Skip to content

Instantly share code, notes, and snippets.

@lakshayg

lakshayg/bolt_docs_CommandLineArgumentReference.md

Last active March 10, 2026 23:20
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save lakshayg/b72c6712a7a74ac88f66ba9bd9bc3695 to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save lakshayg/b72c6712a7a74ac88f66ba9bd9bc3695 to your computer and use it in GitHub Desktop.
Download ZIP
llvm-bolt --help
Raw
bolt_docs_CommandLineArgumentReference.md

BOLT - a post-link optimizer developed to speed up large applications

SYNOPSIS

llvm-bolt <executable> [-o outputfile] <executable>.bolt [-data=perf.fdata] [options]

OPTIONS

Generic options:

  • -h

    Alias for --help

  • --help

    Display available options (--help-hidden for more)

  • --help-hidden

    Display all available options

  • --help-list

    Display list of available options (--help-list-hidden for more)

  • --help-list-hidden

    Display list of all available options

  • --version

    Display the version of this program

Output options:

  • --bolt-info

    Write bolt info section in the output binary

  • -o <string>

    output file

  • -w <string>

    Save recorded profile to a file

BOLT generic options:

  • --align-text=<uint>

    Alignment of .text section

  • --allow-stripped

    Allow processing of stripped binaries

  • --alt-inst-feature-size=<uint>

    Size of feature field in .altinstructions

  • --alt-inst-has-padlen

    Specify that .altinstructions has padlen field

  • --asm-dump[=<dump folder>]

    Dump function into assembly

  • -b

    Alias for -data

  • --bolt-id=<string>

    Add any string to tag this execution in the output binary via bolt info section

  • --break-funcs=<func1,func2,func3,...>

    List of functions to core dump on (debugging)

  • --check-encoding

    Perform verification of LLVM instruction encoding/decoding. Every instruction in the input is decoded and re-encoded. If the resulting bytes do not match the input, a warning message is printed.

  • --comp-dir-override=<string>

    Overrides DW_AT_comp_dir, and provides an alternative base location, which is used with DW_AT_dwo_name to construct a path to *.dwo files.

  • --create-debug-names-section

    Creates .debug_names section, if the input binary doesn't have it already, for DWARF5 CU/TUs.

  • --cu-processing-batch-size=<uint>

    Specifies the size of batches for processing CUs. Higher number has better performance, but more memory usage. Default value is 1.

  • --data=<string>

    data file

  • --data2=<string>

    data file

  • --debug-skeleton-cu

    Prints out offsets for abbrev and debug_info of Skeleton CUs that get patched.

  • --debug-thread-count=<uint>

    Specifies the number of threads to be used when processing DWO debug information.

  • --dot-tooltip-code

    Add basic block instructions as tool tips on nodes

  • --dump-alt-instructions

    Dump Linux alternative instructions info

  • --dump-cg=<string>

    Dump callgraph to the given file

  • --dump-data

    Dump parsed bolt data for debugging

  • --dump-dot-all

    Dump function CFGs to graphviz format after each stage;enable '-print-loops' for color-coded blocks

  • --dump-dot-func=<func1,func2,func3...>

    Dump function CFGs to graphviz format for specified functions only; takes function name patterns (regex supported). Note: C++ function names must be passed using their mangled names

  • --dump-linux-exceptions

    Dump Linux kernel exception table

  • --dump-orc

    Dump raw ORC unwind information (sorted)

  • --dump-para-sites

    Dump Linux kernel paravitual patch sites

  • --dump-pci-fixups

    Dump Linux kernel PCI fixup table

  • --dump-smp-locks

    Dump Linux kernel SMP locks

  • --dump-static-calls

    Dump Linux kernel static calls

  • --dump-static-keys

    Dump Linux kernel static keys jump table

  • --dwarf-output-path=<string>

    Path to where .dwo files or dwp file will be written out to.

  • --dwp=<string>

    Path and name to DWP file.

  • --dyno-stats

    Print execution info based on profile

  • --dyno-stats-all

    Print dyno stats after each stage

  • --dyno-stats-scale=<uint>

    Scale to be applied while reporting dyno stats

  • --enable-bat

    Write BOLT Address Translation tables

  • --force-data-relocations

    Force relocations to data sections to always be processed

  • --force-patch

    Force patching of original entry points

  • --funcs=<func1,func2,func3,...>

    Limit optimizations to functions from the list

  • --funcs-file=<string>

    File with list of functions to optimize

  • --funcs-file-no-regex=<string>

    File with list of functions to optimize (non-regex)

  • --funcs-no-regex=<func1,func2,func3,...>

    Limit optimizations to functions from the list (non-regex)

  • --hot-data

    Hot data symbols support (relocation mode)

  • --hot-functions-at-end

    If reorder-functions is used, order functions putting hottest last

  • --hot-text

    Generate hot text symbols. Apply this option to a precompiled binary that manually calls into hugify, such that at runtime hugify call will put hot code into 2M pages. This requires relocation.

  • --hot-text-move-sections=<sec1,sec2,sec3,...>

    List of sections containing functions used for hugifying hot text. BOLT makes sure these functions are not placed on the same page as the hot text. (default='.stub,.mover').

  • --insert-retpolines

    Run retpoline insertion pass

  • --keep-aranges

    Keep or generate .debug_aranges section if .gdb_index is written

  • --keep-tmp

    Preserve intermediate .o file

  • --lite

    Skip processing of cold functions

  • --log-file=<string>

    Redirect journaling to a file instead of stdout/stderr

  • --long-jump-labels

    Always use long jumps/nops for Linux kernel static keys

  • --match-profile-with-function-hash

    Match profile with function hash

  • --max-data-relocations=<uint>

    Maximum number of data relocations to process

  • --max-funcs=<uint>

    Maximum number of functions to process

  • --no-huge-pages

    Use regular size pages for code alignment

  • --no-threads

    Disable multithreading

  • --pad-funcs=<func1:pad1,func2:pad2,func3:pad3,...>

    List of functions to pad with amount of bytes

  • --print-mappings

    Print mappings in the legend, between characters/blocks and text sections (default false).

  • --profile-format=<value>

    Format to dump profile output in aggregation mode, default is fdata

    • fdata: offset-based plaintext format
    • yaml: dense YAML representation

  • --r11-availability=<value>

    Determine the availability of r11 before indirect branches

    • never: r11 not available
    • always: r11 available before calls and jumps
    • abi: r11 available before calls but not before jumps

  • --relocs

    Use relocations in the binary (default=autodetect)

  • --remove-symtab

    Remove .symtab section

  • --reorder-skip-symbols=<symbol1,symbol2,symbol3,...>

    List of symbol names that cannot be reordered

  • --reorder-symbols=<symbol1,symbol2,symbol3,...>

    List of symbol names that can be reordered

  • --retpoline-lfence

    Determine if lfence instruction should exist in the retpoline

  • --skip-funcs=<func1,func2,func3,...>

    List of functions to skip

  • --skip-funcs-file=<string>

    File with list of functions to skip

  • --strict

    Trust the input to be from a well-formed source

  • --tasks-per-thread=<uint>

    Number of tasks to be created per thread

  • --terminal-trap

    Assume that execution stops at trap instruction

  • --thread-count=<uint>

    Number of threads

  • --top-called-limit=<uint>

    Maximum number of functions to print in top called functions section

  • --trap-avx512

    In relocation mode trap upon entry to any function that uses AVX-512 instructions

  • --trap-old-code

    Insert traps in old function bodies (relocation mode)

  • --update-debug-sections

    Update DWARF debug sections of the executable

  • --use-gnu-stack

    Use GNU_STACK program header for new segment (workaround for issues with strip/objcopy)

  • --use-old-text

    Reuse space in old .text if possible (relocation mode)

  • -v <uint>

    Set verbosity level for diagnostic output

BOLT optimization options:

  • --align-blocks

    Align basic blocks

  • --align-blocks-min-size=<uint>

    Minimal size of the basic block that should be aligned

  • --align-blocks-threshold=<uint>

    Align only blocks with frequency larger than containing function execution frequency specified in percent. E.g. 1000 means aligning blocks that are 10 times more frequently executed than the containing function.

  • --align-functions=<uint>

    Align functions at a given value (relocation mode)

  • --align-functions-max-bytes=<uint>

    Maximum number of bytes to use to align functions

  • --assume-abi

    Assume the ABI is never violated

  • --block-alignment=<uint>

    Boundary to use for alignment of basic blocks

  • --bolt-seed=<uint>

    Seed for randomization

  • --cg-from-perf-data

    Use perf data directly when constructing the call graph for stale functions

  • --cg-ignore-recursive-calls

    Ignore recursive calls when constructing the call graph

  • --cg-use-split-hot-size

    Use hot/cold data on basic blocks to determine hot sizes for call graph functions

  • --cold-threshold=<uint>

    Tenths of percents of main entry frequency to use as a threshold when evaluating whether a basic block is cold (0 means it is only considered cold if the block has zero samples). Default: 0

  • --elim-link-veneers

    Run veneer elimination pass

  • --eliminate-unreachable

    Eliminate unreachable code

  • --equalize-bb-counts

    Use same count for BBs that should have equivalent count (used in non-LBR and shrink wrapping)

  • --execution-count-threshold=<uint>

    Perform profiling accuracy-sensitive optimizations only if function execution count >= the threshold (default: 0)

  • --fix-block-counts

    Adjust block counts based on outgoing branch counts

  • --fix-func-counts

    Adjust function counts based on basic blocks execution count

  • --force-inline=<func1,func2,func3,...>

    List of functions to always consider for inlining

  • --frame-opt=<value>

    Optimize stack frame accesses

    • none: do not perform frame optimization
    • hot: perform FOP on hot functions
    • all: perform FOP on all functions

  • --frame-opt-rm-stores

    Apply additional analysis to remove stores (experimental)

  • --function-order=<string>

    File containing an ordered list of functions to use for function reordering

  • --generate-function-order=<string>

    File to dump the ordered list of functions to use for function reordering

  • --generate-link-sections=<string>

    Generate a list of function sections in a format suitable for inclusion in a linker script

  • --group-stubs

    Share stubs across functions

  • --hugify

    Automatically put hot code on 2MB page(s) (hugify) at runtime. No manual call to hugify is needed in the binary (which is what --hot-text relies on).

  • --icf=<value>

    Fold functions with identical code

    • all: Enable identical code folding
    • none: Disable identical code folding (default)
    • safe: Enable safe identical code folding

  • --icp

    Alias for --indirect-call-promotion

  • --icp-calls-remaining-percent-threshold=<uint>

    The percentage threshold against remaining unpromoted indirect call count for the promotion for calls

  • --icp-calls-topn

    Alias for --indirect-call-promotion-calls-topn

  • --icp-calls-total-percent-threshold=<uint>

    The percentage threshold against total count for the promotion for calls

  • --icp-eliminate-loads

    Enable load elimination using memory profiling data when performing ICP

  • --icp-funcs=<func1,func2,func3,...>

    List of functions to enable ICP for

  • --icp-inline

    Only promote call targets eligible for inlining

  • --icp-jt-remaining-percent-threshold=<uint>

    The percentage threshold against remaining unpromoted indirect call count for the promotion for jump tables

  • --icp-jt-targets

    Alias for --icp-jump-tables-targets

  • --icp-jt-topn

    Alias for --indirect-call-promotion-jump-tables-topn

  • --icp-jt-total-percent-threshold=<uint>

    The percentage threshold against total count for the promotion for jump tables

  • --icp-jump-tables-targets

    For jump tables, optimize indirect jmp targets instead of indices

  • --icp-mp-threshold

    Alias for --indirect-call-promotion-mispredict-threshold

  • --icp-old-code-sequence

    Use old code sequence for promoted calls

  • --icp-top-callsites=<uint>

    Optimize hottest calls until at least this percentage of all indirect calls frequency is covered. 0 = all callsites

  • --icp-topn

    Alias for --indirect-call-promotion-topn

  • --icp-use-mp

    Alias for --indirect-call-promotion-use-mispredicts

  • --indirect-call-promotion=<value>

    Indirect call promotion

    • none: do not perform indirect call promotion
    • calls: perform ICP on indirect calls
    • jump-tables: perform ICP on jump tables
    • all: perform ICP on calls and jump tables

  • --indirect-call-promotion-calls-topn=<uint>

    Limit number of targets to consider when doing indirect call promotion on calls. 0 = no limit

  • --indirect-call-promotion-jump-tables-topn=<uint>

    Limit number of targets to consider when doing indirect call promotion on jump tables. 0 = no limit

  • --indirect-call-promotion-topn=<uint>

    Limit number of targets to consider when doing indirect call promotion. 0 = no limit

  • --indirect-call-promotion-use-mispredicts

    Use misprediction frequency for determining whether or not ICP should be applied at a callsite. The -indirect-call-promotion-mispredict-threshold value will be used by this heuristic

  • --infer-fall-throughs

    Infer execution count for fall-through blocks

  • --infer-stale-profile

    Infer counts from stale profile data.

