[libcamera-devel] [PATCH v5 06/10] ipa: raspberry: replace abs() with std::abs()

[Kieran Bingham]

Quoting Nicholas Roth via libcamera-devel (2022-10-28 04:17:22)
> From: Nicholas Roth <nicholas at rothemail.net>
> 
> pwl.cpp uses abs() instead of std::abs(), which causes unexpected
> behavior in the Clang compiler used for Android. Replace with
> C++-standard absolute value function std::abs(), which supports
> double-precision absolute values in a standard way.
> 
> Signed-off-by: Nicholas Roth <nicholas at rothemail.net>

>From Jacopo on v1:

Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

And from me:

Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

Though we really might have to do a bit of extra validation here:

 https://stackoverflow.com/questions/21392627/abs-vs-stdabs-what-does-the-reference-say

Seems a bit worrying.

Naush - any idea here? 


> ---
>  src/ipa/raspberrypi/controller/pwl.cpp | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/src/ipa/raspberrypi/controller/pwl.cpp b/src/ipa/raspberrypi/controller/pwl.cpp
> index c59f5fa1..70c2e24b 100644
> --- a/src/ipa/raspberrypi/controller/pwl.cpp
> +++ b/src/ipa/raspberrypi/controller/pwl.cpp
> @@ -6,6 +6,7 @@
>   */
>  
>  #include <cassert>
> +#include <cmath>
>  #include <stdexcept>
>  
>  #include "pwl.h"
> @@ -168,7 +169,7 @@ Pwl Pwl::compose(Pwl const &other, const double eps) const
>         while (thisSpan != (int)points_.size() - 1) {
>                 double dx = points_[thisSpan + 1].x - points_[thisSpan].x,
>                        dy = points_[thisSpan + 1].y - points_[thisSpan].y;
> -               if (abs(dy) > eps &&
> +               if (std::abs(dy) > eps &&
>                     otherSpan + 1 < (int)other.points_.size() &&
>                     points_[thisSpan + 1].y >=
>                             other.points_[otherSpan + 1].x + eps) {
> @@ -181,7 +182,7 @@ Pwl Pwl::compose(Pwl const &other, const double eps) const
>                                  points_[thisSpan].y) *
>                                         dx / dy;
>                         thisY = other.points_[++otherSpan].x;
> -               } else if (abs(dy) > eps && otherSpan > 0 &&
> +               } else if (std::abs(dy) > eps && otherSpan > 0 &&
>                            points_[thisSpan + 1].y <=
>                                    other.points_[otherSpan - 1].x - eps) {
>                         /*
> -- 
> 2.34.1
>