H. Peter Anvin a écrit : > Michael Matz wrote: >> Hi, >> >> On Wed, 5 Mar 2008, Aurelien Jarno wrote: >> >>>> So I think gcc at least needs an *option* to revert to the old >>>> behavior, >>>> and there's a good argument to make it the default for now, at least >>>> for >>>> x86/x86-64 on Linux. >>> And for other kernels. I tested OpenBSD 4.1, FreeBSD 6.3, NetBSD 4.0, >>> they have the same behaviour as Linux, that is they don't clear DF >>> before calling the signal handler. >> >> Sigh. We could perhaps insert a cld for all functions which can be >> recognized as possible signal handlers and call other unknown or >> string functions. But it's probably even faster to emit cld in front >> of the inline copies of mem functions again :-( >> > > Well, there is a (slight) difference: you know that a called function > will not clobber your DF state; it's only the entry condition which is > imprecise. > > The best would be if this could be controlled by a flag, which we can > flip once kernel fixes has been around for long enough.
I have to agree there. Whatever the decision that gcc will take, distributions will reenable the old behaviour for some time for to allow upgrades from a previous version. Providing a flag to switch the behaviour (whatever the default behaviour) will help a lot. -- .''`. Aurelien Jarno | GPG: 1024D/F1BCDB73 : :' : Debian developer | Electrical Engineer `. `' [EMAIL PROTECTED] | [EMAIL PROTECTED] `- people.debian.org/~aurel32 | www.aurel32.net
