Separate the OoO-ness from speculative-ness

Article: PhysX87: Software Deficiency
By: slacker (s.delete@this.lack.er), July 21, 2010 7:45 pm
Room: Moderated Discussions
? (0xe2.0x9a.0x9b@gmail.com) on 7/21/10 wrote:
---------------------------
>anon (anon@anon.com) on 7/21/10 wrote:
>---------------------------
>>On the contrary, I think your assertion that pipelining requires speculative execution is wrong.
>
>I am not saying that. I am saying this:....

"Even mere pipelining entails a small dose of speculative execution !!!

I will repeat it one more time, because it seems to me that you are
completely missing this: Even mere pipelining entails a small dose of
speculation !!!"

How foolish of us to confuse your words with your intentions!


>Code: Hi there, CPU, my friend. I want you to execute me.
>
>CPU: No problem. Hand me the first couple of your instructions.
>
>Code: Only a couple of them? You mean you don't want to see all of them?
>
>CPU: That's right.
>
>Code: But but, then, you aren't going to know what I am going to do.
>
>CPU: Don't worry. I will manage.
>
>Code: How?

I knew this was the problem; you are playing loose and fast with your terminology.


>>Caches have nothing to do with speculative execution that you were talking about.
>
>What are you saying? That if a contemporary CPU (Core2 or whatever) decides to
>allocate a cache-line for data at address 0x1230, it is not making any speculations
>about future uses of that piece of data?

You are expanding and abusing the term "speculative execution," which is both pointless and inane. It has a narrow definition in hardware circles; speculative execution is the execution of code which has not yet been determined by the program stream to be necessary.

- Prefetching code and data is not speculative execution
- Decoding instructions in to microops is not speculative execution
- Caching data is not speculative execution

But if we're going to be silly about terminology, then let's go crazy:

- A microprocessor speculates that its circuits have not failed after each clock cycle

- A microprocessor speculates that it is being supplied with sufficient electric potential to power the circuits properly

