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Ryujinx/ARMeilleure/CodeGen/X86/Assembler.cs
jhorv 5131b71437
Reducing memory allocations (#4537)
* add RecyclableMemoryStream dependency and MemoryStreamManager

* organize BinaryReader/BinaryWriter extensions

* add StreamExtensions to reduce need for BinaryWriter

* simple replacments of MemoryStream with RecyclableMemoryStream

* add write ReadOnlySequence<byte> support to IVirtualMemoryManager

* avoid 0-length array creation

* rework IpcMessage and related types to greatly reduce memory allocation by using RecylableMemoryStream, keeping streams around longer, avoiding their creation when possible, and avoiding creation of BinaryReader and BinaryWriter when possible

* reduce LINQ-induced memory allocations with custom methods to query KPriorityQueue

* use RecyclableMemoryStream in StreamUtils, and use StreamUtils in EmbeddedResources

* add constants for nanosecond/millisecond conversions

* code formatting

* XML doc adjustments

* fix: StreamExtension.WriteByte not writing non-zero values for lengths <= 16

* XML Doc improvements. Implement StreamExtensions.WriteByte() block writes for large-enough count values.

* add copyless path for StreamExtension.Write(ReadOnlySpan<int>)

* add default implementation of IVirtualMemoryManager.Write(ulong, ReadOnlySequence<byte>); remove previous explicit implementations

* code style fixes

* remove LINQ completely from KScheduler/KPriorityQueue by implementing a custom struct-based enumerator
2023-03-17 13:14:50 +01:00

