atomicAdd - perform an atomic addition to a variable

       Copyright © 2012-2014 Khronos Group

[FIXME: source]                                    11/18/2024                                      ATOMICADD(3G)

intatomicAdd(inoutintmem,intdata);uintatomicAdd(inoutuintmem,uintdata);

atomicAdd performs an atomic addition of data to the contents of mem and returns the original contents of
       mem from before the addition occured. The contents of the memory being updated by the atomic operation
       are guaranteed not to be modified by any other assignment or atomic memory function in any shader
       invocation between the time the original value is read and the time the new value is written.

       Atomic memory functions are supported only for a limited set of variables. A shader will fail to compile
       if the value passed to the mem argument of an atomic memory function does not correspond to a buffer or
       shared variable. It is acceptable to pass an element of an array or a single component of a vector to the
       mem argument of an atomic memory function, as long as the underlying array or vector is a buffer or
       shared variable.

       atomicAdd - perform an atomic addition to a variable

mem
           The variable to use as the target of the operation.

       data
           The data to be added to mem.

atomicAnd(), atomicOr(), atomicXor(), atomicMin(), atomicMax(), atomicExchange(), atomicCompSwap()

       ┌───────────┬───────────────────────────────────────────────────────────────────────────────────┐
       │           │        OpenGLShadingLanguageVersion                                            │
       ├───────────┼──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┤
       │ Function  │ 1.10 │ 1.20 │ 1.30 │ 1.40 │ 1.50 │ 3.30 │ 4.00 │ 4.10 │ 4.20 │ 4.30 │ 4.40 │ 4.50 │
       │ Name      │      │      │      │      │      │      │      │      │      │      │      │      │
       ├───────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
       │ atomicAdd │  -   │  -   │  -   │  -   │  -   │  -   │  -   │  -   │  -   │  ✔   │  ✔   │  ✔   │
       └───────────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┘