https://gcc.gnu.org/bugzilla/show_bug.cgi?id=32667
--- Comment #57 from Rich Felker <bugdal at aerifal dot cx> --- I think one could reasonably envision an implementation that does some sort of vector loads/stores where, due to some performance constraint or avoiding special casing for possible page boundary past the end of the copy, it only wants to load N bits at a time, but the efficient store instruction always stores a full vector of 2N bits. Of course, one could also argue quite reasonably that this is a weird enough thing to do that the implementation should then just check for src==dest and early-out. I'm far less concerned about whether such mechanical breakage exists, and more concerned about the consequences of LTO/whole-program-analysis where something in the translation process can see the violated restrict qualifier, infer UB, and blow everything up. The change being requested here is really one of removing the restrict qualification from the arguments and making a custom weaker condition. This may in turn have consequences on what types of transformations are possible.
