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Use bforest::Map for representing live ranges.

Browse Source 
Get rid of the per-value Vec in the LiveRange data type and use a
bforest::Map instead to represent the live-in intervals for non-local
live ranges.

This has some advantages:

- The memory footprint of a local live range is reduced from 40 to 20
  bytes, and
- Clearing the Liveness data structure is now a constant time operation
  which doesn't call free().
- The potentially quadratic behavior when computing large live ranges is
  controlled by the logarithmic B-tree operations.
This commit is contained in:
Jakob Stoklund Olesen
2017-12-04 13:43:10 -08:00
parent 27d5543adc
commit feaea238bc
9 changed files with 279 additions and 215 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
lib/cretonne/src/regalloc/coalescing.rs
View File

@@ -157,13 +157,11 @@ impl DomForest {
layout,
domtree,
};
let ctx = liveness.context(layout);
for node in merged {
if let Some(parent) = self.push_node(node, layout, domtree) {
// Check if `parent` live range contains `node.def`.
let lr = liveness.get(parent).expect(
"No live range for parent value",
);
if lr.overlaps_def(node.def, layout.pp_ebb(node.def), layout) {
if liveness[parent].overlaps_def(node.def, layout.pp_ebb(node.def), ctx) {
// Interference detected. Get the `(a, b)` order right in the error.
return Err(if node.set == 0 {
(node.value, parent)
@@ -447,7 +445,11 @@ impl<'a> Context<'a> {
if self.liveness
.get(a)
.expect("No live range for interfering value")
.reaches_use(pred_inst, pred_ebb, &self.func.layout)
.reaches_use(
pred_inst,
pred_ebb,
self.liveness.context(&self.func.layout),
)
{
// Splitting at `pred_inst` wouldn't resolve the interference, so we need to
// start over.

19
lib/cretonne/src/regalloc/coloring.rs
View File

@@ -44,7 +44,7 @@
use cursor::{Cursor, EncCursor};
use dominator_tree::DominatorTree;
use ir::{Ebb, Inst, Value, Function, ValueLoc, SigRef};
use ir::{Ebb, Inst, Value, Function, Layout, ValueLoc, SigRef};
use ir::{InstBuilder, AbiParam, ArgumentLoc, ValueDef};
use isa::{RegUnit, RegClass, RegInfo, regs_overlap};
use isa::{TargetIsa, EncInfo, RecipeConstraints, OperandConstraint, ConstraintKind};
@@ -54,7 +54,7 @@ use regalloc::affinity::Affinity;
use regalloc::allocatable_set::AllocatableSet;
use regalloc::live_value_tracker::{LiveValue, LiveValueTracker};
use regalloc::liveness::Liveness;
use regalloc::liverange::LiveRange;
use regalloc::liverange::{LiveRange, LiveRangeContext};
use regalloc::solver::{Solver, SolverError};
use std::mem;
@@ -542,8 +542,8 @@ impl<'a> Context<'a> {
if op.regclass.contains(cur_reg) {
// This code runs after calling `solver.inputs_done()` so we must identify
// the new variable as killed or live-through.
let layout = &self.cur.func.layout;
if self.liveness[value].killed_at(inst, layout.pp_ebb(inst), layout) {
let ctx = self.liveness.context(&self.cur.func.layout);
if self.liveness[value].killed_at(inst, ctx.order.pp_ebb(inst), ctx) {
self.solver.add_killed_var(value, op.regclass, cur_reg);
} else {
self.solver.add_through_var(value, op.regclass, cur_reg);
@@ -572,7 +572,7 @@ impl<'a> Context<'a> {
//
// Values with a global live range that are not live in to `dest` could appear as branch
// arguments, so they can't always be un-diverted.
self.undivert_regs(|lr, func| lr.is_livein(dest, &func.layout));
self.undivert_regs(|lr, ctx| lr.is_livein(dest, ctx));
// Now handle the EBB arguments.
let br_args = self.cur.func.dfg.inst_variable_args(inst);
@@ -642,13 +642,13 @@ impl<'a> Context<'a> {
/// are reallocated to their global register assignments.
fn undivert_regs<Pred>(&mut self, mut pred: Pred)
where
Pred: FnMut(&LiveRange, &Function) -> bool,
Pred: FnMut(&LiveRange, LiveRangeContext<Layout>) -> bool,
{
for rdiv in self.divert.all() {
let lr = self.liveness.get(rdiv.value).expect(
"Missing live range for diverted register",
);
if pred(lr, &self.cur.func) {
if pred(lr, self.liveness.context(&self.cur.func.layout)) {
if let Affinity::Reg(rci) = lr.affinity {
let rc = self.reginfo.rc(rci);
// Stack diversions should not be possible here. The only live transiently
@@ -882,17 +882,18 @@ impl<'a> Context<'a> {
use ir::instructions::BranchInfo::*;
let inst = self.cur.current_inst().expect("Not on an instruction");
let ctx = self.liveness.context(&self.cur.func.layout);
match self.cur.func.dfg[inst].analyze_branch(&self.cur.func.dfg.value_lists) {
NotABranch => false,
SingleDest(ebb, _) => {
let lr = &self.liveness[value];
lr.is_livein(ebb, &self.cur.func.layout)
lr.is_livein(ebb, ctx)
}
Table(jt) => {
let lr = &self.liveness[value];
!lr.is_local() &&
self.cur.func.jump_tables[jt].entries().any(|(_, ebb)| {
lr.is_livein(ebb, &self.cur.func.layout)
lr.is_livein(ebb, ctx)
})
}
}

