preshaping before the 3d lut, such as with a 1d lut, is a common way to handle hdr tone mapping as well. See for example https://gpuopen.com/wp-content/uploads/

preshaping before the 3d lut, such as with a 1d lut, is a common way to handle hdr tone mapping as well. See for example https://gpuopen.com/wp-content/uploads/2016/03/GdcVdrLottes.pdf https://gpuopen.com/wp-content/uploads/2016/03/GdcVdrLottes....