Ubuntu Manpage: llvm-profdata - Profile data tool

NAME

       llvm-profdata - Profile data tool

SYNOPSIS

       llvm-profdata command [args…]

DESCRIPTION

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

COMMANDS

       • merge

       • show

       • overlap

MERGE

SYNOPSIS
llvm-profdata merge [options] [filename…]

DESCRIPTION
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.

OPTIONS
--help Print a summary of command line options.

--output=<output>, -o
Specify the output file name. Output cannot be - as the resulting indexed profile
data can’t be written to standard output.

--weighted-input=<weight,filename>
Specify an input file name along with a weight. The profile counts of the supplied
filename will be scaled (multiplied) by the supplied weight, where weight is a
decimal integer >= 1. Input files specified without using this option are assigned
a default weight of 1. Examples are shown below.

--input-files=<path>, -f
Specify a file which contains a list of files to merge. The entries in this file
are newline-separated. Lines starting with ‘#’ are skipped. Entries may be of the
form <filename> or <weight>,<filename>.

--remapping-file=<path>, -r
Specify a file which contains a remapping from symbol names in the input profile to
the symbol names that should be used in the output profile. The file should consist
of lines of the form <input-symbol> <output-symbol>. Blank lines and lines
starting with # are skipped.

The llvm-cxxmap tool can be used to generate the symbol remapping file.

--instr (default)
Specify that the input profile is an instrumentation-based profile.

--sample
Specify that the input profile is a sample-based profile.

The format of the generated file can be generated in one of three ways:

--binary (default)

Emit the profile using a binary encoding. For instrumentation-based profile the
output format is the indexed binary format.

--extbinary

Emit the profile using an extensible binary encoding. This option can only be used
with sample-based profile. The extensible binary encoding can be more compact with
compression enabled and can be loaded faster than the default binary encoding.

--text

Emit the profile in text mode. This option can also be used with both sample-based
and instrumentation-based profile. When this option is used the profile will be
dumped in the text format that is parsable by the profile reader.

--gcc

Emit the profile using GCC’s gcov format (Not yet supported).

--sparse[=true|false]
Do not emit function records with 0 execution count. Can only be used in
conjunction with -instr. Defaults to false, since it can inhibit compiler
optimization during PGO.

--num-threads=<N>, -j
Use N threads to perform profile merging. When N=0, llvm-profdata auto-detects an
appropriate number of threads to use. This is the default.

--failure-mode=[any|all]
Set the failure mode. There are two options: ‘any’ causes the merge command to fail
if any profiles are invalid, and ‘all’ causes the merge command to fail only if all
profiles are invalid. If ‘all’ is set, information from any invalid profiles is
excluded from the final merged product. The default failure mode is ‘any’.

--prof-sym-list=<path>
Specify a file which contains a list of symbols to generate profile symbol list in
the profile. This option can only be used with sample-based profile in extbinary
format. The entries in this file are newline-separated.

--compress-all-sections=[true|false]
Compress all sections when writing the profile. This option can only be used with
sample-based profile in extbinary format.

--use-md5=[true|false]
Use MD5 to represent string in name table when writing the profile. This option
can only be used with sample-based profile in extbinary format.

--gen-partial-profile=[true|false]
Mark the profile to be a partial profile which only provides partial profile
coverage for the optimized target. This option can only be used with sample-based
profile in extbinary format.

--supplement-instr-with-sample=<file>
Supplement an instrumentation profile with sample profile. The sample profile is
the input of the flag. Output will be in instrumentation format (only works with
-instr).

--zero-counter-threshold=<float>
For the function which is cold in instr profile but hot in sample profile, if the
ratio of the number of zero counters divided by the total number of counters is
above the threshold, the profile of the function will be regarded as being harmful
for performance and will be dropped.

--instr-prof-cold-threshold=<int>
User specified cold threshold for instr profile which will override the cold
threshold got from profile summary.

--suppl-min-size-threshold=<int>
If the size of a function is smaller than the threshold, assume it can be inlined
by PGO early inliner and it will not be adjusted based on sample profile.

--debug-info=<path>
Specify the executable or .dSYM that contains debug info for the raw profile. When
-debug-info-correlate was used for instrumentation, use this option to correlate
the raw profile.

EXAMPLES
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

SHOW

SYNOPSIS
llvm-profdata show [options] [filename]

DESCRIPTION
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.

OPTIONS
--all-functions
Print details for every function.

--counts
Print the counter values for the displayed functions.

--function=<string>
Print details for a function if the function’s name contains the given string.

--help Print a summary of command line options.

--output=<output>, -o
Specify the output file name. If output is - or it isn’t specified, then the
output is sent to standard output.

--instr (default)
Specify that the input profile is an instrumentation-based profile.

--text Instruct the profile dumper to show profile counts in the text format of the
instrumentation-based profile data representation. By default, the profile
information is dumped in a more human readable form (also in text) with
annotations.

--topn=<n>
Instruct the profile dumper to show the top n functions with the hottest basic
blocks in the summary section. By default, the topn functions are not dumped.

--sample
Specify that the input profile is a sample-based profile.

--memop-sizes
Show the profiled sizes of the memory intrinsic calls for shown functions.

--value-cutoff=<n>
Show only those functions whose max count values are greater or equal to n. By
default, the value-cutoff is set to 0.

--list-below-cutoff
Only output names of functions whose max count value are below the cutoff value.

--showcs
Only show context sensitive profile counts. The default is to filter all context
sensitive profile counts.

--show-prof-sym-list=[true|false]
Show profile symbol list if it exists in the profile. This option is only
meaningful for sample-based profile in extbinary format.

--show-sec-info-only=[true|false]
Show basic information about each section in the profile. This option is only
meaningful for sample-based profile in extbinary format.

OVERLAP

   SYNOPSIS
       llvm-profdata overlap [options] [base profile file] [test profile file]

   DESCRIPTION
       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%.

   OPTIONS
       --function=<string>
              Print details for a function if the function’s name contains the given string.

       --help Print a summary of command line options.

       --output=<output>, -o
              Specify  the  output  file  name.   If  output is - or it isn’t specified, then the
              output is sent to standard output.

       --value-cutoff=<n>
              Show only those functions whose max count values are greater or  equal  to  n.   By
              default, the value-cutoff is set to max of unsigned long long.

       --cs   Only  show overlap for the context sensitive profile counts. The default is to show
              non-context sensitive profile counts.

EXIT STATUS

       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.

AUTHOR

       Maintained by the LLVM Team (https://llvm.org/).

COPYRIGHT

       2003-2022, LLVM Project