GPU and CPU floating point equivalence

We have an algorithm that has been running floating point on CPUs for years, creating images.
We're moving the algorithm onto GPU, but the client strongly insists that the output must be identical between CPU and GPU.
We have fixed point implementations for both CPU and GPU, so we can meet this criteria, however the fixed point introduces small inaccuracies at extreme corner cases, so we would like to avoid using this where possible.
So we would like to know if floating point operations on Intel GPU and Intel CPU will always result in the same floating point output, thus removing the need for the fixed point implementation in all-Intel environments.
Can you tell me whether this assumption is reasonable?