Messages in this thread | | | Subject | Re: [patch] string.h speedup, cld-2.3.30-A1 | From | Andreas Schwab <> | Date | 29 Nov 1999 14:48:54 +0100 |
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Henrik Olsen <henrik@iaeste.dk> writes:
|> On Sat, 27 Nov 1999, Linus Torvalds wrote: |> > On Sat, 27 Nov 1999, Oliver Xymoron wrote: |> > > On Sat, 27 Nov 1999, Ingo Molnar wrote: |> > > |> > > > much of the remaining 284 cld's is still unjustified, because '*a = *b;' |> > > > type of structure copies are inlined by GCC. (GCC generates a cld because |> > > > user-space has to be prepared to be interrupted by uncooperative signal |> > > > handlers and the like). |> > > |> > > What!? A signal handler can change flags? Then there's a lot more for GCC |> > > to worry about than the direction flag.. |> > |> > A normal signal handler cannot change flags, because they will obviously |> > be restored on signal exit. |> > |> > However, I'm not sure that "longjmp()" does the same. You'd have to check |> > libc souces to see if setjmp saves the flags.. |> > |> > Linus |> Libc longjmp() does, glibc longjmp() doesn't.
The flags are considered call clobbered, so setjmp does not save them.
-- Andreas Schwab "And now for something SuSE Labs completely different." schwab@suse.de SuSE GmbH, Schanzäckerstr. 10, D-90443 Nürnberg
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