On Wed, Aug 22, 2018 at 07:14:42AM -0400, Derrick Stolee wrote: > The other thing I was going to recommend (and I'll try to test this out > myself later) is to see if 'the_hash_algo->rawsz' is being treated as a > volatile variable, since it is being referenced through a pointer. Perhaps > storing the value locally and then casing on it would help? I tried various sprinkling of "const" around the declarations to make it clear that the values wouldn't change once we saw them. But I couldn't detect any difference. At most I think that would let us hoist the "if" out of the loop, but gcc still seems unwilling to expand the memcmp when there are other branches. I think if that's the thing we want to have happen, we really do need to just write it out on that branch rather than saying "memcmp". -Peff