[lkml]   [2010]   [May]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [patch 2/3] ipc: use shifts to extract seq/idx
    On 05/20/2010 09:00 AM, Nick Piggin wrote:
    > All the ipc ids and sequences are signed integers, so power of 2
    > sequence multiplier does not work so well. Convert it to use shifts,
    > which improves generated code particularly in ipc_lock/ipc_lock_check
    > fast paths.
    Have you checked the asm output?
    I would expect that gcc auto-optimizes constant divides by power-of-two.


     \ /
      Last update: 2010-05-20 20:17    [from the cache]
    ©2003-2014 Jasper Spaans. hosted at Digital Ocean