By: Wilco (Wilco.dijkstra.delete@this.ntlworld.com), December 22, 2018 4:37 am
Room: Moderated Discussions
Travis Downs (travis.downs.delete@this.gmail.com) on December 21, 2018 5:45 pm wrote:
> Wilco (Wilco.dijkstra.delete@this.ntlworld.com) on December 21, 2018 3:43 pm wrote:
> > That's not true - besides reducing I-cache misses, you also get a wider decode and rename for
> > free.
>
> Agreed about decode to some extent (it may not be exactly free if the decoder has to do the cracking),
> but as far as rename goes, doesn't cracking generally occur before rename, generally at or around decode?
> So by the time the ops hit the renamer you haven't saved anything vs two separate instructions.
Modern OoO cores do cracking at dispatch (eg. Cortex-A72 has 3-wide decode and rename but 5-wide dispatch, so it can crack 2 instructions per cycle).
Wilco
> Wilco (Wilco.dijkstra.delete@this.ntlworld.com) on December 21, 2018 3:43 pm wrote:
> > That's not true - besides reducing I-cache misses, you also get a wider decode and rename for
> > free.
>
> Agreed about decode to some extent (it may not be exactly free if the decoder has to do the cracking),
> but as far as rename goes, doesn't cracking generally occur before rename, generally at or around decode?
> So by the time the ops hit the renamer you haven't saved anything vs two separate instructions.
Modern OoO cores do cracking at dispatch (eg. Cortex-A72 has 3-wide decode and rename but 5-wide dispatch, so it can crack 2 instructions per cycle).
Wilco
Topic | Posted By | Date |
---|---|---|
RISC-V Summit Proceedings | Gabriele Svelto | 2018/12/19 08:36 AM |
RISC-V gut feelings | Konrad Schwarz | 2018/12/20 04:30 AM |
RISC-V inferior to ARMv8 | Heikki Kultala | 2018/12/20 07:36 AM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/20 01:31 PM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/20 02:18 PM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/21 03:43 AM |
RISC-V inferior to ARMv8 | Ronald Maas | 2018/12/21 09:35 AM |
RISC-V inferior to ARMv8 | juanrga | 2018/12/21 10:28 AM |
RISC-V inferior to ARMv8 | Maynard Handley | 2018/12/21 02:39 PM |
RISC-V inferior to ARMv8 | anon | 2018/12/21 03:38 PM |
RISC-V inferior to ARMv8 | juanrga | 2018/12/23 04:39 AM |
With similar logic nor do frequency (NT) | Megol | 2018/12/23 09:45 AM |
RISC-V inferior to ARMv8 | juanrga | 2018/12/23 04:44 AM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/23 06:21 AM |
RISC-V inferior to ARMv8 | Michael S | 2018/12/20 03:24 PM |
RISC-V inferior to ARMv8 | anon | 2018/12/20 04:22 PM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/21 06:16 PM |
RISC-V inferior to ARMv8 | anon | 2018/12/22 03:53 AM |
Execution runtimes and Spectre | Foo_ | 2018/12/22 06:02 AM |
RISC-V inferior to ARMv8 | Adrian | 2018/12/20 08:51 PM |
RISC-V inferior to ARMv8 | Doug S | 2018/12/20 11:10 PM |
RISC-V inferior to ARMv8 | Adrian | 2018/12/20 11:38 PM |
RISC-V inferior to ARMv8 | Michael S | 2018/12/21 02:31 AM |
RISC-V inferior to ARMv8 | Adrian | 2018/12/21 03:23 AM |
RISC-V inferior to ARMv8 | random person | 2018/12/21 02:04 AM |
RISC-V inferior to ARMv8 | dmcq | 2018/12/21 04:27 AM |
RISC-V inferior to ARMv8 | juanrga | 2018/12/21 10:36 AM |
RISC-V inferior to ARMv8 | Doug S | 2018/12/21 12:02 PM |
RISC-V inferior to ARMv8 | juanrga | 2018/12/21 10:23 AM |
RISC-V inferior to ARMv8 | Adrian | 2018/12/20 11:21 PM |
RISC-V inferior to ARMv8 | anon | 2018/12/21 01:48 AM |
