Some((new_layout, new_interned)) = new_interned_layout {
// Write the interned lambda set layout into our thread-local cache.
self.record(new_layout, new_interned);
}
full_lambda_set
}
fn insert_recursive(&mut self, arena: &'a Bump, normalized_layout: Layout<'a>) -> InLayout<'a> {
// - Check if the normalized layout already has an interned slot. If it does we're done, since no
// recursive layout would ever have have VOID as the recursion pointer.
// - If not, allocate a slot and compute the recursive layout with the recursion pointer
// resolving to the new slot.
// - Point the resolved and normalized layout to the new slot.
let global = &self.parent;
let normalized_hash = hash(normalized_layout);
let mut new_interned_full_layout = None;
let (&mut _, &mut interned) = self
.map
.raw_entry_mut()
.from_key_hashed_nocheck(normalized_hash, &normalized_layout)
.or_insert_with(|| {
let WrittenGlobalRecursive {
interned_layout,
full_layout,
} = global.get_or_insert_hashed_normalized_recursive(
arena,
normalized_layout,
normalized_hash,
);
// The new filled-in layout isn't present in our thread; make sure it is for future
// reference.
new_interned_full_layout = Some(full_layout);
(normalized_layout, interned_layout)
});
if let Some(full_layout) = new_interned_full_layout {
self.record(full_layout, interned);
}
interned
}
fn get(&self, key: InLayout<'a>) -> Layout<'a> {
if let Some(Some(value)) = self.vec.borrow().get(key.0) {
return *value;
}
let value = self.parent.get(key);
self.record(value, key);
value
}
fn target_info(&self) -> TargetInfo {
self.target_info
}
}
impl<'a> STLayoutInterner<'a> {
/// Creates a new single threaded interner with the given capacity.
pub fn with_capacity(cap: usize, target_info: TargetInfo) -> Self {
let mut interner = Self {
map: BumpMap::with_capacity_and_hasher(cap, default_hasher()),
normalized_lambda_set_map: BumpMap::with_capacity_and_hasher(cap, default_hasher()),
vec: Vec::with_capacity(cap),
target_info,
};
fill_reserved_layouts(&mut interner);
interner
}
/// Promotes the [STLayoutInterner] back to a [GlobalLayoutInterner].
///
/// You should *only* use this if you need to go from a single-threaded to a concurrent context,
/// or in a case where you explicitly need access to [TLLayoutInterner]s.
pub fn into_global(self) -> GlobalLayoutInterner<'a> {
let STLayoutInterner {
map,
normalized_lambda_set_map,
vec,
target_info,
} = self;
GlobalLayoutInterner(Arc::new(GlobalLayoutInternerInner {
map: Mutex::new(map),
normalized_lambda_set_map: Mutex::new(normalized_lambda_set_map),
vec: RwLock::new(vec),
target_info,
}))
}
pub fn is_empty(&self) -> bool {
self.vec.is_empty()
}
}
macro_rules! st_impl {
($($lt:lifetime)? $interner:ident) => {
impl<'a$(, $lt)?> LayoutInterner<'a> for $interner<'a$(, $lt)?> {
fn insert(&mut self, value: Layout<'a>) -> InLayout<'a> {
let hash = hash(value);
let (_, interned) = self
.map
.raw_entry_mut()
.from_key_hashed_nocheck(hash, &value)
.or_insert_with(|| {
let interned = InLayout(self.vec.len(), Default::default());
self.vec.push(value);
(value, interned)
});
*interned
}
fn insert_lambda_set(
&mut self,
arena: &'a Bump,
args: &'a &'a [InLayout<'a>],
ret: InLayout<'a>,
set: &'a &'a [(Symbol, &'a [InLayout<'a>])],
set_may_have_naked_rec_ptr: bool,
representation: InLayout<'a>,
) -> LambdaSet<'a> {
// IDEA:
// - check if the "normalized" lambda set (with a void full_layout slot) maps to an
// inserted lambda set
// - if so, use that one immediately
// - otherwise, allocate a new slot, intern the lambda set, and then fill the slot in
let normalized_lambda_set =
make_normalized_lamdba_set(args, ret, set, representation);
if let Some(lambda_set) = self.normalized_lambda_set_map.get(&normalized_lambda_set)
{
return *lambda_set;
}
// This lambda set must be new to the interner, reserve a slot and fill it in.
