http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56719
--- Comment #5 from felix-gcc at fefe dot de 2013-03-25 15:06:02 UTC --- Yes. However I'd hope that fixing this case would mean that gcc also catches the case where it is split to multiple if statements. I think this statement came about because they had a range check and someone pointed out that checking foo*4>0xffff could be circumvented via an integer overflow if foo is untrusted and very large. There are smarter ways to do this but it's not completely mind-bogglingly incomprehensible why this code would come about. I have in fact been advocating for a while that programmers should rather spell out their security checks as plainly as possible and let the compiler optimize them and remove superfluous checks. See http://www.fefe.de/source-code-optimization.pdf if you are interested.
