The present invention discloses a processor comprising three-dimensional memory (3D-M) array (3D-processor). Instead of logic-based computation (LBC), the 3D-processor uses memory-based computation (MBC). It comprises an array of computing elements, with each computing element comprising an arithmetic logic circuit (ALC) and a 3D-M-based look-up table (3DM-LUT). The ALC performs arithmetic operations on the LUT data, while the 3DM-LUT is stored in at least one 3D-M array.