pseudo Instruction usage

Hi, I have an question which sounds pretty naive… (sorry, I just stepped into LLVM Backend first time)

I saw many backend source codes having Pseudo Instruction Type.

But I wonder what this Instruction type means

I feel confused with ‘pseudo code’ with algorithm terminology.

Could anyone make this clear what is different from those two concepts?

A “pseudo-instruction” in LLVM is a MachineInstr which doesn’t correspond to a specific assembly instruction. It’s a placeholder which will get converted to a real instruction or series of instructions by some later pass.