On 17/01/2017 15:05, Andrew Haley wrote: > On 17/01/17 12:11, Mason wrote: > >> Jeffrey's link to Ian's blog seems to clear some of the confusion. >> http://www.airs.com/blog/archives/120 > > Well, yeah, but clearly that blog is wrong: > >> There is a clear difference on a processor which does not use >> ordinary twos-complement arithmetic: -fwrapv requires >> twos-complement overflow, and -fno-strict-overflow does >> not. However, no such processor is in common use today. In practice, >> I think that the code generated by the two options will always >> behave the same. Perhaps that statement was true in 2007 (when gcc 4.2 was released) and the behavior was subsequently changed by some new optimization? Regards.
