Ryujinx/ARMeilleure/CodeGen/RegisterAllocators/CopyResolver.cs
Andrey Sukharev 4da44e09cb
Make structs readonly when applicable (#4002)
* Make all structs readonly when applicable. It should reduce amount of needless defensive copies

* Make structs with trivial boilerplate equality code record structs

* Remove unnecessary readonly modifiers from TextureCreateInfo

* Make BitMap structs readonly too
2022-12-05 14:47:39 +01:00

259 lines
No EOL
8.9 KiB
C#

using ARMeilleure.IntermediateRepresentation;
using System;
using System.Collections.Generic;
using static ARMeilleure.IntermediateRepresentation.Operand.Factory;
using static ARMeilleure.IntermediateRepresentation.Operation.Factory;
namespace ARMeilleure.CodeGen.RegisterAllocators
{
class CopyResolver
{
private class ParallelCopy
{
private readonly struct Copy
{
public Register Dest { get; }
public Register Source { get; }
public OperandType Type { get; }
public Copy(Register dest, Register source, OperandType type)
{
Dest = dest;
Source = source;
Type = type;
}
}
private readonly List<Copy> _copies;
public int Count => _copies.Count;
public ParallelCopy()
{
_copies = new List<Copy>();
}
public void AddCopy(Register dest, Register source, OperandType type)
{
_copies.Add(new Copy(dest, source, type));
}
public void Sequence(List<Operation> sequence)
{
Dictionary<Register, Register> locations = new Dictionary<Register, Register>();
Dictionary<Register, Register> sources = new Dictionary<Register, Register>();
Dictionary<Register, OperandType> types = new Dictionary<Register, OperandType>();
Queue<Register> pendingQueue = new Queue<Register>();
Queue<Register> readyQueue = new Queue<Register>();
foreach (Copy copy in _copies)
{
locations[copy.Source] = copy.Source;
sources[copy.Dest] = copy.Source;
types[copy.Dest] = copy.Type;
pendingQueue.Enqueue(copy.Dest);
}
foreach (Copy copy in _copies)
{
// If the destination is not used anywhere, we can assign it immediately.
if (!locations.ContainsKey(copy.Dest))
{
readyQueue.Enqueue(copy.Dest);
}
}
while (pendingQueue.TryDequeue(out Register current))
{
Register copyDest;
Register origSource;
Register copySource;
while (readyQueue.TryDequeue(out copyDest))
{
origSource = sources[copyDest];
copySource = locations[origSource];
OperandType type = types[copyDest];
EmitCopy(sequence, GetRegister(copyDest, type), GetRegister(copySource, type));
locations[origSource] = copyDest;
if (origSource == copySource && sources.ContainsKey(origSource))
{
readyQueue.Enqueue(origSource);
}
}
copyDest = current;
origSource = sources[copyDest];
copySource = locations[origSource];
if (copyDest != copySource)
{
OperandType type = types[copyDest];
type = type.IsInteger() ? OperandType.I64 : OperandType.V128;
EmitXorSwap(sequence, GetRegister(copyDest, type), GetRegister(copySource, type));
locations[origSource] = copyDest;
Register swapOther = copySource;
if (copyDest != locations[sources[copySource]])
{
// Find the other swap destination register.
// To do that, we search all the pending registers, and pick
// the one where the copy source register is equal to the
// current destination register being processed (copyDest).
foreach (Register pending in pendingQueue)
{
// Is this a copy of pending <- copyDest?
if (copyDest == locations[sources[pending]])
{
swapOther = pending;
break;
}
}
}
// The value that was previously at "copyDest" now lives on
// "copySource" thanks to the swap, now we need to update the
// location for the next copy that is supposed to copy the value
// that used to live on "copyDest".
locations[sources[swapOther]] = copySource;
}
}
}
private static void EmitCopy(List<Operation> sequence, Operand x, Operand y)
{
sequence.Add(Operation(Instruction.Copy, x, y));
}
private static void EmitXorSwap(List<Operation> sequence, Operand x, Operand y)
{
sequence.Add(Operation(Instruction.BitwiseExclusiveOr, x, x, y));
sequence.Add(Operation(Instruction.BitwiseExclusiveOr, y, y, x));
sequence.Add(Operation(Instruction.BitwiseExclusiveOr, x, x, y));
}
}
private Queue<Operation> _fillQueue = null;
private Queue<Operation> _spillQueue = null;
private ParallelCopy _parallelCopy = null;
public bool HasCopy { get; private set; }
public void AddSplit(LiveInterval left, LiveInterval right)
{
if (left.Local != right.Local)
{
throw new ArgumentException("Intervals of different variables are not allowed.");
}
OperandType type = left.Local.Type;
if (left.IsSpilled && !right.IsSpilled)
{
// Move from the stack to a register.
AddSplitFill(left, right, type);
}
else if (!left.IsSpilled && right.IsSpilled)
{
// Move from a register to the stack.
AddSplitSpill(left, right, type);
}
else if (!left.IsSpilled && !right.IsSpilled && left.Register != right.Register)
{
// Move from one register to another.
AddSplitCopy(left, right, type);
}
else if (left.SpillOffset != right.SpillOffset)
{
// This would be the stack-to-stack move case, but this is not supported.
throw new ArgumentException("Both intervals were spilled.");
}
}
private void AddSplitFill(LiveInterval left, LiveInterval right, OperandType type)
{
if (_fillQueue == null)
{
_fillQueue = new Queue<Operation>();
}
Operand register = GetRegister(right.Register, type);
Operand offset = Const(left.SpillOffset);
_fillQueue.Enqueue(Operation(Instruction.Fill, register, offset));
HasCopy = true;
}
private void AddSplitSpill(LiveInterval left, LiveInterval right, OperandType type)
{
if (_spillQueue == null)
{
_spillQueue = new Queue<Operation>();
}
Operand offset = Const(right.SpillOffset);
Operand register = GetRegister(left.Register, type);
_spillQueue.Enqueue(Operation(Instruction.Spill, default, offset, register));
HasCopy = true;
}
private void AddSplitCopy(LiveInterval left, LiveInterval right, OperandType type)
{
if (_parallelCopy == null)
{
_parallelCopy = new ParallelCopy();
}
_parallelCopy.AddCopy(right.Register, left.Register, type);
HasCopy = true;
}
public Operation[] Sequence()
{
List<Operation> sequence = new List<Operation>();
if (_spillQueue != null)
{
while (_spillQueue.TryDequeue(out Operation spillOp))
{
sequence.Add(spillOp);
}
}
_parallelCopy?.Sequence(sequence);
if (_fillQueue != null)
{
while (_fillQueue.TryDequeue(out Operation fillOp))
{
sequence.Add(fillOp);
}
}
return sequence.ToArray();
}
private static Operand GetRegister(Register reg, OperandType type)
{
return Register(reg.Index, reg.Type, type);
}
}
}