let slot = unsafe { InLayout::from_index(self.vec.len()) };
self.vec.push(Layout::VOID_NAKED);
let set = if set_may_have_naked_rec_ptr {
reify::reify_lambda_set_captures(arena, self, slot, set)
} else {
set
};
let lambda_set = LambdaSet {
args,
ret,
set,
representation,
full_layout: slot,
};
self.vec[slot.0] = Layout::LambdaSet(lambda_set);
let _old = self.map.insert(Layout::LambdaSet(lambda_set), slot);
debug_assert!(_old.is_none());
let _old = self.normalized_lambda_set_map
.insert(normalized_lambda_set, lambda_set);
debug_assert!(_old.is_none());
lambda_set
}
fn insert_recursive(
&mut self,
arena: &'a Bump,
normalized_layout: Layout<'a>,
) -> InLayout<'a> {
// IDEA:
// - check if the normalized layout (with a void recursion pointer) maps to an
// inserted lambda set
// - if so, use that one immediately
// - otherwise, allocate a new slot, update the recursive layout, and intern
if let Some(in_layout) = self.map.get(&normalized_layout) {
return *in_layout;
}
// This recursive layout must be new to the interner, reserve a slot and fill it in.
let slot = unsafe { InLayout::from_index(self.vec.len()) };
self.vec.push(Layout::VOID_NAKED);
let full_layout =
reify::reify_recursive_layout(arena, self, slot, normalized_layout);
self.vec[slot.0] = full_layout;
self.map.insert(normalized_layout, slot);
self.map.insert(full_layout, slot);
slot
}
fn get(&self, key: InLayout<'a>) -> Layout<'a> {
let InLayout(index, _) = key;
self.vec[index]
}
fn target_info(&self) -> TargetInfo {
self.target_info
}
}
};
}
st_impl!(STLayoutInterner);
st_impl!('r LockedGlobalInterner);
mod reify {
use bumpalo::{collections::Vec, Bump};
use roc_module::symbol::Symbol;
use crate::layout::{Builtin, LambdaSet, Layout, UnionLayout};
use super::{InLayout, LayoutInterner};
// TODO: if recursion becomes a problem we could make this iterative
pub fn reify_recursive_layout<'a>(
arena: &'a Bump,
interner: &mut impl LayoutInterner<'a>,
slot: InLayout<'a>,
normalized_layout: Layout<'a>,
) -> Layout<'a> {
match normalized_layout {
Layout::Builtin(builtin) => {
Layout::Builtin(reify_builtin(arena, interner, slot, builtin))
}
Layout::Struct {
field_order_hash,
field_layouts,
} => Layout::Struct {
field_order_hash,
field_layouts: reify_layout_slice(arena, interner, slot, field_layouts),
},
Layout::Boxed(lay) => Layout::Boxed(reify_layout(arena, interner, slot, lay)),
Layout::Union(un) => Layout::Union(reify_union(arena, interner, slot, un)),
Layout::LambdaSet(ls) => Layout::LambdaSet(reify_lambda_set(arena, interner, slot, ls)),
Layout::RecursivePointer(l) => {
// If the layout is not void at its point then it has already been solved as
// another recursive union's layout, do not change it.