3
lib/cretonne/src/regalloc/live_value_tracker.rs
View File

@@ -189,6 +189,7 @@ impl LiveValueTracker {
let idom_live_list = self.idom_sets.get(&idom).expect(
"No stored live set for dominator",
);
let ctx = liveness.context(layout);
// Get just the values that are live-in to `ebb`.
for &value in idom_live_list.as_slice(&self.idom_pool) {
let lr = liveness.get(value).expect(
@@ -196,7 +197,7 @@ impl LiveValueTracker {
);
// Check if this value is live-in here.
if let Some(endpoint) = lr.livein_local_end(ebb, layout) {
if let Some(endpoint) = lr.livein_local_end(ebb, ctx) {
self.live.push(value, endpoint, lr);
}
}

29
lib/cretonne/src/regalloc/liveness.rs
View File

@@ -181,7 +181,7 @@ use ir::dfg::ValueDef;
use ir::{Function, Value, Inst, Ebb, Layout, ProgramPoint};
use isa::{TargetIsa, EncInfo};
use regalloc::affinity::Affinity;
use regalloc::liverange::LiveRange;
use regalloc::liverange::{LiveRange, LiveRangeForest, LiveRangeContext};
use std::mem;
use std::ops::Index;
@@ -247,13 +247,14 @@ fn extend_to_use(
worklist: &mut Vec<Ebb>,
func: &Function,
cfg: &ControlFlowGraph,
forest: &mut LiveRangeForest,
) {
// This is our scratch working space, and we'll leave it empty when we return.
assert!(worklist.is_empty());
// Extend the range locally in `ebb`.
// If there already was a live interval in that block, we're done.
if lr.extend_in_ebb(ebb, to, &func.layout) {
if lr.extend_in_ebb(ebb, to, &func.layout, forest) {
worklist.push(ebb);
}
@@ -270,7 +271,7 @@ fn extend_to_use(
// We've learned that the value needs to be live-in to the `livein` EBB.
// Make sure it is also live at all predecessor branches to `livein`.
for (pred, branch) in cfg.pred_iter(livein) {
if lr.extend_in_ebb(pred, branch, &func.layout) {
if lr.extend_in_ebb(pred, branch, &func.layout, forest) {
// This predecessor EBB also became live-in. We need to process it later.
worklist.push(pred);
}
@@ -285,6 +286,9 @@ pub struct Liveness {
/// The live ranges that have been computed so far.
ranges: LiveRangeSet,
/// Memory pool for the live ranges.
forest: LiveRangeForest,
/// Working space for the `extend_to_use` algorithm.
/// This vector is always empty, except for inside that function.
/// It lives here to avoid repeated allocation of scratch memory.
@@ -302,14 +306,21 @@ impl Liveness {
pub fn new() -> Self {
Self {
ranges: LiveRangeSet::new(),
forest: LiveRangeForest::new(),
worklist: Vec::new(),
ebb_params: Vec::new(),
}
}
/// Get a context needed for working with a `LiveRange`.
pub fn context<'a>(&'a self, layout: &'a Layout) -> LiveRangeContext<'a, Layout> {
LiveRangeContext::new(layout, &self.forest)
}
/// Clear all data structures in this liveness analysis.
pub fn clear(&mut self) {
self.ranges.clear();
self.forest.clear();
self.worklist.clear();
self.ebb_params.clear();
}
@@ -359,7 +370,7 @@ impl Liveness {
) -> &mut Affinity {
debug_assert_eq!(Some(ebb), layout.inst_ebb(user));
let lr = self.ranges.get_mut(value).expect("Value has no live range");
let livein = lr.extend_in_ebb(ebb, user, layout);
let livein = lr.extend_in_ebb(ebb, user, layout, &mut self.forest);
assert!(!livein, "{} should already be live in {}", value, ebb);
&mut lr.affinity
}
@@ -416,7 +427,15 @@ impl Liveness {
let lr = get_or_create(&mut self.ranges, arg, isa, func, &enc_info);
// Extend the live range to reach this use.
extend_to_use(lr, ebb, inst, &mut self.worklist, func, cfg);
extend_to_use(
lr,
ebb,
inst,
&mut self.worklist,
func,
cfg,
&mut self.forest,
);
// Apply operand constraint, ignoring any variable arguments after the fixed
// operands described by `operand_constraints`. Variable arguments are either

