On Aug 12, 2012, at 1:57 AM, Vincent Habchi <vi...@macports.org> wrote:
> That’s from the hardware side. Unfortunately, since most people gave up > programming in assembly (what a loss! ;)) in favor of C, its derivatives, or > other various high level languages, there was a need to nail down the width > of various data type. So we ended up with a 'int' 32-bit wide, which was the > most reasonable choice at the time the C was normalized because processors > had 32-bit data and address registers, and as a side benefit, we could bet > that sizeof (int) = sizeof (void *). When these moved to 64-bit, C 'int' > should have followed, since both data and address registers were doubled, but > it was not done (why? Because we would have lacked a 32-bit qualifier? Some > other side effect?). So we ended up with sizeof (int) != sizeof (void *). And > mainly I guess that’s what is meant by '64-bit' from the developer point of > view, besides – of course – utilizing libraries compiled with the 64-bit > instruction set. The reason that sizeof(int) != sizeof(void *) goes back to programmer laziness (really!). For years, files were written that assumed that sizeof(int) was 4 bytes, even though the long data type was explicitly designed for that value, AND types were introduced to the language that explicitly defined bit lengths (int8_t, int16_t, int32_t, int64_t). However, because programmers generally are lazy and didn't want to go back an re-code all of their legacy code to use the new bit-length-defined types, and because the C language "allowed" it (sizeof(char) <= sizeof(short) <= sizeof(int) <= sizeof(long)), the standards body "froze" int as a 32-bit value. -- Glenn L. Austin, Computer Wizard and Race Car Driver <>< "Where there's breath, there's hope!" <http://www.austin-soft.com> _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
