Intel is cheating AnTuTu

By: Klimax (danklima.delete@this.gmail.com), July 17, 2013 10:29 pm
Room: Moderated Discussions
Wilco (Wilco.Dijkstra.delete@this.ntlworld.com) on July 17, 2013 3:33 pm wrote:
> bakaneko (nyan.delete@this.hyan.wan) on July 16, 2013 5:50 am wrote:
> > Wilco (Wilco.Dijkstra.delete@this.ntlworld.com) on July 16, 2013 3:47 am wrote:
> > > bakaneko (nyan.delete@this.hyan.wan) on July 16, 2013 2:42 am wrote:
> > > > Linus Torvalds (torvalds.delete@this.linux-foundation.org) on July 15, 2013 8:45 pm wrote:
> > > > > bakaneko (nyan.delete@this.hyan.wan) on July 15, 2013 7:47 pm wrote:
> > > > > >
> > > > > > As someone who works for ARM as compiler writer,
> > > > > > why don't you tell us in more detail how Intel
> > > > > > cheated?
> > > > >
> > > > > Exophase's post to anandtech was quoted here earlier, I think. It has the relevant details:
> > > > >
> > > > > http://forums.anandtech.com/showthread.php?t=2330027
> > > > >
> > > > > and quite frankly, while optimizing multiple bit operations into a word is a very
> > > > > valid optimization, the code icc generates there seems a fair bit past that.
> > > > >
> > > > > Sure, it could in theory happen with a really smart compiler and lots of generic optimizations.
> > > > > In practice? It really smells like the compiler actively targeting a very particular code-sequence.
> > > > > IOW, compiler cheating. The timing that Exophase points out makes it look worse.
> > > > >
> > > > > And Wilco is right that it smells pretty bad when AnTuTu seems to be so close to
> > > > > intel, and seem to have bent over backwards using recent versions of icc etc.
> > > > >
> > > > > It's all "explainable". But it doesn't pass the smell test.
> > > >
> > > > It's also all besides the point. I would expect a better
> > > > explanation from someone who claims to know their shit about
> > > > compilers than a logical fallacy ("Intel improved their
> > > > compiler recently", "Intel is cheating because it hits one
> > > > function in a certain benchmark"). Instead he nags like his
> > > > marriage has gone bad.
> > >
> > > If you had actually read the whole thread including the links to various articles I posted
> > > then you would have found the detailed explanation that makes it obvious that Intel has been
> > > cheating AnTuTu. Why should I explain all the details again in every post I make?
> >
> > I read the whole thread, but for some reason don't remember
> > anything noteworthy.
> >
> > > > And no, the ICC results aren't that far fetched. Intel
> > > > actually recommends -O3 -xSSSE3_ATOM* with the NDK. Which
> > > > could also explain why Exophase saw optimizations which
> > > > would be counterproductive for bigger programs. (If the
> > > > flags have similar meaning to gcc, where inlining and loop
> > > > unrolling have similar problems.)
> > >
> > > Given the ICC results already dropped 20% after minor changes in AnTuTu it seems this
> > > optimization is no longer effective. And that proves it was very specific to the actual
> > > source code rather than a generic optimization that any compiler does.
> >
> > How is setting/clearing a range of bits not a useful
> > optimization?
>
> Nobody sets multiple adjacent bits in memory one at a time. Even if one did so it would
> typically be a few bits, certainly not hundreds or thousands. Having seen and written
> various implementations of bit-sets I know how the typical ones look like.
>
> > And how does this - just because this is not an optimization
> > any compiler does (Or at least gcc with -Os) - suddenly make
> > this an benchmark busting trick? Oh, yes because the time
> > frame fits.
>
> Nobody writes code like this, so no compiler implements this optimization. So yes, ICC gaining
> this optimization just before AnTuTu switched to ICC is proof that the optimization was added
> to break AnTuTu. If ICC had implemented this particular optimization for many years then it
> would be a different matter of course (although that still doesn't explain exactly why AnTuTu
> switched to a non-standard compiler with options tuned for AnTuTu just for x86).
So far no proof yet. Do you have any? Any evidence at all?
< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
ARM at Computexanon2013/06/03 07:54 AM
  ARM at ComputexExophase2013/06/03 08:31 AM
    ARM at ComputexWilco2013/06/03 09:52 AM
      ARM at ComputexExophase2013/06/03 11:02 AM
        ARM at Computexnone2013/06/03 12:28 PM
          ARM at ComputexAlberto2013/06/04 09:41 AM
            ARM at Computexanon2013/06/04 12:36 PM
              ARM at ComputexWilco2013/06/04 02:56 PM
                ARM at ComputexDavid Kanter2013/06/04 03:51 PM
                  ARM at ComputexNobodyatAll2013/06/04 04:53 PM
                  ARM at Computexanon2013/06/04 05:53 PM
        ARM at ComputexWilco2013/06/03 12:47 PM
    ARM at Computexanon2013/06/04 03:03 AM
      ARM at ComputexDavid Kanter2013/06/04 07:16 AM
      ARM at ComputexExophase2013/06/04 09:36 AM
        ARM at ComputexWilco2013/06/04 03:09 PM
          ARM at ComputexNobodyatAll2013/06/04 03:23 PM
          ARM at ComputexDavid Kanter2013/06/04 04:00 PM
            ARM at Computexnone2013/06/05 04:26 AM
              ARM at Computexanon2013/06/05 06:19 AM
              ARM at Computexaaron spink2013/06/05 02:04 PM
                Saltwell Outperforming A15...With Less Power!!!Jason2013/06/07 12:56 PM
                  Saltwell Outperforming A15...With Less Power!!!John2013/06/08 05:28 AM
                    Saltwell Outperforming A15...With Less Power!!!Kevin G2013/06/08 01:18 PM
                      Saltwell Outperforming A15...With Less Power!!!David Kanter2013/06/08 07:43 PM
                      Saltwell Outperforming A15...With Less Power!!!tarlinian2013/06/09 01:00 PM
                        Saltwell Outperforming A15...With Less Power!!!none2013/06/09 02:11 PM
                          Saltwell Outperforming A15...With Less Power!!!none2013/07/10 10:46 AM
                            Saltwell Outperforming A15...With Less Power!!!Wilco2013/07/10 06:59 PM
                              Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/10 09:03 PM
                                Saltwell Outperforming A15...With Less Power!!!anon2013/07/10 09:29 PM
                                  Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/10 10:30 PM
                                    Saltwell Outperforming A15...With Less Power!!!Wilco2013/07/11 12:04 AM
                                      Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/11 02:10 AM
                                        Saltwell Outperforming A15...With Less Power!!!anon2013/07/11 03:10 AM
                                        Saltwell Outperforming A15...With Less Power!!!Wilco2013/07/11 03:43 AM
                                        Saltwell Outperforming A15...With Less Power!!!Steve2013/07/14 07:10 PM
                                          Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/14 09:55 PM
                                          Saltwell Outperforming A15...With Less Power!!!bakaneko2013/07/15 01:03 AM
                                            Saltwell Outperforming A15...With Less Power!!!anon2013/07/16 12:07 AM
                                              Saltwell Outperforming A15...With Less Power!!!bakaneko2013/07/16 05:25 AM
                                                Saltwell Outperforming A15...With Less Power!!!none2013/07/16 05:34 AM
                                                Saltwell Outperforming A15...With Less Power!!!Exophase2013/07/16 09:34 AM
                                                  Saltwell Outperforming A15...With Less Power!!!bakaneko2013/07/18 01:24 PM
                                                    Saltwell Outperforming A15...With Less Power!!!none2013/07/18 02:26 PM
                                    Saltwell Outperforming A15...With Less Power!!!anon2013/07/11 01:50 AM
                                      Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/11 10:25 PM
                                        Saltwell Outperforming A15...With Less Power!!!anon2013/07/11 10:45 PM
                                          Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/11 11:10 PM
                                            Saltwell Outperforming A15...With Less Power!!!anon2013/07/12 12:52 AM
                                    Saltwell Outperforming A15...With Less Power!!!Gabriele Svelto2013/07/11 03:20 AM
                                      Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/11 10:51 PM
                                Saltwell Outperforming A15...With Less Power!!!bakaneko2013/07/10 11:02 PM
                                  Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/10 11:28 PM
                                    Saltwell Outperforming A15...With Less Power!!!none2013/07/11 12:49 AM
                                      Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/11 02:00 AM
                                        Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/11 02:02 AM
                                        Saltwell Outperforming A15...With Less Power!!!none2013/07/11 03:44 AM
