llvm-profdata [-output=output] file1 file2
The experimental llvm-profdata tool reads two profile data files generated by PGO instrumentation and generates a file with merged data.
The profile data format itself is currently textual.
This option selects the output filename. If not specified, output is to stdout.
llvm-profdata returns 1 if it cannot read input files or there is a mismatch between their data.