  • --inline-all

    Inline all functions

  • --inline-ap

    Adjust function profile after inlining

  • --inline-limit=<uint>

    Maximum number of call sites to inline

  • --inline-max-iters=<uint>

    Maximum number of inline iterations

  • --inline-memcpy

    Inline memcpy using optimized instruction sequences (X86: 'rep movsb', AArch64: width-optimized register operations)

  • --inline-small-functions

    Inline functions if increase in size is less than defined by -inline-small- functions-bytes

  • --inline-small-functions-bytes=<uint>

    Max number of bytes for the function to be considered small for inlining purposes

  • --instrument

    Instrument code to generate accurate profile data

  • --iterative-guess

    In non-LBR mode, guess edge counts using iterative technique

  • --jt-footprint-optimize-for-icache

    With jt-footprint-reduction, only process PIC jumptables and turn off other transformations that increase code size

  • --jt-footprint-reduction

    Make jump tables size smaller at the cost of using more instructions at jump sites

  • --jump-tables=<value>

    Jump tables support (default=basic)

    • none: do not optimize functions with jump tables
    • basic: optimize functions with jump tables
    • move: move jump tables to a separate section
    • split: split jump tables section into hot and cold based on function execution frequency
    • aggressive: aggressively split jump tables section based on usage of the tables

  • --keep-nops

    Keep no-op instructions. By default they are removed.

  • --lite-threshold-count=<uint>

    Similar to '-lite-threshold-pct' but specify threshold using absolute function call count. I.e. limit processing to functions executed at least the specified number of times.

  • --lite-threshold-pct=<uint>

    Threshold (in percent) for selecting functions to process in lite mode. Higher threshold means fewer functions to process. E.g threshold of 90 means only top 10 percent of functions with profile will be processed.

  • --match-with-call-graph

    Match functions with call graph

  • --memcpy1-spec=<func1,func2:cs1:cs2,func3:cs1,...>

    List of functions with call sites for which to specialize memcpy() for size 1

  • --min-branch-clusters

    Use a modified clustering algorithm geared towards minimizing branches

  • --name-similarity-function-matching-threshold=<uint>

    Match functions using namespace and edit distance.

  • --no-inline

    Disable all inlining (overrides other inlining options)

  • --no-scan

    Do not scan cold functions for external references (may result in slower binary)

  • --peepholes=<value>

    Enable peephole optimizations

    • none: disable peepholes
    • double-jumps: remove double jumps when able
    • tailcall-traps: insert tail call traps
    • useless-branches: remove useless conditional branches
    • all: enable all peephole optimizations

  • --plt=<value>

    Optimize PLT calls (requires linking with -znow on non-x86 architectures)

    • none: do not optimize PLT calls
    • hot: optimize executed (hot) PLT calls
    • all: optimize all PLT calls

  • --preserve-blocks-alignment

    Try to preserve basic block alignment

  • --profile-ignore-hash

    Ignore hash while reading function profile

  • --profile-use-dfs

    Use DFS order for YAML profile

  • --reg-reassign

    Reassign registers so as to avoid using REX prefixes in hot code

  • --reorder-blocks=<value>

    Change layout of basic blocks in a function

    • none: do not reorder basic blocks
    • reverse: layout blocks in reverse order
    • normal: perform optimal layout based on profile
    • branch-predictor: perform optimal layout prioritizing branch predictions
    • cache: perform optimal layout prioritizing I-cache behavior
    • cache+: perform layout optimizing I-cache behavior
    • ext-tsp: perform layout optimizing I-cache behavior
    • cluster-shuffle: perform random layout of clusters

  • --reorder-data=<section1,section2,section3,...>

    List of sections to reorder

  • --reorder-data-algo=<value>

    Algorithm used to reorder data sections

    • count: sort hot data by read counts
    • funcs: sort hot data by hot function usage and count

  • --reorder-data-inplace

    Reorder data sections in place

  • --reorder-data-max-bytes=<uint>

    Maximum number of bytes to reorder

  • --reorder-data-max-symbols=<uint>

    Maximum number of symbols to reorder

  • --reorder-functions=<value>

    Reorder and cluster functions (works only with relocations)

    • none: do not reorder functions
    • exec-count: order by execution count
    • hfsort: use hfsort algorithm
    • hfsort+: use cache-directed sort
    • cdsort: use cache-directed sort
    • pettis-hansen: use Pettis-Hansen algorithm
    • random: reorder functions randomly
    • user: use function order specified by -function-order

  • --reorder-functions-use-hot-size

    Use a function's hot size when doing clustering

  • --report-bad-layout=<uint>

    Print top functions with suboptimal code layout on input

  • --report-stale

    Print the list of functions with stale profile

  • --runtime-hugify-lib=<string>

    Specify file name of the runtime hugify library

  • --runtime-instrumentation-lib=<string>

    Specify file name of the runtime instrumentation library

  • --runtime-lib-init-hook=<value>

    Primary target for hooking runtime library initialization, used in fallback order of availability in input binary (entry_point -> init -> init_array) (default: entry_point)

    • entry_point: use ELF Header Entry Point
    • init: use ELF DT_INIT entry
    • init_array: use ELF .init_array entry

  • --sctc-mode=<value>

    Mode for simplify conditional tail calls

    • always: always perform sctc
    • preserve: only perform sctc when branch direction is preserved
    • heuristic: use branch prediction data to control sctc

  • --sequential-disassembly

    Performs disassembly sequentially

  • --shrink-wrapping-threshold=<uint>

    Percentage of prologue execution count to use as threshold when evaluating whether a block is cold enough to be profitable to move eligible spills there

  • --simplify-conditional-tail-calls

    Simplify conditional tail calls by removing unnecessary jumps

  • --simplify-rodata-loads

    Simplify loads from read-only sections by replacing the memory operand with the constant found in the corresponding section

  • --split-align-threshold=<uint>

    When deciding to split a function, apply this alignment while doing the size comparison (see -split-threshold). Default value: 2.

  • --split-all-cold

    Outline as many cold basic blocks as possible

  • --split-eh

    Split C++ exception handling code

  • --split-functions

    Split functions into fragments

  • --split-strategy=<value>

    Strategy used to partition blocks into fragments

    • profile2: split each function into a hot and cold fragment using profiling information
    • cdsplit: split each function into a hot, warm, and cold fragment using profiling information
    • random2: split each function into a hot and cold fragment at a randomly chosen split point (ignoring any available profiling information)
    • randomN: split each function into N fragments at a randomly chosen split points (ignoring any available profiling information)
    • all: split all basic blocks of each function into fragments such that each fragment contains exactly a single basic block

  • --split-threshold=<uint>

    Split function only if its main size is reduced by more than given amount of bytes. Default value: 0, i.e. split iff the size is reduced. Note that on some architectures the size can increase after splitting.

  • --stale-matching-max-func-size=<uint>

    The maximum size of a function to consider for inference.

  • --stale-matching-min-matched-block=<uint>

    Percentage threshold of matched basic blocks at which stale profile inference is executed.

  • --stale-threshold=<uint>

    Maximum percentage of stale functions to tolerate (default: 100)

  • --stoke

    Turn on the stoke analysis

  • --strip-rep-ret

    Strip 'repz' prefix from 'repz retq' sequence (on by default)

  • --tail-duplication=<value>

    Duplicate unconditional branches that cross a cache line

    • none: do not apply
    • aggressive: aggressive strategy
    • moderate: moderate strategy
    • cache: cache-aware duplication strategy

  • --tsp-threshold=<uint>

    Maximum number of hot basic blocks in a function for which to use a precise TSP solution while re-ordering basic blocks

  • --use-aggr-reg-reassign

    Use register liveness analysis to try to find more opportunities for -reg- reassign optimization

  • --use-compact-aligner

    Use compact approach for aligning functions

  • --use-edge-counts

    Use edge count data when doing clustering

  • --verify-cfg

    Verify the CFG after every pass

  • --x86-align-branch-boundary-hot-only

    Only apply branch boundary alignment in hot code

  • --x86-strip-redundant-address-size

    Remove redundant Address-Size override prefix

BOLT instrumentation options:

llvm-bolt <executable> -instrument [-o outputfile] <instrumented-executable>

  • --conservative-instrumentation

    Disable instrumentation optimizations that sacrifice profile accuracy (for debugging, default: false)

  • --instrument-calls

    Record profile for inter-function control flow activity (default: true)

  • --instrument-hot-only

    Only insert instrumentation on hot functions (needs profile, default: false)

  • --instrumentation-binpath=<string>

    Path to instrumented binary in case if /proc/self/map_files is not accessible due to access restriction issues

  • --instrumentation-file=<string>

    File name where instrumented profile will be saved (default: /tmp/prof.fdata)

  • --instrumentation-file-append-pid

    Append PID to saved profile file name (default: false)

  • --instrumentation-no-counters-clear

    Don't clear counters across dumps (use with instrumentation-sleep-time option)

  • --instrumentation-sleep-time=<uint>

    Interval between profile writes (default: 0 = write only at program end). This is useful for service workloads when you want to dump profile every X minutes or if you are killing the program and the profile is not being dumped at the end.

  • --instrumentation-wait-forks

    Wait until all forks of instrumented process will finish (use with instrumentation-sleep-time option)

BOLT printing options:

  • --print-aliases

    Print aliases when printing objects

  • --print-all

    Print functions after each stage

  • --print-cfg

    Print functions after CFG construction

  • --print-debug-info

    Print debug info when printing functions

  • --print-disasm

    Print function after disassembly

  • --print-dyno-opcode-stats=<uint>

    Print per instruction opcode dyno stats and the functionnames:BB offsets of the nth highest execution counts

  • --print-dyno-stats-only

    While printing functions output dyno-stats and skip instructions

  • --print-exceptions

    Print exception handling data

  • --print-globals

    Print global symbols after disassembly

  • --print-jump-tables

    Print jump tables

  • --print-loops

    Print loop related information

  • --print-mem-data

    Print memory data annotations when printing functions

  • --print-normalized

    Print functions after CFG is normalized

  • --print-only=<func1,func2,func3,...>

    List of functions to print

  • --print-orc

    Print ORC unwind information for instructions

  • --print-profile

    Print functions after attaching profile

  • --print-profile-stats

    Print profile quality/bias analysis

  • --print-pseudo-probes=<value>

    Print pseudo probe info

    • decode: decode probes section from binary
    • address_conversion: update address2ProbesMap with output block address
    • encoded_probes: display the encoded probes in binary section
    • all: enable all debugging printout