                                          Saltwell Outperforming A15...With Less Power!!!Michael S2013/07/11 04:33 AM
                                            Saltwell Outperforming A15...With Less Power!!!none2013/07/11 04:58 AM
                                              Saltwell Outperforming A15...With Less Power!!!none2013/07/11 04:59 AM
                                              Saltwell Outperforming A15...With Less Power!!!Wilco2013/07/11 06:40 AM
                                                Saltwell Outperforming A15...With Less Power!!!Michael S2013/07/11 07:34 AM
                                                  Saltwell Outperforming A15...With Less Power!!!none2013/07/11 07:50 AM
                                              Saltwell Outperforming A15...With Less Power!!!Michael S2013/07/11 08:02 AM
                                          Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/11 09:11 PM
                                      Saltwell Outperforming A15...With Less Power!!!Michael S2013/07/11 03:12 AM
                                        Saltwell Outperforming A15...With Less Power!!!none2013/07/11 03:51 AM
                                          Saltwell Outperforming A15...With Less Power!!!Wilco2013/07/11 04:03 AM
                                            Saltwell Outperforming A15...With Less Power!!!none2013/07/11 04:12 AM
                                              Saltwell Outperforming A15...With Less Power!!!Wilco2013/07/11 06:26 AM
                                                Saltwell Outperforming A15...With Less Power!!!none2013/07/11 07:29 AM
                                                Saltwell Outperforming A15...With Less Power!!!Wilco2013/07/12 03:08 AM
                                                  Saltwell Outperforming A15...With Less Power!!!Michael S2013/07/12 03:25 AM
                                              Saltwell Outperforming A15...With Less Power!!!Klimax2013/07/11 10:55 PM
                                                Saltwell Outperforming A15...With Less Power!!!Megol2013/07/13 06:20 AM
                                    Java/Dalvik benchmarksbakaneko2013/07/11 01:26 AM
                                  Saltwell Outperforming A15...With Less Power!!!Linus Torvalds2013/07/11 09:57 AM
                                    Saltwell Outperforming A15...With Less Power!!!Linus Torvalds2013/07/11 10:20 AM
                                      Saltwell Outperforming A15...With Less Power!!!Ian Ameline2013/07/11 02:20 PM
                                      Saltwell Outperforming A15...With Less Power!!!Sylvain Collange2013/07/12 01:29 AM
                                        Saltwell Outperforming A15...With Less Power!!!Wilco2013/07/12 02:51 AM
                                          Saltwell Outperforming A15...With Less Power!!!Sylvain Collange2013/07/12 05:00 AM
                                      Saltwell Outperforming A15...With Less Power!!!bakaneko2013/07/12 02:28 AM
                                        Saltwell Outperforming A15...With Less Power!!!Linus Torvalds2013/07/12 08:11 AM
                                          Saltwell Outperforming A15...With Less Power!!!bakaneko2013/07/12 09:12 AM
                                          Saltwell Outperforming A15...With Less Power!!!2013/07/12 09:48 AM
                                            Saltwell Outperforming A15...With Less Power!!!Linus Torvalds2013/07/12 10:14 AM
                                              JIT2013/07/13 04:50 AM
                                                How'd you get this flower symbol as your user name ?anon2013/07/13 08:20 AM
                                                  How'd you get this flower symbol as your user name ?Doug S Ꭳ❂〄☢⚓♜☎♬⚄☠2013/07/13 09:12 AM
                                                JITx2013/07/15 05:43 AM
                                    Not reallyAnon2013/07/11 10:21 AM
                                    consistency, pleaseMichael S2013/07/11 10:22 AM
                                      consistency, pleaseLinus Torvalds2013/07/11 10:52 AM
                                        consistency, pleaseMichael S2013/07/11 01:43 PM
                                          consistency, pleaseLinus Torvalds2013/07/11 02:12 PM
                                            consistency, pleaseMark Roulo2013/07/11 02:54 PM
                                              the discussion was about absence of AVX in Silvermont (NT)Michael S2013/07/11 02:59 PM
                                                the discussion was about absence of AVX in SilvermontMark Roulo2013/07/11 03:19 PM
                                                  the discussion was about absence of AVX in SilvermontLinus Torvalds2013/07/12 08:16 AM
                                                    Thank youMark Roulo2013/07/12 08:58 AM
                                                    the discussion was about absence of AVX in Silvermontanon2013/07/12 09:10 AM
                                                      Not really (again)Anon2013/07/12 09:26 AM
