Loop unrolling is obviously a form of inlining. Perhaps OP is considering the case. "No backwards branches. For a long loop no branch back is clearly silly. Is

Loop unrolling is obviously a form of inlining. Perhaps OP is considering the case. "No backwards branches. For a long loop no branch back is clearly silly. Is unrolling and inlining part of it worthwhile? How does it help or hider readability, unnecessary operation identification, (eg repeated intialisation) and bug identification? Does it have a tension with execution time? These answers would likely be different in 2019. SIMD intrinsics anyone because compilers can't do it well at all. Function with a descriptive name that is called or just write it all right there probably with a comment right where the function call would have been and right where it would have returned..? We're talking low level optimisation or he wouldn't be having the discussion in terms of c++ etc. Duff is frequent touchstone is such a discussion although not mandatory by any means. (He said trying to get a little of such discussion going ;-)