- Virtually all software speculates that the instruction semantics on a processor adhere to some specification (ISA) without actually confirming the semantics.
< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
A bit off baseJohn Mann2010/07/07 07:04 AM
  A bit off baseDavid Kanter2010/07/07 11:28 AM
    SSE vs x87Joel Hruska2010/07/07 12:53 PM
      SSE vs x87Michael S2010/07/07 01:07 PM
        SSE vs x87hobold2010/07/08 05:12 AM
      SSE vs x87David Kanter2010/07/07 02:55 PM
        SSE vs x87Andi Kleen2010/07/08 02:43 AM
          80 bit FPRicardo B2010/07/08 07:35 AM
            80 bit FPDavid Kanter2010/07/08 11:14 AM
              80 bit FPKevin G2010/07/08 02:12 PM
                80 bit FPIan Ollmann2010/07/19 12:49 AM
                  80 bit FPDavid Kanter2010/07/19 11:33 AM
                    80 bit FPAnil Maliyekkel2010/07/19 04:49 PM
                      80 bit FPrwessel2010/07/19 05:41 PM
                    80 bit FPMatt Waldhauer2010/07/21 11:11 AM
            80 bit FPEmil Briggs2010/07/22 09:06 AM
    A bit off baseJohn Mann2010/07/08 11:06 AM
      A bit off baseDavid Kanter2010/07/08 11:27 AM
        A bit off baseIan Ameline2010/07/09 10:10 AM
          A bit off baseMichael S2010/07/10 02:13 PM
            A bit off baseIan Ameline2010/07/11 07:51 AM
  A bit off baseDavid Kanter2010/07/07 09:46 PM
    A bit off baseAnon2010/07/08 12:47 AM
      A bit off baseanon2010/07/08 02:15 AM
        A bit off baseGabriele Svelto2010/07/08 04:11 AM
          Physics engine historyPeter Clare2010/07/08 04:49 AM
            Physics engine historyNull Pointer Exception2010/07/08 06:07 AM
              Physics engine historyRalf2010/07/08 03:09 PM
                Physics engine historyDavid Kanter2010/07/08 04:16 PM
                  Physics engine historysJ2010/07/08 11:36 PM
                    Physics engine historyGabriele Svelto2010/07/09 12:59 AM
                      Physics engine historysJ2010/07/13 06:35 AM
                    Physics engine historyDavid Kanter2010/07/09 09:25 AM
                      Physics engine historysJ2010/07/13 06:49 AM
                      Physics engine historyfvdbergh2010/07/13 07:27 AM
    A bit off baseJohn Mann2010/07/08 11:11 AM
      A bit off baseDavid Kanter2010/07/08 11:31 AM
        150 GFLOP/s measured?anon2010/07/08 07:10 PM
          150 GFLOP/s measured?David Kanter2010/07/08 07:53 PM
            150 GFLOP/s measured?Aaron Spink2010/07/08 09:05 PM
              150 GFLOP/s measured?anon2010/07/08 09:31 PM
                150 GFLOP/s measured?Aaron Spink2010/07/08 10:43 PM
                  150 GFLOP/s measured?David Kanter2010/07/08 11:27 PM
                    150 GFLOP/s measured?Ian Ollmann2010/07/19 01:14 AM
                      150 GFLOP/s measured?anon2010/07/19 06:39 AM
                        150 GFLOP/s measured?hobold2010/07/19 07:26 AM
                          Philosophy for achieving peakDavid Kanter2010/07/19 11:49 AM
                      150 GFLOP/s measured?Linus Torvalds2010/07/19 07:36 AM
                        150 GFLOP/s measured?Richard Cownie2010/07/19 08:42 AM
                          150 GFLOP/s measured?Aaron Spink2010/07/19 08:56 AM
                            150 GFLOP/s measured?hobold2010/07/19 09:30 AM
                              150 GFLOP/s measured?Groo2010/07/19 02:31 PM
                                150 GFLOP/s measured?hobold2010/07/19 04:17 PM
                                  150 GFLOP/s measured?Groo2010/07/19 06:18 PM
                              150 GFLOP/s measured?Anon2010/07/19 06:18 PM
                            150 GFLOP/s measured?Mark Roulo2010/07/19 11:47 AM
                              150 GFLOP/s measured?slacker2010/07/19 12:55 PM
                                150 GFLOP/s measured?Mark Roulo2010/07/19 01:00 PM
                              150 GFLOP/s measured?anonymous422010/07/25 12:31 PM
                            150 GFLOP/s measured?Richard Cownie2010/07/19 12:41 PM
                              150 GFLOP/s measured?Linus Torvalds2010/07/19 02:57 PM
                                150 GFLOP/s measured?Richard Cownie2010/07/19 04:10 PM
                                150 GFLOP/s measured?Richard Cownie2010/07/19 04:10 PM
                                  150 GFLOP/s measured?hobold2010/07/19 04:25 PM
                                  150 GFLOP/s measured?Linus Torvalds2010/07/19 04:31 PM
                                    150 GFLOP/s measured?Richard Cownie2010/07/20 06:04 AM
                                150 GFLOP/s measured?jrl2010/07/20 01:18 AM
                            150 GFLOP/s measured?anonymous422010/07/25 12:00 PM
                              150 GFLOP/s measured?David Kanter2010/07/25 12:52 PM
                          150 GFLOP/s measured?Anon2010/07/19 06:15 PM
                            150 GFLOP/s measured?Linus Torvalds2010/07/19 07:27 PM
                              150 GFLOP/s measured?Anon2010/07/19 09:54 PM
                                150 GFLOP/s measured?anon2010/07/19 11:45 PM
                        150 GFLOP/s measured?hobold2010/07/19 09:14 AM
                          150 GFLOP/s measured?Linus Torvalds2010/07/19 11:56 AM
                            150 GFLOP/s measured?a reader2010/07/21 08:16 PM
                              150 GFLOP/s measured?Linus Torvalds2010/07/21 09:05 PM
                                150 GFLOP/s measured?anon2010/07/22 02:09 AM
                                  150 GFLOP/s measured?a reader2010/07/22 07:53 PM
                                    150 GFLOP/s measured?gallier22010/07/23 05:58 AM
                                      150 GFLOP/s measured?a reader2010/07/25 08:35 AM
                                        150 GFLOP/s measured?David Kanter2010/07/25 11:49 AM
                                          150 GFLOP/s measured?a reader2010/07/26 07:03 PM
                                            150 GFLOP/s measured?Michael S2010/07/28 01:38 AM
                                              150 GFLOP/s measured?Gabriele Svelto2010/07/28 01:44 AM
                                    150 GFLOP/s measured?anon2010/07/23 04:55 PM
