From mboxrd@z Thu Jan 1 00:00:00 1970 From: mrs@wrs.com (Mike Stump) To: egcs@cygnus.com, hadsell@blueskystudios.com Subject: Re: sizeof bool > sizeof int ?!? Date: Fri, 21 Aug 1998 19:47:00 -0000 Message-id: <199808220104.SAA21655@kankakee.wrs.com> X-SW-Source: 1998-08/msg00735.html > Date: Thu, 20 Aug 1998 12:04:47 -0400 > From: Richard Hadsell > To: EGCS mailing list > Richard Hadsell wrote: > > > > > I realize that some (all?) alpha processors do not handle 1-byte data > > > efficiently. I hope that the situation will change with future > > > versions. But it's hard to believe that alphas don't have an efficient > > > instruction set for (4-byte) int data. What about short data? Are they > > > handled as badly as 1-byte data? > > > > > > I would prefer that bool be implemented with the best performance in > > > mind, including the effects of using memory efficiently, too. > > > > I haven't seen any comments from the compiler group on their decision to > > implement bool as an 8-byte datum on alphas. If the performance is so > > much better that it is worth the cost in memory usage, why is an int > > only 4 bytes. Since the standard allows it to be as big as a long, why > > not? I thought that we could expect an int to be whatever size gives > > the best integer performance. > > > > So I don't understand why a bool is any longer than an int. What other > > considerations were there in making the decision? > Comments anyone ? No. Well, ok, I wasn't going to comment, but let me make one meta comment about this. The most persuasive comment is one from a benchmark type person that measures the performance in a couple of different and realistic ways and makes a statement about the performance characteristics, the rest of us can sit back and debate if we want to blow the 5%, and save the space, and maybe be better to the cache. Random comments from random people that say `wow, man, 8 bytes instead of one bit, sounds like a bug' is less interesting to me.