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fitzgen wants to merge 1 commit into from
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Use an arena-based BTree library #88

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1 change: 1 addition & 0 deletions Cargo.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@ description = "Backtracking register allocator inspired from IonMonkey"
repository = "https://github.com/bytecodealliance/regalloc2"

[dependencies]
arena-btree = { path = "../arena-btree" }
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@cfallin cfallin Sep 23, 2022

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should refer to published crate here

log = { version = "0.4.8", default-features = false }
smallvec = "1.6.1"
fxhash = "0.2.1"
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66 changes: 59 additions & 7 deletions src/ion/data_structures.rs
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Expand Up @@ -20,9 +20,10 @@ use crate::{
define_index, Allocation, Block, Edit, Function, Inst, MachineEnv, Operand, PReg, ProgPoint,
RegClass, VReg,
};
use arena_btree::{Arena, BTreeMap};
use smallvec::SmallVec;
use std::cmp::Ordering;
use std::collections::{BTreeMap, HashMap, HashSet};
use std::collections::{HashMap, HashSet};
use std::fmt::Debug;

/// A range from `from` (inclusive) to `to` (exclusive).
Expand Down Expand Up @@ -286,12 +287,25 @@ pub struct VRegData {
pub class: Option<RegClass>,
}

#[derive(Clone, Debug)]
#[derive(Debug)]
pub struct PRegData {
pub allocations: LiveRangeSet,
pub is_stack: bool,
}

impl PRegData {
pub fn clone(&self, arena: &mut Arena<LiveRangeKey, LiveRangeIndex>) -> Self {
PRegData {
allocations: self.allocations.clone(arena),
is_stack: self.is_stack,
}
}

pub fn drop(self, arena: &mut Arena<LiveRangeKey, LiveRangeIndex>) {
self.allocations.drop(arena);
}
}

#[derive(Clone, Debug)]
pub struct MultiFixedRegFixup {
pub pos: ProgPoint,
Expand Down Expand Up @@ -361,7 +375,7 @@ impl BlockparamIn {
}
}

#[derive(Clone, Debug)]
#[derive(Debug)]
pub struct Env<'a, F: Function> {
pub func: &'a F,
pub env: &'a MachineEnv,
Expand All @@ -371,6 +385,7 @@ pub struct Env<'a, F: Function> {
pub blockparam_outs: Vec<BlockparamOut>,
pub blockparam_ins: Vec<BlockparamIn>,

pub arena: Arena<LiveRangeKey, LiveRangeIndex>,
pub ranges: Vec<LiveRange>,
pub bundles: Vec<LiveBundle>,
pub spillsets: Vec<SpillSet>,
Expand Down Expand Up @@ -432,6 +447,17 @@ pub struct Env<'a, F: Function> {
pub annotations_enabled: bool,
}

impl<'a, F: Function> Drop for Env<'a, F> {
fn drop(&mut self) {
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@cfallin cfallin Sep 23, 2022

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I don't think we actually need this, given that we know our key and index types are Copy (u32s in fact)?

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@cfallin cfallin Sep 23, 2022

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(Perhaps in trivial cases the empty drop impl means things optimize away, but I'd be a little skeptical of LLVM's ability to do that here in concert with the use of the drain iters etc)

for preg in self.pregs.drain(..) {
preg.drop(&mut self.arena);
}
for slot in self.spillslots.drain(..) {
slot.drop(&mut self.arena);
}
}
}

impl<'a, F: Function> Env<'a, F> {
/// Get the VReg (with bundled RegClass) from a vreg index.
#[inline]
Expand All @@ -457,13 +483,27 @@ impl<'a, F: Function> Env<'a, F> {
}
}

#[derive(Clone, Debug)]
#[derive(Debug)]
pub struct SpillSlotData {
pub ranges: LiveRangeSet,
pub slots: u32,
pub alloc: Allocation,
}

impl SpillSlotData {
pub fn clone(&self, arena: &mut Arena<LiveRangeKey, LiveRangeIndex>) -> Self {
SpillSlotData {
ranges: self.ranges.clone(arena),
slots: self.slots,
alloc: self.alloc,
}
}

pub fn drop(self, arena: &mut Arena<LiveRangeKey, LiveRangeIndex>) {
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@cfallin cfallin Sep 23, 2022

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Likewise here, not needed given knowledge of key/value types?

self.ranges.drop(arena);
}
}

#[derive(Clone, Debug)]
pub struct SpillSlotList {
pub slots: SmallVec<[SpillSlotIndex; 32]>,
Expand Down Expand Up @@ -495,11 +535,23 @@ pub struct PrioQueueEntry {
pub reg_hint: PReg,
}