402
lib/cretonne/src/regalloc/liverange.rs
View File

@@ -107,11 +107,11 @@
//! of coalescing, so we would need to roll our own.
//!
use bforest;
use entity::SparseMapValue;
use ir::{Inst, Ebb, Value, Layout, ProgramPoint, ExpandedProgramPoint, ProgramOrder};
use regalloc::affinity::Affinity;
use std::cmp::Ordering;
use std::marker::PhantomData;
/// Global live range of a single SSA value.
///
@@ -165,52 +165,54 @@ pub struct GenLiveRange<PO: ProgramOrder> {
/// Additional live-in intervals sorted in program order.
///
/// This vector is empty for most values which are only used in one EBB.
/// This map is empty for most values which are only used in one EBB.
///
/// Invariants:
/// A map entry `ebb -> inst` means that the live range is live-in to `ebb`, continuing up to
/// `inst` which may belong to a later EBB in the program order.
///
/// - Sorted, disjoint: For all `i < j`: `liveins[i].end < liveins[j].begin`.
/// - Not overlapping defining EBB: For all `i`:
/// `liveins[i].end < def_begin` or `liveins[i].begin > def_end`.
liveins: Vec<Interval>,
unused: PhantomData<PO>,
/// The entries are non-overlapping, and none of them overlap the EBB where the value is
/// defined.
liveins: bforest::Map<Ebb, Inst, PO>,
}
/// An additional contiguous interval of a global live range.
///
/// This represents a live-in interval for a single EBB, or a coalesced set of live-in intervals
/// for contiguous EBBs where all but the last live-in interval covers the whole EBB.
///
#[derive(Copy, Clone)]
pub struct Interval {
/// Interval starting point.
///
/// Since this interval does not represent the def of the value, it must begin at an EBB header
/// where the value is live-in.
pub begin: Ebb,
/// Interval end point.
///
/// The only interval end point that can be an EBB header is `def_end` above in a dead def
/// live range for an unused EBB argument. All other intervals must end at an instruction --
/// either the last use in the EBB or the last branch/jump that can reach a use.
///
/// When this represents multiple contiguous live-in intervals, this is the end point of the
/// last interval. The other intervals end at the terminator instructions of their respective
/// EBB.
pub end: Inst,
/// Context information needed to query a `LiveRange`.
pub struct LiveRangeContext<'a, PO: 'a + ProgramOrder> {
/// Ordering of EBBs.
pub order: &'a PO,
/// Memory pool.
pub forest: &'a bforest::MapForest<Ebb, Inst, PO>,
}
impl Interval {
/// Extend the interval end point to reach `to`, but only if it would make the interval longer.
fn extend_to<PO: ProgramOrder>(&mut self, to: Inst, order: &PO) {
if order.cmp(to, self.end) == Ordering::Greater {
self.end = to;
impl<'a, PO: ProgramOrder> LiveRangeContext<'a, PO> {
/// Make a new context.
pub fn new(
order: &'a PO,
forest: &'a bforest::MapForest<Ebb, Inst, PO>,
) -> LiveRangeContext<'a, PO> {
LiveRangeContext { order, forest }
}
}
impl<'a, PO: ProgramOrder> Clone for LiveRangeContext<'a, PO> {
fn clone(&self) -> Self {
LiveRangeContext {
order: self.order,
forest: self.forest,
}
}
}
impl<'a, PO: ProgramOrder> Copy for LiveRangeContext<'a, PO> {}
/// Forest of B-trees used for storing live ranges.
pub type LiveRangeForest = bforest::MapForest<Ebb, Inst, Layout>;
impl<PO: ProgramOrder> bforest::Comparator<Ebb> for PO {
fn cmp(&self, a: Ebb, b: Ebb) -> Ordering {
self.cmp(a, b)
}
}
impl<PO: ProgramOrder> GenLiveRange<PO> {
/// Create a new live range for `value` defined at `def`.
///
@@ -221,28 +223,10 @@ impl<PO: ProgramOrder> GenLiveRange<PO> {
affinity,
def_begin: def,
def_end: def,
liveins: Vec::new(),
unused: PhantomData,
liveins: bforest::Map::new(),
}
}
/// Find the live-in interval containing `ebb`, if any.
///
/// Return `Ok(n)` if `liveins[n]` already contains `ebb`.
