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Optimize LSRA (#2563)

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* Optimize `TryAllocateRegWithtoutSpill` a bit

* Add a fast path for when all registers are live.
* Do not query `GetOverlapPosition` if the register is already in use
  (i.e: free position is 0).

* Do not allocate child split list if not parent

* Turn `LiveRange` into a reference struct

`LiveRange` is now a reference wrapping struct like `Operand` and
`Operation`.

It has also been changed into a singly linked-list. In micro-benchmarks
traversing the linked-list was faster than binary search on `List<T>`.
Even for quite large input sizes (e.g: 1,000,000), surprisingly.

Could be because the code gen for traversing the linked-list is much
much cleaner and there is no virtual dispatch happening when checking if
intervals overlaps.

* Turn `LiveInterval` into an iterator

The LSRA allocates in forward order and never inspect previous
`LiveInterval` once they are expired. Something similar can be done for
the `LiveRange`s within the `LiveInterval`s themselves.

The `LiveInterval` is turned into a iterator which expires `LiveRange`
within it. The iterator is moved forward along with interval walking
code, i.e: AllocateInterval(context, interval, cIndex).

* Remove `LinearScanAllocator.Sources`

Local methods are less susceptible to do allocations than lambdas.

* Optimize `GetOverlapPosition(interval)` a bit

Time complexity should be in O(n+m) instead of O(nm) now.

* Optimize `NumberLocals` a bit

Use the same idea as in `HybridAllocator` to store the visited state
in the MSB of the Operand's value instead of using a `HashSet<T>`.

* Optimize `InsertSplitCopies` a bit

Avoid allocating a redundant `CopyResolver`.

* Optimize `InsertSplitCopiesAtEdges` a bit

Avoid redundant allocations of `CopyResolver`.

* Use stack allocation for `freePositions`

Avoid redundant computations.

* Add `UseList`

Replace `SortedIntegerList` with an even more specialized data
structure. It allocates memory on the arena allocators and does not
require copying use positions when splitting it.

* Turn `LiveInterval` into a reference struct

`LiveInterval` is now a reference wrapping struct like `Operand` and
`Operation`.

The rationale behind turning this in a reference wrapping struct is
because a `LiveInterval` is associated with each local variable, and
these intervals may themselves be split further. I've seen translations
having up to 8000 local variables.

To make the `LiveInterval` unmanaged, a new data structure called
`LiveIntervalList` was added to store child splits. This differs from
`SortedList<,>` because it can contain intervals with the same start
position.

Really wished we got some more of C++ template in C#. :^(

* Optimize `GetChildSplit` a bit

No need to inspect the remaining ranges if we've reached a range which
starts after position, since the split list is ordered.

* Optimize `CopyResolver` a bit

Lazily allocate the fill, spill and parallel copy structures since most
of the time only one of them is needed.

* Optimize `BitMap.Enumerator` a bit

Marking `MoveNext` as `AggressiveInlining` allows RyuJIT to promote the
`Enumerator` struct into registers completely, reducing load/store code
a lot since it does not have to store the struct on the stack for ABI
purposes.

* Use stack allocation for `use/blockedPositions`

* Optimize `AllocateWithSpill` a bit

* Address feedback

* Make `LiveInterval.AddRange(,)` more conservative

Produces no diff against master, but just for good measure.
This commit is contained in:
FICTURE7 2021-10-09 01:15:44 +04:00 committed by GitHub
parent c54a14d0b8
commit 69093cf2d6
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9 changed files with 675 additions and 496 deletions
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4
ARMeilleure/Allocators.cs
View file

@ -10,11 +10,15 @@ namespace ARMeilleure
[ThreadStatic] private static ArenaAllocator _operands; [ThreadStatic] private static ArenaAllocator _operands;
[ThreadStatic] private static ArenaAllocator _operations; [ThreadStatic] private static ArenaAllocator _operations;
[ThreadStatic] private static ArenaAllocator _references; [ThreadStatic] private static ArenaAllocator _references;
[ThreadStatic] private static ArenaAllocator _liveRanges;
[ThreadStatic] private static ArenaAllocator _liveIntervals;
public static ArenaAllocator Default => GetAllocator(ref _default, 256 * 1024, 4); public static ArenaAllocator Default => GetAllocator(ref _default, 256 * 1024, 4);
public static ArenaAllocator Operands => GetAllocator(ref _operands, 64 * 1024, 8); public static ArenaAllocator Operands => GetAllocator(ref _operands, 64 * 1024, 8);
public static ArenaAllocator Operations => GetAllocator(ref _operations, 64 * 1024, 8); public static ArenaAllocator Operations => GetAllocator(ref _operations, 64 * 1024, 8);
public static ArenaAllocator References => GetAllocator(ref _references, 64 * 1024, 8); public static ArenaAllocator References => GetAllocator(ref _references, 64 * 1024, 8);
public static ArenaAllocator LiveRanges => GetAllocator(ref _liveRanges, 64 * 1024, 8);
public static ArenaAllocator LiveIntervals => GetAllocator(ref _liveIntervals, 64 * 1024, 8);
[MethodImpl(MethodImplOptions.AggressiveInlining)] [MethodImpl(MethodImplOptions.AggressiveInlining)]
private static ArenaAllocator GetAllocator(ref ArenaAllocator alloc, uint pageSize, uint pageCount) private static ArenaAllocator GetAllocator(ref ArenaAllocator alloc, uint pageSize, uint pageCount)

