1. A data processing system for monitoring execution of instructions, the data processing system comprising: one or more processors, one or more computer-readable storage devices, and one or more computer readable memories; computer program instructions stored on the one or more computer-readable storage devices for execution by the one or more processors via the one or more memories for identifying an instruction for execution; computer program instructions stored on the one or more computer-readable storage devices for execution by the one or more processors via the one or more memories for comparing an address of the instruction to an address of a register in the processor; computer program instructions stored on the one or more computer-readable storage devices for execution by the one or more processors via the one or more memories for determining, responsive to comparing the address of the instruction to the address of the register in the processor, whether the instruction is within a contiguous range of instructions; computer program instructions stored on the one or more computer-readable storage devices for execution by the one or more processors via the one or more memories for counting, responsive to determining that the instruction is within the contiguous range of instructions, at least one of a number of times the contiguous range of instructions is entered during execution of a program and a first number of times the instruction has been executed; and computer program instructions stored on the one or more computer-readable storage devices for execution by the one or more processors via the one or more memories for providing, responsive to counting one of the first number of times the contiguous range of instructions is entered during execution of the program and the first number of times the instruction has been executed, a result of the counting.