I am going through the lib/Target/X86/X86InstrArithmetic.td file where there is a definition for a multiclass as follows
multiclass ArithBinOp_F<bits<8> BaseOpc, bits<8> BaseOpc2, bits<8> BaseOpc4,
string mnemonic, Format RegMRM, Format MemMRM,
bit CommutableRR, bit ConvertibleToThreeAddress>
This for arithmetic operators like ADD,XOR,AND etc.
Can anyone throw some light on the three different opcodes used namely BaseOpc , BasecOp2, BaseOpc4 ?
Also, I am looking for some free opcodes to assign to new instructions, If someone could guide on this then It would be great?