In message: <[EMAIL PROTECTED]> [EMAIL PROTECTED] (Dag-Erling Smørgrav) writes: : Warner Losh <[EMAIL PROTECTED]> writes: : > Can we not have special flags for tinderbox builds? It make : > pre-commit testing a big pita. How about just -O on both head and : > in RELENG_6? : : As I have repeatedly pointed out in the past, -O2 catches more bugs : because it enables optimizations which require more extensive coverage : analysis.
Then it should be the default, standard flag. : > The kernel make files have special magic to disable the parts of -O2 : > that are known to be bad because tinderbox uses -O2, despite efforts : > in the past to stop the practice. : : The kernel has special magic to disable strict aliasing checks because : certain people regularly commit kernel code which violates C aliasing : rules and refuse to fix it. The userland code does not need these : hacks because I spent a lot of time and effort fixing aliasing bugs in : e.g. libalias. The optimizations are disable because they do not work. It is really that simple. The kernel has lots and lots of these problems, it is true. : Aliasing violations are not trivial matters; they prevent the compiler : from optimizing code which (for instance) accesses structure members : through pointers to the structure. There is a lot of this in the : kernel. I agree. However, I think it is unreasonable to have one set of defaults, then another set that committers are held to. This leads to lots of problems. My bottom line is that as a committer, you are expected to not break the builds with the default flags. The tinderbox runs at a different level, thereby creating the impression that someone has done something wrong when it happens to blow up, when in fact they have not. If -O2 is so good w/o the -fno-strict-alias, then it should be the default so we catch these bugs. I'm not arguing against -O2 because it isn't useful. I'm arguing because it isn't the default. Warner _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"