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llvm-profdata - Profile data tool


:program:`llvm-profdata` command [args...]


The :program:`llvm-profdata` tool is a small utility for working with profile data files.



:program:`llvm-profdata merge` [options] [filename...]


:program:`llvm-profdata merge` takes several profile data files generated by PGO instrumentation and merges them together into a single indexed profile data file.

By default profile data is merged without modification. This means that the relative importance of each input file is proportional to the number of samples or counts it contains. In general, the input from a longer training run will be interpreted as relatively more important than a shorter run. Depending on the nature of the training runs it may be useful to adjust the weight given to each input file by using the -weighted-input option.

Profiles passed in via -weighted-input, -input-files, or via positional arguments are processed once for each time they are seen.



Basic Usage

Merge three profiles:

llvm-profdata merge foo.profdata bar.profdata baz.profdata -output merged.profdata

Weighted Input

The input file foo.profdata is especially important, multiply its counts by 10:

llvm-profdata merge -weighted-input=10,foo.profdata bar.profdata baz.profdata -output merged.profdata

Exactly equivalent to the previous invocation (explicit form; useful for programmatic invocation):

llvm-profdata merge -weighted-input=10,foo.profdata -weighted-input=1,bar.profdata -weighted-input=1,baz.profdata -output merged.profdata



:program:`llvm-profdata show` [options] [filename]


:program:`llvm-profdata show` takes a profile data file and displays the information about the profile counters for this file and for any of the specified function(s).

If filename is omitted or is -, then llvm-profdata show reads its input from standard input.




:program:`llvm-profdata overlap` [options] [base profile file] [test profile file]


:program:`llvm-profdata overlap` takes two profile data files and displays the overlap of counter distribution between the whole files and between any of the specified functions.

In this command, overlap is defined as follows: Suppose base profile file has the following counts: {c1_1, c1_2, ..., c1_n, c1_u_1, c2_u_2, ..., c2_u_s}, and test profile file has {c2_1, c2_2, ..., c2_n, c2_v_1, c2_v_2, ..., c2_v_t}. Here c{1|2}_i (i = 1 .. n) are matched counters and c1_u_i (i = 1 .. s) and c2_v_i (i = 1 .. v) are unmatched counters (or counters only existing in) base profile file and test profile file, respectively. Let sum_1 = c1_1 + c1_2 + ... + c1_n + c1_u_1 + c2_u_2 + ... + c2_u_s, and sum_2 = c2_1 + c2_2 + ... + c2_n + c2_v_1 + c2_v_2 + ... + c2_v_t. overlap = min(c1_1/sum_1, c2_1/sum_2) + min(c1_2/sum_1, c2_2/sum_2) + ... + min(c1_n/sum_1, c2_n/sum_2).

The result overlap distribution is a percentage number, ranging from 0.0% to 100.0%, where 0.0% means there is no overlap and 100.0% means a perfect overlap.

Here is an example, if base profile file has counts of {400, 600}, and test profile file has matched counts of {60000, 40000}. The overlap is 80%.



:program:`llvm-profdata` returns 1 if the command is omitted or is invalid, if it cannot read input files, or if there is a mismatch between their data.