Is there a way to identify and remove fast option from a call Instruction?

Hi I would like to detect If a call Instruction has fast option enabled and then disable it, I digged into llvm-project/llvm/include/llvm/IR/FMF.h and Found that isFast() and setFast() could be useful for my purpose, however I’m not sure If they mean do what I expect them to do, by reading the comments its not very clear. My objective is to remove the fast option from a call inst.

%call3 = call fast fastcc noundef <8 x float> @ZL13_mm256_mul_psDv8_fS(<8 x float> noundef %0, <8 x float> noundef %power.0)

I would like to make this simple transformation, also as a follow-up what analyses if any? on these flags be invalidated once such a transformation is made. I’m sorry if any of this sounds foolish don’t mind me, I’m only a beginner!