[PATCH] ipa/rpi/controller: Use fabs for calculating absolute values

[Kieran Bingham]

Hi Maarten,

Thank you for highlighting this. I'm curious that it hasn't come up in
our builds yet! What version of clang are you using?

Quoting Maarten Lankhorst (2024-08-15 10:37:15)
> I was getting the following error in clang:
> ../src/ipa/rpi/controller/rpi/awb.cpp:508:6: error: using integer absolute value function 'abs' when argument is of floating point type [-Werror,-Wabsolute-value]
>         if (abs(denominator) > eps) {
>             ^
> ../src/ipa/rpi/controller/rpi/awb.cpp:508:6: note: use function 'std::abs' instead

Is there a preference against the recommended std::abs?

>         if (abs(denominator) > eps) {
>             ^~~
>             std::abs
> 
> Signed-off-by: Maarten Lankhorst <dev at lankhorst.se>
> ---
>  src/ipa/rpi/controller/rpi/awb.cpp | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/ipa/rpi/controller/rpi/awb.cpp b/src/ipa/rpi/controller/rpi/awb.cpp
> index f45525bc..c5750c84 100644
> --- a/src/ipa/rpi/controller/rpi/awb.cpp
> +++ b/src/ipa/rpi/controller/rpi/awb.cpp
> @@ -505,7 +505,7 @@ static double interpolateQuadatric(ipa::Pwl::Point const &a, ipa::Pwl::Point con
>         const double eps = 1e-3;
>         ipa::Pwl::Point ca = c - a, ba = b - a;
>         double denominator = 2 * (ba.y() * ca.x() - ca.y() * ba.x());
> -       if (abs(denominator) > eps) {
> +       if (fabs(denominator) > eps) {
>                 double numerator = ba.y() * ca.x() * ca.x() - ca.y() * ba.x() * ba.x();
>                 double result = numerator / denominator + a.x();
>                 return std::max(a.x(), std::min(c.x(), result));
> -- 
> 2.39.2
>