51
ARMeilleure/CodeGen/RegisterAllocators/CopyResolver.cs
View file

@ -1,6 +1,7 @@
using ARMeilleure.IntermediateRepresentation; using ARMeilleure.IntermediateRepresentation;
using System; using System;
using System.Collections.Generic; using System.Collections.Generic;
using static ARMeilleure.IntermediateRepresentation.Operand.Factory; using static ARMeilleure.IntermediateRepresentation.Operand.Factory;
using static ARMeilleure.IntermediateRepresentation.Operation.Factory; using static ARMeilleure.IntermediateRepresentation.Operation.Factory;
@ -25,7 +26,7 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
} }
} }
private List<Copy> _copies; private readonly List<Copy> _copies;
public int Count => _copies.Count; public int Count => _copies.Count;
@ -146,21 +147,12 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
} }
} }
private Queue<Operation> _fillQueue = new Queue<Operation>(); private Queue<Operation> _fillQueue = null;
private Queue<Operation> _spillQueue = new Queue<Operation>(); private Queue<Operation> _spillQueue = null;
private ParallelCopy _parallelCopy = null;
private ParallelCopy _parallelCopy;
public bool HasCopy { get; private set; } public bool HasCopy { get; private set; }
public CopyResolver()
{
_fillQueue = new Queue<Operation>();
_spillQueue = new Queue<Operation>();
_parallelCopy = new ParallelCopy();
}
public void AddSplit(LiveInterval left, LiveInterval right) public void AddSplit(LiveInterval left, LiveInterval right)
{ {
if (left.Local != right.Local) if (left.Local != right.Local)
@ -194,8 +186,12 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
private void AddSplitFill(LiveInterval left, LiveInterval right, OperandType type) private void AddSplitFill(LiveInterval left, LiveInterval right, OperandType type)
{ {
Operand register = GetRegister(right.Register, type); if (_fillQueue == null)
{
_fillQueue = new Queue<Operation>();
}
Operand register = GetRegister(right.Register, type);
Operand offset = Const(left.SpillOffset); Operand offset = Const(left.SpillOffset);
_fillQueue.Enqueue(Operation(Instruction.Fill, register, offset)); _fillQueue.Enqueue(Operation(Instruction.Fill, register, offset));
@ -205,8 +201,12 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
private void AddSplitSpill(LiveInterval left, LiveInterval right, OperandType type) private void AddSplitSpill(LiveInterval left, LiveInterval right, OperandType type)
{ {
Operand offset = Const(right.SpillOffset); if (_spillQueue == null)
{
_spillQueue = new Queue<Operation>();
}
Operand offset = Const(right.SpillOffset);
Operand register = GetRegister(left.Register, type); Operand register = GetRegister(left.Register, type);
_spillQueue.Enqueue(Operation(Instruction.Spill, default, offset, register)); _spillQueue.Enqueue(Operation(Instruction.Spill, default, offset, register));
@ -216,6 +216,11 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
private void AddSplitCopy(LiveInterval left, LiveInterval right, OperandType type) private void AddSplitCopy(LiveInterval left, LiveInterval right, OperandType type)
{ {
if (_parallelCopy == null)
{
_parallelCopy = new ParallelCopy();
}
_parallelCopy.AddCopy(right.Register, left.Register, type); _parallelCopy.AddCopy(right.Register, left.Register, type);
HasCopy = true; HasCopy = true;
@ -225,16 +230,22 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
List<Operation> sequence = new List<Operation>(); List<Operation> sequence = new List<Operation>();
while (_spillQueue.TryDequeue(out Operation spillOp)) if (_spillQueue != null)
{ {
sequence.Add(spillOp); while (_spillQueue.TryDequeue(out Operation spillOp))
{
sequence.Add(spillOp);
}
} }
_parallelCopy.Sequence(sequence); _parallelCopy?.Sequence(sequence);
while (_fillQueue.TryDequeue(out Operation fillOp)) if (_fillQueue != null)
{ {
sequence.Add(fillOp); while (_fillQueue.TryDequeue(out Operation fillOp))
{
sequence.Add(fillOp);
}
} }
return sequence.ToArray(); return sequence.ToArray();