1456 lines
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45 KiB
C#

using ARMeilleure.CodeGen.Linking;
using ARMeilleure.IntermediateRepresentation;
using Ryujinx.Common.Memory;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;
namespace ARMeilleure.CodeGen.X86
{
partial class Assembler
{
private const int ReservedBytesForJump = 1;
private const int OpModRMBits = 24;
private const byte RexPrefix = 0x40;
private const byte RexWPrefix = 0x48;
private const byte LockPrefix = 0xf0;
private const int MaxRegNumber = 15;
private struct Jump
{
public bool IsConditional { get; }
public X86Condition Condition { get; }
public Operand JumpLabel { get; }
public long? JumpTarget { get; set; }
public long JumpPosition { get; }
public long Offset { get; set; }
public int InstSize { get; set; }
public Jump(Operand jumpLabel, long jumpPosition)
{
IsConditional = false;
Condition = 0;
JumpLabel = jumpLabel;
JumpTarget = null;
JumpPosition = jumpPosition;
Offset = 0;
InstSize = 0;
}
public Jump(X86Condition condition, Operand jumpLabel, long jumpPosition)
{
IsConditional = true;
Condition = condition;
JumpLabel = jumpLabel;
JumpTarget = null;
JumpPosition = jumpPosition;
Offset = 0;
InstSize = 0;
}
}
private struct Reloc
{
public int JumpIndex { get; set; }
public int Position { get; set; }
public Symbol Symbol { get; set; }
}
private readonly List<Jump> _jumps;
private readonly List<Reloc> _relocs;
private readonly Dictionary<Operand, long> _labels;
private readonly Stream _stream;
public bool HasRelocs => _relocs != null;
public Assembler(Stream stream, bool relocatable)
{
_stream = stream;
_labels = new Dictionary<Operand, long>();
_jumps = new List<Jump>();
_relocs = relocatable ? new List<Reloc>() : null;
}
public void MarkLabel(Operand label)
{
_labels.Add(label, _stream.Position);
}
public void Add(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Add);
}
public void Addsd(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Addsd);
}
public void Addss(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Addss);
}
public void And(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.And);
}
public void Bsr(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Bsr);
}
public void Bswap(Operand dest)
{
WriteInstruction(dest, default, dest.Type, X86Instruction.Bswap);
}
public void Call(Operand dest)
{
WriteInstruction(dest, default, OperandType.None, X86Instruction.Call);
}
public void Cdq()
{
WriteByte(0x99);
}
public void Cmovcc(Operand dest, Operand source, OperandType type, X86Condition condition)
{
ref readonly InstructionInfo info = ref _instTable[(int)X86Instruction.Cmovcc];
WriteOpCode(dest, default, source, type, info.Flags, info.OpRRM | (int)condition, rrm: true);
}
public void Cmp(Operand src1, Operand src2, OperandType type)
{
WriteInstruction(src1, src2, type, X86Instruction.Cmp);
}
public void Cqo()
{
WriteByte(0x48);
WriteByte(0x99);
}
public void Cmpxchg(Operand memOp, Operand src)
{
Debug.Assert(memOp.Kind == OperandKind.Memory);
WriteByte(LockPrefix);
WriteInstruction(memOp, src, src.Type, X86Instruction.Cmpxchg);
}
public void Cmpxchg16(Operand memOp, Operand src)
{
Debug.Assert(memOp.Kind == OperandKind.Memory);
WriteByte(LockPrefix);
WriteByte(0x66);
WriteInstruction(memOp, src, src.Type, X86Instruction.Cmpxchg);
}
public void Cmpxchg16b(Operand memOp)
{
Debug.Assert(memOp.Kind == OperandKind.Memory);
WriteByte(LockPrefix);
WriteInstruction(memOp, default, OperandType.None, X86Instruction.Cmpxchg16b);
}
public void Cmpxchg8(Operand memOp, Operand src)
{
Debug.Assert(memOp.Kind == OperandKind.Memory);
WriteByte(LockPrefix);
WriteInstruction(memOp, src, src.Type, X86Instruction.Cmpxchg8);
}
public void Comisd(Operand src1, Operand src2)
{
WriteInstruction(src1, default, src2, X86Instruction.Comisd);
}
public void Comiss(Operand src1, Operand src2)
{
WriteInstruction(src1, default, src2, X86Instruction.Comiss);
}
public void Cvtsd2ss(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Cvtsd2ss);
}
public void Cvtsi2sd(Operand dest, Operand src1, Operand src2, OperandType type)