/// Otherwise, return `Err(n)` with the index where such an interval should be inserted.
fn find_ebb_interval(&self, ebb: Ebb, order: &PO) -> Result<usize, usize> {
self.liveins
.binary_search_by(|intv| order.cmp(intv.begin, ebb))
.or_else(|n| {
// The interval at `n-1` may cover `ebb`.
if n > 0 && order.cmp(self.liveins[n - 1].end, ebb) == Ordering::Greater {
Ok(n - 1)
} else {
Err(n)
}
})
}
/// Extend the local interval for `ebb` so it reaches `to` which must belong to `ebb`.
/// Create a live-in interval if necessary.
///
@@ -254,7 +238,13 @@ impl<PO: ProgramOrder> GenLiveRange<PO> {
///
/// The return value can be used to detect if we just learned that the value is live-in to
/// `ebb`. This can trigger recursive extensions in `ebb`'s CFG predecessor blocks.
pub fn extend_in_ebb(&mut self, ebb: Ebb, to: Inst, order: &PO) -> bool {
pub fn extend_in_ebb(
&mut self,
ebb: Ebb,
to: Inst,
order: &PO,
forest: &mut bforest::MapForest<Ebb, Inst, PO>,
) -> bool {
// First check if we're extending the def interval.
//
// We're assuming here that `to` never precedes `def_begin` in the same EBB, but we can't
@@ -275,68 +265,60 @@ impl<PO: ProgramOrder> GenLiveRange<PO> {
}
// Now check if we're extending any of the existing live-in intervals.
match self.find_ebb_interval(ebb, order) {
Ok(n) => {
// We have an interval that contains `ebb`, so we can simply extend it.
self.liveins[n].extend_to(to, order);
let mut c = self.liveins.cursor(forest, order);
let first_time_livein;
// If `to` is the terminator and the value lives in the successor EBB,
// coalesce the two intervals.
if let Some(next) = self.liveins.get(n + 1).cloned() {
if order.is_ebb_gap(to, next.begin) {
self.liveins[n].extend_to(next.end, order);
self.liveins.remove(n + 1);
}
}
false
if let Some(end) = c.goto(ebb) {
// There's an interval beginning at `ebb`. See if it extends.
first_time_livein = false;
if order.cmp(end, to) == Ordering::Less {
*c.value_mut().unwrap() = to;
} else {
return first_time_livein;
}
Err(n) => {
// Insert a new live-in interval at `n`, or coalesce to predecessor or successor
// if possible.
// Determine if the new live-in range touches the predecessor or successor range
// and can therefore be coalesced to them.
let (coalesce_prev, coalesce_next) = {
let prev = n.checked_sub(1).and_then(|i| self.liveins.get(i));
let next = self.liveins.get(n);
(
prev.map_or(false, |prev| order.is_ebb_gap(prev.end, ebb)),
next.map_or(false, |next| order.is_ebb_gap(to, next.begin)),
)
};
match (coalesce_prev, coalesce_next) {
// Extend predecessor interval to cover new and successor intervals
(true, true) => {
let end = self.liveins[n].end;
self.liveins[n - 1].extend_to(end, order);
self.liveins.remove(n);
} else {
// There's no interval beginning at `ebb`, but we could still be live-in at `ebb` with
// a coalesced interval that begins before and ends after.
if let Some((_, end)) = c.prev() {
if order.cmp(end, ebb) == Ordering::Greater {
// Yep, the previous interval overlaps `ebb`.
first_time_livein = false;
if order.cmp(end, to) == Ordering::Less {
*c.value_mut().unwrap() = to;
} else {
return first_time_livein;
}
// Extend predecessor interval to cover new interval
(true, false) => {
self.liveins[n - 1].extend_to(to, order);
}
// Extend successor interval to cover new interval
(false, true) => {
self.liveins[n].begin = ebb;
}
// Cannot coalesce; insert new interval
(false, false) => {
self.liveins.insert(
n,
Interval {
begin: ebb,
end: to,
},
);
} else {
first_time_livein = true;
// The current interval does not overlap `ebb`, but it may still be possible to
// coalesce with it.
if order.is_ebb_gap(end, ebb) {
*c.value_mut().unwrap() = to;
} else {
c.insert(ebb, to);
}
}
true
} else {
// There is no existing interval before `ebb`.
first_time_livein = true;
c.insert(ebb, to);
}
}
// Now `c` to left pointing at an interval that ends in `to`.