386
ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs
View file

@ -20,17 +20,13 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
private const int RegistersCount = 16; private const int RegistersCount = 16;
private HashSet<int> _blockEdges; private HashSet<int> _blockEdges;
private LiveRange[] _blockRanges; private LiveRange[] _blockRanges;
private BitMap[] _blockLiveIn; private BitMap[] _blockLiveIn;
private List<LiveInterval> _intervals; private List<LiveInterval> _intervals;
private LiveInterval[] _parentIntervals; private LiveInterval[] _parentIntervals;
private List<(IntrusiveList<Operation>, Operation)> _operationNodes; private List<(IntrusiveList<Operation>, Operation)> _operationNodes;
private int _operationsCount; private int _operationsCount;
private class AllocationContext private class AllocationContext
@ -45,6 +41,11 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
public int IntUsedRegisters { get; set; } public int IntUsedRegisters { get; set; }
public int VecUsedRegisters { get; set; } public int VecUsedRegisters { get; set; }
private readonly int[] _intFreePositions;
private readonly int[] _vecFreePositions;
private readonly int _intFreePositionsCount;
private readonly int _vecFreePositionsCount;
public AllocationContext(StackAllocator stackAlloc, RegisterMasks masks, int intervalsCount) public AllocationContext(StackAllocator stackAlloc, RegisterMasks masks, int intervalsCount)
{ {
StackAlloc = stackAlloc; StackAlloc = stackAlloc;
@ -52,6 +53,43 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
Active = new BitMap(Allocators.Default, intervalsCount); Active = new BitMap(Allocators.Default, intervalsCount);
Inactive = new BitMap(Allocators.Default, intervalsCount); Inactive = new BitMap(Allocators.Default, intervalsCount);
PopulateFreePositions(RegisterType.Integer, out _intFreePositions, out _intFreePositionsCount);
PopulateFreePositions(RegisterType.Vector, out _vecFreePositions, out _vecFreePositionsCount);
void PopulateFreePositions(RegisterType type, out int[] positions, out int count)
{
positions = new int[RegistersCount];
count = BitOperations.PopCount((uint)masks.GetAvailableRegisters(type));
int mask = masks.GetAvailableRegisters(type);
for (int i = 0; i < positions.Length; i++)
{
if ((mask & (1 << i)) != 0)
{
positions[i] = int.MaxValue;
}
}
}
}
public void GetFreePositions(RegisterType type, in Span<int> positions, out int count)
{
if (type == RegisterType.Integer)
{
_intFreePositions.CopyTo(positions);
count = _intFreePositionsCount;
}
else
{
Debug.Assert(type == RegisterType.Vector);
_vecFreePositions.CopyTo(positions);
count = _vecFreePositionsCount;
}
} }
public void MoveActiveToInactive(int bit) public void MoveActiveToInactive(int bit)
@ -132,6 +170,8 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
LiveInterval interval = _intervals[iIndex]; LiveInterval interval = _intervals[iIndex];
interval.Forward(current.GetStart());
if (interval.GetEnd() < current.GetStart()) if (interval.GetEnd() < current.GetStart())
{ {
context.Active.Clear(iIndex); context.Active.Clear(iIndex);
@ -147,6 +187,8 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
LiveInterval interval = _intervals[iIndex]; LiveInterval interval = _intervals[iIndex];
interval.Forward(current.GetStart());
if (interval.GetEnd() < current.GetStart()) if (interval.GetEnd() < current.GetStart())
{ {
context.Inactive.Clear(iIndex); context.Inactive.Clear(iIndex);
@ -167,45 +209,48 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
RegisterType regType = current.Local.Type.ToRegisterType(); RegisterType regType = current.Local.Type.ToRegisterType();
int availableRegisters = context.Masks.GetAvailableRegisters(regType); Span<int> freePositions = stackalloc int[RegistersCount];
int[] freePositions = new int[RegistersCount]; context.GetFreePositions(regType, freePositions, out int freePositionsCount);
for (int index = 0; index < RegistersCount; index++)
{
if ((availableRegisters & (1 << index)) != 0)
{
freePositions[index] = int.MaxValue;
}
}
foreach (int iIndex in context.Active) foreach (int iIndex in context.Active)
{ {
LiveInterval interval = _intervals[iIndex]; LiveInterval interval = _intervals[iIndex];
Register reg = interval.Register;
if (interval.Register.Type == regType) if (reg.Type == regType)
{ {
freePositions[interval.Register.Index] = 0; freePositions[reg.Index] = 0;
freePositionsCount--;
} }
} }
// If all registers are already active, return early. No point in inspecting the inactive set to look for
// holes.
if (freePositionsCount == 0)
{
return false;
}
foreach (int iIndex in context.Inactive) foreach (int iIndex in context.Inactive)
{ {
LiveInterval interval = _intervals[iIndex]; LiveInterval interval = _intervals[iIndex];
Register reg = interval.Register;
if (interval.Register.Type == regType) ref int freePosition = ref freePositions[reg.Index];
if (reg.Type == regType && freePosition != 0)
{ {
int overlapPosition = interval.GetOverlapPosition(current); int overlapPosition = interval.GetOverlapPosition(current);
if (overlapPosition != LiveInterval.NotFound && freePositions[interval.Register.Index] > overlapPosition) if (overlapPosition != LiveInterval.NotFound && freePosition > overlapPosition)
{ {
freePositions[interval.Register.Index] = overlapPosition; freePosition = overlapPosition;
} }
} }
} }
int selectedReg = GetHighestValueIndex(freePositions); int selectedReg = GetHighestValueIndex(freePositions);
int selectedNextUse = freePositions[selectedReg]; int selectedNextUse = freePositions[selectedReg];
// Intervals starts and ends at odd positions, unless they span an entire // Intervals starts and ends at odd positions, unless they span an entire
@ -227,8 +272,6 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
} }
else if (selectedNextUse < current.GetEnd()) else if (selectedNextUse < current.GetEnd())
{ {
Debug.Assert(selectedNextUse > current.GetStart(), "Trying to split interval at the start.");
LiveInterval splitChild = current.Split(selectedNextUse); LiveInterval splitChild = current.Split(selectedNextUse);
if (splitChild.UsesCount != 0) if (splitChild.UsesCount != 0)
@ -263,44 +306,35 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
RegisterType regType = current.Local.Type.ToRegisterType(); RegisterType regType = current.Local.Type.ToRegisterType();
int availableRegisters = context.Masks.GetAvailableRegisters(regType); Span<int> usePositions = stackalloc int[RegistersCount];
Span<int> blockedPositions = stackalloc int[RegistersCount];
