Custom Instructions

[Ian Lance Taylor]

Nick <nikos_ikono1989@yahoo.gr> writes:

> the problem starts at the basics: no matter how much i've looked in the
> interwebs, i still don't understand i386-opc.tbl. for example, i don't know what
> the parts of this line mean: "mov, 2, 0xc6, 0x0, 1, 0, W|Modrm|No_sSuf|No_ldSuf,
>
> { Imm8|Imm16|Imm32|Imm32S,
> Reg8|Reg16|Reg32|Reg64|Byte|Word|Dword|Qword|Unspecified|BaseIndex|Disp8|Disp16|
>
> Disp32|Disp32S
> }". ok, "mov" is the mnemonic, "2" is (guess) the number of operands, in
> brackets the type of operands accepted (not all of them clear), but what about
> the two hexadecimal values, the "1" and "0"(if not "0" then something like
> "Cpu386", "Cpu64"), "No_*Suf"?

See struct insn_template in opcodes/i386-opc.h.

> one further question would be, do i have to change other files as well (e.g.
> i386-opc.h, i386-init.h etc)?

It sort of depends on what you want to do, but probably not.

Ian