optimize CrossEntropyBinary cost function (via Bas)
optimize CrossEntropyBinary cost function (via Bas)

fewer assignments (possibly better GPU compounding)
fewer operations (no more negates)

NervanaSystems/neon,Jokeren/neon,Jokeren/neon,NervanaSystems/neon,Jokeren/neon,NervanaSystems/neon,Jokeren/neon,NervanaSystems/neon