Re: [Qemu-trivial] [Qemu-devel] [PATCH] fpu/softfloat.c: Remove pointless shift of always-zero value

[Aurelien Jarno <aurelien@aurel32.net>]

On Mon, Sep 24, 2012 at 05:28:35PM +0100, Peter Maydell wrote:
> In float16_to_float32, when returning an infinity, just pass zero
> as the mantissa argument to packFloat32(), rather than shifting
> a value which we know must be zero.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> Spotted by the clang static analyzer. This brings this code into line with
> the other float-to-float conversion functions and was probably a harmless
> cut-n-paste error from the normal-return codepath.
> 
>  fpu/softfloat.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fpu/softfloat.c b/fpu/softfloat.c
> index b29256a..01a28ca 100644
> --- a/fpu/softfloat.c
> +++ b/fpu/softfloat.c
> @@ -3007,7 +3007,7 @@ float32 float16_to_float32(float16 a, flag ieee STATUS_PARAM)
>          if (aSig) {
>              return commonNaNToFloat32(float16ToCommonNaN(a STATUS_VAR) STATUS_VAR);
>          }
> -        return packFloat32(aSign, 0xff, aSig << 13);
> +        return packFloat32(aSign, 0xff, 0);
>      }
>      if (aExp == 0) {
>          int8 shiftCount;
> -- 
> 1.7.9.5

Good catch!

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>

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