#[derive(Clone, Debug)]
#[derive(Debug)]
pub struct LiveRangeSet {
pub btree: BTreeMap<LiveRangeKey, LiveRangeIndex>,
}

impl LiveRangeSet {
pub fn clone(&self, arena: &mut Arena<LiveRangeKey, LiveRangeIndex>) -> LiveRangeSet {
LiveRangeSet {
btree: self.btree.clone(arena),
}
}

pub fn drop(self, arena: &mut Arena<LiveRangeKey, LiveRangeIndex>) {
self.btree.drop(arena);
}
}

#[derive(Clone, Copy, Debug)]
pub struct LiveRangeKey {
pub from: u32,
Expand Down Expand Up @@ -588,9 +640,9 @@ impl PrioQueue {
}

impl LiveRangeSet {
pub(crate) fn new() -> Self {
pub(crate) fn new(arena: &Arena<LiveRangeKey, LiveRangeIndex>) -> Self {
Self {
btree: BTreeMap::new(),
btree: BTreeMap::new(arena),
}
}
}
Expand Down
25 changes: 14 additions & 11 deletions src/ion/liveranges.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -25,10 +25,12 @@ use crate::{
Allocation, Block, Function, Inst, InstPosition, Operand, OperandConstraint, OperandKind,
OperandPos, PReg, ProgPoint, RegAllocError, VReg,
};
use arena_btree::Arena;
use fxhash::{FxHashMap, FxHashSet};
use slice_group_by::GroupByMut;
use smallvec::{smallvec, SmallVec};
use std::collections::{HashSet, VecDeque};
use std::mem;

/// A spill weight computed for a certain Use.
#[derive(Clone, Copy, Debug)]
Expand Down Expand Up @@ -101,13 +103,13 @@ impl std::ops::Add<SpillWeight> for SpillWeight {
impl<'a, F: Function> Env<'a, F> {
pub fn create_pregs_and_vregs(&mut self) {
// Create PRegs from the env.
self.pregs.resize(
PReg::NUM_INDEX,
PRegData {
allocations: LiveRangeSet::new(),
is_stack: false,
},
);
let arena = mem::replace(&mut self.arena, Arena::new());
self.pregs.resize_with(PReg::NUM_INDEX, || PRegData {
allocations: LiveRangeSet::new(&arena),
is_stack: false,
});
self.arena = arena;

for &preg in &self.env.fixed_stack_slots {
self.pregs[preg.index()].is_stack = true;
}
Expand Down Expand Up @@ -307,10 +309,11 @@ impl<'a, F: Function> Env<'a, F> {
pub fn add_liverange_to_preg(&mut self, range: CodeRange, reg: PReg) {
trace!("adding liverange to preg: {:?} to {}", range, reg);
let preg_idx = PRegIndex::new(reg.index());
self.pregs[preg_idx.index()]
.allocations
.btree
.insert(LiveRangeKey::from_range(&range), LiveRangeIndex::invalid());
self.pregs[preg_idx.index()].allocations.btree.insert(
&mut self.arena,
LiveRangeKey::from_range(&range),
LiveRangeIndex::invalid(),
);
}

pub fn is_live_in(&mut self, block: Block, vreg: VRegIndex) -> bool {
Expand Down
9 changes: 5 additions & 4 deletions src/ion/merge.rs
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Expand Up @@ -250,10 +250,11 @@ impl<'a, F: Function> Env<'a, F> {
if let Some(preg) = self.func.is_pinned_vreg(self.vreg(vreg)) {
for entry in &self.vregs[vreg.index()].ranges {
let key = LiveRangeKey::from_range(&entry.range);
self.pregs[preg.index()]
.allocations
.btree
.insert(key, LiveRangeIndex::invalid());
self.pregs[preg.index()].allocations.btree.insert(
&mut self.arena,
key,
LiveRangeIndex::invalid(),
);
}
continue;
}
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14 changes: 9 additions & 5 deletions src/ion/mod.rs
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Expand Up @@ -15,7 +15,9 @@

use crate::cfg::CFGInfo;
use crate::{Function, MachineEnv, Output, PReg, ProgPoint, RegAllocError, RegClass};
use arena_btree::Arena;
use std::collections::HashMap;
use std::mem;

pub(crate) mod data_structures;
pub use data_structures::Stats;
Expand Down Expand Up @@ -55,6 +57,8 @@ impl<'a, F: Function> Env<'a, F> {
blockparam_outs: vec![],
blockparam_ins: vec![],
bundles: Vec::with_capacity(n),

