On 24 February 2015 at 18:39, Markus Armbruster <arm...@redhat.com> wrote: > Eric Blake <ebl...@redhat.com> writes: >> Because 0x8000000000000000u is only required to be a 'long', and on >> 32-bit machines, your constant would overflow long. See, for example, >> commit 5cb6be2ca. You NEED the 'll' suffix to ensure that the compiler >> doesn't reject the constant as an overflow. > > Not true.
You need ULL because certain versions of gcc will warn if you do not. (I have a feeling this includes the elderly gcc I currently use for mingw builds.) You could argue that this is a gcc bug, and somebody probably did given that newer gcc don't warn about this. However we should always use ULL (or LL) for 64-bit constants, to avoid confusing those versions of gcc. thanks -- PMM
