3.4.122 –xF

Allow function–level reordering by the Performance Analyzer.

Allow the reordering of functions (subprograms) in the core image using the compiler, the performance analyzer and the linker. If you compile with the -xF option, then run the analyzer, you can generate a map file that optimizes the ordering of the functions in memory depending on how they are used together. A subsequent link to build the executable file can be directed to use that map by using the linker -Mmapfile option. It places each function from the executable file into a separate section. (The f95 —Mpath option also passes a regular file to the linker; see the description of the f95 —Mpath option.)

Reordering the subprograms in memory is useful only when the application text page fault time is consuming a large percentage of the application time. Otherwise, reordering may not improve the overall performance of the application. See the Program Performance Analysis Tools manual for further information on the analyzer.