OS Manuals

/usr/lib/llvm15/bin/llvm-exegesis

low-level virtual machine - core frameworks

From llvm15 15.0.7-r9 (os), captured 2026-11-05 by running llvm-exegesis --help (exit 0). permalink

USAGE: llvm-exegesis [options]

OPTIONS:

Color Options:

  --color                                           - Use colors in output (default=autodetect)

General options:

  --allow-ginsert-as-artifact                       - Allow G_INSERT to be considered an artifact. Hack around AMDGPU test infinite loops.
  --bounds-checking-single-trap                     - Use one trap block per function
  --debugify-func-limit=<ulong>                     - Set max number of processed functions per pass.
  --debugify-level=<value>                          - Kind of debug info to add
    =locations                                      -   Locations only
    =location+variables                             -   Locations and Variables
  --debugify-quiet                                  - Suppress verbose debugify output
  --disable-i2p-p2i-opt                             - Disables inttoptr/ptrtoint roundtrip optimization
  --dot-cfg-mssa=<file name for generated dot file> - file name for generated dot file
  --enable-cse-in-irtranslator                      - Should enable CSE in irtranslator
  --enable-cse-in-legalizer                         - Should enable CSE in Legalizer
  --enable-name-compression                         - Enable name/filename string compression
  --experimental-debug-variable-locations           - Use experimental new value-tracking variable locations
  --fs-profile-debug-bw-threshold=<uint>            - Only show debug message if the source branch weight is greater  than this value.
  --fs-profile-debug-prob-diff-threshold=<uint>     - Only show debug message if the branch probility is greater than this value (in percentage).
  --generate-merged-base-profiles                   - When generating nested context-sensitive profiles, always generate extra base profile for function with all its context profiles merged into it.
  --mir-strip-debugify-only                         - Should mir-strip-debug only strip debug info from debugified modules by default
  --opaque-pointers                                 - Use opaque pointers
  --sample-profile-check-record-coverage=<N>        - Emit a warning if less than N% of records in the input profile are matched to the IR.
  --sample-profile-check-sample-coverage=<N>        - Emit a warning if less than N% of samples in the input profile are matched to the IR.
  --sample-profile-max-propagate-iterations=<uint>  - Maximum number of iterations to go through when propagating sample block/edge weights through the CFG.
  --x86-align-branch=<string>                       - Specify types of branches to align (plus separated list of types):
                                                      jcc      indicates conditional jumps
                                                      fused    indicates fused conditional jumps
                                                      jmp      indicates direct unconditional jumps
                                                      call     indicates direct and indirect calls
                                                      ret      indicates rets
                                                      indirect indicates indirect unconditional jumps
  --x86-align-branch-boundary=<uint>                - Control how the assembler should align branches with NOP. If the boundary's size is not 0, it should be a power of 2 and no less than 32. Branches will be aligned to prevent from being across or against the boundary of specified size. The default value 0 does not align branches.
  --x86-branches-within-32B-boundaries              - Align selected instructions to mitigate negative performance impact of Intel's micro code update for errata skx102.  May break assumptions about labels corresponding to particular instructions, and should be used with caution.
  --x86-pad-max-prefix-size=<uint>                  - Maximum number of prefixes to use for padding

Generic Options:

  --help                                            - Display available options (--help-hidden for more)
  --help-list                                       - Display list of available options (--help-list-hidden for more)
  --version                                         - Display the version of this program

llvm-exegesis analysis options:

  --analysis-clustering=<value>                     - the clustering algorithm to use
    =dbscan                                         -   use DBSCAN/OPTICS algorithm
    =naive                                          -   one cluster per opcode
  --analysis-clustering-epsilon=<number>            - epsilon for benchmark point clustering
  --analysis-clusters-output-file=<string>          -
  --analysis-display-unstable-clusters              - if there is more than one benchmark for an opcode, said benchmarks may end up not being clustered into the same cluster if the measured performance characteristics are different. by default all such opcodes are filtered out. this flag will instead show only such unstable opcodes
  --analysis-inconsistencies-output-file=<string>   -
  --analysis-inconsistency-epsilon=<number>         - epsilon for detection of when the cluster is different from the LLVM schedule profile values
  --analysis-numpoints=<uint>                       - minimum number of points in an analysis cluster (dbscan only)

llvm-exegesis benchmark options:

  --dump-object-to-disk                             - dumps the generated benchmark object to disk and prints a message to access it
  --ignore-invalid-sched-class                      - ignore instructions that do not define a sched class
  --loop-body-size=<uint>                           - when repeating the instruction snippet by looping over it, duplicate the snippet until the loop body contains at least this many instruction
  --max-configs-per-opcode=<uint>                   - allow to snippet generator to generate at most that many configs
  --num-repetitions=<uint>                          - number of time to repeat the asm snippet
  --opcode-index=<int>                              - opcode to measure, by index, or -1 to measure all opcodes
  --opcode-name=<string>                            - comma-separated list of opcodes to measure, by name
  --repetition-mode=<value>                         - how to repeat the instruction snippet
    =duplicate                                      -   Duplicate the snippet
    =loop                                           -   Loop over the snippet
    =min                                            -   All of the above and take the minimum of measurements
  --snippets-file=<string>                          - code snippets to measure

llvm-exegesis benchmark x86-options:

  --x86-lbr-sample-period=<uint>                    - The sample period (nbranches/sample), used for LBR sampling

llvm-exegesis options:

