This microbenchmark performs random lookups into an array of 64-byte payloads through a pointer table. It is useful for evaluating irregular memory accesses and the effect of software prefetching.

From the random pointer access benchmark directory, use the provided Makefile to build the binary with an optimizing C++ compiler:

make

Set CXX, CXXFLAGS, or LDFLAGS on the command line to override the defaults. Run make clean to remove the compiled binary.

The executable accepts the number of payload slots (array_size), the number of random lookups to execute, and optional flags:

./random_pointer_access <array_size> <num_lookups> [--prefetch-distance N] [--verify]

• If --prefetch-distance is omitted or zero, the benchmark performs lookups without software prefetching.
• Setting a positive N issues a lookahead preload before each dereference so you can explore the effect of prefetch distance tuning.
• Passing --verify performs a correctness check on the gathered payloads.

Example:

./random_pointer_access 1048576 2000000 --prefetch-distance 8
./random_pointer_access 1048576 2000000 --verify

On 64-bit systems, the program allocates 72 bytes for each array entry and 68 bytes for each lookup entry; ensure the system has sufficient memory for the requested array_size and num_lookups.