Bug 852

Summary:	implement grevlut*
Product:	Libre-SOC's first SoC	Reporter:	Luke Kenneth Casson Leighton <lkcl>
Component:	Source Code	Assignee:	Luke Kenneth Casson Leighton <lkcl>
Status:	CONFIRMED ---
Severity:	enhancement	CC:	andy.miroshnikov, ghostmansd, libre-soc-bugs, lkcl, programmerjake
Priority:	---
Version:	unspecified
Hardware:	Other
OS:	Linux
URL:	https://libre-soc.org/openpower/sv/bitmanip/
See Also:	https://bugs.libre-soc.org/show_bug.cgi?id=755
NLnet milestone:	NLnet.2022-08-107.ongoing	total budget (EUR) for completion of task and all subtasks:	2000
budget (EUR) for this task, excluding subtasks' budget:	2000	parent task for budget allocation:	1027
child tasks for budget allocation:		The table of payments (in EUR) for this task; TOML format:	jacob=1200 lkcl=800
Bug Depends on:
Bug Blocks:	836

Description Luke Kenneth Casson Leighton 2022-06-14 18:03:41 BST

OP_GREVLUT is needed, replacing OP_GREV, same process as for bug #755
and likely morphing that code.  formal correctness proof is needed,
unit tests etc.  TODO list (edit this comment):

Comment 1 Jacob Lifshay 2022-08-14 09:29:27 BST

lkcl, the commit where you disabled grev's tests should probably be reverted, because grev* will be an assembler alias for grevlut* with the appropriate immediate -- we want to test that that works.

https://git.libre-soc.org/?p=openpower-isa.git;a=commitdiff;h=657a78c6fb89eddf49feb70905801c683c2155f3

Comment 2 Luke Kenneth Casson Leighton 2022-08-14 10:30:45 BST

(In reply to Jacob Lifshay from comment #1)
> lkcl, the commit where you disabled grev's tests should probably be
> reverted, because grev* will be an assembler alias for grevlut* with the
> appropriate immediate -- we want to test that that works.

there are no assembler aliases in sv/trans/svp64.py's translator
(and none are going to be added).
 
when grevlut has been implemented it will become appropriate to
rewrite the grev unit tests to explicitly use the correct assembler
instruction.

until then the tests remain disabled so as not to have to spend time
hunting through old commits for removed code.

Comment 3 Dmitry Selyutin 2023-11-12 18:51:14 GMT

Hi folks, any updates on this task? I've been checking cold case of bug #836 which strives to add support for grevlut/grevluti for binutils.

Comment 4 Luke Kenneth Casson Leighton 2023-11-12 21:20:20 GMT

(In reply to Dmitry Selyutin from comment #3)
> Hi folks, any updates on this task? I've been checking cold case of bug #836
> which strives to add support for grevlut/grevluti for binutils.

you're welcome to implement it, if you like. i will help.