  • --print-relocations

    Print relocations when printing functions/objects

  • --print-reordered-data

    Print section contents after reordering

  • --print-retpoline-insertion

    Print functions after retpoline insertion pass

  • --print-sdt

    Print all SDT markers

  • --print-sections

    Print all registered sections

  • --print-unknown

    Print names of functions with unknown control flow

  • --time-build

    Print time spent constructing binary functions

  • --time-rewrite

    Print time spent in rewriting passes

  • --print-after-branch-fixup

    Print function after fixing local branches

  • --print-after-jt-footprint-reduction

    Print function after jt-footprint-reduction pass

  • --print-after-lowering

    Print function after instruction lowering

  • --print-cache-metrics

    Calculate and print various metrics for instruction cache

  • --print-clusters

    Print clusters

  • --print-estimate-edge-counts

    Print function after edge counts are set for no-LBR profile

  • --print-finalized

    Print function after CFG is finalized

  • --print-fix-relaxations

    Print functions after fix relaxations pass

  • --print-fix-riscv-calls

    Print functions after fix RISCV calls pass

  • --print-fop

    Print functions after frame optimizer pass

  • --print-function-statistics=<uint>

    Print statistics about basic block ordering

  • --print-icf

    Print functions after ICF optimization

  • --print-icp

    Print functions after indirect call promotion

  • --print-inline

    Print functions after inlining optimization

  • --print-large-functions

    Print functions that could not be overwritten due to excessive size

  • --print-longjmp

    Print functions after longjmp pass

  • --print-optimize-bodyless

    Print functions after bodyless optimization

  • --print-output-address-range

    Print output address range for each basic block in the function whenBinaryFunction::print is called

  • --print-peepholes

    Print functions after peephole optimization

  • --print-plt

    Print functions after PLT optimization

  • --print-regreassign

    Print functions after regreassign pass

  • --print-reordered

    Print functions after layout optimization

  • --print-reordered-functions

    Print functions after clustering

  • --print-sctc

    Print functions after conditional tail call simplification

  • --print-simplify-rodata-loads

    Print functions after simplification of RO data loads

  • --print-sorted-by=<value>

    Print functions sorted by order of dyno stats

    • executed-forward-branches: executed forward branches
    • taken-forward-branches: taken forward branches
    • executed-backward-branches: executed backward branches
    • taken-backward-branches: taken backward branches
    • executed-unconditional-branches: executed unconditional branches
    • all-function-calls: all function calls
    • indirect-calls: indirect calls
    • PLT-calls: PLT calls
    • executed-instructions: executed instructions
    • executed-load-instructions: executed load instructions
    • executed-store-instructions: executed store instructions
    • taken-jump-table-branches: taken jump table branches
    • taken-unknown-indirect-branches: taken unknown indirect branches
    • total-branches: total branches
    • taken-branches: taken branches
    • non-taken-conditional-branches: non-taken conditional branches
    • taken-conditional-branches: taken conditional branches
    • all-conditional-branches: all conditional branches
    • linker-inserted-veneer-calls: linker-inserted veneer calls
    • all: sorted by all names