int[] usePositions = new int[RegistersCount]; context.GetFreePositions(regType, usePositions, out _);
int[] blockedPositions = new int[RegistersCount]; context.GetFreePositions(regType, blockedPositions, out _);
for (int index = 0; index < RegistersCount; index++)
{
if ((availableRegisters & (1 << index)) != 0)
{
usePositions[index] = int.MaxValue;
blockedPositions[index] = int.MaxValue;
}
}
void SetUsePosition(int index, int position)
{
usePositions[index] = Math.Min(usePositions[index], position);
}
void SetBlockedPosition(int index, int position)
{
blockedPositions[index] = Math.Min(blockedPositions[index], position);
SetUsePosition(index, position);
}
foreach (int iIndex in context.Active) foreach (int iIndex in context.Active)
{ {
LiveInterval interval = _intervals[iIndex]; LiveInterval interval = _intervals[iIndex];
Register reg = interval.Register;
if (!interval.IsFixed && interval.Register.Type == regType) if (reg.Type == regType)
{ {
int nextUse = interval.NextUseAfter(current.GetStart()); ref int usePosition = ref usePositions[reg.Index];
ref int blockedPosition = ref blockedPositions[reg.Index];
if (nextUse != -1) if (interval.IsFixed)
{ {
SetUsePosition(interval.Register.Index, nextUse); usePosition = 0;
blockedPosition = 0;
}
else
{
int nextUse = interval.NextUseAfter(current.GetStart());
if (nextUse != LiveInterval.NotFound && usePosition > nextUse)
{
usePosition = nextUse;
}
} }
} }
} }
@ -308,45 +342,36 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
foreach (int iIndex in context.Inactive) foreach (int iIndex in context.Inactive)
{ {
LiveInterval interval = _intervals[iIndex]; LiveInterval interval = _intervals[iIndex];
Register reg = interval.Register;
if (!interval.IsFixed && interval.Register.Type == regType && interval.Overlaps(current)) if (reg.Type == regType)
{ {
int nextUse = interval.NextUseAfter(current.GetStart()); ref int usePosition = ref usePositions[reg.Index];
ref int blockedPosition = ref blockedPositions[reg.Index];
if (nextUse != -1) if (interval.IsFixed)
{ {
SetUsePosition(interval.Register.Index, nextUse); int overlapPosition = interval.GetOverlapPosition(current);
if (overlapPosition != LiveInterval.NotFound)
{
blockedPosition = Math.Min(blockedPosition, overlapPosition);
usePosition = Math.Min(usePosition, overlapPosition);
}
} }
} else if (interval.Overlaps(current))
}
foreach (int iIndex in context.Active)
{
LiveInterval interval = _intervals[iIndex];
if (interval.IsFixed && interval.Register.Type == regType)
{
SetBlockedPosition(interval.Register.Index, 0);
}
}
foreach (int iIndex in context.Inactive)
{
LiveInterval interval = _intervals[iIndex];
if (interval.IsFixed && interval.Register.Type == regType)
{
int overlapPosition = interval.GetOverlapPosition(current);
if (overlapPosition != LiveInterval.NotFound)
{ {
SetBlockedPosition(interval.Register.Index, overlapPosition); int nextUse = interval.NextUseAfter(current.GetStart());
if (nextUse != LiveInterval.NotFound && usePosition > nextUse)
{
usePosition = nextUse;
}
} }
} }
} }
int selectedReg = GetHighestValueIndex(usePositions); int selectedReg = GetHighestValueIndex(usePositions);
int currentFirstUse = current.FirstUse(); int currentFirstUse = current.FirstUse();
Debug.Assert(currentFirstUse >= 0, "Current interval has no uses."); Debug.Assert(currentFirstUse >= 0, "Current interval has no uses.");
@ -405,24 +430,24 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
} }
} }
private static int GetHighestValueIndex(int[] array) private static int GetHighestValueIndex(Span<int> span)
{ {
int higuest = array[0]; int highest = span[0];
if (higuest == int.MaxValue) if (highest == int.MaxValue)
{ {
return 0; return 0;
} }
int selected = 0; int selected = 0;
for (int index = 1; index < array.Length; index++) for (int index = 1; index < span.Length; index++)
{ {
int current = array[index]; int current = span[index];
if (higuest < current) if (highest < current)
{ {
higuest = current; highest = current;
selected = index; selected = index;
if (current == int.MaxValue) if (current == int.MaxValue)
@ -543,21 +568,21 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
CopyResolver GetCopyResolver(int position) CopyResolver GetCopyResolver(int position)
{ {
CopyResolver copyResolver = new CopyResolver(); if (!copyResolvers.TryGetValue(position, out CopyResolver copyResolver))
if (copyResolvers.TryAdd(position, copyResolver))
{ {
return copyResolver; copyResolver = new CopyResolver();
copyResolvers.Add(position, copyResolver);
} }
return copyResolvers[position]; return copyResolver;
} }
foreach (LiveInterval interval in _intervals.Where(x => x.IsSplit)) foreach (LiveInterval interval in _intervals.Where(x => x.IsSplit))
{ {
LiveInterval previous = interval; LiveInterval previous = interval;
foreach (LiveInterval splitChild in interval.SplitChilds()) foreach (LiveInterval splitChild in interval.SplitChildren())
{ {
int splitPosition = splitChild.GetStart(); int splitPosition = splitChild.GetStart();
@ -607,6 +632,12 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
return block.Index >= blocksCount; return block.Index >= blocksCount;
} }
// Reset iterators to beginning because GetSplitChild depends on the state of the iterator.
foreach (LiveInterval interval in _intervals)
{
interval.Reset();
}
for (BasicBlock block = cfg.Blocks.First; block != null; block = block.ListNext) for (BasicBlock block = cfg.Blocks.First; block != null; block = block.ListNext)
{ {
if (IsSplitEdgeBlock(block)) if (IsSplitEdgeBlock(block))
@ -629,7 +660,7 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
succIndex = successor.GetSuccessor(0).Index; succIndex = successor.GetSuccessor(0).Index;
} }
CopyResolver copyResolver = new CopyResolver(); CopyResolver copyResolver = null;
foreach (int iIndex in _blockLiveIn[succIndex]) foreach (int iIndex in _blockLiveIn[succIndex])
{ {
@ -646,13 +677,18 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
LiveInterval left = interval.GetSplitChild(lEnd); LiveInterval left = interval.GetSplitChild(lEnd);
LiveInterval right = interval.GetSplitChild(rStart); LiveInterval right = interval.GetSplitChild(rStart);
if (left != null && right != null && left != right) if (left != default && right != default && left != right)
{ {
if (copyResolver == null)
{
copyResolver = new CopyResolver();
}
copyResolver.AddSplit(left, right); copyResolver.AddSplit(left, right);
} }
} }
if (!copyResolver.HasCopy) if (copyResolver == null || !copyResolver.HasCopy)
{ {
continue; continue;
} }
@ -699,10 +735,8 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
