That's not the same thing. An instruction set is an inherent aspect of a CPU; you can't have a CPU without one. Also, you can emulate or translate instruction sets between general-purpose CPUs, or in most cases just recompile the higher-level source code. The underlying logic will be executed regardless.
> […] An instruction set is an inherent aspect of a CPU; you can't have a CPU without one.
Oh, yes, you can.
The following examples of
– Transport triggered architecture
– Dataflow architecture
– Optical and quantum computing
represent viable, general purpose (not general availability), albeit experimental, CPU's without instruction sets. That is, none of them have anything similar to «movq $1, %r0» or «add.w %r2, %r0, %r1».
FPGA's are another and a more conventional example of a general purpose (even if specialised) CPU without an instruction set.
Does that mean that x86 has a specific purpose now and is no longer a general purpose CPU?