Layout::RecursivePointer(if l == Layout::VOID { slot } else { l })
}
}
}
fn reify_layout<'a>(
arena: &'a Bump,
interner: &mut impl LayoutInterner<'a>,
slot: InLayout<'a>,
layout: InLayout<'a>,
) -> InLayout<'a> {
let layout = reify_recursive_layout(arena, interner, slot, interner.get(layout));
interner.insert(layout)
}
fn reify_layout_slice<'a>(
arena: &'a Bump,
interner: &mut impl LayoutInterner<'a>,
slot: InLayout<'a>,
layouts: &[InLayout<'a>],
) -> &'a [InLayout<'a>] {
let mut slice = Vec::with_capacity_in(layouts.len(), arena);
for &layout in layouts {
slice.push(reify_layout(arena, interner, slot, layout));
}
slice.into_bump_slice()
}
fn reify_layout_slice_slice<'a>(
arena: &'a Bump,
interner: &mut impl LayoutInterner<'a>,
slot: InLayout<'a>,
layouts: &[&[InLayout<'a>]],
) -> &'a [&'a [InLayout<'a>]] {
let mut slice = Vec::with_capacity_in(layouts.len(), arena);
for &layouts in layouts {
slice.push(reify_layout_slice(arena, interner, slot, layouts));
}
slice.into_bump_slice()
}
fn reify_builtin<'a>(
arena: &'a Bump,
interner: &mut impl LayoutInterner<'a>,
slot: InLayout<'a>,
builtin: Builtin<'a>,
) -> Builtin<'a> {
match builtin {
Builtin::Int(_)
| Builtin::Float(_)
| Builtin::Bool
| Builtin::Decimal
| Builtin::Str => builtin,
Builtin::List(elem) => Builtin::List(reify_layout(arena, interner, slot, elem)),
}
}
fn reify_union<'a>(
arena: &'a Bump,
interner: &mut impl LayoutInterner<'a>,
slot: InLayout<'a>,
union: UnionLayout<'a>,
) -> UnionLayout<'a> {
match union {
UnionLayout::NonRecursive(tags) => {
UnionLayout::NonRecursive(reify_layout_slice_slice(arena, interner, slot, tags))
}
UnionLayout::Recursive(tags) => {
UnionLayout::Recursive(reify_layout_slice_slice(arena, interner, slot, tags))
}
UnionLayout::NonNullableUnwrapped(fields) => {
UnionLayout::NonNullableUnwrapped(reify_layout_slice(arena, interner, slot, fields))
}
UnionLayout::NullableWrapped {
nullable_id,
other_tags,
} => UnionLayout::NullableWrapped {
nullable_id,
other_tags: reify_layout_slice_slice(arena, interner, slot, other_tags),
},
UnionLayout::NullableUnwrapped {
nullable_id,
other_fields,
} => UnionLayout::NullableUnwrapped {
nullable_id,
other_fields: reify_layout_slice(arena, interner, slot, other_fields),
},
}
}
fn reify_lambda_set<'a>(
arena: &'a Bump,
interner: &mut impl LayoutInterner<'a>,
slot: InLayout<'a>,
lambda_set: LambdaSet<'a>,
) -> LambdaSet<'a> {
let LambdaSet {
args,
ret,
set,
representation,
full_layout: _,
} = lambda_set;
let args = reify_layout_slice(arena, interner, slot, args);
let ret = reify_layout(arena, interner, slot, ret);
let set = {
let mut new_set = Vec::with_capacity_in(set.len(), arena);
for (lambda, captures) in set.iter() {
new_set.push((*lambda, reify_layout_slice(arena, interner, slot, captures)));
}
new_set.into_bump_slice()
};
let representation = reify_layout(arena, interner, slot, representation);
interner.insert_lambda_set(
arena,
arena.alloc(args),
ret,
arena.alloc(set),
true,
representation,
)
}
pub fn reify_lambda_set_captures<'a>(
arena: &'a Bump,
interner: &mut impl LayoutInterner<'a>,
slot: InLayout<'a>,
set: &[(Symbol, &'a [InLayout<'a>])],
) -> &'a &'a [(Symbol, &'a [InLayout<'a>])] {