RISC-V inferior to ARMv8 | Adrian | 2018/12/21 03:44 AM |
RISC-V inferior to ARMv8 | anon | 2018/12/21 05:24 AM |
RISC-V inferior to ARMv8 | Adrian | 2018/12/21 04:09 AM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/21 04:28 AM |
RISC-V inferior to ARMv8 | Michael S | 2018/12/21 02:27 AM |
RISC-V inferior to ARMv8 | Gabriele Svelto | 2018/12/21 01:09 PM |
RISC-V inferior to ARMv8 | Maynard Handley | 2018/12/21 02:58 PM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/21 03:43 PM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/21 05:45 PM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/22 04:37 AM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/22 06:54 AM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/22 10:32 AM |
Cracking is not free | Gabriele Svelto | 2018/12/22 02:09 AM |
Cracking is not free | Wilco | 2018/12/22 04:32 AM |
Cracking is not free | Travis Downs | 2018/12/22 07:07 AM |
Cracking is not free | Wilco | 2018/12/22 07:38 AM |
Cracking is not free | Travis Downs | 2018/12/22 07:47 AM |
Cracking is not free | Wilco | 2018/12/22 10:24 AM |
Cracking is not free | Travis Downs | 2018/12/25 03:41 PM |
Cracking is not free | anon.1 | 2018/12/25 08:14 PM |
multi-instruction decode and rename | Paul A. Clayton | 2018/12/22 06:45 PM |
Cracking is not free | Gabriele Svelto | 2018/12/22 12:30 PM |
Cracking is not free | Wilco | 2018/12/23 06:48 AM |
Cracking is not free | Michael S | 2018/12/23 08:09 AM |
Cracking is not free | Gabriele Svelto | 2018/12/26 02:53 PM |
RISC-V inferior to ARMv8 | rwessel | 2018/12/21 01:13 PM |
RISC-V inferior to ARMv8 | Seni | 2018/12/21 02:33 PM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/21 03:33 PM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/21 05:49 PM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/22 04:58 AM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/22 07:03 AM |
RISC-V inferior to ARMv8 | Wilco | 2018/12/22 07:22 AM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/22 07:40 AM |
RISC-V inferior to ARMv8 | dmcq | 2018/12/21 03:57 AM |
RISC-V inferior to ARMv8 | Konrad Schwarz | 2018/12/21 02:25 AM |
RISC-V inferior to ARMv8 | j | 2018/12/21 10:46 AM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/21 06:08 PM |
RISC-V inferior to ARMv8 | dmcq | 2018/12/22 07:45 AM |
RISC-V inferior to ARMv8 | Travis Downs | 2018/12/22 07:50 AM |
RISC-V inferior to ARMv8 | Michael S | 2018/12/22 08:15 AM |
RISC-V inferior to ARMv8 | dmcq | 2018/12/22 10:41 AM |
RISC-V inferior to ARMv8 | AnonQ | 2018/12/22 08:13 AM |
RISC-V gut feelings | dmcq | 2018/12/20 07:41 AM |
RISC-V initial take | Konrad Schwarz | 2018/12/21 02:17 AM |
RISC-V initial take | dmcq | 2018/12/21 03:23 AM |
RISC-V gut feelings | Montaray Jack | 2018/12/22 02:56 PM |
RISC-V gut feelings | dmcq | 2018/12/23 04:38 AM |
RISC-V Summit Proceedings | juanrga | 2018/12/21 10:47 AM |
RISC-V Summit Proceedings | dmcq | 2018/12/22 06:21 AM |
RISC-V Summit Proceedings | Montaray Jack | 2018/12/22 02:03 PM |
RISC-V Summit Proceedings | dmcq | 2018/12/23 04:39 AM |
RISC-V Summit Proceedings | anon2 | 2018/12/21 10:57 AM |
RISC-V Summit Proceedings | Michael S | 2018/12/22 08:36 AM |
RISC-V Summit Proceedings | Anon | 2018/12/22 05:51 PM |
Not Stanford MIPS but commercial MIPS | Paul A. Clayton | 2018/12/23 03:05 AM |
Not Stanford MIPS but commercial MIPS | Michael S | 2018/12/23 03:49 AM |
Not Stanford MIPS but commercial MIPS | dmcq | 2018/12/23 04:52 AM |