| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Wed, 06 Nov 2013 09:17:03 -0800 From: Ben Greear <greearb@...delatech.com> To: Clemens Ladisch <clemens@...isch.de> CC: Linux Kernel Mailing List <linux-kernel@...r.kernel.org> Subject: Re: Is __ffs64 supposed to be zero based? On 11/06/2013 03:52 AM, Clemens Ladisch wrote: > Ben Greear wrote: >> Similarly named methods elsewhere seem to indicate it is supposed to be >> ones-based counting (ie, bit (1<<0) would be considred 'bit 1'. > > ffs() is defined to use one-based counting: > <http://pubs.opengroup.org/onlinepubs/9699919799/functions/ffs.html> > > __ffs() uses zero-based counting. On gcc, it's likely to be implemented > with__builtin_ctz*(), whose documentation says: > | Returns the number of trailing 0-bits in x, starting at the least > | significant bit position. Thanks for the information! Ben -- Ben Greear <greearb@...delatech.com> Candela Technologies Inc http://www.candelatech.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists