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From:   Charles Papon <charles.papon.90@gmail.com>
Date:   Thu, 8 Aug 2019 14:18:53 +0200
Message-ID: <CAMabmMJ3beMcs38Boe11qcsQvqY+9u=2OqA0vCSKdL=n-cK9GQ@mail.gmail.com>
Subject: Re: [PATCH] riscv: kbuild: drop CONFIG_RISCV_ISA_C
To:     Bin Meng <bmeng.cn@gmail.com>
Cc:     Paul Walmsley <paul.walmsley@sifive.com>,
        Atish Patra <atish.patra@wdc.com>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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Please do not drop it.

Compressed instruction extension has some specific overhead in small
RISC-V FPGA softcore, especialy in the ones which can't implement the
register file read in a asynchronous manner because of the FPGA
technology.
What are reasons to enforce RVC ?

On Wed, Aug 7, 2019 at 2:29 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> On Wed, Aug 7, 2019 at 10:30 AM Paul Walmsley <paul.walmsley@sifive.com> wrote:
> >
> >
> > The baseline ISA support requirement for the RISC-V Linux kernel
> > mandates compressed instructions, so it doesn't make sense for
> > compressed instruction support to be configurable.
> >
> > Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
> > Cc: Atish Patra <atish.patra@wdc.com>
> >
> > ---
> >  arch/riscv/Kconfig  | 10 ----------
> >  arch/riscv/Makefile |  2 +-
> >  2 files changed, 1 insertion(+), 11 deletions(-)
> >
>
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
>
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