  --benchmarks-file=<string>                        - File to read (analysis mode) or write (latency/uops/inverse_throughput modes) benchmark results. “-” uses stdin/stdout.
  --mcpu=<string>                                   - cpu name to use for pfm counters, leave empty to autodetect
  --mode=<value>                                    - the mode to run
    =latency                                        -   Instruction Latency
    =inverse_throughput                             -   Instruction Inverse Throughput
    =uops                                           -   Uop Decomposition
    =analysis                                       -   Analysis
  --result-aggregation-mode=<value>                 - How to aggregate multi-values result
    =min                                            -   Keep min reading
    =max                                            -   Keep max reading
    =mean                                           -   Compute mean of all readings
    =min-variance                                   -   Keep readings set with min-variance
Options (47)
OptionDescriptionSource
--color- Use colors in output (default=autodetect)help
--allow-ginsert-as-artifact- Allow G_INSERT to be considered an artifact.help
--bounds-checking-single-trap- Use one trap block per functionhelp
--debugify-func-limit ulong- Set max number of processed functions per pass.help
--debugify-level value- Kind of debug info to add =locations - Locations only =location+variables - Locations and Variableshelp
--debugify-quiet- Suppress verbose debugify outputhelp
--disable-i2p-p2i-opt- Disables inttoptr/ptrtoint roundtrip optimizationhelp
--enable-cse-in-irtranslator- Should enable CSE in irtranslatorhelp
--enable-cse-in-legalizer- Should enable CSE in Legalizerhelp
--enable-name-compression- Enable name/filename string compressionhelp
--experimental-debug-variable-locations- Use experimental new value-tracking variable locationshelp
--fs-profile-debug-bw-threshold uint- Only show debug message if the source branch weight is greater than this value.help
--fs-profile-debug-prob-diff-threshold uint- Only show debug message if the branch probility is greater than this value (in percentage).help
--generate-merged-base-profiles- When generating nested context-sensitive profiles, always generate extra base profile for function with all its context profiles merged into it.help
--mir-strip-debugify-only- Should mir-strip-debug only strip debug info from debugified modules by defaulthelp
--opaque-pointers- Use opaque pointershelp
--sample-profile-check-record-coverage N- Emit a warning if less than N% of records in the input profile are matched to the IR.help
--sample-profile-check-sample-coverage N- Emit a warning if less than N% of samples in the input profile are matched to the IR.help
--sample-profile-max-propagate-iterations uint- Maximum number of iterations to go through when propagating sample block/edge weights through the CFG.help
--x86-align-branch string- Specify types of branches to align (plus separated list of types): jcc indicates conditional jumps fused indicates fused conditional jumps jmp indicates direct unconditional jumps call indicates…help
--x86-align-branch-boundary uint- Control how the assembler should align branches with NOP.help
--x86-branches-within-32B-boundaries- Align selected instructions to mitigate negative performance impact of Intel's micro code update for errata skx102.help
--x86-pad-max-prefix-size uint- Maximum number of prefixes to use for paddinghelp
--help- Display available options (--help-hidden for more)help
--help-list- Display list of available options (--help-list-hidden for more)help
--version- Display the version of this programhelp
--analysis-clustering value- the clustering algorithm to use =dbscan - use DBSCAN/OPTICS algorithm =naive - one cluster per opcodehelp
--analysis-clustering-epsilon number- epsilon for benchmark point clusteringhelp
--analysis-clusters-output-file string-help
--analysis-display-unstable-clusters- if there is more than one benchmark for an opcode, said benchmarks may end up not being clustered into the same cluster if the measured performance characteristics are different.help
--analysis-inconsistencies-output-file string-help
--analysis-inconsistency-epsilon number- epsilon for detection of when the cluster is different from the LLVM schedule profile valueshelp
--analysis-numpoints uint- minimum number of points in an analysis cluster (dbscan only)help
--dump-object-to-disk- dumps the generated benchmark object to disk and prints a message to access ithelp
--ignore-invalid-sched-class- ignore instructions that do not define a sched classhelp
--loop-body-size uint- when repeating the instruction snippet by looping over it, duplicate the snippet until the loop body contains at least this many instructionhelp
--max-configs-per-opcode uint- allow to snippet generator to generate at most that many configshelp
--num-repetitions uint- number of time to repeat the asm snippethelp
--opcode-index int- opcode to measure, by index, or -1 to measure all opcodeshelp
--opcode-name string- comma-separated list of opcodes to measure, by namehelp
--repetition-mode value- how to repeat the instruction snippet =duplicate - Duplicate the snippet =loop - Loop over the snippet =min - All of the above and take the minimum of measurementshelp
--snippets-file string- code snippets to measurehelp
--x86-lbr-sample-period uint- The sample period (nbranches/sample), used for LBR samplinghelp
--benchmarks-file string- File to read (analysis mode) or write (latency/uops/inverse_throughput modes) benchmark results.help
--mcpu string- cpu name to use for pfm counters, leave empty to autodetecthelp
--mode value- the mode to run =latency - Instruction Latency =inverse_throughput - Instruction Inverse Throughput =uops - Uop Decomposition =analysis - Analysishelp
--result-aggregation-mode value- How to aggregate multi-values result =min - Keep min reading =max - Keep max reading =mean - Compute mean of all readings =min-variance - Keep readings set with min-variancehelp

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.