{
WriteInstruction(dest, src1, src2, X86Instruction.Cvtsi2sd, type);
}
public void Cvtsi2ss(Operand dest, Operand src1, Operand src2, OperandType type)
{
WriteInstruction(dest, src1, src2, X86Instruction.Cvtsi2ss, type);
}
public void Cvtss2sd(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Cvtss2sd);
}
public void Div(Operand source)
{
WriteInstruction(default, source, source.Type, X86Instruction.Div);
}
public void Divsd(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Divsd);
}
public void Divss(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Divss);
}
public void Idiv(Operand source)
{
WriteInstruction(default, source, source.Type, X86Instruction.Idiv);
}
public void Imul(Operand source)
{
WriteInstruction(default, source, source.Type, X86Instruction.Imul128);
}
public void Imul(Operand dest, Operand source, OperandType type)
{
if (source.Kind != OperandKind.Register)
{
throw new ArgumentException($"Invalid source operand kind \"{source.Kind}\".");
}
WriteInstruction(dest, source, type, X86Instruction.Imul);
}
public void Imul(Operand dest, Operand src1, Operand src2, OperandType type)
{
ref readonly InstructionInfo info = ref _instTable[(int)X86Instruction.Imul];
if (src2.Kind != OperandKind.Constant)
{
throw new ArgumentException($"Invalid source 2 operand kind \"{src2.Kind}\".");
}
if (IsImm8(src2.Value, src2.Type) && info.OpRMImm8 != BadOp)
{
WriteOpCode(dest, default, src1, type, info.Flags, info.OpRMImm8, rrm: true);
WriteByte(src2.AsByte());
}
else if (IsImm32(src2.Value, src2.Type) && info.OpRMImm32 != BadOp)
{
WriteOpCode(dest, default, src1, type, info.Flags, info.OpRMImm32, rrm: true);
WriteInt32(src2.AsInt32());
}
else
{
throw new ArgumentException($"Failed to encode constant 0x{src2.Value:X}.");
}
}
public void Insertps(Operand dest, Operand src1, Operand src2, byte imm)
{
WriteInstruction(dest, src1, src2, X86Instruction.Insertps);
WriteByte(imm);
}
public void Jcc(X86Condition condition, Operand dest)
{
if (dest.Kind == OperandKind.Label)
{
_jumps.Add(new Jump(condition, dest, _stream.Position));
// ReservedBytesForJump
WriteByte(0);
}
else
{
throw new ArgumentException("Destination operand must be of kind Label", nameof(dest));
}
}
public void Jcc(X86Condition condition, long offset)
{
if (ConstFitsOnS8(offset))
{
WriteByte((byte)(0x70 | (int)condition));
WriteByte((byte)offset);
}
else if (ConstFitsOnS32(offset))
{
WriteByte(0x0f);
WriteByte((byte)(0x80 | (int)condition));
WriteInt32((int)offset);
}
else
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
}
public void Jmp(long offset)
{
if (ConstFitsOnS8(offset))
{
WriteByte(0xeb);
WriteByte((byte)offset);
}
else if (ConstFitsOnS32(offset))
{
WriteByte(0xe9);
WriteInt32((int)offset);
}
else
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
}
public void Jmp(Operand dest)
{
if (dest.Kind == OperandKind.Label)
{
_jumps.Add(new Jump(dest, _stream.Position));
// ReservedBytesForJump
WriteByte(0);
}
else
{
WriteInstruction(dest, default, OperandType.None, X86Instruction.Jmp);
}
}
public void Ldmxcsr(Operand dest)
{
WriteInstruction(dest, default, OperandType.I32, X86Instruction.Ldmxcsr);
}
public void Lea(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Lea);
}
public void LockOr(Operand dest, Operand source, OperandType type)
{
WriteByte(LockPrefix);
WriteInstruction(dest, source, type, X86Instruction.Or);
}
public void Mov(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Mov);
}
public void Mov16(Operand dest, Operand source)
{
WriteInstruction(dest, source, OperandType.None, X86Instruction.Mov16);
}
public void Mov8(Operand dest, Operand source)
{
WriteInstruction(dest, source, OperandType.None, X86Instruction.Mov8);
}
public void Movd(Operand dest, Operand source)
{
ref readonly InstructionInfo info = ref _instTable[(int)X86Instruction.Movd];
if (source.Type.IsInteger() || source.Kind == OperandKind.Memory)
{
WriteOpCode(dest, default, source, OperandType.None, info.Flags, info.OpRRM, rrm: true);
}
else
{
WriteOpCode(dest, default, source, OperandType.None, info.Flags, info.OpRMR);
}