let mut reified_set = Vec::with_capacity_in(set.len(), arena);
for (f, captures) in set.iter() {
let reified_captures = reify_layout_slice(arena, interner, slot, captures);
reified_set.push((*f, reified_captures));
}
arena.alloc(reified_set.into_bump_slice())
}
}
mod equiv {
use crate::layout::{self, Layout, UnionLayout};
use super::{InLayout, LayoutInterner};
pub fn equivalent<'a>(
stack: &mut Vec<(InLayout<'a>, InLayout<'a>)>,
interner: &impl LayoutInterner<'a>,
l1: InLayout<'a>,
l2: InLayout<'a>,
) -> bool {
stack.push((l1, l2));
macro_rules! equiv_fields {
($fields1:expr, $fields2:expr) => {{
if $fields1.len() != $fields2.len() {
return false;
}
stack.extend($fields1.iter().copied().zip($fields2.iter().copied()));
}};
}
macro_rules! equiv_unions {
($tags1:expr, $tags2:expr) => {{
if $tags1.len() != $tags2.len() {
return false;
}
for (payloads1, payloads2) in $tags1.iter().zip($tags2) {
equiv_fields!(payloads1, payloads2)
}
}};
}
while let Some((l1, l2)) = stack.pop() {
if l1 == l2 {
continue;
}
use Layout::*;
match (interner.get(l1), interner.get(l2)) {
(RecursivePointer(rec), _) => stack.push((rec, l2)),
(_, RecursivePointer(rec)) => stack.push((l1, rec)),
(Builtin(b1), Builtin(b2)) => {
use crate::layout::Builtin::*;
match (b1, b2) {
(List(e1), List(e2)) => stack.push((e1, e2)),
(b1, b2) => {
if b1 != b2 {
return false;
}
}
}
}
(
Struct {
field_order_hash: foh1,
field_layouts: fl1,
},
Struct {
field_order_hash: foh2,
field_layouts: fl2,
},
) => {
if foh1 != foh2 {
return false;
}
equiv_fields!(fl1, fl2)
}
(Boxed(b1), Boxed(b2)) => stack.push((b1, b2)),
(Union(u1), Union(u2)) => {
use UnionLayout::*;
match (u1, u2) {
(NonRecursive(tags1), NonRecursive(tags2)) => equiv_unions!(tags1, tags2),
(Recursive(tags1), Recursive(tags2)) => equiv_unions!(tags1, tags2),
(NonNullableUnwrapped(fields1), NonNullableUnwrapped(fields2)) => {
equiv_fields!(fields1, fields2)
}
(
NullableWrapped {
nullable_id: null_id1,
other_tags: tags1,
},
NullableWrapped {
nullable_id: null_id2,
other_tags: tags2,
},
) => {
if null_id1 != null_id2 {
return false;
}
equiv_unions!(tags1, tags2)
}
(
NullableUnwrapped {
nullable_id: null_id1,
other_fields: fields1,
},
NullableUnwrapped {
nullable_id: null_id2,
other_fields: fields2,
},
) => {
if null_id1 != null_id2 {
return false;
}
equiv_fields!(fields1, fields2)
}
_ => return false,
}
}
(
LambdaSet(layout::LambdaSet {
args: args1,
ret: ret1,
set: set1,
representation: repr1,
full_layout: _,
}),
LambdaSet(layout::LambdaSet {
args: args2,
ret: ret2,
set: set2,
representation: repr2,
full_layout: _,
}),
) => {
for ((fn1, captures1), (fn2, captures2)) in (**set1).iter().zip(*set2) {
if fn1 != fn2 {
return false;
}
equiv_fields!(captures1, captures2);
}
equiv_fields!(args1, args2);
stack.push((ret1, ret2));
stack.push((repr1, repr2));
}
_ => return false,
}
}
true
}
}
#[cfg(test)]
mod insert_lambda_set {
use bumpalo::Bump;
use roc_module::symbol::Symbol;
use roc_target::TargetInfo;
use crate::layout::{LambdaSet, Layout};
use super::{GlobalLayoutInterner, InLayout, LayoutInterner};
const TARGET_INFO: TargetInfo = TargetInfo::default_x86_64();
const TEST_SET: &&[(Symbol, &[InLayout])] =
&(&[(Symbol::ATTR_ATTR, &[Layout::UNIT] as &[_])] as &[_]);
