1. A numerical controller for a machine tool, for executing a machining program in a predetermined execution cycle and executing one or more auxiliary programs from among a plurality of auxiliary programs within the execution cycle, comprising: a CPU equipped in the numerical controller, the CPU to implement: a decoding unit configured to analyze the machining program and the plurality of auxiliary programs; a command element extraction unit configured to determine presence or absence of a relationship between the auxiliary programs, based on analysis result of the decoding unit; a load computing unit configured to compute a processing time of the machining program and processing times of the plurality of auxiliary programs, based on the analysis result of the decoding unit; an execution sequence computing unit configured to compute an execution sequence of the machining program and the plurality of auxiliary programs to execute the auxiliary programs that have the relationship with each other within a same execution cycle, responsive to the processing time of the machining program and the processing times of the plurality of auxiliary programs; a different load computing unit configured to measure the processing time of the machining program and the processing times of the auxiliary programs when the machining program and the auxiliary programs are executed in the execution processing unit; the execution sequence computing unit reconsiders the execution sequence, based on the processing time of the machining program and the processing times of the auxiliary programs that were measured by the different load computing unit; and an execution processing unit configured to execute the machining program and the auxiliary programs in accordance with the computed execution sequence.