Bug 1215 - sv.bc needs to loop on scalar BI
Summary: sv.bc needs to loop on scalar BI
Status: RESOLVED FIXED
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/br...
Depends on:
Blocks:
 
Reported: 2023-11-27 08:43 GMT by Luke Kenneth Casson Leighton
Modified: 2023-11-27 14:19 GMT (History)
2 users (show)

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Description Luke Kenneth Casson Leighton 2023-11-27 08:43:15 GMT 
just as with sv.cmpi/ff and in the maxloc example there
is a need to loop on scalar in sv.bc*

in this case however it should have been looping anyway
because BI is a *source* not a destination.

this is the mistake:

https://git.libre-soc.org/?p=openpower-isa.git;a=blob;f=src/openpower/decoder/isa/caller.py;h=07aa8bb0b8c2f70bcd623351198c1366242917ba;hb=HEAD#l2247

* DONE: fixed mistake
* TODO: branches page
Comment 1 Luke Kenneth Casson Leighton 2023-11-27 09:46:05 GMT 
TODO: note in the spec that BI is a source. do a quick Programmer Note
to say "if single needed use 1<<r3 predicate mask or other single-bit mask"
Comment 2 Luke Kenneth Casson Leighton 2023-11-27 14:06:51 GMT 
commit 2eb5abb845808c436797f3a5449f847fefdacca8 (origin/master, origin/HEAD, master)
Author: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date:   Mon Nov 27 10:08:43 2023 +0000

    got sv.bc working for pospopcount
Comment 3 Luke Kenneth Casson Leighton 2023-11-27 14:19:11 GMT 
added note on sv.bc use of 1<<r3 recommended for single-scalar test
https://git.libre-soc.org/?p=libreriscv.git;a=commitdiff;h=739d73fb4a