Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Wed, 25 Apr 2012 03:12:35 +0400
From: Solar Designer <>
Subject: GPU eager execution (was: New patch for OpenCL SHA-512)

On Thu, Mar 22, 2012 at 08:00:54AM +0100, magnum wrote:
> I believe both AMD's and Nvidia's compilers generate code for eager
> execution in many cases (that is, unless the conditional blocks are too
> large or too complex). I don't know much details but I suppose the real
> problems begin when they do not: Normally all threads in a workgroup
> execute in sync.

FWIW, this presentation on GCN:

gives some generated code samples that show that there's some hardware
support for eager execution - "exec mask" (tells which of the work-items
execute for real?) and the s_cbranch_vccz and s_cbranch_execz
instructions (branch for real if the "exec mask" would remain full or if
it became zero, respectively?)


Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.