  • --print-sorted-by-order=<value>

    Use ascending or descending order when printing functions ordered by dyno stats

  • --print-split

    Print functions after code splitting

  • --print-stoke

    Print functions after stoke analysis

  • --print-uce

    Print functions after unreachable code elimination

  • --print-veneer-elimination

    Print functions after veneer elimination pass

  • --time-opts

    Print time spent in each optimization

  • --print-all-options

    Print all option values after command line parsing

  • --print-options

    Print non-default options after command line parsing

Raw
llvm_bolt23_help.txt
OVERVIEW: BOLT - Binary Optimization and Layout Tool
USAGE: llvm-bolt [options] <executable> <executable>
OPTIONS:
BOLT generic options:
--bolt-id=<string> - add any string to tag this execution in the output binary via bolt info section
--compact-code-model - generate code for binaries <128MB on AArch64
--create-debug-names-section - Creates .debug_names section, if the input binary doesn't have it already, for DWARF5 CU/TUs.
--data=<string> - <data file>
--data2=<string> - <data file>
--debug-thread-count=<uint> - specifies thread count for the multithreading for updating DWO debug info
--dump-cg=<string> - dump callgraph to the given file
--dwarf-output-path=<string> - Path to where .dwo files will be written out to.
--dyno-stats - print execution info based on profile
--enable-bat - write BOLT Address Translation tables
--hot-data - hot data symbols support (relocation mode)
--hot-functions-at-end - if reorder-functions is used, order functions putting hottest last
--hot-text - Generate hot text symbols. Apply this option to a precompiled binary that manually calls into hugify, such that at runtime hugify call will put hot code into 2M pages. This requires relocation.
--hot-text-move-sections=<sec1,sec2,sec3,...> - list of sections containing functions used for hugifying hot text. BOLT makes sure these functions are not placed on the same page as the hot text. (default='.stub,.mover').
--insert-retpolines - run retpoline insertion pass
--lite - skip processing of cold functions
--no-threads - disable multithreading
--print-profile-stats - print profile quality/bias analysis
--r11-availability=<value> - determine the availability of r11 before indirect branches
=never - r11 not available
=always - r11 available before calls and jumps
=abi - r11 available before calls but not before jumps
--relocs - use relocations in the binary (default=autodetect)
--remove-symtab - Remove .symtab section
--strict - trust the input to be from a well-formed source
--tasks-per-thread=<uint> - number of tasks to be created per thread
--thread-count=<uint> - number of threads
--update-debug-sections - update DWARF debug sections of the executable
--use-gnu-stack - use GNU_STACK program header for new segment (workaround for issues with strip/objcopy)
--use-old-text - reuse space in old .text if possible (relocation mode)
-v <uint> - set verbosity level for diagnostic output
BOLT instrumentation options:
--conservative-instrumentation - disable instrumentation optimizations that sacrifice profile accuracy (for debugging, default: false)
--instrument-calls - record profile for inter-function control flow activity (default: true)
--instrument-hot-only - only insert instrumentation on hot functions (needs profile, default: false)
--instrumentation-binpath=<string> - path to instrumented binary in case if /proc/self/map_files is not accessible due to access restriction issues
--instrumentation-file=<string> - file name where instrumented profile will be saved (default: /tmp/prof.fdata)
--instrumentation-file-append-pid - append PID to saved profile file name (default: false)
--instrumentation-max-size=<uint> - Set max memory size of the instrumentation bump allocator default: 0x6400000)
--instrumentation-no-counters-clear - Don't clear counters across dumps (use with instrumentation-sleep-time option)
--instrumentation-sleep-time=<uint> - interval between profile writes (default: 0 = write only at program end). This is useful for service workloads when you want to dump profile every X minutes or if you are killing the program and the profile is not being dumped at the end.
--instrumentation-wait-forks - Wait until all forks of instrumented process will finish (use with instrumentation-sleep-time option)
--no-lse-atomics - generate instrumentation code sequence without using LSE atomic instruction
BOLT optimization options:
--align-blocks - align basic blocks
--align-functions=<uint> - align functions at a given value (relocation mode)
--align-functions-max-bytes=<uint> - maximum number of bytes to use to align functions
--assume-abi - assume the ABI is never violated
--block-alignment=<uint> - boundary to use for alignment of basic blocks
--cg-from-perf-data - use perf data directly when constructing the call graph for stale functions
--cg-ignore-recursive-calls - ignore recursive calls when constructing the call graph
--cg-use-split-hot-size - use hot/cold data on basic blocks to determine hot sizes for call graph functions
--eliminate-unreachable - eliminate unreachable code
--frame-opt=<value> - optimize stack frame accesses
=none - do not perform frame optimization
=hot - perform FOP on hot functions
=all - perform FOP on all functions
--frame-opt-rm-stores - apply additional analysis to remove stores (experimental)
--function-order=<string> - file containing an ordered list of functions to use for function reordering
--generate-function-order=<string> - file to dump the ordered list of functions to use for function reordering
--generate-link-sections=<string> - generate a list of function sections in a format suitable for inclusion in a linker script
--group-stubs - share stubs across functions
--hugify - Automatically put hot code on 2MB page(s) (hugify) at runtime. No manual call to hugify is needed in the binary (which is what --hot-text relies on).
--icf - fold functions with identical code
--icf=<value> - fold functions with identical code
=all - Enable identical code folding
=1 - Enable identical code folding
=<empty> - Enable identical code folding
=none - Disable identical code folding (default)
=0 - Disable identical code folding (default)
=safe - Enable safe identical code folding
--icp-eliminate-loads - enable load elimination using memory profiling data when performing ICP
--indirect-call-promotion=<value> - indirect call promotion
=none - do not perform indirect call promotion
=calls - perform ICP on indirect calls
=jump-tables - perform ICP on jump tables
=all - perform ICP on calls and jump tables
--indirect-call-promotion-calls-topn=<uint> - limit number of targets to consider when doing indirect call promotion on calls. 0 = no limit
--indirect-call-promotion-jump-tables-topn=<uint> - limit number of targets to consider when doing indirect call promotion on jump tables. 0 = no limit
--indirect-call-promotion-mispredict-threshold=<uint> - misprediction threshold for skipping ICP on an indirect call
--indirect-call-promotion-topn=<uint> - limit number of targets to consider when doing indirect call promotion. 0 = no limit
--indirect-call-promotion-use-mispredicts - use misprediction frequency for determining whether or not ICP should be applied at a callsite. The -indirect-call-promotion-mispredict-threshold value will be used by this heuristic
--inline-all - inline all functions
--inline-ap - adjust function profile after inlining
--inline-memcpy - inline memcpy using size-specific optimized instructions (X86: 'rep movsb', AArch64: width-optimized register operations)
--inline-small-functions - inline functions if increase in size is less than defined by -inline-small-functions-bytes
--instrument - instrument code to generate accurate profile data
--jt-footprint-optimize-for-icache - with jt-footprint-reduction, only process PIC jumptables and turn off other transformations that increase code size
--jt-footprint-reduction - make jump tables size smaller at the cost of using more instructions at jump sites
--jump-tables=<value> - jump tables support (default=basic)
=none - do not optimize functions with jump tables
=basic - optimize functions with jump tables
=move - move jump tables to a separate section
=split - split jump tables section into hot and cold based on function execution frequency
=aggressive - aggressively split jump tables section based on usage of the tables
--memcpy1-spec=<func1,func2:cs1:cs2,func3:cs1,...> - list of functions with call sites for which to specialize memcpy() for size 1
--no-inline - disable all inlining (overrides other inlining options)
--peepholes=<value> - enable peephole optimizations
=none - disable peepholes
=double-jumps - remove double jumps when able
=tailcall-traps - insert tail call traps
=useless-branches - remove useless conditional branches
=all - enable all peephole optimizations
--plt=<value> - optimize PLT calls (requires linking with -znow on non-x86 architectures)
=none - do not optimize PLT calls
=hot - optimize executed (hot) PLT calls
=all - optimize all PLT calls
--preserve-blocks-alignment - try to preserve basic block alignment
--print-cache-metrics - calculate and print various metrics for instruction cache
--print-function-statistics=<uint> - print statistics about basic block ordering
--print-large-functions - print functions that could not be overwritten due to excessive size
--print-sorted-by=<value> - print functions sorted by order of dyno stats
=executed-forward-branches - executed forward branches
=taken-forward-branches - taken forward branches
=executed-backward-branches - executed backward branches
=taken-backward-branches - taken backward branches
=executed-unconditional-branches - executed unconditional branches
=all-function-calls - all function calls
=indirect-calls - indirect calls
=PLT-calls - PLT calls
=executed-instructions - executed instructions
=executed-load-instructions - executed load instructions
=executed-store-instructions - executed store instructions
=taken-jump-table-branches - taken jump table branches
=taken-unknown-indirect-branches - taken unknown indirect branches
=total-branches - total branches
=taken-branches - taken branches
=non-taken-conditional-branches - non-taken conditional branches
=taken-conditional-branches - taken conditional branches
=all-conditional-branches - all conditional branches
=linker-inserted-veneer-calls - linker-inserted veneer calls
=all - sorted by all names
--print-sorted-by-order=<value> - use ascending or descending order when printing functions ordered by dyno stats
=ascending - Ascending order
=descending - Descending order
--reg-reassign - reassign registers so as to avoid using REX prefixes in hot code
--reorder-blocks=<value> - change layout of basic blocks in a function
=none - do not reorder basic blocks
=reverse - layout blocks in reverse order
=normal - perform optimal layout based on profile
=branch-predictor - perform optimal layout prioritizing branch predictions
=cache - perform optimal layout prioritizing I-cache behavior
=cache+ - perform layout optimizing I-cache behavior
=ext-tsp - perform layout optimizing I-cache behavior
=cluster-shuffle - perform random layout of clusters
--reorder-data=<section1,section2,section3,...> - list of sections to reorder
--reorder-data-algo=<value> - algorithm used to reorder data sections
=count - sort hot data by read counts
=funcs - sort hot data by hot function usage and count
--reorder-data-inplace - reorder data sections in place
--reorder-data-max-bytes=<uint> - maximum number of bytes to reorder
--reorder-data-max-symbols=<uint> - maximum number of symbols to reorder
--reorder-functions=<value> - reorder and cluster functions (works only with relocations)
=none - do not reorder functions
=exec-count - order by execution count
=hfsort - use hfsort algorithm
=hfsort+ - use cache-directed sort
=cdsort - use cache-directed sort
=pettis-hansen - use Pettis-Hansen algorithm
=random - reorder functions randomly
=user - use function order specified by -function-order
--reorder-functions-use-hot-size - use a function's hot size when doing clustering
--runtime-hugify-lib=<string> - specify path of the runtime hugify library
--runtime-instrumentation-lib=<string> - specify path of the runtime instrumentation library
--sctc-mode=<value> - mode for simplify conditional tail calls
=always - always perform sctc
=preserve - only perform sctc when branch direction is preserved
=heuristic - use branch prediction data to control sctc
--sequential-disassembly - performs disassembly sequentially
--shorten-instructions - shorten instructions
--shrink-wrapping-threshold=<uint> - Percentage of prologue execution count to use as threshold when evaluating whether a block is cold enough to be profitable to move eligible spills there
--simplify-conditional-tail-calls - simplify conditional tail calls by removing unnecessary jumps
--simplify-rodata-loads - simplify loads from read-only sections by replacing the memory operand with the constant found in the corresponding section
--split-all-cold - outline as many cold basic blocks as possible
--split-functions - split functions into fragments
--split-strategy=<value> - strategy used to partition blocks into fragments
=profile2 - split each function into a hot and cold fragment using profiling information
=cdsplit - split each function into a hot, warm, and cold fragment using profiling information
=random2 - split each function into a hot and cold fragment at a randomly chosen split point (ignoring any available profiling information)
=randomN - split each function into N fragments at a randomly chosen split points (ignoring any available profiling information)
=all - split all basic blocks of each function into fragments such that each fragment contains exactly a single basic block
--stoke - turn on the stoke analysis
--strip-rep-ret - strip 'repz' prefix from 'repz retq' sequence (on by default)
--time-opts - print time spent in each optimization
--use-aggr-reg-reassign - use register liveness analysis to try to find more opportunities for -reg-reassign optimization
--use-compact-aligner - Use compact approach for aligning functions
--use-edge-counts - use edge count data when doing clustering
--x86-align-branch-boundary-hot-only - only apply branch boundary alignment in hot code
--x86-strip-redundant-address-size - Remove redundant Address-Size override prefix
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
Output options:
-o <string> - <output file>
-w <string> - save recorded profile to a file
Raw
llvm_bolt23_help_hidden.txt
OVERVIEW: BOLT - Binary Optimization and Layout Tool
USAGE: llvm-bolt [options] <executable> <executable>
OPTIONS:
BOLT generic options:
--align-text=<uint> - alignment of .text section
--allow-stripped - allow processing of stripped binaries
--alt-inst-feature-size=<uint> - size of feature field in .altinstructions
--alt-inst-has-padlen - specify that .altinstructions has padlen field
--asm-dump[=<dump folder>] - dump function into assembly
-b - alias for -data
--bolt-id=<string> - add any string to tag this execution in the output binary via bolt info section
--break-funcs=<func1,func2,func3,...> - list of functions to core dump on (debugging)
--check-encoding - perform verification of LLVM instruction encoding/decoding. Every instruction in the input is decoded and re-encoded. If the resulting bytes do not match the input, a warning message is printed.
--clone-constant-island - clone constant islands
--comp-dir-override=<string> - overrides DW_AT_comp_dir, and provides an alternative base location, which is used with DW_AT_dwo_name to construct a path to *.dwo files.
--compact-code-model - generate code for binaries <128MB on AArch64
--create-debug-names-section - Creates .debug_names section, if the input binary doesn't have it already, for DWARF5 CU/TUs.
--cu-processing-batch-size=<uint> - Specifies the size of batches for processing CUs. Higher number has better performance, but more memory usage. Default value is 1.
--custom-allocation-vma=<ulong> - use a custom address at which new code will be put, bypassing BOLT's logic to detect where to put code
