Shared code for array min/max functions

[kofa73]

Suggested by @TurboGit here: #19026 (comment)

There are many places where the min/max of a 3 or 4-element float or double array is calculated. The aim was to provide a shared implementation. Later, it turned out we already have some:

openmp_maths.h already has

DT_OMP_DECLARE_SIMD(aligned(vector:16))
static inline float v_maxf(const float vector[3])

and

DT_OMP_DECLARE_SIMD(aligned(vector:16))
static inline float v_minf(const float vector[3])

There is also dt_vector_channel_max in common/math.h from @ralfbrown edbaa84. As I understand it, that's vectorised code, it looks very surprising to me (counter-intuitive, with the extra allocations and extra work), but perf tuning is magic. :-)

We have a few places that may not be aligned, there are some that use 4 components, and there are a few in double precision.

[TurboGit]

Minor style comment, apart from that it is good to go to me. TIA.

[TurboGit]

Thanks! I'll handle the const.

[kofa73]

Thanks! I was away of the computer most of today, saw the last couple of messages only now.

[TurboGit]

No problem, the changes were trivial and you've done already all the hard work.

[zisoft]

With this PR merged, the compilation of noiceprofile.c is broken.

This is not detected by CI, but it breaks the nightly builds:

[738/965] Building C object share/darktable/tools/noise/CMakeFiles/darktable-noiseprofile.dir/noiseprofile.c.o
FAILED: [code=1] share/darktable/tools/noise/CMakeFiles/darktable-noiseprofile.dir/noiseprofile.c.o
/usr/bin/cc -DGDK_DISABLE_DEPRECATED -DGTK_DISABLE_DEPRECATED -DGTK_DISABLE_SINGLE_INCLUDES -DOS_OBJECT_USE_OBJC=0 -D_XOPEN_SOURCE=700 -I/Users/mario/src/darktable/build/share/darktable/tools/noise -I/Users/mario/src/darktable/tools/noise -fopenmp-version=51 -D_DARWIN_C_SOURCE -Wall -Wformat -Wformat-security -Wshadow -Wtype-limits -Wvla -Wthread-safety -Wno-unknown-pragmas -Wno-error=varargs -Wno-format-truncation -Wno-error=address-of-packed-member -Wno-typedef-redefinition -g -fPIE -MD -MT share/darktable/tools/noise/CMakeFiles/darktable-noiseprofile.dir/noiseprofile.c.o -MF share/darktable/tools/noise/CMakeFiles/darktable-noiseprofile.dir/noiseprofile.c.o.d -o share/darktable/tools/noise/CMakeFiles/darktable-noiseprofile.dir/noiseprofile.c.o -c /Users/mario/src/darktable/tools/noise/noiseprofile.c
In file included from /Users/mario/src/darktable/tools/noise/noiseprofile.c:6:
/Users/mario/src/darktable/tools/noise/../../src/common/dttypes.h:30:10: fatal error: 'gmodule.h' file not found
   30 | #include <gmodule.h>
      |          ^~~~~~~~~~~
1 error generated.

To reproduce you need to compile with -DBUILD_NOISE_TOOLS=ON

[kofa73]

Will look into it ASAP

[zisoft]

ok, this can be fixed by adding

    find_package(PkgConfig)
    pkg_check_modules(GMODULE REQUIRED gmodule-2.0)
    include_directories(${GMODULE_INCLUDE_DIRS})

in src/darktable/tools/noise/CMakeLists.txt

I will provide a PR, ok?