2007/11/21, Matthew Burgess <[EMAIL PROTECTED]>: > But see http://www.ussg.iu.edu/hypermail/linux/kernel/0711.2/1296.html - the > kernel uses it's own abs macro, so GCC never sees the call to abs(). > Therefore the kernel tarball isn't a suitable candidate to try finding > instances of this bug in.
Correct, but it is still a good estimate of the number of instances where the result of abs() (built-in or not) is multiplied by something. > I'd hazard a guess that something like mplayer or ffmpeg might be more > suitable given the heavy use of maths in them...but it really is just a > guess. So far, 3.3.x, 3.4.x, 4.1.x and 4.2.x are known to fail and we've not > had a single instance of this bug reported. So, either there is very > little/no code that triggers the bug, or its affects aren't noticeable in the > apps that do trigger it. I'm not saying that the testsuites for LFS/BLFS > packages provide 100% coverage (my experience in the field has taught me not > to be so naive), but all my builds pass them with the exception of the known > failures. I will do a local build of the LiveCD with a patched gcc. The patch is different from the official fix: I added a warning that fires if gcc sees negative_const * abs(something). The intention is to grep through the logs for this new warning and thus count all cases that the old gcc has miscompiled on the old LiveCD. -- Alexander E. Patrakov -- http://linuxfromscratch.org/mailman/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
