Ryujinx/ARMeilleure/CodeGen/Arm64/CodeGenContext.cs

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C#
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using ARMeilleure.CodeGen.Linking;
using ARMeilleure.CodeGen.RegisterAllocators;
using ARMeilleure.IntermediateRepresentation;
using System;
using System.Collections.Generic;
using System.IO;
namespace ARMeilleure.CodeGen.Arm64
{
class CodeGenContext
{
private const int BccInstLength = 4;
private const int CbnzInstLength = 4;
private const int LdrLitInstLength = 4;
private Stream _stream;
public int StreamOffset => (int)_stream.Length;
public AllocationResult AllocResult { get; }
public Assembler Assembler { get; }
public BasicBlock CurrBlock { get; private set; }
public bool HasCall { get; }
public int CallArgsRegionSize { get; }
public int FpLrSaveRegionSize { get; }
private readonly Dictionary<BasicBlock, long> _visitedBlocks;
private readonly Dictionary<BasicBlock, List<(ArmCondition Condition, long BranchPos)>> _pendingBranches;
private struct ConstantPoolEntry
{
public readonly int Offset;
public readonly Symbol Symbol;
public readonly List<(Operand, int)> LdrOffsets;
public ConstantPoolEntry(int offset, Symbol symbol)
{
Offset = offset;
Symbol = symbol;
LdrOffsets = new List<(Operand, int)>();
}
}
private readonly Dictionary<ulong, ConstantPoolEntry> _constantPool;
private bool _constantPoolWritten;
private long _constantPoolOffset;
private ArmCondition _jNearCondition;
private Operand _jNearValue;
private long _jNearPosition;
private readonly bool _relocatable;
public CodeGenContext(AllocationResult allocResult, int maxCallArgs, int blocksCount, bool relocatable)
{
_stream = new MemoryStream();
AllocResult = allocResult;
Assembler = new Assembler(_stream);
bool hasCall = maxCallArgs >= 0;
HasCall = hasCall;
if (maxCallArgs < 0)
{
maxCallArgs = 0;
}
CallArgsRegionSize = maxCallArgs * 16;
FpLrSaveRegionSize = hasCall ? 16 : 0;
_visitedBlocks = new Dictionary<BasicBlock, long>();
_pendingBranches = new Dictionary<BasicBlock, List<(ArmCondition, long)>>();
_constantPool = new Dictionary<ulong, ConstantPoolEntry>();
_relocatable = relocatable;
}
public void EnterBlock(BasicBlock block)
{
CurrBlock = block;
long target = _stream.Position;
if (_pendingBranches.TryGetValue(block, out var list))
{
foreach (var tuple in list)
{
_stream.Seek(tuple.BranchPos, SeekOrigin.Begin);
WriteBranch(tuple.Condition, target);
}
_stream.Seek(target, SeekOrigin.Begin);
_pendingBranches.Remove(block);
}
_visitedBlocks.Add(block, target);
}
public void JumpTo(BasicBlock target)
{
JumpTo(ArmCondition.Al, target);
}
public void JumpTo(ArmCondition condition, BasicBlock target)
{
if (_visitedBlocks.TryGetValue(target, out long offset))
{
WriteBranch(condition, offset);
}
else
{
if (!_pendingBranches.TryGetValue(target, out var list))
{
list = new List<(ArmCondition, long)>();
_pendingBranches.Add(target, list);
}
list.Add((condition, _stream.Position));
_stream.Seek(BccInstLength, SeekOrigin.Current);
}
}
private void WriteBranch(ArmCondition condition, long to)
{
int imm = checked((int)(to - _stream.Position));
if (condition != ArmCondition.Al)
{
Assembler.B(condition, imm);
}
else
{
Assembler.B(imm);
}
}
public void JumpToNear(ArmCondition condition)
{
_jNearCondition = condition;
_jNearPosition = _stream.Position;
_stream.Seek(BccInstLength, SeekOrigin.Current);
}
public void JumpToNearIfNotZero(Operand value)
{
_jNearValue = value;
_jNearPosition = _stream.Position;
_stream.Seek(CbnzInstLength, SeekOrigin.Current);
}
public void JumpHere()
{
long currentPosition = _stream.Position;
long offset = currentPosition - _jNearPosition;
_stream.Seek(_jNearPosition, SeekOrigin.Begin);
if (_jNearValue != default)
{
Assembler.Cbnz(_jNearValue, checked((int)offset));
_jNearValue = default;
}
else
{
Assembler.B(_jNearCondition, checked((int)offset));
}
_stream.Seek(currentPosition, SeekOrigin.Begin);
}
public void ReserveRelocatableConstant(Operand rt, Symbol symbol, ulong value)
{
if (!_constantPool.TryGetValue(value, out ConstantPoolEntry cpe))
{
cpe = new ConstantPoolEntry(_constantPool.Count * sizeof(ulong), symbol);
_constantPool.Add(value, cpe);
}
cpe.LdrOffsets.Add((rt, (int)_stream.Position));
_stream.Seek(LdrLitInstLength, SeekOrigin.Current);
}
private long WriteConstantPool()
{
if (_constantPoolWritten)
{
return _constantPoolOffset;
}
long constantPoolBaseOffset = _stream.Position;
foreach (ulong value in _constantPool.Keys)
{
WriteUInt64(value);
}
foreach (ConstantPoolEntry cpe in _constantPool.Values)
{
foreach ((Operand rt, int ldrOffset) in cpe.LdrOffsets)
{
_stream.Seek(ldrOffset, SeekOrigin.Begin);
int absoluteOffset = checked((int)(constantPoolBaseOffset + cpe.Offset));
int pcRelativeOffset = absoluteOffset - ldrOffset;
Assembler.LdrLit(rt, pcRelativeOffset);
}
}
_stream.Seek(constantPoolBaseOffset + _constantPool.Count * sizeof(ulong), SeekOrigin.Begin);
_constantPoolOffset = constantPoolBaseOffset;
_constantPoolWritten = true;
return constantPoolBaseOffset;
}
public (byte[], RelocInfo) GetCode()
{
long constantPoolBaseOffset = WriteConstantPool();
byte[] code = new byte[_stream.Length];
long originalPosition = _stream.Position;
_stream.Seek(0, SeekOrigin.Begin);
_stream.Read(code, 0, code.Length);
_stream.Seek(originalPosition, SeekOrigin.Begin);
RelocInfo relocInfo;
if (_relocatable)
{
RelocEntry[] relocs = new RelocEntry[_constantPool.Count];
int index = 0;
foreach (ConstantPoolEntry cpe in _constantPool.Values)
{
if (cpe.Symbol.Type != SymbolType.None)
{
int absoluteOffset = checked((int)(constantPoolBaseOffset + cpe.Offset));
relocs[index++] = new RelocEntry(absoluteOffset, cpe.Symbol);
}
}
if (index != relocs.Length)
{
Array.Resize(ref relocs, index);
}
relocInfo = new RelocInfo(relocs);
}
else
{
relocInfo = new RelocInfo(new RelocEntry[0]);
}
return (code, relocInfo);
}
private void WriteUInt64(ulong value)
{
_stream.WriteByte((byte)(value >> 0));
_stream.WriteByte((byte)(value >> 8));
_stream.WriteByte((byte)(value >> 16));
_stream.WriteByte((byte)(value >> 24));
_stream.WriteByte((byte)(value >> 32));
_stream.WriteByte((byte)(value >> 40));
_stream.WriteByte((byte)(value >> 48));
_stream.WriteByte((byte)(value >> 56));
}
}
}