8 wide vs 6 wide

By: dmcq (dmcq.delete@this.fano.co.uk), November 15, 2016 4:28 am
Room: Moderated Discussions
Wilco (Wilco.Dijkstra.delete@this.ntlworld.com) on November 15, 2016 2:43 am wrote:
> dmcq (dmcq.delete@this.fano.co.uk) on November 15, 2016 2:17 am wrote:
> > Wilco (Wilco.Dijkstra.delete@this.ntlworld.com) on November 14, 2016 3:53 pm wrote:
> > >.....
> > >
> > > ARM quotes micro-op ratio of 1.08 for Cortex-A72, so yes that means ~95% of executed instructions
> > > are a single micro-op. Denver isn't relevant here, and we don't have any details about Vulcan.
> > >
> > > Wilco
> >
> > No that doesn't follow. As well as instructions that are split there are also ones that
> > are fused, especially for constructing constants. And I'm not sure what they do about
> > unconditional branches, why should they form micro-ops at all? It is just a ratio between
> > instructions and micro-ops that almost by chance happens to be so close to 1.
>
> No it's not by chance. An OoO core emits at least 1 micro op for all instructions,
> including NOPs and even fused instructions in some cases. Pretty much all commonly
> used instructions are a single micro op, you can check this yourself.
>
> Wilco

You're right it follows then okay. I wondered about improving the handling of short shifts when I looked at that. For instance it looks like a shift and add instruction has a latency of 2 and a throughput of 1 using the multiply unit whereas either a shift or an add would have a latency of 1 and a throughput of 2 using the integer units. I guess it just shows tradeoff in design aren't easy.
< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Neat die area comparison imageRob2016/10/21 05:39 PM
  Neat die area comparison imageanonymou52016/10/21 06:44 PM
    Neat die area comparison imageMr. Camel2016/10/22 04:58 AM
      Neat die area comparison imageHeikki Kultala2016/10/22 05:19 AM
        Neat die area comparison imageMr. Camel2016/10/22 07:10 AM
          Neat die area comparison imageMr. Camel2016/10/22 07:15 AM
          different caches...Heikki Kultala2016/10/22 08:29 AM
            Broadwell includes LLC, just for comparisionanon2016/10/22 08:52 AM
              Broadwell includes LLC, just for comparisionjuanrga2016/10/23 06:09 AM
                Broadwell includes LLC, just for comparisionanon2016/10/23 07:25 AM
                  Broadwell includes LLC, just for comparisionjuanrga2016/10/25 09:57 AM
                    Broadwell includes LLC, just for comparisionSimon Farnsworth2016/10/25 11:03 AM
                      Broadwell includes LLC, just for comparisionjuanrga2016/10/28 02:02 AM
                        Broadwell includes LLC, just for comparisionanon2016/10/28 04:13 AM
                          Broadwell includes LLC, just for comparisionjuanrga2016/10/29 09:47 PM
                            Broadwell includes LLC, just for comparisionTravis2016/10/30 06:34 PM
                              Broadwell includes LLC, just for comparisionjuanrga2016/10/31 04:35 AM
                                Broadwell includes LLC, just for comparisionSimon Farnsworth2016/10/31 04:42 AM
                                Broadwell includes LLC, just for comparisionanon2016/11/01 12:56 PM
                                  Broadwell includes LLC, just for comparisionMaynard Handley2016/11/01 01:37 PM
                                    Broadwell includes LLC, just for comparisionanon2016/11/01 04:22 PM
                                      Broadwell includes LLC, just for comparisionMaynard Handley2016/11/01 07:30 PM
                                        Broadwell includes LLC, just for comparisionanon2016/11/02 06:15 AM
                                          Broadwell includes LLC, just for comparisionMaynard Handley2016/11/02 09:23 AM
                                            Broadwell includes LLC, just for comparisionanon2016/11/02 11:50 AM
                                  Broadwell includes LLC, just for comparisionSimon Farnsworth2016/11/02 02:48 AM
                        Broadwell includes LLC, just for comparisionSimon Farnsworth2016/10/28 06:19 AM
                          Broadwell includes LLC, just for comparisionjuanrga2016/10/29 10:15 PM
                            Broadwell includes LLC, just for comparisionSimon Farnsworth2016/10/30 12:31 PM
                        Broadwell includes LLC, just for comparisionRicardo B2016/10/29 05:30 PM
                    underclocked is different than designed for low clock speedHeikki Kultala2016/10/25 11:47 PM
                      underclocked is different than designed for low clock speedMaynard Handley2016/10/26 10:07 AM
                      That wasn't the pointjuanrga2016/10/28 02:15 AM
                        Even without the point you have invalid comparisonHeikki Kultala2016/10/28 09:03 AM
                          8 wide vs 6 widejuanrga2016/10/29 10:41 PM
                            8 wide vs 6 wideWilco2016/10/30 05:00 AM
                              8 wide vs 6 wideDoug S2016/10/30 12:20 PM
                                8 wide vs 6 wideWilco2016/10/30 01:12 PM
                                8 wide vs 6 widejuanrga2016/10/30 02:56 PM
                                  8 wide vs 6 wideTravis2016/10/30 07:13 PM
                                    8 wide vs 6 widejuanrga2016/10/31 04:55 AM
                                      8 wide vs 6 wideanon2016/11/01 01:00 PM
                                        SoftMachinesnone2016/11/02 03:57 AM
