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Re: [PATCH v2] fpu/softfloat: set invalid excp flag for RISC-V muladd in
From: |
Alistair Francis |
Subject: |
Re: [PATCH v2] fpu/softfloat: set invalid excp flag for RISC-V muladd instructions |
Date: |
Thu, 22 Apr 2021 10:05:23 +1000 |
On Wed, Apr 21, 2021 at 12:17 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 4/19/21 6:31 PM, frank.chang@sifive.com wrote:
> > From: Frank Chang<frank.chang@sifive.com>
> >
> > In IEEE 754-2008 spec:
> > Invalid operation exception is signaled when doing:
> > fusedMultiplyAdd(0, Inf, c) or fusedMultiplyAdd(Inf, 0, c)
> > unless c is a quiet NaN; if c is a quiet NaN then it is
> > implementation defined whether the invalid operation exception
> > is signaled.
> >
> > In RISC-V Unprivileged ISA spec:
> > The fused multiply-add instructions must set the invalid
> > operation exception flag when the multiplicands are Inf and
> > zero, even when the addend is a quiet NaN.
> >
> > This commit set invalid operation execption flag for RISC-V when
> > multiplicands of muladd instructions are Inf and zero.
> >
> > Signed-off-by: Frank Chang<frank.chang@sifive.com>
> > ---
> > fpu/softfloat-specialize.c.inc | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
>
> Alistair, will you take this via your riscv queue?
Yep, getting it now
Alistair
>
>
> r~
>