debug_assert_eq!(c.value(), Some(to));
// See if it can be coalesced with the following interval.
if let Some((next_ebb, next_end)) = c.next() {
if order.is_ebb_gap(to, next_ebb) {
// Remove this interval and extend the previous end point to `next_end`.
c.remove();
c.prev();
*c.value_mut().unwrap() = next_end;
}
}
first_time_livein
}
/// Is this the live range of a dead value?
@@ -387,59 +369,77 @@ impl<PO: ProgramOrder> GenLiveRange<PO> {
/// If the live range is live through all of `ebb`, the terminator of `ebb` is a correct
/// answer, but it is also possible that an even later program point is returned. So don't
/// depend on the returned `Inst` to belong to `ebb`.
pub fn livein_local_end(&self, ebb: Ebb, order: &PO) -> Option<Inst> {
self.find_ebb_interval(ebb, order).ok().map(|n| {
self.liveins[n].end
})
pub fn livein_local_end(&self, ebb: Ebb, ctx: LiveRangeContext<PO>) -> Option<Inst> {
self.liveins
.get_or_less(ebb, ctx.forest, ctx.order)
.and_then(|(_, inst)| {
// We have an entry that ends at `inst`.
if ctx.order.cmp(inst, ebb) == Ordering::Greater {
Some(inst)
} else {
None
}
})
}
/// Is this value live-in to `ebb`?
///
/// An EBB argument is not considered to be live in.
pub fn is_livein(&self, ebb: Ebb, order: &PO) -> bool {
self.livein_local_end(ebb, order).is_some()
pub fn is_livein(&self, ebb: Ebb, ctx: LiveRangeContext<PO>) -> bool {
self.livein_local_end(ebb, ctx).is_some()
}
/// Get all the live-in intervals.
pub fn liveins(&self) -> &[Interval] {
&self.liveins
///
/// Note that the intervals are stored in a compressed form so each entry may span multiple
/// EBBs where the value is live in.
pub fn liveins<'a>(
&'a self,
ctx: LiveRangeContext<'a, PO>,
) -> bforest::MapIter<'a, Ebb, Inst, PO> {
self.liveins.iter(ctx.forest)
}
/// Check if this live range overlaps a definition in `ebb`.
pub fn overlaps_def(&self, def: ExpandedProgramPoint, ebb: Ebb, order: &PO) -> bool {
pub fn overlaps_def(
&self,
def: ExpandedProgramPoint,
ebb: Ebb,
ctx: LiveRangeContext<PO>,
) -> bool {
// Check for an overlap with the local range.
if order.cmp(def, self.def_begin) != Ordering::Less &&
order.cmp(def, self.def_end) == Ordering::Less
if ctx.order.cmp(def, self.def_begin) != Ordering::Less &&
ctx.order.cmp(def, self.def_end) == Ordering::Less
{
return true;
}
// Check for an overlap with a live-in range.
match self.livein_local_end(ebb, order) {
Some(inst) => order.cmp(def, inst) == Ordering::Less,
match self.livein_local_end(ebb, ctx) {
Some(inst) => ctx.order.cmp(def, inst) == Ordering::Less,
None => false,
}
}
/// Check if this live range reaches a use at `user` in `ebb`.
pub fn reaches_use(&self, user: Inst, ebb: Ebb, order: &PO) -> bool {
pub fn reaches_use(&self, user: Inst, ebb: Ebb, ctx: LiveRangeContext<PO>) -> bool {
// Check for an overlap with the local range.
if order.cmp(user, self.def_begin) == Ordering::Greater &&
order.cmp(user, self.def_end) != Ordering::Greater
if ctx.order.cmp(user, self.def_begin) == Ordering::Greater &&
ctx.order.cmp(user, self.def_end) != Ordering::Greater
{
return true;
}
// Check for an overlap with a live-in range.
match self.livein_local_end(ebb, order) {
Some(inst) => order.cmp(user, inst) != Ordering::Greater,
match self.livein_local_end(ebb, ctx) {
Some(inst) => ctx.order.cmp(user, inst) != Ordering::Greater,
None => false,
}
}
/// Check if this live range is killed at `user` in `ebb`.
pub fn killed_at(&self, user: Inst, ebb: Ebb, order: &PO) -> bool {
self.def_local_end() == user.into() || self.livein_local_end(ebb, order) == Some(user)
pub fn killed_at(&self, user: Inst, ebb: Ebb, ctx: LiveRangeContext<PO>) -> bool {
self.def_local_end() == user.into() || self.livein_local_end(ebb, ctx) == Some(user)
}
}
@@ -452,7 +452,8 @@ impl<PO: ProgramOrder> SparseMapValue<Value> for GenLiveRange<PO> {