Operand register = GetRegister(current); Operand register = GetRegister(current);
IList<int> usePositions = current.UsePositions(); foreach (int usePosition in current.UsePositions())
for (int i = usePositions.Count - 1; i >= 0; i--)
{ {
int usePosition = -usePositions[i];
(_, Operation operation) = GetOperationNode(usePosition); (_, Operation operation) = GetOperationNode(usePosition);
for (int index = 0; index < operation.SourcesCount; index++) for (int index = 0; index < operation.SourcesCount; index++)
@ -759,7 +793,6 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
private void NumberLocals(ControlFlowGraph cfg) private void NumberLocals(ControlFlowGraph cfg)
{ {
_operationNodes = new List<(IntrusiveList<Operation>, Operation)>(); _operationNodes = new List<(IntrusiveList<Operation>, Operation)>();
_intervals = new List<LiveInterval>(); _intervals = new List<LiveInterval>();
for (int index = 0; index < RegistersCount; index++) for (int index = 0; index < RegistersCount; index++)
@ -768,7 +801,18 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
_intervals.Add(new LiveInterval(new Register(index, RegisterType.Vector))); _intervals.Add(new LiveInterval(new Register(index, RegisterType.Vector)));
} }
HashSet<Operand> visited = new HashSet<Operand>(); // The "visited" state is stored in the MSB of the local's value.
const ulong VisitedMask = 1ul << 63;
bool IsVisited(Operand local)
{
return (local.GetValueUnsafe() & VisitedMask) != 0;
}
void SetVisited(Operand local)
{
local.GetValueUnsafe() |= VisitedMask;
}
_operationsCount = 0; _operationsCount = 0;
@ -784,11 +828,13 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
Operand dest = node.GetDestination(i); Operand dest = node.GetDestination(i);
if (dest.Kind == OperandKind.LocalVariable && visited.Add(dest)) if (dest.Kind == OperandKind.LocalVariable && !IsVisited(dest))
{ {
dest.NumberLocal(_intervals.Count); dest.NumberLocal(_intervals.Count);
_intervals.Add(new LiveInterval(dest)); _intervals.Add(new LiveInterval(dest));
SetVisited(dest);
} }
} }
} }
@ -824,19 +870,45 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
for (Operation node = block.Operations.First; node != default; node = node.ListNext) for (Operation node = block.Operations.First; node != default; node = node.ListNext)
{ {
Sources(node, (source) => for (int i = 0; i < node.SourcesCount; i++)
{ {
int id = GetOperandId(source); VisitSource(node.GetSource(i));
}
if (!liveKill.IsSet(id))
{
liveGen.Set(id);
}
});
for (int i = 0; i < node.DestinationsCount; i++) for (int i = 0; i < node.DestinationsCount; i++)
{ {
Operand dest = node.GetDestination(i); VisitDestination(node.GetDestination(i));
}
void VisitSource(Operand source)
{
if (IsLocalOrRegister(source.Kind))
{
int id = GetOperandId(source);
if (!liveKill.IsSet(id))
{
liveGen.Set(id);
}
}
else if (source.Kind == OperandKind.Memory)
{
MemoryOperand memOp = source.GetMemory();
if (memOp.BaseAddress != default)
{
VisitSource(memOp.BaseAddress);
}
if (memOp.Index != default)
{
VisitSource(memOp.Index);
}
}
}
void VisitDestination(Operand dest)
{
liveKill.Set(GetOperandId(dest)); liveKill.Set(GetOperandId(dest));
} }
} }
@ -920,34 +992,65 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
continue; continue;
} }
foreach (Operation node in BottomOperations(block)) for (Operation node = block.Operations.Last; node != default; node = node.ListPrevious)
{ {
operationPos -= InstructionGap; operationPos -= InstructionGap;
for (int i = 0; i < node.DestinationsCount; i++) for (int i = 0; i < node.DestinationsCount; i++)
{ {
Operand dest = node.GetDestination(i); VisitDestination(node.GetDestination(i));
LiveInterval interval = _intervals[GetOperandId(dest)];
interval.SetStart(operationPos + 1);
interval.AddUsePosition(operationPos + 1);
} }
Sources(node, (source) => for (int i = 0; i < node.SourcesCount; i++)
{ {
LiveInterval interval = _intervals[GetOperandId(source)]; VisitSource(node.GetSource(i));
}
interval.AddRange(blockStart, operationPos + 1);
interval.AddUsePosition(operationPos);
});
if (node.Instruction == Instruction.Call) if (node.Instruction == Instruction.Call)
{ {
AddIntervalCallerSavedReg(context.Masks.IntCallerSavedRegisters, operationPos, RegisterType.Integer); AddIntervalCallerSavedReg(context.Masks.IntCallerSavedRegisters, operationPos, RegisterType.Integer);
AddIntervalCallerSavedReg(context.Masks.VecCallerSavedRegisters, operationPos, RegisterType.Vector); AddIntervalCallerSavedReg(context.Masks.VecCallerSavedRegisters, operationPos, RegisterType.Vector);
} }
void VisitSource(Operand source)
{
if (IsLocalOrRegister(source.Kind))
{
LiveInterval interval = _intervals[GetOperandId(source)];
interval.AddRange(blockStart, operationPos + 1);
interval.AddUsePosition(operationPos);
}
else if (source.Kind == OperandKind.Memory)
{
MemoryOperand memOp = source.GetMemory();
if (memOp.BaseAddress != default)
{
VisitSource(memOp.BaseAddress);
}
if (memOp.Index != default)
{
VisitSource(memOp.Index);
}
}
}
void VisitDestination(Operand dest)
{
LiveInterval interval = _intervals[GetOperandId(dest)];
interval.SetStart(operationPos + 1);
interval.AddUsePosition(operationPos + 1);
}
} }
} }
foreach (LiveInterval interval in _parentIntervals)
{
interval.Reset();
}
} }
private void AddIntervalCallerSavedReg(int mask, int operationPos, RegisterType regType) private void AddIntervalCallerSavedReg(int mask, int operationPos, RegisterType regType)
@ -987,45 +1090,6 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
return (register.Index << 1) | (register.Type == RegisterType.Vector ? 1 : 0); return (register.Index << 1) | (register.Type == RegisterType.Vector ? 1 : 0);
} }
private static IEnumerable<Operation> BottomOperations(BasicBlock block)
{
Operation node = block.Operations.Last;
while (node != default)
{
yield return node;
node = node.ListPrevious;
}
}
private static void Sources(Operation node, Action<Operand> action)
{
for (int index = 0; index < node.SourcesCount; index++)
{
Operand source = node.GetSource(index);
if (IsLocalOrRegister(source.Kind))
{
action(source);
}
else if (source.Kind == OperandKind.Memory)
{
MemoryOperand memOp = source.GetMemory();
if (memOp.BaseAddress != default)
{
action(memOp.BaseAddress);
}
if (memOp.Index != default)
{
action(memOp.Index);
}
}
}
}
private static bool IsLocalOrRegister(OperandKind kind) private static bool IsLocalOrRegister(OperandKind kind)
{ {
return kind == OperandKind.LocalVariable || return kind == OperandKind.LocalVariable ||