}
public void Movdqu(Operand dest, Operand source)
{
WriteInstruction(dest, default, source, X86Instruction.Movdqu);
}
public void Movhlps(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Movhlps);
}
public void Movlhps(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Movlhps);
}
public void Movq(Operand dest, Operand source)
{
ref readonly InstructionInfo info = ref _instTable[(int)X86Instruction.Movd];
InstructionFlags flags = info.Flags | InstructionFlags.RexW;
if (source.Type.IsInteger() || source.Kind == OperandKind.Memory)
{
WriteOpCode(dest, default, source, OperandType.None, flags, info.OpRRM, rrm: true);
}
else if (dest.Type.IsInteger() || dest.Kind == OperandKind.Memory)
{
WriteOpCode(dest, default, source, OperandType.None, flags, info.OpRMR);
}
else
{
WriteInstruction(dest, source, OperandType.None, X86Instruction.Movq);
}
}
public void Movsd(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Movsd);
}
public void Movss(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Movss);
}
public void Movsx16(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Movsx16);
}
public void Movsx32(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Movsx32);
}
public void Movsx8(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Movsx8);
}
public void Movzx16(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Movzx16);
}
public void Movzx8(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Movzx8);
}
public void Mul(Operand source)
{
WriteInstruction(default, source, source.Type, X86Instruction.Mul128);
}
public void Mulsd(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Mulsd);
}
public void Mulss(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Mulss);
}
public void Neg(Operand dest)
{
WriteInstruction(dest, default, dest.Type, X86Instruction.Neg);
}
public void Not(Operand dest)
{
WriteInstruction(dest, default, dest.Type, X86Instruction.Not);
}
public void Or(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Or);
}
public void Pclmulqdq(Operand dest, Operand source, byte imm)
{
WriteInstruction(dest, default, source, X86Instruction.Pclmulqdq);
WriteByte(imm);
}
public void Pcmpeqw(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Pcmpeqw);
}
public void Pextrb(Operand dest, Operand source, byte imm)
{
WriteInstruction(dest, default, source, X86Instruction.Pextrb);
WriteByte(imm);
}
public void Pextrd(Operand dest, Operand source, byte imm)
{
WriteInstruction(dest, default, source, X86Instruction.Pextrd);
WriteByte(imm);
}
public void Pextrq(Operand dest, Operand source, byte imm)
{
WriteInstruction(dest, default, source, X86Instruction.Pextrq);
WriteByte(imm);
}
public void Pextrw(Operand dest, Operand source, byte imm)
{
WriteInstruction(dest, default, source, X86Instruction.Pextrw);
WriteByte(imm);
}
public void Pinsrb(Operand dest, Operand src1, Operand src2, byte imm)
{
WriteInstruction(dest, src1, src2, X86Instruction.Pinsrb);
WriteByte(imm);
}
public void Pinsrd(Operand dest, Operand src1, Operand src2, byte imm)
{
WriteInstruction(dest, src1, src2, X86Instruction.Pinsrd);
WriteByte(imm);
}
public void Pinsrq(Operand dest, Operand src1, Operand src2, byte imm)
{
WriteInstruction(dest, src1, src2, X86Instruction.Pinsrq);
WriteByte(imm);
}
public void Pinsrw(Operand dest, Operand src1, Operand src2, byte imm)
{
WriteInstruction(dest, src1, src2, X86Instruction.Pinsrw);
WriteByte(imm);
}
public void Pop(Operand dest)
{
if (dest.Kind == OperandKind.Register)
{
WriteCompactInst(dest, 0x58);
}
else
{
WriteInstruction(dest, default, dest.Type, X86Instruction.Pop);
}
}
public void Popcnt(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Popcnt);
}
public void Pshufd(Operand dest, Operand source, byte imm)
{
WriteInstruction(dest, default, source, X86Instruction.Pshufd);
WriteByte(imm);
}
public void Push(Operand source)
{
if (source.Kind == OperandKind.Register)
{
WriteCompactInst(source, 0x50);
}
else
{
WriteInstruction(default, source, source.Type, X86Instruction.Push);
}
}
public void Return()
{
WriteByte(0xc3);
}
public void Ror(Operand dest, Operand source, OperandType type)
