[llvm-dev] RISC-V LLVM sync-up call 19 Mar 2020

[Sam Elliott via llvm-dev]

Hi Evandro,

Thank you for writing this proposal.

I presume you have seen the FDPIC proposal on the RISC-V sw-dev mailing list [1]. I am keen that any gp-relative relocations that could be shared between the two proposals are shared and compatible with each other - I think this will make a major difference to maintainability and our ability to document these details.

Am I right in thinking your proposal only has one value for `gp` for the whole program, and thus it does not need to be saved or loaded in function prologs and epilogs?

Sam


[1]: https://groups.google.com/a/groups.riscv.org/forum/#!msg/sw-dev/ZjYUJswknQ4/WYRRylTwAAAJ



> On 19 Mar 2020, at 4:19 pm, Evandro Menezes via llvm-dev <llvm-dev at lists.llvm.org> wrote:
> 
> Here's the draft proposal for the compact code model on RV.  I'd appreciate your feedback before I propose it to the foundation and go about updating the psABI.
> 
> Thank you,
> <Compact Code Model.pdf>
> 
> __ 
> Evandro Menezes ◊ SiFive ◊ Austin, TX
> 
>> On Mar 19, 2020, at 8:58, Alex Bradbury via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>> 
>> For background on these calls, see
>> <http://lists.llvm.org/pipermail/llvm-dev/2019-September/135087.html>.
>> 
>> Reminder: the purpose is to co-ordinate between active contributors.
>> If you have support questions etc then it's best to post to llvm-dev.
>> 
>> We have a call each Thursday at 4pm GMT, via
>> <https://meet.google.com/ske-zcog-spp>.
>> 
>> I've created a shared calendar which may help in keeping track, which
>> is accessible at:
>>  * <https://calendar.google.com/calendar/b/1?cid=bG93cmlzYy5vcmdfMG41cGtlc2ZqY25wMGJoNWhwczFwMGJkODBAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ>
>>  * <https://calendar.google.com/calendar/ical/lowrisc.org_0n5pkesfjcnp0bh5hps1p0bd80%40group.calendar.google.com/public/basic.ics>
>> 
>> Issues to discuss today include the following:
>> * Improving rust code size by not forcing frame pointers
>> <https://github.com/rust-lang/rust/pull/69890>
>> * Compact code model (Evandro)
>> * Update on embedded PIC discussions
>> * Small data limit <https://reviews.llvm.org/D57497>
>> * Bitmanip / experimental extension status
>> * ELF attribute support close to merging
>> <https://reviews.llvm.org/D75833> <https://reviews.llvm.org/D74023>
>> * No other topics were submitted, as always, please do submit things
>> you'd like to discuss
>> 
>> Best,
>> 
>> Alex
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> 
> _______________________________________________
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> llvm-dev at lists.llvm.org
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--
Sam Elliott
Software Developer - LLVM and OpenTitan
lowRISC CIC