Re: [RFC PATCH V3 00/11] riscv: Add vector ISA support

From: Greentime Hu
Date: Sun Mar 08 2020 - 23:44:33 EST


On Sun, Mar 8, 2020 at 5:50 PM <guoren@xxxxxxxxxx> wrote:
>
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
>
> The implementation follow the RISC-V "V" Vector Extension draft v0.8 with
> 128bit-vlen and it's based on linux-5.6-rc3 and tested with qemu [1].
>
> The patch implement basic context switch, sigcontext save/restore and
> ptrace interface with a new regset NT_RISCV_VECTOR. Only fixed 128bit-vlen
> is implemented. We need to discuss about vlen-size for libc sigcontext and
> ptrace (the maximum size of vlen is unlimited in spec).
>
> Puzzle:
> Dave Martin has talked "Growing CPU register state without breaking ABI" [2]
> before, and riscv also met vlen size problem. Let's discuss the common issue
> for all architectures and we need a better solution for unlimited vlen.
>
> Any help are welcomed :)
>
> 1: https://github.com/romanheros/qemu.git branch:vector-upstream-v3

Hi Guo,

Thanks for your patch.
It seems the qemu repo doesn't have this branch?