{
WriteShiftInst(dest, source, type, X86Instruction.Ror);
}
public void Sar(Operand dest, Operand source, OperandType type)
{
WriteShiftInst(dest, source, type, X86Instruction.Sar);
}
public void Shl(Operand dest, Operand source, OperandType type)
{
WriteShiftInst(dest, source, type, X86Instruction.Shl);
}
public void Shr(Operand dest, Operand source, OperandType type)
{
WriteShiftInst(dest, source, type, X86Instruction.Shr);
}
public void Setcc(Operand dest, X86Condition condition)
{
ref readonly InstructionInfo info = ref _instTable[(int)X86Instruction.Setcc];
WriteOpCode(dest, default, default, OperandType.None, info.Flags, info.OpRRM | (int)condition);
}
public void Stmxcsr(Operand dest)
{
WriteInstruction(dest, default, OperandType.I32, X86Instruction.Stmxcsr);
}
public void Sub(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Sub);
}
public void Subsd(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Subsd);
}
public void Subss(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Subss);
}
public void Test(Operand src1, Operand src2, OperandType type)
{
WriteInstruction(src1, src2, type, X86Instruction.Test);
}
public void Xor(Operand dest, Operand source, OperandType type)
{
WriteInstruction(dest, source, type, X86Instruction.Xor);
}
public void Xorps(Operand dest, Operand src1, Operand src2)
{
WriteInstruction(dest, src1, src2, X86Instruction.Xorps);
}
public void WriteInstruction(
X86Instruction inst,
Operand dest,
Operand source,
OperandType type = OperandType.None)
{
WriteInstruction(dest, default, source, inst, type);
}
public void WriteInstruction(X86Instruction inst, Operand dest, Operand src1, Operand src2)
{
if (src2.Kind == OperandKind.Constant)
{
WriteInstruction(src1, dest, src2, inst);
}
else
{
WriteInstruction(dest, src1, src2, inst);
}
}
public void WriteInstruction(
X86Instruction inst,
Operand dest,
Operand src1,
Operand src2,
OperandType type)
{
WriteInstruction(dest, src1, src2, inst, type);
}
public void WriteInstruction(X86Instruction inst, Operand dest, Operand source, byte imm)
{
WriteInstruction(dest, default, source, inst);
WriteByte(imm);
}
public void WriteInstruction(
X86Instruction inst,
Operand dest,
Operand src1,
Operand src2,
Operand src3)
{
// 3+ operands can only be encoded with the VEX encoding scheme.
Debug.Assert(HardwareCapabilities.SupportsVexEncoding);
WriteInstruction(dest, src1, src2, inst);
WriteByte((byte)(src3.AsByte() << 4));
}
public void WriteInstruction(
X86Instruction inst,
Operand dest,
Operand src1,
Operand src2,
byte imm)
{
WriteInstruction(dest, src1, src2, inst);
WriteByte(imm);
}
private void WriteShiftInst(Operand dest, Operand source, OperandType type, X86Instruction inst)
{
if (source.Kind == OperandKind.Register)
{
X86Register shiftReg = (X86Register)source.GetRegister().Index;
Debug.Assert(shiftReg == X86Register.Rcx, $"Invalid shift register \"{shiftReg}\".");
source = default;
}
else if (source.Kind == OperandKind.Constant)
{
source = Operand.Factory.Const((int)source.Value & (dest.Type == OperandType.I32 ? 0x1f : 0x3f));
}
WriteInstruction(dest, source, type, inst);
}
private void WriteInstruction(Operand dest, Operand source, OperandType type, X86Instruction inst)
{
ref readonly InstructionInfo info = ref _instTable[(int)inst];
if (source != default)
{
if (source.Kind == OperandKind.Constant)
{
ulong imm = source.Value;
if (inst == X86Instruction.Mov8)
{
WriteOpCode(dest, default, default, type, info.Flags, info.OpRMImm8);
WriteByte((byte)imm);
}
else if (inst == X86Instruction.Mov16)
{
WriteOpCode(dest, default, default, type, info.Flags, info.OpRMImm32);
WriteInt16((short)imm);
}
else if (IsImm8(imm, type) && info.OpRMImm8 != BadOp)
{
WriteOpCode(dest, default, default, type, info.Flags, info.OpRMImm8);
WriteByte((byte)imm);
}
else if (!source.Relocatable && IsImm32(imm, type) && info.OpRMImm32 != BadOp)
{
WriteOpCode(dest, default, default, type, info.Flags, info.OpRMImm32);
WriteInt32((int)imm);
}
else if (dest != default && dest.Kind == OperandKind.Register && info.OpRImm64 != BadOp)
