Bug 1090 - feedback on OPF SVP64 RFC for "bigint" instructions: ls003.bignum
Summary: feedback on OPF SVP64 RFC for "bigint" instructions: ls003.bignum
Alias: None
Product: Libre-SOC's first SoC
Classification: Unclassified
Component: Specification (show other bugs)
Version: unspecified
Hardware: Other Linux
: --- enhancement
Assignee: Luke Kenneth Casson Leighton
URL: https://libre-soc.org/openpower/sv/rf...
Depends on: 1029
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Reported: 2023-05-25 01:14 BST by Luke Kenneth Casson Leighton
Modified: 2023-12-01 09:33 GMT (History)
5 users (show)

See Also:
NLnet milestone: NLnet.2022-08-051.OPF
total budget (EUR) for completion of task and all subtasks: 2500
budget (EUR) for this task, excluding subtasks' budget: 2500
parent task for budget allocation: 1012
child tasks for budget allocation:
The table of payments (in EUR) for this task; TOML format:
lkcl={amount=1000,submitted=2023-12-01} red={amount=1500,submitted=2023-10-19,paid=2022-11-29}


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Description Luke Kenneth Casson Leighton 2023-05-25 01:14:54 BST
questions and feedback needed on ls003.bignum
also see presentation bug #1029
Comment 1 Paul Mackerras 2023-05-25 06:56:15 BST
Comments from IBM architects regarding the proposal:

The ls003 FX instructions use RC, aliased as RS, as the second output. I think the architecture doesn't alias registers thus. And I think RS is never used as a target.

And for Load with Update instructions (which I think are the only FX instructions that currently have two outputs) the second output register is RA. And, for existing instructions that use RS, RS is in bits 6:10, not bits 21:25 as in ls003.
Comment 2 shriya.sharma 2023-10-19 10:29:12 BST

Comment 3 shriya.sharma 2023-10-19 10:41:58 BST

Comment 4 Luke Kenneth Casson Leighton 2023-10-19 11:41:33 BST
appreciated the feedback, closing this one as the purpose of the milestone
is to solicit feedback for later implementation.