By: Dean M (dean.m8.delete@this.gmail.com), May 16, 2007 11:09 am
Room: Moderated Discussions
Great read. Thanks.
Just a few things:
"...16 XMM registers, which actually occupy 2 slots, since they are 128 bits wide."
This is true for the K8, but not for Barcelona.
From the AMD 10h optimization guide:
"A floating-point XMM register is viewed as one 128-bit register internal to the processor.
Current generation processors cannot write a 64-bit half of a 128-bit XMM register without having a merge dependency on the other 64-bit half."
Also, the K8/Barcelona diagrams would seem to suggest that data is stored from LSU1 and loaded to LSU2, but that's not the case as you yourself have written in the article.
Stores are written (after retirement) from LSU2 exclusively. While loads can be initialized from either LSU1 or LSU2, the actual data is passed directly to the IFFRF (and can be cough by a reservation station or ALU on the way there).
From the same diagram: FPMISC should present its data directly to LSU1, instead of going through a reservation station.
And a typo: 44 Entry Integer Future File – should be 40.
Just a few things:
"...16 XMM registers, which actually occupy 2 slots, since they are 128 bits wide."
This is true for the K8, but not for Barcelona.
From the AMD 10h optimization guide:
"A floating-point XMM register is viewed as one 128-bit register internal to the processor.
Current generation processors cannot write a 64-bit half of a 128-bit XMM register without having a merge dependency on the other 64-bit half."
Also, the K8/Barcelona diagrams would seem to suggest that data is stored from LSU1 and loaded to LSU2, but that's not the case as you yourself have written in the article.
Stores are written (after retirement) from LSU2 exclusively. While loads can be initialized from either LSU1 or LSU2, the actual data is passed directly to the IFFRF (and can be cough by a reservation station or ALU on the way there).
From the same diagram: FPMISC should present its data directly to LSU1, instead of going through a reservation station.
And a typo: 44 Entry Integer Future File – should be 40.
Topic | Posted By | Date |
---|---|---|
Barcelona Article Online | David Kanter | 2007/05/16 03:20 AM |
Barcelona Article Online | PiedPiper | 2007/05/16 05:12 AM |
Yes, I left out a sentence there. Fixed (NT) | David Kanter | 2007/05/16 12:07 PM |
Barcelona Article Online | anonymous | 2007/05/16 06:01 AM |
Barcelona Article Online | Anonymous | 2007/05/16 06:28 PM |
Barcelona Article Online | anonymous | 2007/05/16 07:52 PM |
Barcelona Article Online | Anonymous1 | 2007/05/16 07:08 AM |
Barcelona Article Online | Dean M | 2007/05/16 11:09 AM |
Barcelona Article Online | David Kanter | 2007/05/16 12:38 PM |
Barcelona Article Online | Dean M | 2007/05/16 02:10 PM |
Barcelona Article Online | IntelUser2000 | 2007/05/16 02:59 PM |
Barcelona Article Online | Linus Torvalds | 2007/05/16 03:24 PM |
Barcelona Article Online | David Kanter | 2007/05/16 04:57 PM |
Barcelona Article Online | Michael S | 2007/05/17 05:07 AM |
Barcelona Article Online | IntelUser2000 | 2007/05/18 08:58 PM |
8 socket servers | Doug Siebert | 2007/05/16 04:58 PM |
8 socket servers | Michael S | 2007/05/17 05:20 AM |
8 socket servers | Joe Chang | 2007/05/17 07:38 AM |
8 socket servers | Alex Jones | 2007/05/17 09:35 AM |
8 socket servers | Jose | 2007/05/23 08:23 AM |
8 socket servers | Michael S | 2007/05/23 11:37 AM |
8 socket servers | anonymous | 2007/05/26 03:49 PM |
8 socket servers | Joe Chang | 2007/05/27 01:46 PM |
8 socket servers | Doug Siebert | 2007/05/23 09:56 PM |
8 socket servers | Joe Chang | 2007/05/24 04:33 AM |
8 socket servers | Anonymous | 2007/05/24 11:18 AM |
8 socket servers | Doug Siebert | 2007/05/24 10:47 PM |
8 socket servers | Linus Torvalds | 2007/05/25 10:35 AM |
8 socket servers | Nick | 2007/05/25 02:29 AM |
Performance estimation seems odd | Hotar | 2007/05/17 01:54 AM |
Performance estimation seems odd | David Kanter | 2007/05/17 08:38 AM |
microops vs macroops on page 4 | Peter Lund | 2007/05/17 12:04 PM |
microops vs macroops on page 4 | David Kanter | 2007/05/21 04:51 PM |
microops vs macroops on page 4 | EduardoS | 2007/05/21 05:42 PM |
microops vs macroops on page 4 | dess | 2007/05/21 07:00 PM |
Barcelona Article Online | Peter Lund | 2007/05/17 12:25 PM |
macro-op vs. micro-op | dess | 2007/05/21 07:24 AM |
macro-op vs. micro-op | David Kanter | 2007/05/21 04:38 PM |
macro-op vs. micro-op | dess | 2007/05/21 06:15 PM |
macro-op vs. micro-op | David Kanter | 2007/05/22 12:11 AM |
macro-op vs. micro-op | dess | 2007/05/22 03:56 AM |
macro-op vs. micro-op | Gipsel | 2007/05/22 05:05 AM |
macro-op vs. micro-op | dess | 2007/05/22 05:52 AM |
macro-op vs. micro-op | anonymous | 2007/05/22 06:14 AM |
macro-op vs. micro-op | dess | 2007/05/22 06:44 AM |
macro-op vs. micro-op | EduardoS | 2007/05/22 02:19 PM |
macro-op vs. micro-op | dess | 2007/05/24 08:52 AM |
Stop comparing apples to oranges | EduardoS | 2007/05/22 02:30 PM |
Stop comparing apples to oranges | dess | 2007/05/22 04:09 PM |
Stop comparing apples to oranges | dess | 2007/05/22 04:30 PM |
Stop comparing apples to oranges | EduardoS | 2007/05/22 04:31 PM |
Stop comparing... apples to oranges? | dess | 2007/05/24 09:30 AM |
Stop comparing apples to oranges | anonymous | 2007/05/22 08:12 PM |
Stop comparing apples to oranges | EduardoS | 2007/05/23 02:50 PM |
macro-op vs. micro-op | anonymous | 2007/05/22 06:08 AM |
macro-op vs. micro-op | dess | 2007/05/22 06:40 AM |
macro-op vs. micro-op | anonymous | 2007/05/22 06:48 AM |
macro-op vs. micro-op | dess | 2007/05/21 08:30 PM |
macro-op vs. micro-op | anonymous | 2007/05/22 06:44 AM |
macro-op vs. micro-op | dess | 2007/05/24 09:38 AM |
macro-op vs. micro-op | Michael S | 2007/05/22 05:26 AM |