About if conversion pass (simplifycfg)

Hi,

I’m trying to force if conversion on every if statement in my code (on the ir file), unsuccessfully for now.
I could only obtain some conversion by running -simplifycfg on my ir code, but some statement doesn’t get converted.

Can I force if-conversion on all statement? (how? or why not?)

my guess is that some conversion can be done only at a lower level with machine instruction, but I cannot see why that behavior could not be incorporated to the higher level representation of the code (ir). If my guess is correct, can you explain why?

Thank you