[Libre-soc-isa] [Bug 1091] questions and feedback on ls004 shift/add

bugzilla-daemon at libre-soc.org bugzilla-daemon at libre-soc.org
Sat May 27 11:33:55 BST 2023


Luke Kenneth Casson Leighton <lkcl at lkcl.net> changed:

           What    |Removed                     |Added
                 CC|                            |paulus at ozlabs.org

--- Comment #2 from Luke Kenneth Casson Leighton <lkcl at lkcl.net> ---
moved from https://bugs.libre-soc.org/show_bug.cgi?id=968#c23

(In reply to Paul Mackerras from
> Hopefully this is the right place to submit feedback about ls004; if not
> then Luke could add a pointer to the right place to the OPF gitea issue.

done sorry.

> Comments from IBM architects regarding the proposal:
> The ls004 instructions use "sm" as the name of the shift-amount field. sm is
> not a split field, so the field name should be capitalized.

ahh now i know what capital/lower means.

> (I'm not sure
> what "sm" stands for. "shift minus (1)"? If yes, SHM1 might be a better
> name. (ls004 doesn't include a definition of the field for Section 1.6.3.))

yes this one isn't quite ready for submission, still in draft.
insights still really helpful.

we are trying to avoid yet another definition of "SH" but now i
look at the new Z23-Form it is separate so not likely to be confused

|  0-5  | 6-10 | 11-15 | 16-20 | 21-22 | 23-30 | 31 | Form     |
|  PO   | RT   |  RA   |  RB   |  SH   |  XO   | Rc | Z23-Form |

> An additional comment is that the architecture uses "s" to stand for "Shift"
> in Shift instruction mnemonics, not "sh" as in ls004. (ls003 uses "s".)

noted as action-point, ty.

You are receiving this mail because:
You are on the CC list for the bug.

More information about the Libre-SOC-ISA mailing list