#[cfg(test)]
mod tests {
use super::GenLiveRange;
use super::{GenLiveRange, LiveRangeContext};
use bforest;
use ir::{Inst, Ebb, Value};
use entity::EntityRef;
use ir::{ProgramOrder, ExpandedProgramPoint};
@@ -503,7 +504,11 @@ mod tests {
}
// Validate the live range invariants.
fn validate(&self, lr: &GenLiveRange<ProgOrder>) {
fn validate(
&self,
lr: &GenLiveRange<ProgOrder>,
forest: &bforest::MapForest<Ebb, Inst, ProgOrder>,
) {
// The def interval must cover a single EBB.
let def_ebb = self.pp_ebb(lr.def_begin);
assert_eq!(def_ebb, self.pp_ebb(lr.def_end));
@@ -519,20 +524,20 @@ mod tests {
// Check the live-in intervals.
let mut prev_end = None;
for li in &lr.liveins {
assert_eq!(self.cmp(li.begin, li.end), Ordering::Less);
for (begin, end) in lr.liveins.iter(forest) {
assert_eq!(self.cmp(begin, end), Ordering::Less);
if let Some(e) = prev_end {
assert_eq!(self.cmp(e, li.begin), Ordering::Less);
assert_eq!(self.cmp(e, begin), Ordering::Less);
}
assert!(
self.cmp(lr.def_end, li.begin) == Ordering::Less ||
self.cmp(lr.def_begin, li.end) == Ordering::Greater,
self.cmp(lr.def_end, begin) == Ordering::Less ||
self.cmp(lr.def_begin, end) == Ordering::Greater,
"Interval can't overlap the def EBB"
);
// Save for next round.
prev_end = Some(li.end);
prev_end = Some(end);
}
}
@@ -547,12 +552,14 @@ mod tests {
let i1 = Inst::new(1);
let e2 = Ebb::new(2);
let lr = GenLiveRange::new(v0, i1.into(), Default::default());
let forest = &bforest::MapForest::new();
let ctx = LiveRangeContext::new(PO, forest);
assert!(lr.is_dead());
assert!(lr.is_local());
assert_eq!(lr.def(), i1.into());
assert_eq!(lr.def_local_end(), i1.into());
assert_eq!(lr.livein_local_end(e2, PO), None);
PO.validate(&lr);
assert_eq!(lr.livein_local_end(e2, ctx), None);
PO.validate(&lr, ctx.forest);
}
#[test]
@@ -560,13 +567,15 @@ mod tests {
let v0 = Value::new(0);
let e2 = Ebb::new(2);
let lr = GenLiveRange::new(v0, e2.into(), Default::default());
let forest = &bforest::MapForest::new();
let ctx = LiveRangeContext::new(PO, forest);
assert!(lr.is_dead());
assert!(lr.is_local());
assert_eq!(lr.def(), e2.into());
assert_eq!(lr.def_local_end(), e2.into());
// The def interval of an EBB argument does not count as live-in.
assert_eq!(lr.livein_local_end(e2, PO), None);
PO.validate(&lr);
assert_eq!(lr.livein_local_end(e2, ctx), None);
PO.validate(&lr, ctx.forest);
}
#[test]
@@ -577,17 +586,18 @@ mod tests {
let i12 = Inst::new(12);
let i13 = Inst::new(13);
let mut lr = GenLiveRange::new(v0, i11.into(), Default::default());
let forest = &mut bforest::MapForest::new();
assert_eq!(lr.extend_in_ebb(e10, i13, PO), false);
PO.validate(&lr);
assert_eq!(lr.extend_in_ebb(e10, i13, PO, forest), false);
PO.validate(&lr, forest);
assert!(!lr.is_dead());
assert!(lr.is_local());
assert_eq!(lr.def(), i11.into());
assert_eq!(lr.def_local_end(), i13.into());
// Extending to an already covered inst should not change anything.
assert_eq!(lr.extend_in_ebb(e10, i12, PO), false);
PO.validate(&lr);
assert_eq!(lr.extend_in_ebb(e10, i12, PO, forest), false);
PO.validate(&lr, forest);
assert_eq!(lr.def(), i11.into());
assert_eq!(lr.def_local_end(), i13.into());
}
@@ -600,25 +610,26 @@ mod tests {
let i12 = Inst::new(12);
let i13 = Inst::new(13);
let mut lr = GenLiveRange::new(v0, e10.into(), Default::default());
let forest = &mut bforest::MapForest::new();
// Extending a dead EBB argument in its own block should not indicate that a live-in
// interval was created.
assert_eq!(lr.extend_in_ebb(e10, i12, PO), false);
PO.validate(&lr);
assert_eq!(lr.extend_in_ebb(e10, i12, PO, forest), false);
PO.validate(&lr, forest);
assert!(!lr.is_dead());
assert!(lr.is_local());
assert_eq!(lr.def(), e10.into());
assert_eq!(lr.def_local_end(), i12.into());
// Extending to an already covered inst should not change anything.