arena: Arena::new(),
ranges: Vec::with_capacity(4 * n),
spillsets: Vec::with_capacity(n),
vregs: Vec::with_capacity(n),
Expand Down Expand Up @@ -133,14 +137,14 @@ pub fn run<F: Function>(
Ok(Output {
edits: env
.edits
.into_iter()
.drain(..)
.map(|(pos_prio, edit)| (pos_prio.pos, edit))
.collect(),
allocs: env.allocs,
inst_alloc_offsets: env.inst_alloc_offsets,
allocs: mem::take(&mut env.allocs),
inst_alloc_offsets: mem::take(&mut env.inst_alloc_offsets),
num_spillslots: env.num_spillslots as usize,
debug_locations: env.debug_locations,
safepoint_slots: env.safepoint_slots,
debug_locations: mem::take(&mut env.debug_locations),
safepoint_slots: mem::take(&mut env.safepoint_slots),
stats: env.stats,
})
}
2 changes: 1 addition & 1 deletion src/ion/moves.rs
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Expand Up @@ -1004,7 +1004,7 @@ impl<'a, F: Function> Env<'a, F> {
if !self.pregs[preg.index()]
.allocations
.btree
.contains_key(&key)
.contains_key(&self.arena, &key)
{
let alloc = Allocation::reg(preg);
if moves
Expand Down
21 changes: 13 additions & 8 deletions src/ion/process.rs
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Expand Up @@ -84,7 +84,7 @@ impl<'a, F: Function> Env<'a, F> {
let mut preg_range_iter = self.pregs[reg.index()]
.allocations
.btree
.range(from_key..)
.range(&self.arena, from_key..)
.peekable();
trace!(
"alloc map for {:?} in range {:?}..: {:?}",
Expand Down Expand Up @@ -122,7 +122,7 @@ impl<'a, F: Function> Env<'a, F> {
preg_range_iter = self.pregs[reg.index()]
.allocations
.btree
.range(from_key..)
.range(&self.arena, from_key..)
.peekable();
skips = 0;
}
Expand Down Expand Up @@ -198,10 +198,11 @@ impl<'a, F: Function> Env<'a, F> {
trace!(" -> bundle {:?} assigned to preg {:?}", bundle, preg);
self.bundles[bundle.index()].allocation = Allocation::reg(preg);
for entry in &self.bundles[bundle.index()].ranges {
self.pregs[reg.index()]
.allocations
.btree
.insert(LiveRangeKey::from_range(&entry.range), entry.index);
self.pregs[reg.index()].allocations.btree.insert(
&mut self.arena,
LiveRangeKey::from_range(&entry.range),
entry.index,
);
}

AllocRegResult::Allocated(Allocation::reg(preg))
Expand Down Expand Up @@ -230,7 +231,7 @@ impl<'a, F: Function> Env<'a, F> {
self.pregs[preg_idx.index()]
.allocations
.btree
.remove(&LiveRangeKey::from_range(&entry.range));
.remove(&mut self.arena, &LiveRangeKey::from_range(&entry.range));
}
let prio = self.bundles[bundle.index()].prio;
trace!(" -> prio {}; back into queue", prio);
Expand Down Expand Up @@ -1230,7 +1231,11 @@ impl<'a, F: Function> Env<'a, F> {
from: range.from.prev(),
to: range.from.prev(),
});
for (key, lr) in self.pregs[preg.index()].allocations.btree.range(start..) {
for (key, lr) in self.pregs[preg.index()]
.allocations
.btree
.range(&self.arena, start..)
{
let preg_range = key.to_range();
if preg_range.to <= range.from {
continue;
Expand Down
13 changes: 7 additions & 6 deletions src/ion/spill.rs
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Expand Up @@ -74,7 +74,7 @@ impl<'a, F: Function> Env<'a, F> {
if self.spillslots[spillslot.index()]
.ranges
.btree
.contains_key(&LiveRangeKey::from_range(&entry.range))
.contains_key(&self.arena, &LiveRangeKey::from_range(&entry.range))
{
return false;
}
Expand Down Expand Up @@ -106,10 +106,11 @@ impl<'a, F: Function> Env<'a, F> {
entry.index,
vreg,
);
self.spillslots[spillslot.index()]
.ranges
.btree
.insert(LiveRangeKey::from_range(&entry.range), entry.index);
self.spillslots[spillslot.index()].ranges.btree.insert(
&mut self.arena,
LiveRangeKey::from_range(&entry.range),
entry.index,
);
}
}
}
Expand Down Expand Up @@ -163,7 +164,7 @@ impl<'a, F: Function> Env<'a, F> {
// Allocate a new spillslot.
let spillslot = SpillSlotIndex::new(self.spillslots.len());
self.spillslots.push(SpillSlotData {
ranges: LiveRangeSet::new(),
ranges: LiveRangeSet::new(&self.arena),
alloc: Allocation::none(),
slots: size as u32,
});
Expand Down