This collection provides a similar API to that described in Profile-Guided Meta-Programming. It also provides some useful profile-guided meta-programs.
pgmp uses errortrace to collect exact execution counts of every expression during a sample execution of a program. During subsequent executions, meta-programs (i.e. macros) can load the collected profile data through the API provided by pgmp/api/exact, and inform compile-time decisions based on that profile information.