On Mar 2, 2012, at 1:28 PM, Eli Friedman wrote: >>> I don't think this is really safe; strictly speaking, yes, an int* is >>> required to be appropriately aligned, but in practice neither clang >>> nor gcc has ever tried to enforce that, so making that assumption is >>> going to cause trouble. >> >> Hi Eli, >> >> Is this a vague concern or a specific one? Even GCC-4.2 has been doing this >> optimization. I consider this "fixing a regression compared to GCC", not an >> innovation in optimization. > > I can't point to a specific example off the top of my head, but I do > know that we've suggested switching code that uses unaligned loads to > use memcpy without specifically noting that the type of the pointer > matters.
I agree that there was more fallout from that change than was expected, but that was a case where we were being more aggressive than GCC. There certainly may be some fallout from this change, but I still think it's the right thing to do, and seems less likely to cause a problem than that change. -Chris _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