{
int rexPrefix = GetRexPrefix(dest, source, type, rrm: false);
if (rexPrefix != 0)
{
WriteByte((byte)rexPrefix);
}
WriteByte((byte)(info.OpRImm64 + (dest.GetRegister().Index & 0b111)));
if (HasRelocs && source.Relocatable)
{
_relocs.Add(new Reloc
{
JumpIndex = _jumps.Count - 1,
Position = (int)_stream.Position,
Symbol = source.Symbol
});
}
WriteUInt64(imm);
}
else
{
throw new ArgumentException($"Failed to encode constant 0x{imm:X}.");
}
}
else if (source.Kind == OperandKind.Register && info.OpRMR != BadOp)
{
WriteOpCode(dest, default, source, type, info.Flags, info.OpRMR);
}
else if (info.OpRRM != BadOp)
{
WriteOpCode(dest, default, source, type, info.Flags, info.OpRRM, rrm: true);
}
else
{
throw new ArgumentException($"Invalid source operand kind \"{source.Kind}\".");
}
}
else if (info.OpRRM != BadOp)
{
WriteOpCode(dest, default, source, type, info.Flags, info.OpRRM, rrm: true);
}
else if (info.OpRMR != BadOp)
{
WriteOpCode(dest, default, source, type, info.Flags, info.OpRMR);
}
else
{
throw new ArgumentNullException(nameof(source));
}
}
private void WriteInstruction(
Operand dest,
Operand src1,
Operand src2,
X86Instruction inst,
OperandType type = OperandType.None)
{
ref readonly InstructionInfo info = ref _instTable[(int)inst];
if (src2 != default)
{
if (src2.Kind == OperandKind.Constant)
{
ulong imm = src2.Value;
if ((byte)imm == imm && info.OpRMImm8 != BadOp)
{
WriteOpCode(dest, src1, default, type, info.Flags, info.OpRMImm8);
WriteByte((byte)imm);
}
else
{
throw new ArgumentException($"Failed to encode constant 0x{imm:X}.");
}
}
else if (src2.Kind == OperandKind.Register && info.OpRMR != BadOp)
{
WriteOpCode(dest, src1, src2, type, info.Flags, info.OpRMR);
}
else if (info.OpRRM != BadOp)
{
WriteOpCode(dest, src1, src2, type, info.Flags, info.OpRRM, rrm: true);
}
else
{
throw new ArgumentException($"Invalid source operand kind \"{src2.Kind}\".");
}
}
else if (info.OpRRM != BadOp)
{
WriteOpCode(dest, src1, src2, type, info.Flags, info.OpRRM, rrm: true);
}
else if (info.OpRMR != BadOp)
{
WriteOpCode(dest, src1, src2, type, info.Flags, info.OpRMR);
}
else
{
throw new ArgumentNullException(nameof(src2));
}
}
private void WriteOpCode(
Operand dest,
Operand src1,
Operand src2,
OperandType type,
InstructionFlags flags,
int opCode,
bool rrm = false)
{
int rexPrefix = GetRexPrefix(dest, src2, type, rrm);
if ((flags & InstructionFlags.RexW) != 0)
{
rexPrefix |= RexWPrefix;
}
int modRM = (opCode >> OpModRMBits) << 3;
MemoryOperand memOp = default;
bool hasMemOp = false;
if (dest != default)
{
if (dest.Kind == OperandKind.Register)
{
int regIndex = dest.GetRegister().Index;
modRM |= (regIndex & 0b111) << (rrm ? 3 : 0);
if ((flags & InstructionFlags.Reg8Dest) != 0 && regIndex >= 4)
{
rexPrefix |= RexPrefix;
}
}
else if (dest.Kind == OperandKind.Memory)
{
memOp = dest.GetMemory();
hasMemOp = true;
}
else
{
throw new ArgumentException("Invalid destination operand kind \"" + dest.Kind + "\".");
}
}
if (src2 != default)
{
if (src2.Kind == OperandKind.Register)
{
int regIndex = src2.GetRegister().Index;
modRM |= (regIndex & 0b111) << (rrm ? 0 : 3);
if ((flags & InstructionFlags.Reg8Src) != 0 && regIndex >= 4)
{
rexPrefix |= RexPrefix;
}
}
else if (src2.Kind == OperandKind.Memory && !hasMemOp)
{
memOp = src2.GetMemory();
hasMemOp = true;
}
else
{
throw new ArgumentException("Invalid source operand kind \"" + src2.Kind + "\".");
}
}
bool needsSibByte = false;
bool needsDisplacement = false;
int sib = 0;
if (hasMemOp)
{
// Either source or destination is a memory operand.
Register baseReg = memOp.BaseAddress.GetRegister();
X86Register baseRegLow = (X86Register)(baseReg.Index & 0b111);
needsSibByte = memOp.Index != default || baseRegLow == X86Register.Rsp;
needsDisplacement = memOp.Displacement != 0 || baseRegLow == X86Register.Rbp;
if (needsDisplacement)
{
if (ConstFitsOnS8(memOp.Displacement))
{
modRM |= 0x40;
}
else /* if (ConstFitsOnS32(memOp.Displacement)) */
{
modRM |= 0x80;
}
}
if (baseReg.Index >= 8)
{
Debug.Assert((uint)baseReg.Index <= MaxRegNumber);
rexPrefix |= RexPrefix | (baseReg.Index >> 3);
