Asri-unix.405 net.unix-wizards utzoo!decvax!ucbvax!menlo70!sri-unix!chico!duke!phs!dennis@Berkeley Sun Jan 3 23:26:07 1982 PDP-11 C compiler bug If you're on an 11/34 or 11/60 with 11/45-style floating point, the problem may not be the segmentation registers; there's a deficiency in the hardware, although this only occurs when you use an auto-increment or -decrement floating point instruction as the trapping instruction (ie, the one that causes the fault). The problem is that these two 11s don't have SSR2(?), which records how much each register has changed during an aborted instruction. It is impossible in this case to backup and restart the instruction, and the kernel gives you a memory fault as a reward. On our 11/60, this only showed up once or twice in several years, but then we didn't do too much number-crunching. Of course, this problem shows up no matter what system you run. ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.