| Summary: | feedback on OPF SVP64 RFC for "managment" instructions: ls008 | ||
|---|---|---|---|
| Product: | Libre-SOC's first SoC | Reporter: | Luke Kenneth Casson Leighton <lkcl> |
| Component: | Specification | Assignee: | Dmitry Selyutin <ghostmansd> |
| Status: | CONFIRMED --- | ||
| Severity: | enhancement | CC: | ghostmansd, libre-soc-isa, paulus |
| Priority: | --- | ||
| Version: | unspecified | ||
| Hardware: | Other | ||
| OS: | Linux | ||
| URL: | https://libre-soc.org/openpower/sv/rfc/ls008/ | ||
| 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: |
ghostmansd=1250
lkcl=1250
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| Bug Depends on: | 914, 1040, 1093 | ||
| Bug Blocks: | 1096 | ||
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Description
Luke Kenneth Casson Leighton
2023-05-25 00:35:45 BST
. Luke, could you, please, clarify, what's assumed here with "remove _RT and _RA"? From the page I saw this: Notation, Section 1.3.2 When destination register operands (RT, RS) are prefixed by a single underscore (_RT, _RS) the variable also contains the contents of the instruction field. This avoids confusion in pseudocode when a destination register is assigned (RT <- x) but earlier it was the operand bits that were checked (if RT = 0). I assume that we need to discard the underscore from pseudocode variables, is it correct? (In reply to Dmitry Selyutin from comment #2) > Luke, could you, please, clarify, what's assumed here with "remove _RT and > _RA"? From the page I saw this: > > Notation, Section 1.3.2 > When destination register operands (RT, RS) are prefixed by a single > underscore (_RT, _RS) the variable also contains the contents of the > instruction field. This avoids confusion in pseudocode when a destination > register is assigned (RT <- x) but earlier it was the operand bits that were > checked (if RT = 0). > > I assume that we need to discard the underscore from pseudocode variables, > is it correct? yes. basically (RA) is for accessing the *contents of the regfile* for register RA, where "RA" is just "the register number". however if you want to *assign* to register RA in Power ISA section 1.3 notation you do "RA <- xyz" which obviously does NOT chnge the 5 bits in the binary instruction. this confused the hell out of me so i added _RA notation. unnecessarily. has to go. |