}
if (needsSibByte)
{
sib = (int)baseRegLow;
if (memOp.Index != default)
{
int indexReg = memOp.Index.GetRegister().Index;
Debug.Assert(indexReg != (int)X86Register.Rsp, "Using RSP as index register on the memory operand is not allowed.");
if (indexReg >= 8)
{
Debug.Assert((uint)indexReg <= MaxRegNumber);
rexPrefix |= RexPrefix | (indexReg >> 3) << 1;
}
sib |= (indexReg & 0b111) << 3;
}
else
{
sib |= 0b100 << 3;
}
sib |= (int)memOp.Scale << 6;
modRM |= 0b100;
}
else
{
modRM |= (int)baseRegLow;
}
}
else
{
// Source and destination are registers.
modRM |= 0xc0;
}
Debug.Assert(opCode != BadOp, "Invalid opcode value.");
if ((flags & InstructionFlags.Vex) != 0 && HardwareCapabilities.SupportsVexEncoding)
{
// In a vex encoding, only one prefix can be active at a time. The active prefix is encoded in the second byte using two bits.
int vexByte2 = (flags & InstructionFlags.PrefixMask) switch
{
InstructionFlags.Prefix66 => 1,
InstructionFlags.PrefixF3 => 2,
InstructionFlags.PrefixF2 => 3,
_ => 0
};
if (src1 != default)
{
vexByte2 |= (src1.GetRegister().Index ^ 0xf) << 3;
}
else
{
vexByte2 |= 0b1111 << 3;
}
ushort opCodeHigh = (ushort)(opCode >> 8);
if ((rexPrefix & 0b1011) == 0 && opCodeHigh == 0xf)
{
// Two-byte form.
WriteByte(0xc5);
vexByte2 |= (~rexPrefix & 4) << 5;
WriteByte((byte)vexByte2);
}
else
{
// Three-byte form.
WriteByte(0xc4);
int vexByte1 = (~rexPrefix & 7) << 5;
switch (opCodeHigh)
{
case 0xf: vexByte1 |= 1; break;
case 0xf38: vexByte1 |= 2; break;
case 0xf3a: vexByte1 |= 3; break;
default: Debug.Assert(false, $"Failed to VEX encode opcode 0x{opCode:X}."); break;
}
vexByte2 |= (rexPrefix & 8) << 4;
WriteByte((byte)vexByte1);
WriteByte((byte)vexByte2);
}
opCode &= 0xff;
}
else
{
if (flags.HasFlag(InstructionFlags.Prefix66))
{
WriteByte(0x66);
}
if (flags.HasFlag(InstructionFlags.PrefixF2))
{
WriteByte(0xf2);
}
if (flags.HasFlag(InstructionFlags.PrefixF3))
{
WriteByte(0xf3);
}
if (rexPrefix != 0)
{
WriteByte((byte)rexPrefix);
}
}
if (dest != default && (flags & InstructionFlags.RegOnly) != 0)
{
opCode += dest.GetRegister().Index & 7;
}
if ((opCode & 0xff0000) != 0)
{
WriteByte((byte)(opCode >> 16));
}
if ((opCode & 0xff00) != 0)
{
WriteByte((byte)(opCode >> 8));
}
WriteByte((byte)opCode);
if ((flags & InstructionFlags.RegOnly) == 0)
{
WriteByte((byte)modRM);
if (needsSibByte)
{
WriteByte((byte)sib);
}
if (needsDisplacement)
{
if (ConstFitsOnS8(memOp.Displacement))
{
WriteByte((byte)memOp.Displacement);
}
else /* if (ConstFitsOnS32(memOp.Displacement)) */
{
WriteInt32(memOp.Displacement);
}
}
}
}
private void WriteCompactInst(Operand operand, int opCode)
{
int regIndex = operand.GetRegister().Index;
if (regIndex >= 8)
{
WriteByte(0x41);
}
WriteByte((byte)(opCode + (regIndex & 0b111)));
}
private static int GetRexPrefix(Operand dest, Operand source, OperandType type, bool rrm)
{
int rexPrefix = 0;
if (Is64Bits(type))
{
rexPrefix = RexWPrefix;
}
void SetRegisterHighBit(Register reg, int bit)
{
if (reg.Index >= 8)
{
rexPrefix |= RexPrefix | (reg.Index >> 3) << bit;
}
}
if (dest != default && dest.Kind == OperandKind.Register)
{
SetRegisterHighBit(dest.GetRegister(), rrm ? 2 : 0);
}
if (source != default && source.Kind == OperandKind.Register)
{
SetRegisterHighBit(source.GetRegister(), rrm ? 0 : 2);
}
return rexPrefix;
}
public (byte[], RelocInfo) GetCode()
{
var jumps = CollectionsMarshal.AsSpan(_jumps);
var relocs = CollectionsMarshal.AsSpan(_relocs);
// Write jump relative offsets.
bool modified;
do
{
modified = false;
for (int i = 0; i < jumps.Length; i++)
{
ref Jump jump = ref jumps[i];
// If jump target not resolved yet, resolve it.
if (jump.JumpTarget == null)
{
jump.JumpTarget = _labels[jump.JumpLabel];
}
long jumpTarget = jump.JumpTarget.Value;
long offset = jumpTarget - jump.JumpPosition;
if (offset < 0)
{
for (int j = i - 1; j >= 0; j--)
{
ref Jump jump2 = ref jumps[j];
if (jump2.JumpPosition < jumpTarget)
{
break;
}
offset -= jump2.InstSize - ReservedBytesForJump;
}
}
else
{
for (int j = i + 1; j < jumps.Length; j++)
{
ref Jump jump2 = ref jumps[j];