--data=<string> - <data file>
--data2=<string> - <data file>
--debug-skeleton-cu - prints out offsets for abbrev and debug_info of Skeleton CUs that get patched.
--debug-thread-count=<uint> - specifies thread count for the multithreading for updating DWO debug info
--dot-tooltip-code - add basic block instructions as tool tips on nodes
--dump-alt-instructions - dump Linux alternative instructions info
--dump-cg=<string> - dump callgraph to the given file
--dump-data - dump parsed bolt data for debugging
--dump-dot-all - dump function CFGs to graphviz format after each stage;enable '-print-loops' for color-coded blocks
--dump-dot-func=<func1,func2,func3,...> - dump function CFGs to graphviz format for specified functions only;takes function name patterns (regex supported)
--dump-linux-exceptions - dump Linux kernel exception table
--dump-orc - dump raw ORC unwind information (sorted)
--dump-para-sites - dump Linux kernel paravitual patch sites
--dump-pci-fixups - dump Linux kernel PCI fixup table
--dump-smp-locks - dump Linux kernel SMP locks
--dump-static-calls - dump Linux kernel static calls
--dump-static-keys - dump Linux kernel static keys jump table
--dwarf-output-path=<string> - Path to where .dwo files will be written out to.
--dwp=<string> - Path and name to DWP file.
--dyno-stats - print execution info based on profile
--dyno-stats-all - print dyno stats after each stage
--dyno-stats-scale=<uint> - scale to be applied while reporting dyno stats
--enable-bat - write BOLT Address Translation tables
--fail-on-invalid-padding - treat invalid code padding as error
--force-data-relocations - force relocations to data sections to always be processed
--force-patch - force patching of original entry points to ensure execution follows only the new/optimized code.
--funcs=<func1,func2,func3,...> - limit optimizations to functions from the list
--funcs-file=<string> - file with list of functions to optimize
--funcs-file-no-regex=<string> - file with list of functions to optimize (non-regex)
--funcs-no-regex=<func1,func2,func3,...> - limit optimizations to functions from the list (non-regex)
--hot-data - hot data symbols support (relocation mode)
--hot-functions-at-end - if reorder-functions is used, order functions putting hottest last
--hot-text - Generate hot text symbols. Apply this option to a precompiled binary that manually calls into hugify, such that at runtime hugify call will put hot code into 2M pages. This requires relocation.
--hot-text-move-sections=<sec1,sec2,sec3,...> - list of sections containing functions used for hugifying hot text. BOLT makes sure these functions are not placed on the same page as the hot text. (default='.stub,.mover').
--insert-retpolines - run retpoline insertion pass
--keep-aranges - keep or generate .debug_aranges section if .gdb_index is written
--keep-tmp - preserve intermediate .o file
--lite - skip processing of cold functions
--log-file=<string> - redirect journaling to a file instead of stdout/stderr
--long-jump-labels - always use long jumps/nops for Linux kernel static keys
--max-data-relocations=<uint> - maximum number of data relocations to process
--max-funcs=<uint> - maximum number of functions to process
--no-huge-pages - use regular size pages for code alignment
--no-threads - disable multithreading
--pad-funcs=<func1:pad1,func2:pad2,func3:pad3,...> - list of functions to pad with amount of bytes
--pad-funcs-before=<func1:pad1,func2:pad2,func3:pad3,...> - list of functions to pad with amount of bytes
--print-aliases - print aliases when printing objects
--print-all - print functions after each stage
--print-cfg - print functions after CFG construction
--print-debug-info - print debug info when printing functions
--print-disasm - print function after disassembly
--print-dyno-opcode-stats=<uint> - print per instruction opcode dyno stats and the functionnames:BB offsets of the nth highest execution counts
--print-dyno-stats-only - while printing functions output dyno-stats and skip instructions
--print-exceptions - print exception handling data
--print-globals - print global symbols after disassembly
--print-jump-tables - print jump tables
--print-loops - print loop related information
--print-mem-data - print memory data annotations when printing functions
--print-normalized - print functions after CFG is normalized
--print-only=<func1,func2,func3,...> - list of functions to print
--print-only-file=<string> - file with list of functions to print
--print-orc - print ORC unwind information for instructions
--print-profile - print functions after attaching profile
--print-profile-stats - print profile quality/bias analysis
--print-pseudo-probes=<value> - print pseudo probe info
=decode - decode probes section from binary
=address_conversion - update address2ProbesMap with output block address
=encoded_probes - display the encoded probes in binary section
=all - enable all debugging printout
--print-relocations - print relocations when printing functions/objects
--print-reordered-data - print section contents after reordering
--print-retpoline-insertion - print functions after retpoline insertion pass
--print-sdt - print all SDT markers
--print-sections - print all registered sections
--print-unknown - print names of functions with unknown control flow
--profile-format=<value> - format to dump profile output in aggregation mode, default is fdata
=fdata - offset-based plaintext format
=yaml - dense YAML representation
--r11-availability=<value> - determine the availability of r11 before indirect branches
=never - r11 not available
=always - r11 available before calls and jumps
=abi - r11 available before calls but not before jumps
--relocs - use relocations in the binary (default=autodetect)
--remove-symtab - Remove .symtab section
--reorder-skip-symbols=<symbol1,symbol2,symbol3,...> - list of symbol names that cannot be reordered
--reorder-symbols=<symbol1,symbol2,symbol3,...> - list of symbol names that can be reordered
--retpoline-lfence - determine if lfence instruction should exist in the retpoline
--skip-funcs=<func1,func2,func3,...> - list of functions to skip
--skip-funcs-file=<string> - file with list of functions to skip
--strict - trust the input to be from a well-formed source
--tasks-per-thread=<uint> - number of tasks to be created per thread
--terminal-trap - Assume that execution stops at trap instruction
--terminal-x86-hlt - Assume that execution stops at x86 HLT instruction
--thread-count=<uint> - number of threads
--time-build - print time spent constructing binary functions
--time-rewrite - print time spent in rewriting passes
--top-called-limit=<uint> - maximum number of functions to print in top called functions section
--trap-avx512 - in relocation mode trap upon entry to any function that uses AVX-512 instructions
--trap-old-code - insert traps in old function bodies (relocation mode)
--update-branch-protection - Rewrites pac-ret DWARF CFI instructions (AArch64-only, on by default)
--update-debug-sections - update DWARF debug sections of the executable
--use-gnu-stack - use GNU_STACK program header for new segment (workaround for issues with strip/objcopy)
--use-old-text - reuse space in old .text if possible (relocation mode)
-v <uint> - set verbosity level for diagnostic output
BOLT instrumentation options:
--conservative-instrumentation - disable instrumentation optimizations that sacrifice profile accuracy (for debugging, default: false)
--instrument-calls - record profile for inter-function control flow activity (default: true)
--instrument-hot-only - only insert instrumentation on hot functions (needs profile, default: false)
--instrumentation-binpath=<string> - path to instrumented binary in case if /proc/self/map_files is not accessible due to access restriction issues
--instrumentation-file=<string> - file name where instrumented profile will be saved (default: /tmp/prof.fdata)
--instrumentation-file-append-pid - append PID to saved profile file name (default: false)
--instrumentation-max-size=<uint> - Set max memory size of the instrumentation bump allocator default: 0x6400000)
--instrumentation-no-counters-clear - Don't clear counters across dumps (use with instrumentation-sleep-time option)
--instrumentation-sleep-time=<uint> - interval between profile writes (default: 0 = write only at program end). This is useful for service workloads when you want to dump profile every X minutes or if you are killing the program and the profile is not being dumped at the end.
--instrumentation-wait-forks - Wait until all forks of instrumented process will finish (use with instrumentation-sleep-time option)
--no-lse-atomics - generate instrumentation code sequence without using LSE atomic instruction
BOLT optimization options:
--align-blocks - align basic blocks
--align-blocks-min-size=<uint> - minimal size of the basic block that should be aligned
--align-blocks-threshold=<uint> - align only blocks with frequency larger than containing function execution frequency specified in percent. E.g. 1000 means aligning blocks that are 10 times more frequently executed than the containing function.
--align-functions=<uint> - align functions at a given value (relocation mode)
--align-functions-max-bytes=<uint> - maximum number of bytes to use to align functions
--assume-abi - assume the ABI is never violated
--block-alignment=<uint> - boundary to use for alignment of basic blocks
--bolt-seed=<uint> - seed for randomization
--cg-from-perf-data - use perf data directly when constructing the call graph for stale functions
--cg-ignore-recursive-calls - ignore recursive calls when constructing the call graph
--cg-use-split-hot-size - use hot/cold data on basic blocks to determine hot sizes for call graph functions
--cold-threshold=<uint> - tenths of percents of main entry frequency to use as a threshold when evaluating whether a basic block is cold (0 means it is only considered cold if the block has zero samples). Default: 0
--elim-link-veneers - run veneer elimination pass
--eliminate-unreachable - eliminate unreachable code
--equalize-bb-counts - use same count for BBs that should have equivalent count (used in non-LBR and shrink wrapping)
--execution-count-threshold=<uint> - perform profiling accuracy-sensitive optimizations only if function execution count >= the threshold (default: 0)
--fix-block-counts - adjust block counts based on outgoing branch counts
--fix-func-counts - adjust function counts based on basic blocks execution count
--force-inline=<func1,func2,func3,...> - list of functions to always consider for inlining
--frame-opt=<value> - optimize stack frame accesses
=none - do not perform frame optimization
=hot - perform FOP on hot functions
=all - perform FOP on all functions
--frame-opt-rm-stores - apply additional analysis to remove stores (experimental)
--function-order=<string> - file containing an ordered list of functions to use for function reordering
--generate-function-order=<string> - file to dump the ordered list of functions to use for function reordering
--generate-link-sections=<string> - generate a list of function sections in a format suitable for inclusion in a linker script
--group-stubs - share stubs across functions
--hugify - Automatically put hot code on 2MB page(s) (hugify) at runtime. No manual call to hugify is needed in the binary (which is what --hot-text relies on).
--icf - fold functions with identical code
--icf=<value> - fold functions with identical code
=all - Enable identical code folding
=1 - Enable identical code folding
=<empty> - Enable identical code folding
=none - Disable identical code folding (default)
=0 - Disable identical code folding (default)
=safe - Enable safe identical code folding
--icp - Alias for --indirect-call-promotion
--icp-calls-remaining-percent-threshold=<uint> - The percentage threshold against remaining unpromoted indirect call count for the promotion for calls
--icp-calls-topn - alias for --indirect-call-promotion-calls-topn
--icp-calls-total-percent-threshold=<uint> - The percentage threshold against total count for the promotion for calls
--icp-eliminate-loads - enable load elimination using memory profiling data when performing ICP
--icp-funcs=<func1,func2,func3,...> - list of functions to enable ICP for
--icp-inline - only promote call targets eligible for inlining
--icp-jt-remaining-percent-threshold=<uint> - The percentage threshold against remaining unpromoted indirect call count for the promotion for jump tables
--icp-jt-targets - alias for --icp-jump-tables-targets
--icp-jt-topn - alias for --indirect-call-promotion-jump-tables-topn
--icp-jt-total-percent-threshold=<uint> - The percentage threshold against total count for the promotion for jump tables
--icp-jump-tables-targets - for jump tables, optimize indirect jmp targets instead of indices
--icp-mp-threshold - alias for --indirect-call-promotion-mispredict-threshold
--icp-old-code-sequence - use old code sequence for promoted calls
--icp-top-callsites=<uint> - optimize hottest calls until at least this percentage of all indirect calls frequency is covered. 0 = all callsites
--icp-topn - alias for --indirect-call-promotion-topn
--icp-use-mp - alias for --indirect-call-promotion-use-mispredicts
--indirect-call-promotion=<value> - indirect call promotion
=none - do not perform indirect call promotion
=calls - perform ICP on indirect calls
=jump-tables - perform ICP on jump tables
=all - perform ICP on calls and jump tables
--indirect-call-promotion-calls-topn=<uint> - limit number of targets to consider when doing indirect call promotion on calls. 0 = no limit
--indirect-call-promotion-jump-tables-topn=<uint> - limit number of targets to consider when doing indirect call promotion on jump tables. 0 = no limit
--indirect-call-promotion-mispredict-threshold=<uint> - misprediction threshold for skipping ICP on an indirect call
--indirect-call-promotion-topn=<uint> - limit number of targets to consider when doing indirect call promotion. 0 = no limit
--indirect-call-promotion-use-mispredicts - use misprediction frequency for determining whether or not ICP should be applied at a callsite. The -indirect-call-promotion-mispredict-threshold value will be used by this heuristic
--infer-fall-throughs - infer execution count for fall-through blocks
--infer-stale-profile - Infer counts from stale profile data.
--inline-all - inline all functions
--inline-ap - adjust function profile after inlining
--inline-limit=<uint> - maximum number of call sites to inline
--inline-max-iters=<uint> - maximum number of inline iterations
--inline-memcpy - inline memcpy using size-specific optimized instructions (X86: 'rep movsb', AArch64: width-optimized register operations)
--inline-small-functions - inline functions if increase in size is less than defined by -inline-small-functions-bytes
--inline-small-functions-bytes=<uint> - max number of bytes for the function to be considered small for inlining purposes
--instrument - instrument code to generate accurate profile data
--iterative-guess - in non-LBR mode, guess edge counts using iterative technique
--jt-footprint-optimize-for-icache - with jt-footprint-reduction, only process PIC jumptables and turn off other transformations that increase code size
--jt-footprint-reduction - make jump tables size smaller at the cost of using more instructions at jump sites
--jump-tables=<value> - jump tables support (default=basic)
=none - do not optimize functions with jump tables
=basic - optimize functions with jump tables
=move - move jump tables to a separate section
=split - split jump tables section into hot and cold based on function execution frequency
=aggressive - aggressively split jump tables section based on usage of the tables
--keep-nops - keep no-op instructions. By default they are removed.
--lite-threshold-count=<uint> - similar to '-lite-threshold-pct' but specify threshold using absolute function call count. I.e. limit processing to functions executed at least the specified number of times.
--lite-threshold-pct=<uint> - threshold (in percent) for selecting functions to process in lite mode. Higher threshold means fewer functions to process. E.g threshold of 90 means only top 10 percent of functions with profile will be processed.