446
ARMeilleure/CodeGen/RegisterAllocators/LiveInterval.cs
View file

@ -1,341 +1,291 @@
using ARMeilleure.Common;
using ARMeilleure.IntermediateRepresentation; using ARMeilleure.IntermediateRepresentation;
using System; using System;
using System.Collections.Generic; using System.Collections.Generic;
using System.Diagnostics; using System.Diagnostics;
using System.Linq;
namespace ARMeilleure.CodeGen.RegisterAllocators namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
class LiveInterval : IComparable<LiveInterval> unsafe readonly struct LiveInterval : IComparable<LiveInterval>
{ {
public const int NotFound = -1; public const int NotFound = -1;
private LiveInterval _parent; private struct Data
private SortedIntegerList _usePositions;
public int UsesCount => _usePositions.Count;
private List<LiveRange> _ranges;
private SortedList<int, LiveInterval> _childs;
public bool IsSplit => _childs.Count != 0;
public Operand Local { get; }
public Register Register { get; set; }
public int SpillOffset { get; private set; }
public bool IsSpilled => SpillOffset != -1;
public bool IsFixed { get; }
public bool IsEmpty => _ranges.Count == 0;
public LiveInterval(Operand local = default, LiveInterval parent = null)
{ {
Local = local; public int End;
_parent = parent ?? this; public int SpillOffset;
_usePositions = new SortedIntegerList(); public LiveRange FirstRange;
public LiveRange PrevRange;
public LiveRange CurrRange;
_ranges = new List<LiveRange>(); public LiveInterval Parent;
_childs = new SortedList<int, LiveInterval>(); public UseList Uses;
public LiveIntervalList Children;
public Operand Local;
public Register Register;
public bool IsFixed;
}
private readonly Data* _data;
private ref int End => ref _data->End;
private ref LiveRange FirstRange => ref _data->FirstRange;
private ref LiveRange CurrRange => ref _data->CurrRange;
private ref LiveRange PrevRange => ref _data->PrevRange;
private ref LiveInterval Parent => ref _data->Parent;
private ref UseList Uses => ref _data->Uses;
private ref LiveIntervalList Children => ref _data->Children;
public Operand Local => _data->Local;
public ref Register Register => ref _data->Register;
public ref int SpillOffset => ref _data->SpillOffset;
public bool IsFixed => _data->IsFixed;
public bool IsEmpty => FirstRange == default;
public bool IsSplit => Children.Count != 0;
public bool IsSpilled => SpillOffset != -1;
public int UsesCount => Uses.Count;
public LiveInterval(Operand local = default, LiveInterval parent = default)
{
_data = Allocators.LiveIntervals.Allocate<Data>();
*_data = default;
_data->IsFixed = false;
_data->Local = local;
Parent = parent == default ? this : parent;
Uses = new UseList();
Children = new LiveIntervalList();
FirstRange = default;
CurrRange = default;
PrevRange = default;
SpillOffset = -1; SpillOffset = -1;
} }
public LiveInterval(Register register) : this() public LiveInterval(Register register) : this(local: default, parent: default)
{ {
IsFixed = true; _data->IsFixed = true;
Register = register; Register = register;
} }
public void SetStart(int position) public void Reset()
{ {
if (_ranges.Count != 0) PrevRange = default;
{ CurrRange = FirstRange;
Debug.Assert(position != _ranges[0].End); }
_ranges[0] = new LiveRange(position, _ranges[0].End); public void Forward(int position)
} {
else LiveRange prev = PrevRange;
LiveRange curr = CurrRange;
while (curr != default && curr.Start < position && !curr.Overlaps(position))
{ {
_ranges.Add(new LiveRange(position, position + 1)); prev = curr;
curr = curr.Next;
} }
PrevRange = prev;
CurrRange = curr;
} }
public int GetStart() public int GetStart()
{ {
if (_ranges.Count == 0) Debug.Assert(!IsEmpty, "Empty LiveInterval cannot have a start position.");
{
throw new InvalidOperationException("Empty interval.");
}
return _ranges[0].Start; return FirstRange.Start;
} }
public void SetEnd(int position) public void SetStart(int position)
{ {
if (_ranges.Count != 0) if (FirstRange != default)
{ {
int lastIdx = _ranges.Count - 1; Debug.Assert(position != FirstRange.End);
Debug.Assert(position != _ranges[lastIdx].Start); FirstRange.Start = position;
_ranges[lastIdx] = new LiveRange(_ranges[lastIdx].Start, position);
} }
else else
{ {
_ranges.Add(new LiveRange(position, position + 1)); FirstRange = new LiveRange(position, position + 1);
End = position + 1;
} }
} }
public int GetEnd() public int GetEnd()
{ {
if (_ranges.Count == 0) Debug.Assert(!IsEmpty, "Empty LiveInterval cannot have an end position.");
{
throw new InvalidOperationException("Empty interval.");
}
return _ranges[_ranges.Count - 1].End; return End;
} }
public void AddRange(int start, int end) public void AddRange(int start, int end)
{ {
if (start >= end) Debug.Assert(start < end, $"Invalid range start position {start}, {end}");
if (FirstRange != default)
{ {
throw new ArgumentException("Invalid range start position " + start + ", " + end); // If the new range ends exactly where the first range start, then coalesce together.
} if (end == FirstRange.Start)
int index = _ranges.BinarySearch(new LiveRange(start, end));
if (index >= 0)
{
// New range insersects with an existing range, we need to remove
// all the intersecting ranges before adding the new one.
// We also extend the new range as needed, based on the values of
// the existing ranges being removed.
int lIndex = index;
int rIndex = index;
while (lIndex > 0 && _ranges[lIndex - 1].End >= start)
{ {
lIndex--; FirstRange.Start = start;
return;
} }
// If the new range is already contained, then coalesce together.
while (rIndex + 1 < _ranges.Count && _ranges[rIndex + 1].Start <= end) else if (FirstRange.Overlaps(start, end))
{ {
rIndex++; FirstRange.Start = Math.Min(FirstRange.Start, start);
} FirstRange.End = Math.Max(FirstRange.End, end);
End = Math.Max(End, end);
if (start > _ranges[lIndex].Start) Debug.Assert(FirstRange.Next == default || !FirstRange.Overlaps(FirstRange.Next));
{ return;
start = _ranges[lIndex].Start;
}
if (end < _ranges[rIndex].End)
{
end = _ranges[rIndex].End;
}
_ranges.RemoveRange(lIndex, (rIndex - lIndex) + 1);
InsertRange(lIndex, start, end);
}
else
{
InsertRange(~index, start, end);
}
}
private void InsertRange(int index, int start, int end)
{
// Here we insert a new range on the ranges list.
// If possible, we extend an existing range rather than inserting a new one.
// We can extend an existing range if any of the following conditions are true:
// - The new range starts right after the end of the previous range on the list.
// - The new range ends right before the start of the next range on the list.
// If both cases are true, we can extend either one. We prefer to extend the
// previous range, and then remove the next one, but theres no specific reason
// for that, extending either one will do.
int? extIndex = null;
if (index > 0 && _ranges[index - 1].End == start)
{
start = _ranges[index - 1].Start;
extIndex = index - 1;
}
if (index < _ranges.Count && _ranges[index].Start == end)
{
end = _ranges[index].End;
if (extIndex.HasValue)
{
_ranges.RemoveAt(index);
}
else
{
extIndex = index;
} }
} }
