Seems to be that mix(a, b, 1.0) will not give you b. on nvidia this is not a problem as a was initialized with 0.0, but on AMD it can be any floating point number, resulting that mix(inf, b, 1.0) was still more to inf than to b.
Seems to be that mix(a, b, 1.0) will not give you b. on nvidia this is not a problem as a was initialized with 0.0, but on AMD it can be any floating point number, resulting that mix(inf, b, 1.0) was still more to inf than to b.