--match-profile-with-function-hash - Match profile with function hash
--match-with-call-graph - Match functions with call graph
--memcpy1-spec=<func1,func2:cs1:cs2,func3:cs1,...> - list of functions with call sites for which to specialize memcpy() for size 1
--min-branch-clusters - use a modified clustering algorithm geared towards minimizing branches
--name-similarity-function-matching-threshold=<uint> - Match functions using namespace and edit distance
--no-inline - disable all inlining (overrides other inlining options)
--no-scan - do not scan cold functions for external references (may result in slower binary)
--peepholes=<value> - enable peephole optimizations
=none - disable peepholes
=double-jumps - remove double jumps when able
=tailcall-traps - insert tail call traps
=useless-branches - remove useless conditional branches
=all - enable all peephole optimizations
--percentile-for-profile-quality-check=<uint> - Percentile of profile quality distributions over hottest functions to report.
--plt=<value> - optimize PLT calls (requires linking with -znow on non-x86 architectures)
=none - do not optimize PLT calls
=hot - optimize executed (hot) PLT calls
=all - optimize all PLT calls
--preserve-blocks-alignment - try to preserve basic block alignment
--print-adr-ldr-relaxation - print functions after ADR/LDR Relaxation pass
--print-after-branch-fixup - print function after fixing local branches
--print-after-jt-footprint-reduction - print function after jt-footprint-reduction pass
--print-after-lowering - print function after instruction lowering
--print-cache-metrics - calculate and print various metrics for instruction cache
--print-clusters - print clusters
--print-estimate-edge-counts - print function after edge counts are set for no-LBR profile
--print-finalized - print function after CFG is finalized
--print-fix-relaxations - print functions after fix relaxations pass
--print-fix-riscv-calls - print functions after fix RISCV calls pass
--print-fop - print functions after frame optimizer pass
--print-function-statistics=<uint> - print statistics about basic block ordering
--print-icf - print functions after ICF optimization
--print-icp - print functions after indirect call promotion
--print-inline - print functions after inlining optimization
--print-large-functions - print functions that could not be overwritten due to excessive size
--print-longjmp - print functions after longjmp pass
--print-optimize-bodyless - print functions after bodyless optimization
--print-output-address-range - print output address range for each basic block in the function whenBinaryFunction::print is called
--print-peepholes - print functions after peephole optimization
--print-plt - print functions after PLT optimization
--print-pointer-auth-cfi-analyzer - print functions after PointerAuthCFIAnalyzer pass
--print-pointer-auth-cfi-fixup - print functions after PointerAuthCFIFixup pass
--print-regreassign - print functions after regreassign pass
--print-reordered - print functions after layout optimization
--print-reordered-functions - print functions after clustering
--print-sctc - print functions after conditional tail call simplification
--print-simplify-rodata-loads - print functions after simplification of RO data loads
--print-sorted-by=<value> - print functions sorted by order of dyno stats
=executed-forward-branches - executed forward branches
=taken-forward-branches - taken forward branches
=executed-backward-branches - executed backward branches
=taken-backward-branches - taken backward branches
=executed-unconditional-branches - executed unconditional branches
=all-function-calls - all function calls
=indirect-calls - indirect calls
=PLT-calls - PLT calls
=executed-instructions - executed instructions
=executed-load-instructions - executed load instructions
=executed-store-instructions - executed store instructions
=taken-jump-table-branches - taken jump table branches
=taken-unknown-indirect-branches - taken unknown indirect branches
=total-branches - total branches
=taken-branches - taken branches
=non-taken-conditional-branches - non-taken conditional branches
=taken-conditional-branches - taken conditional branches
=all-conditional-branches - all conditional branches
=linker-inserted-veneer-calls - linker-inserted veneer calls
=all - sorted by all names
--print-sorted-by-order=<value> - use ascending or descending order when printing functions ordered by dyno stats
=ascending - Ascending order
=descending - Descending order
--print-split - print functions after code splitting
--print-stoke - print functions after stoke analysis
--print-uce - print functions after unreachable code elimination
--print-veneer-elimination - print functions after veneer elimination pass
--profile-ignore-hash - ignore hash while reading function profile
--profile-use-dfs - use DFS order for YAML profile
--profile-write-pseudo-probes - Use pseudo probes in profile generation
--reg-reassign - reassign registers so as to avoid using REX prefixes in hot code
--reorder-blocks=<value> - change layout of basic blocks in a function
=none - do not reorder basic blocks
=reverse - layout blocks in reverse order
=normal - perform optimal layout based on profile
=branch-predictor - perform optimal layout prioritizing branch predictions
=cache - perform optimal layout prioritizing I-cache behavior
=cache+ - perform layout optimizing I-cache behavior
=ext-tsp - perform layout optimizing I-cache behavior
=cluster-shuffle - perform random layout of clusters
--reorder-data=<section1,section2,section3,...> - list of sections to reorder
--reorder-data-algo=<value> - algorithm used to reorder data sections
=count - sort hot data by read counts
=funcs - sort hot data by hot function usage and count
--reorder-data-inplace - reorder data sections in place
--reorder-data-max-bytes=<uint> - maximum number of bytes to reorder
--reorder-data-max-symbols=<uint> - maximum number of symbols to reorder
--reorder-functions=<value> - reorder and cluster functions (works only with relocations)
=none - do not reorder functions
=exec-count - order by execution count
=hfsort - use hfsort algorithm
=hfsort+ - use cache-directed sort
=cdsort - use cache-directed sort
=pettis-hansen - use Pettis-Hansen algorithm
=random - reorder functions randomly
=user - use function order specified by -function-order
--reorder-functions-use-hot-size - use a function's hot size when doing clustering
--report-bad-layout=<uint> - print top <uint> functions with suboptimal code layout on input
--report-stale - print the list of functions with stale profile
--runtime-hugify-lib=<string> - specify path of the runtime hugify library
--runtime-instrumentation-lib=<string> - specify path of the runtime instrumentation library
--runtime-lib-init-hook=<value> - Primary target for hooking runtime library initialization, used in fallback order of availabiliy in input binary (entry_point -> init -> init_array) (default: entry_point)
=entry_point - use ELF Header Entry Point
=init - use ELF DT_INIT entry
=init_array - use ELF .init_array entry
--sctc-mode=<value> - mode for simplify conditional tail calls
=always - always perform sctc
=preserve - only perform sctc when branch direction is preserved
=heuristic - use branch prediction data to control sctc
--sequential-disassembly - performs disassembly sequentially
--shorten-instructions - shorten instructions
--shrink-wrapping-threshold=<uint> - Percentage of prologue execution count to use as threshold when evaluating whether a block is cold enough to be profitable to move eligible spills there
--simplify-conditional-tail-calls - simplify conditional tail calls by removing unnecessary jumps
--simplify-rodata-loads - simplify loads from read-only sections by replacing the memory operand with the constant found in the corresponding section
--skip-inline=<func1,func2,func3,...> - list of functions to never consider for inlining
--split-align-threshold=<uint> - when deciding to split a function, apply this alignment while doing the size comparison (see -split-threshold). Default value: 2.
--split-all-cold - outline as many cold basic blocks as possible
--split-eh - split C++ exception handling code
--split-functions - split functions into fragments
--split-strategy=<value> - strategy used to partition blocks into fragments
=profile2 - split each function into a hot and cold fragment using profiling information
=cdsplit - split each function into a hot, warm, and cold fragment using profiling information
=random2 - split each function into a hot and cold fragment at a randomly chosen split point (ignoring any available profiling information)
=randomN - split each function into N fragments at a randomly chosen split points (ignoring any available profiling information)
=all - split all basic blocks of each function into fragments such that each fragment contains exactly a single basic block
--split-threshold=<uint> - split function only if its main size is reduced by more than given amount of bytes. Default value: 0, i.e. split iff the size is reduced. Note that on some architectures the size can increase after splitting.
--stale-matching-max-func-size=<uint> - The maximum size of a function to consider for inference.
--stale-matching-min-matched-block=<uint> - Percentage threshold of matched basic blocks at which stale profile inference is executed.
--stale-threshold=<uint> - maximum percentage of stale functions to tolerate (default: 100)
--stoke - turn on the stoke analysis
--strip-rep-ret - strip 'repz' prefix from 'repz retq' sequence (on by default)
--tail-duplication=<value> - duplicate unconditional branches that cross a cache line
=none - do not apply
=aggressive - aggressive strategy
=moderate - moderate strategy
=cache - cache-aware duplication strategy
--time-opts - print time spent in each optimization
--top-functions-for-profile-quality-check=<uint> - number of hottest functions to print aggregated profile quality stats of.
--tsp-threshold=<uint> - maximum number of hot basic blocks in a function for which to use a precise TSP solution while re-ordering basic blocks
--use-aggr-reg-reassign - use register liveness analysis to try to find more opportunities for -reg-reassign optimization
--use-compact-aligner - Use compact approach for aligning functions
--use-edge-counts - use edge count data when doing clustering
--verify-cfg - verify the CFG after every pass
--x86-align-branch-boundary-hot-only - only apply branch boundary alignment in hot code
--x86-strip-redundant-address-size - Remove redundant Address-Size override prefix
Generic Options:
-h - Alias for --help
--help - Display available options (--help-hidden for more)
--help-hidden - Display all available options
--help-list - Display list of available options (--help-list-hidden for more)
--help-list-hidden - Display list of all available options
--print-all-options - Print all option values after command line parsing
--print-options - Print non-default options after command line parsing
--version - Display the version of this program
Output options:
--bolt-info - write bolt info section in the output binary
-o <string> - <output file>
-w <string> - save recorded profile to a file
Raw
llvm_bolt23_help_list.txt
OVERVIEW: BOLT - Binary Optimization and Layout Tool
USAGE: llvm-bolt [options] <executable> <executable>
OPTIONS:
--align-blocks - align basic blocks
--align-functions=<uint> - align functions at a given value (relocation mode)
--align-functions-max-bytes=<uint> - maximum number of bytes to use to align functions
--assume-abi - assume the ABI is never violated
--block-alignment=<uint> - boundary to use for alignment of basic blocks
--bolt-id=<string> - add any string to tag this execution in the output binary via bolt info section
--cg-from-perf-data - use perf data directly when constructing the call graph for stale functions
--cg-ignore-recursive-calls - ignore recursive calls when constructing the call graph
--cg-use-split-hot-size - use hot/cold data on basic blocks to determine hot sizes for call graph functions
--compact-code-model - generate code for binaries <128MB on AArch64
--conservative-instrumentation - disable instrumentation optimizations that sacrifice profile accuracy (for debugging, default: false)
--create-debug-names-section - Creates .debug_names section, if the input binary doesn't have it already, for DWARF5 CU/TUs.
--data=<string> - <data file>
--data2=<string> - <data file>
--debug-thread-count=<uint> - specifies thread count for the multithreading for updating DWO debug info
--dump-cg=<string> - dump callgraph to the given file
--dwarf-output-path=<string> - Path to where .dwo files will be written out to.
--dyno-stats - print execution info based on profile
--eliminate-unreachable - eliminate unreachable code
--enable-bat - write BOLT Address Translation tables
--frame-opt=<value> - optimize stack frame accesses
=none - do not perform frame optimization
=hot - perform FOP on hot functions
=all - perform FOP on all functions
--frame-opt-rm-stores - apply additional analysis to remove stores (experimental)
--function-order=<string> - file containing an ordered list of functions to use for function reordering
--generate-function-order=<string> - file to dump the ordered list of functions to use for function reordering
--generate-link-sections=<string> - generate a list of function sections in a format suitable for inclusion in a linker script
--group-stubs - share stubs across functions
--help - Display available options (--help-hidden for more)
--hot-data - hot data symbols support (relocation mode)
--hot-functions-at-end - if reorder-functions is used, order functions putting hottest last
--hot-text - Generate hot text symbols. Apply this option to a precompiled binary that manually calls into hugify, such that at runtime hugify call will put hot code into 2M pages. This requires relocation.
--hot-text-move-sections=<sec1,sec2,sec3,...> - list of sections containing functions used for hugifying hot text. BOLT makes sure these functions are not placed on the same page as the hot text. (default='.stub,.mover').
--hugify - Automatically put hot code on 2MB page(s) (hugify) at runtime. No manual call to hugify is needed in the binary (which is what --hot-text relies on).
--icf - fold functions with identical code
--icf=<value> - fold functions with identical code
=all - Enable identical code folding
=1 - Enable identical code folding
=<empty> - Enable identical code folding
=none - Disable identical code folding (default)
=0 - Disable identical code folding (default)
=safe - Enable safe identical code folding
--icp-eliminate-loads - enable load elimination using memory profiling data when performing ICP
--indirect-call-promotion=<value> - indirect call promotion
=none - do not perform indirect call promotion
=calls - perform ICP on indirect calls
=jump-tables - perform ICP on jump tables
=all - perform ICP on calls and jump tables
--indirect-call-promotion-calls-topn=<uint> - limit number of targets to consider when doing indirect call promotion on calls. 0 = no limit
--indirect-call-promotion-jump-tables-topn=<uint> - limit number of targets to consider when doing indirect call promotion on jump tables. 0 = no limit
--indirect-call-promotion-mispredict-threshold=<uint> - misprediction threshold for skipping ICP on an indirect call
--indirect-call-promotion-topn=<uint> - limit number of targets to consider when doing indirect call promotion. 0 = no limit
--indirect-call-promotion-use-mispredicts - use misprediction frequency for determining whether or not ICP should be applied at a callsite. The -indirect-call-promotion-mispredict-threshold value will be used by this heuristic
--inline-all - inline all functions
--inline-ap - adjust function profile after inlining
--inline-memcpy - inline memcpy using size-specific optimized instructions (X86: 'rep movsb', AArch64: width-optimized register operations)
--inline-small-functions - inline functions if increase in size is less than defined by -inline-small-functions-bytes
--insert-retpolines - run retpoline insertion pass
