From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH 01/10] Add support for GCC-4.5's __builtin_unreachable() to compiler.h Date: Sat, 12 Sep 2009 09:22:43 +0200 Message-ID: <10f740e80909120022m72ad5ea7t692fba93cd3114e9@mail.gmail.com> References: <4AA991C1.1050800@caviumnetworks.com> <1252627011-2933-1-git-send-email-ddaney@caviumnetworks.com> <200909111633.00665.mb@bu3sch.de> <4AAA73A4.9010601@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <4AAA73A4.9010601@caviumnetworks.com> List-Archive: List-Post: To: David Daney Cc: Michael Buesch , linuxppc-dev@lists.ozlabs.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, linux-mips@linux-mips.org, Heiko Carstens , linuxppc-dev@ozlabs.org, Paul Mackerras , "H. Peter Anvin" , linux-s390@vger.kernel.org, linux-am33-list@redhat.com, Helge Deller , x86@kernel.org, Ingo Molnar , Mike Frysinger , Ivan Kokshaysky , uclinux-dist-devel@blackfin.uclinux.org, Thomas Gleixner , Richard Henderson , Haavard Skinnemoen , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, ralf@linux-mips.org, Kyle McMartin , linux-alpha@vger.kernel.org, Martin Schwidefsky , linux390@de.ibm.com, Koichi List-ID: On Fri, Sep 11, 2009 at 17:58, David Daney w= rote: > Michael Buesch wrote: >> >> On Friday 11 September 2009 01:56:42 David Daney wrote: >>> >>> +/* Unreachable code */ >>> +#ifndef unreachable >>> +# define unreachable() do { for (;;) ; } while (0) >>> +#endif >> >> # define unreachable() do { } while (1) >> >> ? :) > > Clearly I was not thinking clearly when I wrote that part. =C2=A0RTH = noted the > same thing. =C2=A0I will fix it. However, people are so used to seeing the `do { } while (0)' idiom, that they might miss there's a `1' here, not a `0'. So perhaps it's better to use plain `for (;;)' for infinite loops? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-= m68k.org In personal conversations with technical people, I call myself a hacker= =2E But when I'm talking to journalists I just say "programmer" or something li= ke that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-alpha" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html