                                                        Not really (again)anon2013/07/12 04:40 PM
                                                    the discussion was about absence of AVX in SilvermontLinus Torvalds2013/07/12 09:31 AM
                                                      you are wrong at about 100% of you saidMichael S2013/07/13 10:22 AM
                                                        you are wrong at about 100% of you saidLinus Torvalds2013/07/13 11:08 AM
                                                          you are wrong at about 100% of you saidMichael S2013/07/13 12:13 PM
                                                            you are wrong at about 100% of you saidLinus Torvalds2013/07/13 01:11 PM
                                                            you are wrong at about 100% of you saidvvid2013/07/13 02:20 PM
                                                              you are wrong at about 100% of you saidMichael S2013/07/14 12:38 AM
                                    Saltwell Outperforming A15...With Less Power!!!anon2013/07/11 05:41 PM
                                    Saltwell Outperforming A15...With Less Power!!!bakaneko2013/07/12 02:22 AM
                  Round 2: Baytrail benchmark (yes Antutu!) crushes Snapdragon 800.sammy2013/07/12 10:28 AM
                    Round 2: AnTuTu scores drop dramatically for AtomWilco2013/07/12 10:59 AM
                      Round 2: AnTuTu scores drop dramatically for AtomSteve2013/07/14 07:16 PM
                        Round 2: AnTuTu scores drop dramatically for AtomKlimax2013/07/14 09:59 PM
                        Round 2: AnTuTu scores drop dramatically for AtomDavid Kanter2013/07/15 12:57 PM
                          Intel is cheating AnTuTuWilco2013/07/15 02:43 PM
                            Intel is cheating AnTuTubakaneko2013/07/15 06:47 PM
                              Intel is cheating AnTuTuLinus Torvalds2013/07/15 07:45 PM
                                Intel is cheating AnTuTubakaneko2013/07/16 01:42 AM
                                  Intel is cheating AnTuTuWilco2013/07/16 02:47 AM
                                    Intel is cheating AnTuTubakaneko2013/07/16 04:50 AM
                                      Intel is cheating AnTuTuWilco2013/07/17 02:33 PM
                                        Intel is cheating AnTuTuKlimax2013/07/17 10:29 PM
                                          Intel is cheating AnTuTunone2013/07/17 10:35 PM
                                            Intel is cheating AnTuTuKlimax2013/07/18 12:41 AM
                                              Intel is cheating AnTuTuanon2013/07/18 01:10 AM
                                                Intel is cheating AnTuTuMichael S2013/07/18 02:39 AM
                                                Intel is cheating AnTuTuWilco2013/07/18 03:07 AM
                                                  Intel is cheating AnTuTunone2013/07/18 03:15 AM
                                                    Intel is cheating AnTuTuWilco2013/07/18 04:18 AM
                                                    Intel is cheating AnTuTuMichael S2013/07/18 05:44 AM
                                                      Intel is cheating AnTuTunone2013/07/18 06:47 AM
                                                        strict aliasingMichael S2013/07/18 07:10 AM
                                                          strict aliasing rules have existed since C89 (NT)Ricardo B2013/07/18 04:28 PM
                                                  Intel is cheating AnTuTuKlimax2013/07/18 10:30 AM
                                                Intel is cheating AnTuTuKlimax2013/07/18 10:39 AM
                                                  Intel is cheating AnTuTuanon2013/07/18 11:05 AM
                                                    Intel is cheating AnTuTuKlimax2013/07/19 11:05 PM
                                                      Intel is cheating AnTuTunone2013/07/20 01:50 AM
                                                  Intel is cheating AnTuTunone2013/07/18 11:38 AM
                                                    Intel is cheating AnTuTuKlimax2013/07/19 10:57 PM
                                  Intel is cheating AnTuTuLinus Torvalds2013/07/16 11:32 AM
                                Intel is cheating AnTuTu2013/07/16 02:16 AM
                                  Intel is cheating AnTuTubakaneko2013/07/16 03:55 AM
                                    Intel is cheating AnTuTuWilco2013/07/17 02:46 PM
                                      Intel is cheating AnTuTubakaneko2013/07/18 01:05 PM
                                      Intel is cheating AnTuTuDavid Kanter2013/07/19 01:31 AM
                          Round 2: AnTuTu scores drop dramatically for Atomanon2013/07/15 03:43 PM
                            Round 2: AnTuTu scores drop dramatically for Atomnone2013/07/15 11:15 PM
                          Round 2: AnTuTu scores drop dramatically for AtomGroo2013/07/16 06:35 AM
        ARM at Computexanon2013/06/04 09:43 PM
Reply to this Topic
Name:
Email:
Topic:
Body: No Text
How do you spell avocado?