--instrument - instrument code to generate accurate profile data
--instrument-calls - record profile for inter-function control flow activity (default: true)
--instrument-hot-only - only insert instrumentation on hot functions (needs profile, default: false)
--instrumentation-binpath=<string> - path to instrumented binary in case if /proc/self/map_files is not accessible due to access restriction issues
--instrumentation-file=<string> - file name where instrumented profile will be saved (default: /tmp/prof.fdata)
--instrumentation-file-append-pid - append PID to saved profile file name (default: false)
--instrumentation-max-size=<uint> - Set max memory size of the instrumentation bump allocator default: 0x6400000)
--instrumentation-no-counters-clear - Don't clear counters across dumps (use with instrumentation-sleep-time option)
--instrumentation-sleep-time=<uint> - interval between profile writes (default: 0 = write only at program end). This is useful for service workloads when you want to dump profile every X minutes or if you are killing the program and the profile is not being dumped at the end.
--instrumentation-wait-forks - Wait until all forks of instrumented process will finish (use with instrumentation-sleep-time option)
--jt-footprint-optimize-for-icache - with jt-footprint-reduction, only process PIC jumptables and turn off other transformations that increase code size
--jt-footprint-reduction - make jump tables size smaller at the cost of using more instructions at jump sites
--jump-tables=<value> - jump tables support (default=basic)
=none - do not optimize functions with jump tables
=basic - optimize functions with jump tables
=move - move jump tables to a separate section
=split - split jump tables section into hot and cold based on function execution frequency
=aggressive - aggressively split jump tables section based on usage of the tables
--lite - skip processing of cold functions
--memcpy1-spec=<func1,func2:cs1:cs2,func3:cs1,...> - list of functions with call sites for which to specialize memcpy() for size 1
--no-inline - disable all inlining (overrides other inlining options)
--no-lse-atomics - generate instrumentation code sequence without using LSE atomic instruction
--no-threads - disable multithreading
-o <string> - <output file>
--peepholes=<value> - enable peephole optimizations
=none - disable peepholes
=double-jumps - remove double jumps when able
=tailcall-traps - insert tail call traps
=useless-branches - remove useless conditional branches
=all - enable all peephole optimizations
--plt=<value> - optimize PLT calls (requires linking with -znow on non-x86 architectures)
=none - do not optimize PLT calls
=hot - optimize executed (hot) PLT calls
=all - optimize all PLT calls
--preserve-blocks-alignment - try to preserve basic block alignment
--print-cache-metrics - calculate and print various metrics for instruction cache
--print-function-statistics=<uint> - print statistics about basic block ordering
--print-large-functions - print functions that could not be overwritten due to excessive size
--print-profile-stats - print profile quality/bias analysis
--print-sorted-by=<value> - print functions sorted by order of dyno stats
=executed-forward-branches - executed forward branches
=taken-forward-branches - taken forward branches
=executed-backward-branches - executed backward branches
=taken-backward-branches - taken backward branches
=executed-unconditional-branches - executed unconditional branches
=all-function-calls - all function calls
=indirect-calls - indirect calls
=PLT-calls - PLT calls
=executed-instructions - executed instructions
=executed-load-instructions - executed load instructions
=executed-store-instructions - executed store instructions
=taken-jump-table-branches - taken jump table branches
=taken-unknown-indirect-branches - taken unknown indirect branches
=total-branches - total branches
=taken-branches - taken branches
=non-taken-conditional-branches - non-taken conditional branches
=taken-conditional-branches - taken conditional branches
=all-conditional-branches - all conditional branches
=linker-inserted-veneer-calls - linker-inserted veneer calls
=all - sorted by all names
--print-sorted-by-order=<value> - use ascending or descending order when printing functions ordered by dyno stats
=ascending - Ascending order
=descending - Descending order
--r11-availability=<value> - determine the availability of r11 before indirect branches
=never - r11 not available
=always - r11 available before calls and jumps
=abi - r11 available before calls but not before jumps
--reg-reassign - reassign registers so as to avoid using REX prefixes in hot code
--relocs - use relocations in the binary (default=autodetect)
--remove-symtab - Remove .symtab section
--reorder-blocks=<value> - change layout of basic blocks in a function
=none - do not reorder basic blocks
=reverse - layout blocks in reverse order
=normal - perform optimal layout based on profile
=branch-predictor - perform optimal layout prioritizing branch predictions
=cache - perform optimal layout prioritizing I-cache behavior
=cache+ - perform layout optimizing I-cache behavior
=ext-tsp - perform layout optimizing I-cache behavior
=cluster-shuffle - perform random layout of clusters
--reorder-data=<section1,section2,section3,...> - list of sections to reorder
--reorder-data-algo=<value> - algorithm used to reorder data sections
=count - sort hot data by read counts
=funcs - sort hot data by hot function usage and count
--reorder-data-inplace - reorder data sections in place
--reorder-data-max-bytes=<uint> - maximum number of bytes to reorder
--reorder-data-max-symbols=<uint> - maximum number of symbols to reorder
--reorder-functions=<value> - reorder and cluster functions (works only with relocations)
=none - do not reorder functions
=exec-count - order by execution count
=hfsort - use hfsort algorithm
=hfsort+ - use cache-directed sort
=cdsort - use cache-directed sort
=pettis-hansen - use Pettis-Hansen algorithm
=random - reorder functions randomly
=user - use function order specified by -function-order
--reorder-functions-use-hot-size - use a function's hot size when doing clustering
--runtime-hugify-lib=<string> - specify path of the runtime hugify library
--runtime-instrumentation-lib=<string> - specify path of the runtime instrumentation library
--sctc-mode=<value> - mode for simplify conditional tail calls
=always - always perform sctc
=preserve - only perform sctc when branch direction is preserved
=heuristic - use branch prediction data to control sctc
--sequential-disassembly - performs disassembly sequentially
--shorten-instructions - shorten instructions
--shrink-wrapping-threshold=<uint> - Percentage of prologue execution count to use as threshold when evaluating whether a block is cold enough to be profitable to move eligible spills there
--simplify-conditional-tail-calls - simplify conditional tail calls by removing unnecessary jumps
--simplify-rodata-loads - simplify loads from read-only sections by replacing the memory operand with the constant found in the corresponding section
--split-all-cold - outline as many cold basic blocks as possible
--split-functions - split functions into fragments
--split-strategy=<value> - strategy used to partition blocks into fragments
=profile2 - split each function into a hot and cold fragment using profiling information
=cdsplit - split each function into a hot, warm, and cold fragment using profiling information
=random2 - split each function into a hot and cold fragment at a randomly chosen split point (ignoring any available profiling information)
=randomN - split each function into N fragments at a randomly chosen split points (ignoring any available profiling information)
=all - split all basic blocks of each function into fragments such that each fragment contains exactly a single basic block
--stoke - turn on the stoke analysis
--strict - trust the input to be from a well-formed source
--strip-rep-ret - strip 'repz' prefix from 'repz retq' sequence (on by default)
--tasks-per-thread=<uint> - number of tasks to be created per thread
--thread-count=<uint> - number of threads
--time-opts - print time spent in each optimization
--update-debug-sections - update DWARF debug sections of the executable
--use-aggr-reg-reassign - use register liveness analysis to try to find more opportunities for -reg-reassign optimization
--use-compact-aligner - Use compact approach for aligning functions
--use-edge-counts - use edge count data when doing clustering
--use-gnu-stack - use GNU_STACK program header for new segment (workaround for issues with strip/objcopy)
--use-old-text - reuse space in old .text if possible (relocation mode)
-v <uint> - set verbosity level for diagnostic output
--version - Display the version of this program
-w <string> - save recorded profile to a file
--x86-align-branch-boundary-hot-only - only apply branch boundary alignment in hot code
--x86-strip-redundant-address-size - Remove redundant Address-Size override prefix
Raw
llvm_bolt23_help_list_hidden.txt
OVERVIEW: BOLT - Binary Optimization and Layout Tool
USAGE: llvm-bolt [options] <executable> <executable>
OPTIONS:
--align-blocks - align basic blocks
--align-blocks-min-size=<uint> - minimal size of the basic block that should be aligned
--align-blocks-threshold=<uint> - align only blocks with frequency larger than containing function execution frequency specified in percent. E.g. 1000 means aligning blocks that are 10 times more frequently executed than the containing function.
--align-functions=<uint> - align functions at a given value (relocation mode)
--align-functions-max-bytes=<uint> - maximum number of bytes to use to align functions
--align-text=<uint> - alignment of .text section
--allow-stripped - allow processing of stripped binaries
--alt-inst-feature-size=<uint> - size of feature field in .altinstructions
--alt-inst-has-padlen - specify that .altinstructions has padlen field
--asm-dump[=<dump folder>] - dump function into assembly
--assume-abi - assume the ABI is never violated
-b - alias for -data
--block-alignment=<uint> - boundary to use for alignment of basic blocks
--bolt-id=<string> - add any string to tag this execution in the output binary via bolt info section
--bolt-info - write bolt info section in the output binary
--bolt-seed=<uint> - seed for randomization
--break-funcs=<func1,func2,func3,...> - list of functions to core dump on (debugging)
--cg-from-perf-data - use perf data directly when constructing the call graph for stale functions
--cg-ignore-recursive-calls - ignore recursive calls when constructing the call graph
--cg-use-split-hot-size - use hot/cold data on basic blocks to determine hot sizes for call graph functions
--check-encoding - perform verification of LLVM instruction encoding/decoding. Every instruction in the input is decoded and re-encoded. If the resulting bytes do not match the input, a warning message is printed.
--clone-constant-island - clone constant islands
--cold-threshold=<uint> - tenths of percents of main entry frequency to use as a threshold when evaluating whether a basic block is cold (0 means it is only considered cold if the block has zero samples). Default: 0
--comp-dir-override=<string> - overrides DW_AT_comp_dir, and provides an alternative base location, which is used with DW_AT_dwo_name to construct a path to *.dwo files.
--compact-code-model - generate code for binaries <128MB on AArch64
--conservative-instrumentation - disable instrumentation optimizations that sacrifice profile accuracy (for debugging, default: false)
--create-debug-names-section - Creates .debug_names section, if the input binary doesn't have it already, for DWARF5 CU/TUs.
--cu-processing-batch-size=<uint> - Specifies the size of batches for processing CUs. Higher number has better performance, but more memory usage. Default value is 1.
--custom-allocation-vma=<ulong> - use a custom address at which new code will be put, bypassing BOLT's logic to detect where to put code
--data=<string> - <data file>
--data2=<string> - <data file>
--debug-skeleton-cu - prints out offsets for abbrev and debug_info of Skeleton CUs that get patched.
--debug-thread-count=<uint> - specifies thread count for the multithreading for updating DWO debug info
--dot-tooltip-code - add basic block instructions as tool tips on nodes
--dump-alt-instructions - dump Linux alternative instructions info
--dump-cg=<string> - dump callgraph to the given file
--dump-data - dump parsed bolt data for debugging
--dump-dot-all - dump function CFGs to graphviz format after each stage;enable '-print-loops' for color-coded blocks
--dump-dot-func=<func1,func2,func3,...> - dump function CFGs to graphviz format for specified functions only;takes function name patterns (regex supported)
--dump-linux-exceptions - dump Linux kernel exception table
--dump-orc - dump raw ORC unwind information (sorted)
--dump-para-sites - dump Linux kernel paravitual patch sites
--dump-pci-fixups - dump Linux kernel PCI fixup table
--dump-smp-locks - dump Linux kernel SMP locks
--dump-static-calls - dump Linux kernel static calls
--dump-static-keys - dump Linux kernel static keys jump table
--dwarf-output-path=<string> - Path to where .dwo files will be written out to.
--dwp=<string> - Path and name to DWP file.
--dyno-stats - print execution info based on profile
--dyno-stats-all - print dyno stats after each stage
--dyno-stats-scale=<uint> - scale to be applied while reporting dyno stats
--elim-link-veneers - run veneer elimination pass
--eliminate-unreachable - eliminate unreachable code
--enable-bat - write BOLT Address Translation tables
--equalize-bb-counts - use same count for BBs that should have equivalent count (used in non-LBR and shrink wrapping)
--execution-count-threshold=<uint> - perform profiling accuracy-sensitive optimizations only if function execution count >= the threshold (default: 0)
--fail-on-invalid-padding - treat invalid code padding as error
--fix-block-counts - adjust block counts based on outgoing branch counts
--fix-func-counts - adjust function counts based on basic blocks execution count
--force-data-relocations - force relocations to data sections to always be processed
--force-inline=<func1,func2,func3,...> - list of functions to always consider for inlining
--force-patch - force patching of original entry points to ensure execution follows only the new/optimized code.
--frame-opt=<value> - optimize stack frame accesses
=none - do not perform frame optimization
=hot - perform FOP on hot functions
=all - perform FOP on all functions
--frame-opt-rm-stores - apply additional analysis to remove stores (experimental)
--funcs=<func1,func2,func3,...> - limit optimizations to functions from the list
--funcs-file=<string> - file with list of functions to optimize
--funcs-file-no-regex=<string> - file with list of functions to optimize (non-regex)
--funcs-no-regex=<func1,func2,func3,...> - limit optimizations to functions from the list (non-regex)
--function-order=<string> - file containing an ordered list of functions to use for function reordering
--generate-function-order=<string> - file to dump the ordered list of functions to use for function reordering
--generate-link-sections=<string> - generate a list of function sections in a format suitable for inclusion in a linker script
--group-stubs - share stubs across functions
-h - Alias for --help
--help - Display available options (--help-hidden for more)
--help-hidden - Display all available options
--help-list - Display list of available options (--help-list-hidden for more)
--help-list-hidden - Display list of all available options
--hot-data - hot data symbols support (relocation mode)
--hot-functions-at-end - if reorder-functions is used, order functions putting hottest last
--hot-text - Generate hot text symbols. Apply this option to a precompiled binary that manually calls into hugify, such that at runtime hugify call will put hot code into 2M pages. This requires relocation.
--hot-text-move-sections=<sec1,sec2,sec3,...> - list of sections containing functions used for hugifying hot text. BOLT makes sure these functions are not placed on the same page as the hot text. (default='.stub,.mover').
