Re: [Qemu-devel] [PATCH 2/2] linux-user: Fix incorrect NaN detection in ARM nwfpe emulation

[Aurelien Jarno]

On Thu, Jan 06, 2011 at 06:34:44PM +0000, Peter Maydell wrote:
> The code in the linux-user ARM nwfpe emulation was incorrectly
> checking only for quiet NaNs when it should have been checking
> for any kind of NaN. This is probably because the code in
> question was taken from the Linux kernel, whose copy of the
> softfloat library had been modified so that float*_is_nan()
> returned true for all NaNs, not just quiet ones. The qemu
> equivalent function is float*_is_any_nan(), so use that.
> NB that this code is really obsolete since nobody uses FPE
> for actual arithmetic now; this is just cleanup following
> the recent renaming of the NaN related functions.
> 
> Signed-off-by: Peter Maydell <address@hidden>
> ---
>  linux-user/arm/nwfpe/fpa11_cprt.c |   14 +++++++-------
>  1 files changed, 7 insertions(+), 7 deletions(-)

Acked-by: Aurelien Jarno <address@hidden>

> diff --git a/linux-user/arm/nwfpe/fpa11_cprt.c 
> b/linux-user/arm/nwfpe/fpa11_cprt.c
> index 0e61b58..be54e95 100644
> --- a/linux-user/arm/nwfpe/fpa11_cprt.c
> +++ b/linux-user/arm/nwfpe/fpa11_cprt.c
> @@ -199,21 +199,21 @@ static unsigned int PerformComparison(const unsigned 
> int opcode)
>     {
>        case typeSingle:
>          //printk("single.\n");
> -     if (float32_is_quiet_nan(fpa11->fpreg[Fn].fSingle))
> +     if (float32_is_any_nan(fpa11->fpreg[Fn].fSingle))
>          goto unordered;
>          rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle, 
> &fpa11->fp_status);
>        break;
>  
>        case typeDouble:
>          //printk("double.\n");
> -     if (float64_is_quiet_nan(fpa11->fpreg[Fn].fDouble))
> +     if (float64_is_any_nan(fpa11->fpreg[Fn].fDouble))
>          goto unordered;
>          rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble, 
> &fpa11->fp_status);
>        break;
>  
>        case typeExtended:
>          //printk("extended.\n");
> -     if (floatx80_is_quiet_nan(fpa11->fpreg[Fn].fExtended))
> +     if (floatx80_is_any_nan(fpa11->fpreg[Fn].fExtended))
>          goto unordered;
>          rFn = fpa11->fpreg[Fn].fExtended;
>        break;
> @@ -225,7 +225,7 @@ static unsigned int PerformComparison(const unsigned int 
> opcode)
>     {
>       //printk("Fm is a constant: #%d.\n",Fm);
>       rFm = getExtendedConstant(Fm);
> -     if (floatx80_is_quiet_nan(rFm))
> +     if (floatx80_is_any_nan(rFm))
>          goto unordered;
>     }
>     else
> @@ -235,21 +235,21 @@ static unsigned int PerformComparison(const unsigned 
> int opcode)
>        {
>           case typeSingle:
>             //printk("single.\n");
> -        if (float32_is_quiet_nan(fpa11->fpreg[Fm].fSingle))
> +        if (float32_is_any_nan(fpa11->fpreg[Fm].fSingle))
>             goto unordered;
>             rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle, 
> &fpa11->fp_status);
>           break;
>  
>           case typeDouble:
>             //printk("double.\n");
> -        if (float64_is_quiet_nan(fpa11->fpreg[Fm].fDouble))
> +        if (float64_is_any_nan(fpa11->fpreg[Fm].fDouble))
>             goto unordered;
>             rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble, 
> &fpa11->fp_status);
>           break;
>  
>           case typeExtended:
>             //printk("extended.\n");
> -        if (floatx80_is_quiet_nan(fpa11->fpreg[Fm].fExtended))
> +        if (floatx80_is_any_nan(fpa11->fpreg[Fm].fExtended))
>             goto unordered;
>             rFm = fpa11->fpreg[Fm].fExtended;
>           break;
> -- 
> 1.6.3.3
> 
> 
> 

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
address@hidden                 http://www.aurel32.net