const TEST_ARGS: &&[InLayout] = &(&[Layout::UNIT] as &[_]);
const TEST_RET: InLayout = Layout::UNIT;
#[test]
fn two_threads_write() {
for _ in 0..100 {
let mut arenas: Vec<_> = std::iter::repeat_with(Bump::new).take(10).collect();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let set = TEST_SET;
let repr = Layout::UNIT;
std::thread::scope(|s| {
let mut handles = Vec::with_capacity(10);
for arena in arenas.iter_mut() {
let mut interner = global.fork();
handles.push(s.spawn(move || {
interner.insert_lambda_set(arena, TEST_ARGS, TEST_RET, set, true, repr)
}))
}
let ins: Vec<LambdaSet> = handles.into_iter().map(|t| t.join().unwrap()).collect();
let interned = ins[0];
assert!(ins.iter().all(|in2| interned == *in2));
});
}
}
#[test]
fn insert_then_reintern() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let mut interner = global.fork();
let lambda_set =
interner.insert_lambda_set(arena, TEST_ARGS, TEST_RET, TEST_SET, true, Layout::UNIT);
let lambda_set_layout_in = interner.insert(Layout::LambdaSet(lambda_set));
assert_eq!(lambda_set.full_layout, lambda_set_layout_in);
}
#[test]
fn write_global_then_single_threaded() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let set = TEST_SET;
let repr = Layout::UNIT;
let in1 = {
let mut interner = global.fork();
interner.insert_lambda_set(arena, TEST_ARGS, TEST_RET, set, true, repr)
};
let in2 = {
let mut st_interner = global.unwrap().unwrap();
st_interner.insert_lambda_set(arena, TEST_ARGS, TEST_RET, set, true, repr)
};
assert_eq!(in1, in2);
}
#[test]
fn write_single_threaded_then_global() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let mut st_interner = global.unwrap().unwrap();
let set = TEST_SET;
let repr = Layout::UNIT;
let in1 = st_interner.insert_lambda_set(arena, TEST_ARGS, TEST_RET, set, true, repr);
let global = st_interner.into_global();
let mut interner = global.fork();
let in2 = interner.insert_lambda_set(arena, TEST_ARGS, TEST_RET, set, true, repr);
assert_eq!(in1, in2);
}
}
#[cfg(test)]
mod insert_recursive_layout {
use bumpalo::Bump;
use roc_target::TargetInfo;
use crate::layout::{Builtin, InLayout, Layout, UnionLayout};
use super::{GlobalLayoutInterner, LayoutInterner};
const TARGET_INFO: TargetInfo = TargetInfo::default_x86_64();
fn make_layout<'a>(arena: &'a Bump, interner: &mut impl LayoutInterner<'a>) -> Layout<'a> {
Layout::Union(UnionLayout::Recursive(&*arena.alloc([
&*arena.alloc([
interner.insert(Layout::Builtin(Builtin::List(Layout::NAKED_RECURSIVE_PTR))),
]),
&*arena.alloc_slice_fill_iter([interner.insert(Layout::struct_no_name_order(
&*arena.alloc([Layout::NAKED_RECURSIVE_PTR]),
))]),
])))
}
fn get_rec_ptr_index<'a>(interner: &impl LayoutInterner<'a>, layout: InLayout<'a>) -> usize {
match interner.chase_recursive(layout) {
Layout::Union(UnionLayout::Recursive(&[&[l1], &[l2]])) => {
match (interner.get(l1), interner.get(l2)) {
(
Layout::Builtin(Builtin::List(l1)),
Layout::Struct {
field_order_hash: _,
field_layouts: &[l2],
},
) => match (interner.get(l1), interner.get(l2)) {
(Layout::RecursivePointer(i1), Layout::RecursivePointer(i2)) => {
assert_eq!(i1, i2);
assert_ne!(i1, Layout::VOID);
i1.0
}
_ => unreachable!(),
},
_ => unreachable!(),
}
}
_ => unreachable!(),
}
}
