LLVM-PROFDATA(1)

💖 NAME 💖

Bestie, this is the LLVM-PROFDATA(1) page from LLVM, and it’s all about llvm-profdata — the profile data tool. Periodt. 💅

✨ SYNOPSIS ✨

llvm-profdata command [args...]

🎀 DESCRIPTION 🎀

The llvm-profdata tool is a small utility for working with profile data files. Tiny icon, huge main character energy. 🌟

🔥 COMMANDS 🔥

• merge
• show
• overlap
• order

👑 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. It’s literally giving “bring all your faves into one group chat.” 💬

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. No cap. 🧢

💖 OPTIONS 💖

• --help — Print a summary of command line options. Your little cheat sheet, bestie. 📝
• --output=<output>, -o — Specify the output file name.

Output cannot be - as the resulting indexed profile data can’t be written to standard output. So no piping it to stdout, okay? It’s not that kind of girl. 💀

• --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. Slay. 🫶

• --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. So like, be careful with that one, bestie. ⚠️

• --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.
• --convert-sample-profile-layout=[nest|flat] — Convert the merged profile into a profile with a new layout. Supported layout are nest (Nested profile, the input should be CS flat profile) and flat (Profile with nested inlinees flattened out).
• --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.
• --temporal-profile-trace-reservoir-size — The maximum number of temporal profile traces to be stored in the output profile. If more traces are added, we will use reservoir sampling to select which traces to keep.

Note that changing this value between different merge invocations on the same indexed profile could result in sample bias. The default value is 100. 🫣

• --temporal-profile-max-trace-length — The maximum number of functions in a single temporal profile trace. Longer traces will be truncated. The default value is 1000.

🌸 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 💖

So llvm-profdata show like, opens a profile data file and spills all the tea about its profile counters — and it can zoom in on whichever function(s) you ask about. Obsessed honestly.

And if you don't give it a filename, or you just hit it with -, then it reads its input from standard input. Slay.

👑 OPTIONS 👑

• --all-functions — print the details for every single function. all of them. no skips.
• --binary-ids — print the embedded binary ids chillin' in the profile.
• --counts — print the actual counter values for the functions being displayed.
• --show-format=<text|json|yaml> — emit the output in whichever format you picked, if the profile type you've got supports it. iykyk.
• --function=<string> — print details for a function if that function's name contains the given string.
• --help — print a lil summary of the command line options. we love a helper.
• --output=<output>, -o — name the output file. If output is - or you just don't specify it, the output goes to standard output. classic.
• --instr (default) — declares that the input profile is an instrumentation-based profile.
• --text — tells the profile dumper to show profile counts in the text format of the instrumentation-based profile data representation. By default the profile info gets dumped in a more human readable form (also text, bestie, still text) with annotations.
• --topn=<n> — tells 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. so if you want 'em, you gotta ask 💅
• --sample — declares that the input profile is a sample-based profile.
• --memop-sizes — show the profiled sizes of the memory intrinsic calls for the functions being shown.
• --value-cutoff=<n> — show only those functions whose max count values are greater than or equal to n. By default the value-cutoff is 0.
• --list-below-cutoff — only output the names of functions whose max count value is below the cutoff value. kinda the inverse vibe.
• --profile-version — print the profile version.
• --showcs — only show context sensitive profile counts. The default is to filter out all context sensitive profile counts.
• --show-prof-sym-list=[true|false] — show the profile symbol list if it exists in the profile. This option is only meaningful for sample-based profiles in extbinary format.
• --show-sec-info-only=[true|false] — show basic info about each section in the profile. This one is only meaningful for sample-based profiles in extbinary format.
• --debug-info=<path> — specify the executable or .dSYM that contains the debug info for the raw profile. When -debug-info-correlate was used for instrumentation, use this option to show the correlated functions from the raw profile. 🫶
• --covered — show only the functions that have actually been executed, i.e. functions with non-zero counts.

---

🦋 OVERLAP 🦋

🌸 SYNOPSIS 🌸

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

💜 DESCRIPTION 💜

llvm-profdata overlap takes two profile data files and shows you the overlap of the counter distribution — both for the whole files and for any of the functions you specify. it's giving comparison, it's giving analysis.

Okay so in this command, overlap is defined like this, buckle up: suppose the base profile file has the following counts: {c1_1, c1_2, ..., c1_n, c1_u_1, c2_u_2, ..., c2_u_s}, and the 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 the matched counters, and c1_u_i (i = 1 .. s) and c2_v_i (i = 1 .. v) are the unmatched counters (or, counters only existing in) the base profile file and the 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. Then:

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 resulting overlap distribution is a percentage number, ranging from 0.0% to 100.0%, where 0.0% means there is no overlap at all and 100.0% means a perfect overlap. flawless.

Here's an example bestie ✨ — if the base profile file has counts of {400, 600}, and the test profile file has matched counts of {60000, 40000}, then the overlap is 80%.

🔥 OPTIONS 🔥

• --function=<string> — print details for a function if that function's name contains the given string.
• --help — print a summary of the 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 than or equal to n. By default, the value-cutoff is set to the max of unsigned long long. yeah, the whole thing.
• --cs — only show overlap for the context sensitive profile counts. The default is to show non-context sensitive profile counts.

---

🌈 ORDER 🌈

🧚 SYNOPSIS 🧚

llvm-profdata order [options] [filename]

⭐ DESCRIPTION ⭐

llvm-profdata order uses temporal profiling traces from a profile and finds a function order that reduces the number of page faults for those traces. that output can be passed directly to lld via --symbol-ordering-file= for ELF, or -order-file for Mach-O. and if the traces found in the profile are representative of the real world, then this order should improve startup performance. main character energy fr fr.

🍓 OPTIONS 🍓

• --help — print a summary of the 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.

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💀 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. so like, that's your drama indicator 🚩

🙈 AUTHOR 🙈

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

💅 COPYRIGHT 💅

2003-2023, LLVM Project

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okay that's the whole page bestie, you ate 💖 this was page 17, dated 2023-12-01, and it's the LLVM-PROFDATA(1) manual — go forth and profile responsibly ✨🎀🦋