assert_eq!(lr.extend_in_ebb(e10, i11, PO), false);
PO.validate(&lr);
assert_eq!(lr.extend_in_ebb(e10, i11, PO, forest), false);
PO.validate(&lr, forest);
assert_eq!(lr.def(), e10.into());
assert_eq!(lr.def_local_end(), i12.into());
// Extending further.
assert_eq!(lr.extend_in_ebb(e10, i13, PO), false);
PO.validate(&lr);
assert_eq!(lr.extend_in_ebb(e10, i13, PO, forest), false);
PO.validate(&lr, forest);
assert_eq!(lr.def(), e10.into());
assert_eq!(lr.def_local_end(), i13.into());
}
@@ -634,22 +645,32 @@ mod tests {
let i22 = Inst::new(22);
let i23 = Inst::new(23);
let mut lr = GenLiveRange::new(v0, i11.into(), Default::default());
let forest = &mut bforest::MapForest::new();
assert_eq!(lr.extend_in_ebb(e10, i12, PO), false);
assert_eq!(lr.extend_in_ebb(e10, i12, PO, forest), false);
// Adding a live-in interval.
assert_eq!(lr.extend_in_ebb(e20, i22, PO), true);
PO.validate(&lr);
assert_eq!(lr.livein_local_end(e20, PO), Some(i22));
assert_eq!(lr.extend_in_ebb(e20, i22, PO, forest), true);
PO.validate(&lr, forest);
assert_eq!(
lr.livein_local_end(e20, LiveRangeContext::new(PO, forest)),
Some(i22)
);
// Non-extending the live-in.
assert_eq!(lr.extend_in_ebb(e20, i21, PO), false);
assert_eq!(lr.livein_local_end(e20, PO), Some(i22));
assert_eq!(lr.extend_in_ebb(e20, i21, PO, forest), false);
assert_eq!(
lr.livein_local_end(e20, LiveRangeContext::new(PO, forest)),
Some(i22)
);
// Extending the existing live-in.
assert_eq!(lr.extend_in_ebb(e20, i23, PO), false);
PO.validate(&lr);
assert_eq!(lr.livein_local_end(e20, PO), Some(i23));
assert_eq!(lr.extend_in_ebb(e20, i23, PO, forest), false);
PO.validate(&lr, forest);
assert_eq!(
lr.livein_local_end(e20, LiveRangeContext::new(PO, forest)),
Some(i23)
);
}
#[test]
@@ -663,35 +684,54 @@ mod tests {
let e40 = Ebb::new(40);
let i41 = Inst::new(41);
let mut lr = GenLiveRange::new(v0, i11.into(), Default::default());
let forest = &mut bforest::MapForest::new();
assert_eq!(lr.extend_in_ebb(e30, i31, PO), true);
assert_eq!(lr.liveins.len(), 1);
assert_eq!(lr.extend_in_ebb(e30, i31, PO, forest), true);
assert_eq!(
lr.liveins(LiveRangeContext::new(PO, forest))
.collect::<Vec<_>>(),
[(e30, i31)]
);
// Coalesce to previous
assert_eq!(lr.extend_in_ebb(e40, i41, PO), true);
assert_eq!(lr.liveins.len(), 1);
assert_eq!(lr.liveins[0].begin, e30);
assert_eq!(lr.liveins[0].end, i41);
assert_eq!(lr.extend_in_ebb(e40, i41, PO, forest), true);
assert_eq!(
lr.liveins(LiveRangeContext::new(PO, forest))
.collect::<Vec<_>>(),
[(e30, i41)]
);
// Coalesce to next
assert_eq!(lr.extend_in_ebb(e20, i21, PO), true);
assert_eq!(lr.liveins.len(), 1);
assert_eq!(lr.liveins[0].begin, e20);
assert_eq!(lr.liveins[0].end, i41);
assert_eq!(lr.extend_in_ebb(e20, i21, PO, forest), true);
assert_eq!(
lr.liveins(LiveRangeContext::new(PO, forest))
.collect::<Vec<_>>(),
[(e20, i41)]
);
let mut lr = GenLiveRange::new(v0, i11.into(), Default::default());
assert_eq!(lr.extend_in_ebb(e40, i41, PO), true);
assert_eq!(lr.liveins.len(), 1);
assert_eq!(lr.extend_in_ebb(e40, i41, PO, forest), true);
assert_eq!(
lr.liveins(LiveRangeContext::new(PO, forest))
.collect::<Vec<_>>(),
[(e40, i41)]
);
assert_eq!(lr.extend_in_ebb(e20, i21, PO), true);
assert_eq!(lr.liveins.len(), 2);
assert_eq!(lr.extend_in_ebb(e20, i21, PO, forest), true);
assert_eq!(
lr.liveins(LiveRangeContext::new(PO, forest))
.collect::<Vec<_>>(),
[(e20, i21), (e40, i41)]
);
// Coalesce to previous and next
assert_eq!(lr.extend_in_ebb(e30, i31, PO), true);
assert_eq!(lr.liveins.len(), 1);
assert_eq!(lr.liveins[0].begin, e20);
assert_eq!(lr.liveins[0].end, i41);
assert_eq!(lr.extend_in_ebb(e30, i31, PO, forest), true);
assert_eq!(
lr.liveins(LiveRangeContext::new(PO, forest))
.collect::<Vec<_>>(),
[(e20, i41)]
);
}
// TODO: Add more tests that exercise the binary search algorithm.