#[test]
fn write_two_threads() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let layout = {
let mut interner = global.fork();
make_layout(arena, &mut interner)
};
let in1 = {
let mut interner = global.fork();
interner.insert_recursive(arena, layout)
};
let in2 = {
let mut interner = global.fork();
interner.insert_recursive(arena, layout)
};
assert_eq!(in1, in2);
}
#[test]
fn write_twice_thread_local_single_thread() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let mut interner = global.fork();
let layout = make_layout(arena, &mut interner);
let in1 = interner.insert_recursive(arena, layout);
let rec1 = get_rec_ptr_index(&interner, in1);
let in2 = interner.insert_recursive(arena, layout);
let rec2 = get_rec_ptr_index(&interner, in2);
assert_eq!(in1, in2);
assert_eq!(rec1, rec2);
}
#[test]
fn write_twice_single_thread() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let mut interner = GlobalLayoutInterner::unwrap(global).unwrap();
let layout = make_layout(arena, &mut interner);
let in1 = interner.insert_recursive(arena, layout);
let rec1 = get_rec_ptr_index(&interner, in1);
let in2 = interner.insert_recursive(arena, layout);
let rec2 = get_rec_ptr_index(&interner, in2);
assert_eq!(in1, in2);
assert_eq!(rec1, rec2);
}
#[test]
fn many_threads_read_write() {
for _ in 0..100 {
let mut arenas: Vec<_> = std::iter::repeat_with(Bump::new).take(10).collect();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
std::thread::scope(|s| {
let mut handles = Vec::with_capacity(10);
for arena in arenas.iter_mut() {
let mut interner = global.fork();
let handle = s.spawn(move || {
let layout = make_layout(arena, &mut interner);
let in_layout = interner.insert_recursive(arena, layout);
(in_layout, get_rec_ptr_index(&interner, in_layout))
});
handles.push(handle);
}
let ins: Vec<(InLayout, usize)> =
handles.into_iter().map(|t| t.join().unwrap()).collect();
let interned = ins[0];
assert!(ins.iter().all(|in2| interned == *in2));
});
}
}
#[test]
fn insert_then_reintern() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let mut interner = global.fork();
let layout = make_layout(arena, &mut interner);
let interned_layout = interner.insert_recursive(arena, layout);
let full_layout = interner.get(interned_layout);
assert_ne!(layout, full_layout);
assert_eq!(interner.insert(full_layout), interned_layout);
}
#[test]
fn write_global_then_single_threaded() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let layout = {
let mut interner = global.fork();
make_layout(arena, &mut interner)
};
let in1: InLayout = {
let mut interner = global.fork();
interner.insert_recursive(arena, layout)
};
let in2 = {
let mut st_interner = global.unwrap().unwrap();
st_interner.insert_recursive(arena, layout)
};
assert_eq!(in1, in2);
}
#[test]
fn write_single_threaded_then_global() {
let arena = &Bump::new();
let global = GlobalLayoutInterner::with_capacity(2, TARGET_INFO);
let mut st_interner = global.unwrap().unwrap();
let layout = make_layout(arena, &mut st_interner);
let in1 = st_interner.insert_recursive(arena, layout);
let global = st_interner.into_global();
let mut interner = global.fork();
let in2 = interner.insert_recursive(arena, layout);
assert_eq!(in1, in2);
}
}