if (extIndex.HasValue) FirstRange = new LiveRange(start, end, FirstRange);
{ End = Math.Max(End, end);
_ranges[extIndex.Value] = new LiveRange(start, end);
} Debug.Assert(FirstRange.Next == default || !FirstRange.Overlaps(FirstRange.Next));
else
{
_ranges.Insert(index, new LiveRange(start, end));
}
} }
public void AddUsePosition(int position) public void AddUsePosition(int position)
{ {
// Inserts are in descending order, but ascending is faster for SortedIntegerList<>. Uses.Add(position);
// We flip the ordering, then iterate backwards when using the final list.
_usePositions.Add(-position);
} }
public bool Overlaps(int position) public bool Overlaps(int position)
{ {
return _ranges.BinarySearch(new LiveRange(position, position + 1)) >= 0; LiveRange curr = CurrRange;
}
public bool Overlaps(LiveInterval other) while (curr != default && curr.Start <= position)
{
foreach (LiveRange range in other._ranges)
{ {
if (_ranges.BinarySearch(range) >= 0) if (curr.Overlaps(position))
{ {
return true; return true;
} }
curr = curr.Next;
} }
return false; return false;
} }
public bool Overlaps(LiveInterval other)
{
return GetOverlapPosition(other) != NotFound;
}
public int GetOverlapPosition(LiveInterval other) public int GetOverlapPosition(LiveInterval other)
{ {
foreach (LiveRange range in other._ranges) LiveRange a = CurrRange;
{ LiveRange b = other.CurrRange;
int overlapIndex = _ranges.BinarySearch(range);
if (overlapIndex >= 0) while (a != default)
{
while (b != default && b.Start < a.Start)
{ {
// It's possible that we have multiple overlaps within a single interval, if (a.Overlaps(b))
// in this case, we pick the one with the lowest start position, since
// we return the first overlap position.
while (overlapIndex > 0 && _ranges[overlapIndex - 1].End > range.Start)
{ {
overlapIndex--; return a.Start;
} }
LiveRange overlappingRange = _ranges[overlapIndex]; b = b.Next;
return overlappingRange.Start;
} }
if (b == default)
{
break;
}
else if (a.Overlaps(b))
{
return a.Start;
}
a = a.Next;
} }
return NotFound; return NotFound;
} }
public IEnumerable<LiveInterval> SplitChilds() public ReadOnlySpan<LiveInterval> SplitChildren()
{ {
return _childs.Values; return Parent.Children.Span;
} }
public IList<int> UsePositions() public ReadOnlySpan<int> UsePositions()
{ {
return _usePositions.GetList(); return Uses.Span;
} }
public int FirstUse() public int FirstUse()
{ {
if (_usePositions.Count == 0) return Uses.FirstUse;
{
return NotFound;
}
return -_usePositions.Last();
} }
public int NextUseAfter(int position) public int NextUseAfter(int position)
{ {
int index = _usePositions.FindLessEqualIndex(-position); return Uses.NextUse(position);
return (index >= 0) ? -_usePositions[index] : NotFound;
}
public void RemoveAfter(int position)
{
int index = _usePositions.FindLessEqualIndex(-position);
_usePositions.RemoveRange(0, index + 1);
} }
public LiveInterval Split(int position) public LiveInterval Split(int position)
{ {
LiveInterval right = new LiveInterval(Local, _parent); LiveInterval result = new(Local, Parent);
result.End = End;
int splitIndex = 0; LiveRange prev = PrevRange;
LiveRange curr = CurrRange;
for (; splitIndex < _ranges.Count; splitIndex++) while (curr != default && curr.Start < position && !curr.Overlaps(position))
{ {
LiveRange range = _ranges[splitIndex]; prev = curr;
curr = curr.Next;
if (position > range.Start && position < range.End)
{
right._ranges.Add(new LiveRange(position, range.End));
range = new LiveRange(range.Start, position);
_ranges[splitIndex++] = range;
break;
}
if (range.Start >= position)
{
break;
}
} }
if (splitIndex < _ranges.Count) if (curr.Start >= position)
{ {
int count = _ranges.Count - splitIndex; prev.Next = default;
right._ranges.AddRange(_ranges.GetRange(splitIndex, count)); result.FirstRange = curr;
_ranges.RemoveRange(splitIndex, count); End = prev.End;
}
else
{
result.FirstRange = new LiveRange(position, curr.End, curr.Next);
curr.End = position;
curr.Next = default;
End = curr.End;
} }
int addAfter = _usePositions.FindLessEqualIndex(-position); result.Uses = Uses.Split(position);
for (int index = addAfter; index >= 0; index--)
{
int usePosition = _usePositions[index];
right._usePositions.Add(usePosition);
}
RemoveAfter(position); AddSplitChild(result);
Debug.Assert(_ranges.Count != 0, "Left interval is empty after split."); Debug.Assert(!IsEmpty, "Left interval is empty after split.");
Debug.Assert(!result.IsEmpty, "Right interval is empty after split.");
Debug.Assert(right._ranges.Count != 0, "Right interval is empty after split."); // Make sure the iterator in the new split is pointing to the start.
result.Reset();
AddSplitChild(right); return result;
return right;
} }
private void AddSplitChild(LiveInterval child) private void AddSplitChild(LiveInterval child)
{ {
Debug.Assert(!child.IsEmpty, "Trying to insert a empty interval."); Debug.Assert(!child.IsEmpty, "Trying to insert an empty interval.");
_parent._childs.Add(child.GetStart(), child); Parent.Children.Add(child);
} }
public LiveInterval GetSplitChild(int position) public LiveInterval GetSplitChild(int position)
@ -345,20 +295,24 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
return this; return this;
} }
foreach (LiveInterval splitChild in _childs.Values) foreach (LiveInterval splitChild in SplitChildren())
{ {
if (splitChild.Overlaps(position)) if (splitChild.Overlaps(position))
{ {
return splitChild; return splitChild;
} }
else if (splitChild.GetStart() > position)
{
break;
}
} }
return null; return default;
} }
public bool TrySpillWithSiblingOffset() public bool TrySpillWithSiblingOffset()
{ {
foreach (LiveInterval splitChild in _parent._childs.Values) foreach (LiveInterval splitChild in SplitChildren())
{ {
if (splitChild.IsSpilled) if (splitChild.IsSpilled)
{ {
@ -376,19 +330,65 @@ namespace ARMeilleure.CodeGen.RegisterAllocators
SpillOffset = offset; SpillOffset = offset;
} }
public int CompareTo(LiveInterval other) public int CompareTo(LiveInterval interval)
{ {
if (_ranges.Count == 0 || other._ranges.Count == 0) if (FirstRange == default || interval.FirstRange == default)
{ {
return _ranges.Count.CompareTo(other._ranges.Count); return 0;
} }
return _ranges[0].Start.CompareTo(other._ranges[0].Start); return GetStart().CompareTo(interval.GetStart());
}
public bool Equals(LiveInterval interval)
{
return interval._data == _data;
}
public override bool Equals(object obj)
{
return obj is LiveInterval interval && Equals(interval);
}
public static bool operator ==(LiveInterval a, LiveInterval b)
{
return a.Equals(b);
}
public static bool operator !=(LiveInterval a, LiveInterval b)
{
return !a.Equals(b);
}
public override int GetHashCode()
{
return HashCode.Combine((IntPtr)_data);
} }
public override string ToString() public override string ToString()
{ {
return string.Join("; ", _ranges); LiveInterval self = this;
IEnumerable<string> GetRanges()
{
LiveRange curr = self.CurrRange;
while (curr != default)
{
if (curr == self.CurrRange)
{
yield return "*" + curr;
}
else
{
yield return curr.ToString();
}
curr = curr.Next;
}
}
return string.Join(", ", GetRanges());
} }
} }
} }