                                          SoftMachinesDavid Kanter2016/11/02 08:53 AM
                                        8 wide vs 6 widejuanrga2016/11/03 12:35 PM
                                          8 wide vs 6 wideWilco2016/11/03 02:13 PM
                                            8 wide vs 6 widejuanrga2016/11/03 07:35 PM
                                              8 wide vs 6 wideWilco2016/11/04 01:27 PM
                                                8 wide vs 6 widejuanrga2016/11/04 06:08 PM
                                                  8 wide vs 6 wideWilco2016/11/06 04:52 AM
                                                    8 wide vs 6 widejuanrga2016/11/06 04:56 PM
                                                      8 wide vs 6 wideWilco2016/11/07 04:25 AM
                                              8 wide vs 6 wideAaron Spink2016/11/04 04:08 PM
                                                8 wide vs 6 widejuanrga2016/11/04 06:10 PM
                                            Dunning-Krueger effectHeikki Kultala2016/11/04 03:22 AM
                                              Dunning-Krueger effectitsmydamnation2016/11/04 02:48 PM
                                          8 wide vs 6 wideanon2016/11/04 03:38 AM
                                            8 wide vs 6 widejuanrga2016/11/04 05:05 AM
                                              8 wide vs 6 wideanon2016/11/04 06:12 AM
                                                8 wide vs 6 wideWilco2016/11/04 01:12 PM
                                                  8 wide vs 6 wideanon2016/11/04 02:54 PM
                                                    8 wide vs 6 widejuanrga2016/11/04 05:34 PM
                                                      8 wide vs 6 wideanon2016/11/05 02:14 AM
                                                  8 wide vs 6 widejuanrga2016/11/04 05:39 PM
                                                    8 wide vs 6 wideWilco2016/11/06 05:15 AM
                                                      8 wide vs 6 widejuanrga2016/11/06 05:06 PM
                                                        8 wide vs 6 wideWilco2016/11/07 03:45 AM
                                                          8 wide vs 6 wideDavid Kanter2016/11/07 08:43 PM
                                                            8 wide vs 6 wideWilco2016/11/08 03:57 AM
                                                          8 wide vs 6 widejuanrga2016/11/14 12:12 PM
                                                            8 wide vs 6 wideWilco2016/11/14 04:53 PM
                                                              8 wide vs 6 widedmcq2016/11/15 03:17 AM
                                                                8 wide vs 6 wideWilco2016/11/15 03:43 AM
                                                                  8 wide vs 6 widedmcq2016/11/15 04:28 AM
                                                                  1 µop per instruction is not necessaryPaul A. Clayton2016/11/17 12:09 PM
                                                              8 wide vs 6 widejuanrga2016/11/20 06:56 AM
                                                                8 wide vs 6 wideWilco2016/11/21 05:54 PM
                                                                  8 wide vs 6 widejuanrga2016/11/22 08:49 AM
                                                                    8 wide vs 6 wideWilco2016/11/22 03:25 PM
                                  8 wide vs 6 wideWilco2016/10/31 03:03 AM
                              Skylake can retire 8 uopsDavid Kanter2016/10/31 12:41 AM
                                Skylake can retire 8 uopsjuanrga2016/10/31 04:15 AM
                                  Skylake can retire 8 uopsAlberto2016/11/04 07:22 AM
                            8 wide vs 6 wide bogus numbersHeikki Kultala2016/10/30 06:25 AM
                    Broadwell includes LLC, just for comparisionanon2016/10/26 03:10 AM
                      Pushing the hidden agendajuanrga2016/10/28 03:11 AM
                        Pushing the hidden agendaanon2016/10/28 04:35 AM
      Neat die area comparison imageDavid Hess2016/10/22 01:26 PM
        Neat die area comparison imageanon22016/10/22 05:20 PM
          Neat die area comparison imageDavid Hess2016/10/22 10:31 PM
            Neat die area comparison imageanon22016/10/23 01:50 AM
        Neat die area comparison imageTravis2016/10/24 01:26 PM
          Neat die area comparison imageMaynard Handley2016/10/24 04:27 PM
            Neat die area comparison imagejuanrga2016/10/25 10:02 AM
            Neat die area comparison imageDavid Hess2016/10/25 09:59 PM
              Neat die area comparison imageTravis2016/10/25 10:22 PM
                Neat die area comparison imageDavid Hess2016/10/25 10:37 PM
                  Neat die area comparison imageTravis2016/10/30 06:09 PM
              Neat die area comparison imageGabriele Svelto2016/10/26 02:23 AM
                Neat die area comparison imageDoug S2016/10/26 08:17 AM
                  Neat die area comparison imageJukka Larja2016/10/27 09:28 AM
              Neat die area comparison imageanon2016/10/26 03:32 AM
      Neat die area comparison imagejuanrga2016/10/23 06:29 AM
    Neat die area comparison imageMatthias Waldhauer2016/10/22 06:12 AM
  Neat die area comparison imagejuanrga2016/10/23 05:44 AM
  Neat die area comparison imageGabriele Svelto2016/10/24 02:17 AM
Reply to this Topic
Name:
Email:
Topic:
Body: No Text
How do you spell avocado?