> -----Original Message----- > I would like to say the one thing I have not heard through this > discussion is the real reason why the C standards comittee decided > signed overflow as being undefined. All I can think of is they were > thinking of target that do saturation for plus/minus but wrapping for > multiplications/divide or even targets that trap for some overflow cases > (like x86) but not others. I was on the original C standards committee from its inception through the ANSI standard in 1989 and the ISO standard in 1990, representing first Data General, and then the Open Software Foundation. When the standard was being produced, we had vendors with one's complement machines (Univac, and possibly CDC), signed magnitude machines (Burroughs), word based machines (Univac, Burroughs, Data General, PR1ME, and a university doing a DEC-10 port). While these machines are uncommon now, we did have to keep them in mind while writing the standard. Because of the diversity of actual hardware, the only thing we could say was "don't do that", just like with shifts where the shift value is not in the proper range (and this bit gcc when I was doing the early 88k port). _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