if (jump2.JumpPosition >= jumpTarget)
{
break;
}
offset += jump2.InstSize - ReservedBytesForJump;
}
offset -= ReservedBytesForJump;
}
if (jump.IsConditional)
{
jump.InstSize = GetJccLength(offset);
}
else
{
jump.InstSize = GetJmpLength(offset);
}
// The jump is relative to the next instruction, not the current one.
// Since we didn't know the next instruction address when calculating
// the offset (as the size of the current jump instruction was not known),
// we now need to compensate the offset with the jump instruction size.
// It's also worth noting that:
// - This is only needed for backward jumps.
// - The GetJmpLength and GetJccLength also compensates the offset
// internally when computing the jump instruction size.
if (offset < 0)
{
offset -= jump.InstSize;
}
if (jump.Offset != offset)
{
jump.Offset = offset;
modified = true;
}
}
}
while (modified);
// Write the code, ignoring the dummy bytes after jumps, into a new stream.
_stream.Seek(0, SeekOrigin.Begin);
using var codeStream = MemoryStreamManager.Shared.GetStream();
var assembler = new Assembler(codeStream, HasRelocs);
bool hasRelocs = HasRelocs;
int relocIndex = 0;
int relocOffset = 0;
var relocEntries = hasRelocs
? new RelocEntry[relocs.Length]
: Array.Empty<RelocEntry>();
for (int i = 0; i < jumps.Length; i++)
{
ref Jump jump = ref jumps[i];
// If has relocations, calculate their new positions compensating for jumps.
if (hasRelocs)
{
relocOffset += jump.InstSize - ReservedBytesForJump;
for (; relocIndex < relocEntries.Length; relocIndex++)
{
ref Reloc reloc = ref relocs[relocIndex];
if (reloc.JumpIndex > i)
{
break;
}
relocEntries[relocIndex] = new RelocEntry(reloc.Position + relocOffset, reloc.Symbol);
}
}
Span<byte> buffer = new byte[jump.JumpPosition - _stream.Position];
_stream.Read(buffer);
_stream.Seek(ReservedBytesForJump, SeekOrigin.Current);
codeStream.Write(buffer);
if (jump.IsConditional)
{
assembler.Jcc(jump.Condition, jump.Offset);
}
else
{
assembler.Jmp(jump.Offset);
}
}
// Write remaining relocations. This case happens when there are no jumps assembled.
for (; relocIndex < relocEntries.Length; relocIndex++)
{
ref Reloc reloc = ref relocs[relocIndex];
relocEntries[relocIndex] = new RelocEntry(reloc.Position + relocOffset, reloc.Symbol);
}
_stream.CopyTo(codeStream);
var code = codeStream.ToArray();
var relocInfo = new RelocInfo(relocEntries);
return (code, relocInfo);
}
private static bool Is64Bits(OperandType type)
{
return type == OperandType.I64 || type == OperandType.FP64;
}
private static bool IsImm8(ulong immediate, OperandType type)
{
long value = type == OperandType.I32 ? (int)immediate : (long)immediate;
return ConstFitsOnS8(value);
}
private static bool IsImm32(ulong immediate, OperandType type)
{
long value = type == OperandType.I32 ? (int)immediate : (long)immediate;
return ConstFitsOnS32(value);
}
private static int GetJccLength(long offset)
{
if (ConstFitsOnS8(offset < 0 ? offset - 2 : offset))
{
return 2;
}
else if (ConstFitsOnS32(offset < 0 ? offset - 6 : offset))
{
return 6;
}
else
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
}
private static int GetJmpLength(long offset)
{
if (ConstFitsOnS8(offset < 0 ? offset - 2 : offset))
{
return 2;
}
else if (ConstFitsOnS32(offset < 0 ? offset - 5 : offset))
{
return 5;
}
else
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
}
private static bool ConstFitsOnS8(long value)
{
return value == (sbyte)value;
}
private static bool ConstFitsOnS32(long value)
{
return value == (int)value;
}
private void WriteInt16(short value)
{
WriteUInt16((ushort)value);
}
private void WriteInt32(int value)
{
WriteUInt32((uint)value);
}
private void WriteByte(byte value)
{
_stream.WriteByte(value);
}
private void WriteUInt16(ushort value)
{
_stream.WriteByte((byte)(value >> 0));
_stream.WriteByte((byte)(value >> 8));
}
private void WriteUInt32(uint value)
{
_stream.WriteByte((byte)(value >> 0));
_stream.WriteByte((byte)(value >> 8));
_stream.WriteByte((byte)(value >> 16));
_stream.WriteByte((byte)(value >> 24));
}
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));
}
}
}