  We study the difficulty of computing topological entropy of subshifts
subjected to mixing restrictions. This problem is well-studied for
multidimensional subshifts of finite type : there exists a threshold in the
irreducibility rate where the difficulty jumps from computable to uncomputable,
but its location is an open problem. In this paper, we establish the location
of this threshold for a more general class, subshifts with decidable languages,
in any dimension.