                                      150 GFLOP/s measured?slacker2010/07/24 12:48 AM
                                        150 GFLOP/s measured?anon2010/07/24 02:36 AM
                                    150 GFLOP/s measured?Vincent Diepeveen2010/07/27 05:37 PM
                                      150 GFLOP/s measured??2010/07/27 11:42 PM
                                        150 GFLOP/s measured?slacker2010/07/28 05:55 AM
                                      Intel's clock rate projectionsAM2010/07/28 02:03 AM
                                        nostalgia ain't what it used to besomeone2010/07/28 05:38 AM
                                          Intel's clock rate projectionsAM2010/07/28 10:12 PM
                        Separate the OoO-ness from speculative-ness?2010/07/20 07:19 AM
                          Separate the OoO-ness from speculative-nessMark Christiansen2010/07/20 02:26 PM
                          Separate the OoO-ness from speculative-nessslacker2010/07/20 06:04 PM
                            Separate the OoO-ness from speculative-nessMatt Sayler2010/07/20 06:10 PM
                              Separate the OoO-ness from speculative-nessslacker2010/07/20 09:37 PM
                                Separate the OoO-ness from speculative-ness?2010/07/20 11:51 PM
                                  Separate the OoO-ness from speculative-nessanon2010/07/21 02:16 AM
                                    Separate the OoO-ness from speculative-ness?2010/07/21 07:05 AM
                                      Software conventionsPaul A. Clayton2010/07/21 08:52 AM
                                        Software conventions?2010/07/22 05:43 AM
                                      SpeculationDavid Kanter2010/07/21 10:32 AM
                                        Pipelining affects the ISA?2010/07/22 10:58 PM
                                          Pipelining affects the ISA?2010/07/22 11:14 PM
                                          Pipelining affects the ISArwessel2010/07/23 12:03 AM
                                            Pipelining affects the ISA?2010/07/23 05:50 AM
                                            Pipelining affects the ISA?2010/07/23 06:10 AM
                                              Pipelining affects the ISAThiago Kurovski2010/07/23 02:59 PM
                                                Pipelining affects the ISAanon2010/07/24 07:35 AM
                                                  Pipelining affects the ISAThiago Kurovski2010/07/24 11:12 AM
                                          Pipelining affects the ISAGabriele Svelto2010/07/26 02:50 AM
                                            Pipelining affects the ISAIlleglWpns2010/07/26 05:14 AM
                                              Pipelining affects the ISAMichael S2010/07/26 03:33 PM
                                      Separate the OoO-ness from speculative-nessanon2010/07/21 05:53 PM
                                        Separate the OoO-ness from speculative-ness?2010/07/22 04:15 AM
                                          Separate the OoO-ness from speculative-nessanon2010/07/22 04:27 AM
                                      Separate the OoO-ness from speculative-nessslacker2010/07/21 07:45 PM
                                        Separate the OoO-ness from speculative-nessanon2010/07/22 01:57 AM
                                        Separate the OoO-ness from speculative-ness?2010/07/22 05:26 AM
                                          Separate the OoO-ness from speculative-nessDan Downs2010/07/22 08:14 AM
                                          Confusing and not very useful definitionDavid Kanter2010/07/22 12:41 PM
                                            Confusing and not very useful definition?2010/07/22 10:58 PM
                                              Confusing and not very useful definitionUngo2010/07/24 12:06 PM
                                                Confusing and not very useful definition?2010/07/25 10:23 PM
                            Separate the OoO-ness from speculative-nesssomeone2010/07/20 08:02 PM
                              Separate the OoO-ness from speculative-nessThiago Kurovski2010/07/21 04:13 PM
            You are just quoting SINGLE precision flops? OMG what planet do you live? Vincent Diepeveen2010/07/19 10:26 AM
              The prior poster was talking about SP (NT)David Kanter2010/07/19 11:34 AM
                All FFT's need double precisionVincent Diepeveen2010/07/19 02:02 PM
                  All FFT's need double precisionDavid Kanter2010/07/19 02:09 PM
                    All FFT's need double precisionVincent Diepeveen2010/07/19 04:06 PM
                  All FFT's need double precision - notMichael S2010/07/20 01:16 AM
                    All FFT's need double precision - notUngo2010/07/21 12:04 AM
                      All FFT's need double precision - notMichael S2010/07/21 02:35 PM
                      All FFT's need double precision - notEduardoS2010/07/21 02:52 PM
                        All FFT's need double precision - notAnon2010/07/21 05:23 PM
                          All FFT's need double precision - notRicardo B2010/07/26 07:46 AM
                        I'm on a boat!anon2010/07/22 11:42 AM
                        All FFT's need double precision - notVincent Diepeveen2010/07/24 11:39 PM
                          All FFT's need double precision - notslacker2010/07/25 03:27 AM
                            All FFT's need double precision - notRicardo B2010/07/26 07:40 AM
                          All FFT's need double precision - notEduardoS2010/07/25 08:37 AM
                            All FFT's need double precision - notMichael S2010/07/25 10:43 AM
                    All FFT's need double precision - notVincent Diepeveen2010/07/24 11:19 PM
      A bit off baseEduardoS2010/07/08 04:08 PM
        A bit off baseGroo2010/07/08 06:11 PM
          A bit off basejohn mann2010/07/08 06:58 PM
            All right...let's cool it...David Kanter2010/07/08 07:54 PM
    A bit off baseVincent Diepeveen2010/07/19 03:36 PM
Reply to this Topic
Name:
Email:
Topic:
Body: No Text
How do you spell avocado?