public Encoding(ModRM modRM, Sib? sib = null, int displacement = 0)
{
this.Segment = null;
this.AddressSizeOverride = false;
this.BaseRegExtension = false;
this.IndexRegExtension = false;
this.ModRM = modRM;
this.Sib = sib;
this.Displacement = displacement;
}
public Encoding(ImmutableLegacyPrefixList legacyPrefixes, Xex xex,
ModRM modRM, Sib? sib = null, int displacement = 0)
{
this.Segment = legacyPrefixes.SegmentOverride;
this.AddressSizeOverride = legacyPrefixes.HasAddressSizeOverride;
this.BaseRegExtension = xex.BaseRegExtension;
this.IndexRegExtension = xex.IndexRegExtension;
this.ModRM = modRM;
this.Sib = sib;
this.Displacement = displacement;
}
private readonly ulong immediate; // 8 bytes
#endregion
#region Constructors
private Instruction(Builder builder)
{
legacyPrefixes = builder.LegacyPrefixes;
xex = builder.Xex; // Validate if redundant with prefixes
mainByte = builder.OpcodeByte;
modRM = builder.ModRM.GetValueOrDefault();
sib = builder.Sib.GetValueOrDefault(); // Validate if necessary
displacement = builder.Displacement; // Validate with mod/sib
immediate = builder.Immediate; // Truncate to size
flags = 0;
flags |= (Flags)((int)builder.DefaultAddressSize << (int)Flags.DefaultAddressSize_Shift);
if (builder.ModRM.HasValue) flags |= Flags.HasModRM;
flags |= (Flags)(builder.ImmediateSizeInBytes << (int)Flags.ImmediateSizeInBytes_Shift);
}
public static DisplacementSize GetDisplacementSize(this ModRM modRM, Sib sib, AddressSize addressSize)
{
switch (modRM & ModRM.Mod_Mask)
{
case ModRM.Mod_IndirectDisplacement8:
return DisplacementSize._8;
case ModRM.Mod_IndirectLongDisplacement:
return addressSize == AddressSize._16 ? DisplacementSize._16 : DisplacementSize._32;
case ModRM.Mod_Direct: return 0;
}
// Mod = 0
if (addressSize == AddressSize._16)
return GetRM(modRM) == 6 ? DisplacementSize._16 : DisplacementSize._0;
if (GetRM(modRM) == 5) return DisplacementSize._32;
// 32-bit mode, mod = 0, RM = 6 (sib byte)
return (sib & Sib.Base_Mask) == Sib.Base_Special ? DisplacementSize._32 : DisplacementSize._0;
}
private void Write(Sib sib) => Write((byte)sib);
