#version 310 es
layout(local_size_x = 1) in;

layout(std430, binding = 0) readonly buffer SSBO
{
    mat4 mvp;
    vec4 in_data[];
};

layout(std430, binding = 1) writeonly buffer SSBO2
{
    vec4 out_data[];
};

void main()
{
    uint ident = gl_GlobalInvocationID.x;
    vec4 idat = in_data[ident];

    int k = 0;

    // Continue with side effects.
    while (++k < 10)
    {
        idat *= 2.0;
        k++;
    }

    // Again used here ...
    for (uint i = 0u; i < 16u; i++, k++)
        for (uint j = 0u; j < 30u; j++)
            idat = mvp * idat;

    do
    {
        k++;
    } while (k > 10);
    out_data[ident] = idat;
}