Fast Bounds Checking Using Debug Register

The ability to check memory references against their associated array/buffer bounds helps programmers to detect programming errors involving address overruns early on and thus avoid many difficult bugs down the line. This paper proposes a novel approach called Boud to the array bounds checking problem that exploits the debug register hardware in modern CPUs. Boud allocates a debug register to monitor accesses to an array or buffer within a loop so that accesses stepping outside the array's or buffer's bound will trigger a breakpoint exception. Because the number of debug registers is typically small, in cases when hardware bounds checking is not possible, Boud falls back to software bounds checking.