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

[Laurent Pinchart]

On Fri, Aug 16, 2024 at 03:40:45PM +0200, Milan Zamazal wrote:
> Kieran Bingham <kieran.bingham at ideasonboard.com> writes:
> 
> > 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?
> 
> It happens to me too, with clang 18.1.6 on Fedora 40.

I'm very surprised, I tested with clang 18.1.8 locally and didn't see
any error. I would have fixed it already otherwise :-)

> > 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));

-- 
Regards,

Laurent Pinchart