40
ARMeilleure/CodeGen/RegisterAllocators/LiveIntervalList.cs Normal file
View file

@ -0,0 +1,40 @@
using System;
namespace ARMeilleure.CodeGen.RegisterAllocators
{
unsafe struct LiveIntervalList
{
private LiveInterval* _items;
private int _count;
private int _capacity;
public int Count => _count;
public Span<LiveInterval> Span => new(_items, _count);
public void Add(LiveInterval interval)
{
if (_count + 1 > _capacity)
{
var oldSpan = Span;
_capacity = Math.Max(4, _capacity * 2);
_items = Allocators.References.Allocate<LiveInterval>((uint)_capacity);
var newSpan = Span;
oldSpan.CopyTo(newSpan);
}
int position = interval.GetStart();
int i = _count - 1;
while (i >= 0 && _items[i].GetStart() > position)
{
_items[i + 1] = _items[i--];
}
_items[i + 1] = interval;
_count++;
}
}
}

73
ARMeilleure/CodeGen/RegisterAllocators/LiveRange.cs
View file

@ -2,30 +2,73 @@ using System;
namespace ARMeilleure.CodeGen.RegisterAllocators namespace ARMeilleure.CodeGen.RegisterAllocators
{ {
struct LiveRange : IComparable<LiveRange> unsafe readonly struct LiveRange : IEquatable<LiveRange>
{ {
public int Start { get; } private struct Data
public int End { get; }
public LiveRange(int start, int end)
{ {
Start = start; public int Start;
End = end; public int End;
public LiveRange Next;
} }
public int CompareTo(LiveRange other) private readonly Data* _data;
{
if (Start < other.End && other.Start < End)
{
return 0;
}
return Start.CompareTo(other.Start); public ref int Start => ref _data->Start;
public ref int End => ref _data->End;
public ref LiveRange Next => ref _data->Next;
public LiveRange(int start, int end, LiveRange next = default)
{
_data = Allocators.LiveRanges.Allocate<Data>();
Start = start;
End = end;
Next = next;
}
public bool Overlaps(int start, int end)
{
return Start < end && start < End;
}
public bool Overlaps(LiveRange range)
{
return Start < range.End && range.Start < End;
}
public bool Overlaps(int position)
{
return position >= Start && position < End;
}
public bool Equals(LiveRange range)
{
return range._data == _data;
}
public override bool Equals(object obj)
{
return obj is LiveRange range && Equals(range);
}
public static bool operator ==(LiveRange a, LiveRange b)
{
return a.Equals(b);
}
public static bool operator !=(LiveRange a, LiveRange b)
{
return !a.Equals(b);
}
public override int GetHashCode()
{
return HashCode.Combine((IntPtr)_data);
} }
public override string ToString() public override string ToString()
{ {
return $"[{Start}, {End}["; return $"[{Start}, {End})";
} }
} }
} }

84
ARMeilleure/CodeGen/RegisterAllocators/UseList.cs Normal file
View file

@ -0,0 +1,84 @@
using System;
namespace ARMeilleure.CodeGen.RegisterAllocators
{
unsafe struct UseList
{
private int* _items;
private int _capacity;
private int _count;
public int Count => _count;
public int FirstUse => _count > 0 ? _items[_count - 1] : LiveInterval.NotFound;
public Span<int> Span => new(_items, _count);
public void Add(int position)
{
if (_count + 1 > _capacity)
{
var oldSpan = Span;
_capacity = Math.Max(4, _capacity * 2);
_items = Allocators.Default.Allocate<int>((uint)_capacity);
var newSpan = Span;
oldSpan.CopyTo(newSpan);
}
// Use positions are usually inserted in descending order, so inserting in descending order is faster,
// since the number of half exchanges is reduced.
int i = _count - 1;
while (i >= 0 && _items[i] < position)
{
_items[i + 1] = _items[i--];
}
_items[i + 1] = position;
_count++;
}
public int NextUse(int position)
{
int index = NextUseIndex(position);
return index != LiveInterval.NotFound ? _items[index] : LiveInterval.NotFound;
}
public int NextUseIndex(int position)
{
int i = _count - 1;
if (i == -1 || position > _items[0])
{
return LiveInterval.NotFound;
}
while (i >= 0 && _items[i] < position)
{
i--;
}
return i;
}
public UseList Split(int position)
{
int index = NextUseIndex(position);
// Since the list is in descending order, the new split list takes the front of the list and the current
// list takes the back of the list.
UseList result = new();
result._count = index + 1;
result._capacity = result._count;
result._items = _items;
_count = _count - result._count;
_capacity = _count;
_items = _items + result._count;
return result;
}
}
}

14
ARMeilleure/Common/BitMap.cs
View file

@ -2,6 +2,7 @@ using System;
using System.Collections; using System.Collections;
using System.Collections.Generic; using System.Collections.Generic;
using System.Numerics; using System.Numerics;
using System.Runtime.CompilerServices;
namespace ARMeilleure.Common namespace ARMeilleure.Common
{ {
@ -170,12 +171,12 @@ namespace ARMeilleure.Common
public struct Enumerator : IEnumerator<int> public struct Enumerator : IEnumerator<int>
{ {
private int _index; private long _index;
private long _mask; private long _mask;
private int _bit; private int _bit;
private readonly BitMap _map; private readonly BitMap _map;
public int Current => _index * IntSize + _bit; public int Current => (int)_index * IntSize + _bit;
object IEnumerator.Current => Current; object IEnumerator.Current => Current;
public Enumerator(BitMap map) public Enumerator(BitMap map)
@ -186,6 +187,7 @@ namespace ARMeilleure.Common
_map = map; _map = map;
} }
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public bool MoveNext() public bool MoveNext()
{ {
if (_mask != 0) if (_mask != 0)
@ -193,14 +195,18 @@ namespace ARMeilleure.Common
_mask &= ~(1L << _bit); _mask &= ~(1L << _bit);
} }
// Manually hoist these loads, because RyuJIT does not.
long count = (uint)_map._count;
long* masks = _map._masks;
while (_mask == 0) while (_mask == 0)
{ {
if (++_index >= _map._count) if (++_index >= count)
{ {
return false; return false;
} }
_mask = _map._masks[_index]; _mask = masks[_index];
} }
_bit = BitOperations.TrailingZeroCount(_mask); _bit = BitOperations.TrailingZeroCount(_mask);

73
ARMeilleure/Common/SortedIntegerList.cs
View file

@ -1,73 +0,0 @@
using System;
using System.Collections.Generic;
namespace ARMeilleure.Common
{
public class SortedIntegerList
{
private List<int> _items;
public int Count => _items.Count;
public int this[int index]
{
get
{
return _items[index];
}
set
{
_items[index] = value;
}
}
public SortedIntegerList()
{
_items = new List<int>();
}
public bool Add(int value)
{
if (_items.Count == 0 || value > Last())
{
_items.Add(value);
return true;
}
else
{
int index = _items.BinarySearch(value);
if (index >= 0)
{
return false;
}
_items.Insert(-1 - index, value);
return true;
}
}
public int FindLessEqualIndex(int value)
{
int index = _items.BinarySearch(value);
return (index < 0) ? (-2 - index) : index;
}
public void RemoveRange(int index, int count)
{
if (count > 0)
{
_items.RemoveRange(index, count);
}
}
public int Last()
{
return _items[Count - 1];
}
public List<int> GetList()
{
return _items;
}
}
}