5
lib/cretonne/src/regalloc/spilling.rs
View File

@@ -300,16 +300,17 @@ impl<'a> Context<'a> {
for (idx, (op, &arg)) in constraints.ins.iter().zip(args).enumerate() {
let mut reguse = RegUse::new(arg, idx, op.regclass.into());
let lr = &self.liveness[arg];
let ctx = self.liveness.context(&self.cur.func.layout);
match op.kind {
ConstraintKind::Stack => continue,
ConstraintKind::FixedReg(_) => reguse.fixed = true,
ConstraintKind::Tied(_) => {
// A tied operand must kill the used value.
reguse.tied = !lr.killed_at(inst, ebb, &self.cur.func.layout);
reguse.tied = !lr.killed_at(inst, ebb, ctx);
}
ConstraintKind::FixedTied(_) => {
reguse.fixed = true;
reguse.tied = !lr.killed_at(inst, ebb, &self.cur.func.layout);
reguse.tied = !lr.killed_at(inst, ebb, ctx);
}
ConstraintKind::Reg => {}
}

3
lib/cretonne/src/verifier/cssa.rs
View File

@@ -89,7 +89,8 @@ impl<'a> CssaVerifier<'a> {
// Knowing that values are in RPO order, we can check for interference this
// way.
if self.liveness[prev_val].overlaps_def(def, def_ebb, &self.func.layout) {
let ctx = self.liveness.context(&self.func.layout);
if self.liveness[prev_val].overlaps_def(def, def_ebb, ctx) {
return err!(val, "Value def in {} interferes with {}", vreg, prev_val);
}
}

17
lib/cretonne/src/verifier/liveness.rs
View File

@@ -129,18 +129,18 @@ impl<'a> LivenessVerifier<'a> {
/// Is `lr` live at the use `inst`?
fn live_at_use(&self, lr: &LiveRange, inst: Inst) -> bool {
let l = &self.func.layout;
let ctx = self.liveness.context(&self.func.layout);
// Check if `inst` is in the def range, not including the def itself.
if l.cmp(lr.def(), inst) == Ordering::Less &&
l.cmp(inst, lr.def_local_end()) != Ordering::Greater
if ctx.order.cmp(lr.def(), inst) == Ordering::Less &&
ctx.order.cmp(inst, lr.def_local_end()) != Ordering::Greater
{
return true;
}
// Otherwise see if `inst` is in one of the live-in ranges.
match lr.livein_local_end(l.inst_ebb(inst).unwrap(), l) {
Some(end) => l.cmp(inst, end) != Ordering::Greater,
match lr.livein_local_end(ctx.order.inst_ebb(inst).unwrap(), ctx) {
Some(end) => ctx.order.cmp(inst, end) != Ordering::Greater,
None => false,
}
}
@@ -205,12 +205,11 @@ impl<'a> LivenessVerifier<'a> {
}
// Now check the live-in intervals against the CFG.
for &livein in lr.liveins() {
let mut ebb = livein.begin;
for (mut ebb, end) in lr.liveins(self.liveness.context(l)) {
if !l.is_ebb_inserted(ebb) {
return err!(loc, "{} livein at {} which is not in the layout", val, ebb);
}
let end_ebb = match l.inst_ebb(livein.end) {
let end_ebb = match l.inst_ebb(end) {
Some(e) => e,
None => {
return err!(
@@ -218,7 +217,7 @@ impl<'a> LivenessVerifier<'a> {
"{} livein for {} ends at {} which is not in the layout",
val,
ebb,
livein.end
end
)
}
};

4
lib/cretonne/src/verifier/locations.rs
View File

@@ -282,7 +282,7 @@ impl<'a> LocationVerifier<'a> {
SingleDest(ebb, _) => {
for d in divert.all() {
let lr = &liveness[d.value];
if lr.is_livein(ebb, &self.func.layout) {
if lr.is_livein(ebb, liveness.context(&self.func.layout)) {
return err!(
inst,
"{} is diverted to {} and live in to {}",
@@ -297,7 +297,7 @@ impl<'a> LocationVerifier<'a> {
for d in divert.all() {
let lr = &liveness[d.value];
for (_, ebb) in self.func.jump_tables[jt].entries() {
if lr.is_livein(ebb, &self.func.layout) {
if lr.is_livein(ebb, liveness.context(&self.func.layout)) {
return err!(
inst,
"{} is diverted to {} and live in to {}",