--hugify - Automatically put hot code on 2MB page(s) (hugify) at runtime. No manual call to hugify is needed in the binary (which is what --hot-text relies on).
--icf - fold functions with identical code
--icf=<value> - fold functions with identical code
=all - Enable identical code folding
=1 - Enable identical code folding
=<empty> - Enable identical code folding
=none - Disable identical code folding (default)
=0 - Disable identical code folding (default)
=safe - Enable safe identical code folding
--icp - Alias for --indirect-call-promotion
--icp-calls-remaining-percent-threshold=<uint> - The percentage threshold against remaining unpromoted indirect call count for the promotion for calls
--icp-calls-topn - alias for --indirect-call-promotion-calls-topn
--icp-calls-total-percent-threshold=<uint> - The percentage threshold against total count for the promotion for calls
--icp-eliminate-loads - enable load elimination using memory profiling data when performing ICP
--icp-funcs=<func1,func2,func3,...> - list of functions to enable ICP for
--icp-inline - only promote call targets eligible for inlining
--icp-jt-remaining-percent-threshold=<uint> - The percentage threshold against remaining unpromoted indirect call count for the promotion for jump tables
--icp-jt-targets - alias for --icp-jump-tables-targets
--icp-jt-topn - alias for --indirect-call-promotion-jump-tables-topn
--icp-jt-total-percent-threshold=<uint> - The percentage threshold against total count for the promotion for jump tables
--icp-jump-tables-targets - for jump tables, optimize indirect jmp targets instead of indices
--icp-mp-threshold - alias for --indirect-call-promotion-mispredict-threshold
--icp-old-code-sequence - use old code sequence for promoted calls
--icp-top-callsites=<uint> - optimize hottest calls until at least this percentage of all indirect calls frequency is covered. 0 = all callsites
--icp-topn - alias for --indirect-call-promotion-topn
--icp-use-mp - alias for --indirect-call-promotion-use-mispredicts
--indirect-call-promotion=<value> - indirect call promotion
=none - do not perform indirect call promotion
=calls - perform ICP on indirect calls
=jump-tables - perform ICP on jump tables
=all - perform ICP on calls and jump tables
--indirect-call-promotion-calls-topn=<uint> - limit number of targets to consider when doing indirect call promotion on calls. 0 = no limit
--indirect-call-promotion-jump-tables-topn=<uint> - limit number of targets to consider when doing indirect call promotion on jump tables. 0 = no limit
--indirect-call-promotion-mispredict-threshold=<uint> - misprediction threshold for skipping ICP on an indirect call
--indirect-call-promotion-topn=<uint> - limit number of targets to consider when doing indirect call promotion. 0 = no limit
--indirect-call-promotion-use-mispredicts - use misprediction frequency for determining whether or not ICP should be applied at a callsite. The -indirect-call-promotion-mispredict-threshold value will be used by this heuristic
--infer-fall-throughs - infer execution count for fall-through blocks
--infer-stale-profile - Infer counts from stale profile data.
--inline-all - inline all functions
--inline-ap - adjust function profile after inlining
--inline-limit=<uint> - maximum number of call sites to inline
--inline-max-iters=<uint> - maximum number of inline iterations
--inline-memcpy - inline memcpy using size-specific optimized instructions (X86: 'rep movsb', AArch64: width-optimized register operations)
--inline-small-functions - inline functions if increase in size is less than defined by -inline-small-functions-bytes
--inline-small-functions-bytes=<uint> - max number of bytes for the function to be considered small for inlining purposes
--insert-retpolines - run retpoline insertion pass
--instrument - instrument code to generate accurate profile data
--instrument-calls - record profile for inter-function control flow activity (default: true)
--instrument-hot-only - only insert instrumentation on hot functions (needs profile, default: false)
--instrumentation-binpath=<string> - path to instrumented binary in case if /proc/self/map_files is not accessible due to access restriction issues
--instrumentation-file=<string> - file name where instrumented profile will be saved (default: /tmp/prof.fdata)
--instrumentation-file-append-pid - append PID to saved profile file name (default: false)
--instrumentation-max-size=<uint> - Set max memory size of the instrumentation bump allocator default: 0x6400000)
--instrumentation-no-counters-clear - Don't clear counters across dumps (use with instrumentation-sleep-time option)
--instrumentation-sleep-time=<uint> - interval between profile writes (default: 0 = write only at program end). This is useful for service workloads when you want to dump profile every X minutes or if you are killing the program and the profile is not being dumped at the end.
--instrumentation-wait-forks - Wait until all forks of instrumented process will finish (use with instrumentation-sleep-time option)
--iterative-guess - in non-LBR mode, guess edge counts using iterative technique
--jt-footprint-optimize-for-icache - with jt-footprint-reduction, only process PIC jumptables and turn off other transformations that increase code size
--jt-footprint-reduction - make jump tables size smaller at the cost of using more instructions at jump sites
--jump-tables=<value> - jump tables support (default=basic)
=none - do not optimize functions with jump tables
=basic - optimize functions with jump tables
=move - move jump tables to a separate section
=split - split jump tables section into hot and cold based on function execution frequency
=aggressive - aggressively split jump tables section based on usage of the tables
--keep-aranges - keep or generate .debug_aranges section if .gdb_index is written
--keep-nops - keep no-op instructions. By default they are removed.
--keep-tmp - preserve intermediate .o file
--lite - skip processing of cold functions
--lite-threshold-count=<uint> - similar to '-lite-threshold-pct' but specify threshold using absolute function call count. I.e. limit processing to functions executed at least the specified number of times.
--lite-threshold-pct=<uint> - threshold (in percent) for selecting functions to process in lite mode. Higher threshold means fewer functions to process. E.g threshold of 90 means only top 10 percent of functions with profile will be processed.
--log-file=<string> - redirect journaling to a file instead of stdout/stderr
--long-jump-labels - always use long jumps/nops for Linux kernel static keys
--match-profile-with-function-hash - Match profile with function hash
--match-with-call-graph - Match functions with call graph
--max-data-relocations=<uint> - maximum number of data relocations to process
--max-funcs=<uint> - maximum number of functions to process
--memcpy1-spec=<func1,func2:cs1:cs2,func3:cs1,...> - list of functions with call sites for which to specialize memcpy() for size 1
--min-branch-clusters - use a modified clustering algorithm geared towards minimizing branches
--name-similarity-function-matching-threshold=<uint> - Match functions using namespace and edit distance
--no-huge-pages - use regular size pages for code alignment
--no-inline - disable all inlining (overrides other inlining options)
--no-lse-atomics - generate instrumentation code sequence without using LSE atomic instruction
--no-scan - do not scan cold functions for external references (may result in slower binary)
--no-threads - disable multithreading
-o <string> - <output file>
--pad-funcs=<func1:pad1,func2:pad2,func3:pad3,...> - list of functions to pad with amount of bytes
--pad-funcs-before=<func1:pad1,func2:pad2,func3:pad3,...> - list of functions to pad with amount of bytes
--peepholes=<value> - enable peephole optimizations
=none - disable peepholes
=double-jumps - remove double jumps when able
=tailcall-traps - insert tail call traps
=useless-branches - remove useless conditional branches
=all - enable all peephole optimizations
--percentile-for-profile-quality-check=<uint> - Percentile of profile quality distributions over hottest functions to report.
--plt=<value> - optimize PLT calls (requires linking with -znow on non-x86 architectures)
=none - do not optimize PLT calls
=hot - optimize executed (hot) PLT calls
=all - optimize all PLT calls
--preserve-blocks-alignment - try to preserve basic block alignment
--print-adr-ldr-relaxation - print functions after ADR/LDR Relaxation pass
--print-after-branch-fixup - print function after fixing local branches
--print-after-jt-footprint-reduction - print function after jt-footprint-reduction pass
--print-after-lowering - print function after instruction lowering
--print-aliases - print aliases when printing objects
--print-all - print functions after each stage
--print-all-options - Print all option values after command line parsing
--print-cache-metrics - calculate and print various metrics for instruction cache
--print-cfg - print functions after CFG construction
--print-clusters - print clusters
--print-debug-info - print debug info when printing functions
--print-disasm - print function after disassembly
--print-dyno-opcode-stats=<uint> - print per instruction opcode dyno stats and the functionnames:BB offsets of the nth highest execution counts
--print-dyno-stats-only - while printing functions output dyno-stats and skip instructions
--print-estimate-edge-counts - print function after edge counts are set for no-LBR profile
--print-exceptions - print exception handling data
--print-finalized - print function after CFG is finalized
--print-fix-relaxations - print functions after fix relaxations pass
--print-fix-riscv-calls - print functions after fix RISCV calls pass
--print-fop - print functions after frame optimizer pass
--print-function-statistics=<uint> - print statistics about basic block ordering
--print-globals - print global symbols after disassembly
--print-icf - print functions after ICF optimization
--print-icp - print functions after indirect call promotion
--print-inline - print functions after inlining optimization
--print-jump-tables - print jump tables
--print-large-functions - print functions that could not be overwritten due to excessive size
--print-longjmp - print functions after longjmp pass
--print-loops - print loop related information
--print-mem-data - print memory data annotations when printing functions
--print-normalized - print functions after CFG is normalized
--print-only=<func1,func2,func3,...> - list of functions to print
--print-only-file=<string> - file with list of functions to print
--print-optimize-bodyless - print functions after bodyless optimization
--print-options - Print non-default options after command line parsing
--print-orc - print ORC unwind information for instructions
--print-output-address-range - print output address range for each basic block in the function whenBinaryFunction::print is called
--print-peepholes - print functions after peephole optimization
--print-plt - print functions after PLT optimization
--print-pointer-auth-cfi-analyzer - print functions after PointerAuthCFIAnalyzer pass
--print-pointer-auth-cfi-fixup - print functions after PointerAuthCFIFixup pass
--print-profile - print functions after attaching profile
--print-profile-stats - print profile quality/bias analysis
--print-pseudo-probes=<value> - print pseudo probe info
=decode - decode probes section from binary
=address_conversion - update address2ProbesMap with output block address
=encoded_probes - display the encoded probes in binary section
=all - enable all debugging printout
--print-regreassign - print functions after regreassign pass
--print-relocations - print relocations when printing functions/objects
--print-reordered - print functions after layout optimization
--print-reordered-data - print section contents after reordering
--print-reordered-functions - print functions after clustering
--print-retpoline-insertion - print functions after retpoline insertion pass
--print-sctc - print functions after conditional tail call simplification
--print-sdt - print all SDT markers
--print-sections - print all registered sections
--print-simplify-rodata-loads - print functions after simplification of RO data loads
--print-sorted-by=<value> - print functions sorted by order of dyno stats
=executed-forward-branches - executed forward branches
=taken-forward-branches - taken forward branches
=executed-backward-branches - executed backward branches
=taken-backward-branches - taken backward branches
=executed-unconditional-branches - executed unconditional branches
=all-function-calls - all function calls
=indirect-calls - indirect calls
=PLT-calls - PLT calls
=executed-instructions - executed instructions
=executed-load-instructions - executed load instructions
=executed-store-instructions - executed store instructions
=taken-jump-table-branches - taken jump table branches
=taken-unknown-indirect-branches - taken unknown indirect branches
=total-branches - total branches
=taken-branches - taken branches
=non-taken-conditional-branches - non-taken conditional branches
=taken-conditional-branches - taken conditional branches
=all-conditional-branches - all conditional branches
=linker-inserted-veneer-calls - linker-inserted veneer calls
=all - sorted by all names
--print-sorted-by-order=<value> - use ascending or descending order when printing functions ordered by dyno stats
=ascending - Ascending order
=descending - Descending order
--print-split - print functions after code splitting
--print-stoke - print functions after stoke analysis
--print-uce - print functions after unreachable code elimination
--print-unknown - print names of functions with unknown control flow
--print-veneer-elimination - print functions after veneer elimination pass
--profile-format=<value> - format to dump profile output in aggregation mode, default is fdata
=fdata - offset-based plaintext format
=yaml - dense YAML representation
--profile-ignore-hash - ignore hash while reading function profile
--profile-use-dfs - use DFS order for YAML profile
--profile-write-pseudo-probes - Use pseudo probes in profile generation
--r11-availability=<value> - determine the availability of r11 before indirect branches
=never - r11 not available
=always - r11 available before calls and jumps
=abi - r11 available before calls but not before jumps
--reg-reassign - reassign registers so as to avoid using REX prefixes in hot code
--relocs - use relocations in the binary (default=autodetect)
--remove-symtab - Remove .symtab section
--reorder-blocks=<value> - change layout of basic blocks in a function
=none - do not reorder basic blocks
=reverse - layout blocks in reverse order
=normal - perform optimal layout based on profile
=branch-predictor - perform optimal layout prioritizing branch predictions
=cache - perform optimal layout prioritizing I-cache behavior
=cache+ - perform layout optimizing I-cache behavior
=ext-tsp - perform layout optimizing I-cache behavior
=cluster-shuffle - perform random layout of clusters
--reorder-data=<section1,section2,section3,...> - list of sections to reorder
--reorder-data-algo=<value> - algorithm used to reorder data sections
=count - sort hot data by read counts
=funcs - sort hot data by hot function usage and count
--reorder-data-inplace - reorder data sections in place
--reorder-data-max-bytes=<uint> - maximum number of bytes to reorder
--reorder-data-max-symbols=<uint> - maximum number of symbols to reorder
--reorder-functions=<value> - reorder and cluster functions (works only with relocations)
=none - do not reorder functions
=exec-count - order by execution count
=hfsort - use hfsort algorithm
=hfsort+ - use cache-directed sort
=cdsort - use cache-directed sort
=pettis-hansen - use Pettis-Hansen algorithm
=random - reorder functions randomly
=user - use function order specified by -function-order
--reorder-functions-use-hot-size - use a function's hot size when doing clustering
--reorder-skip-symbols=<symbol1,symbol2,symbol3,...> - list of symbol names that cannot be reordered
--reorder-symbols=<symbol1,symbol2,symbol3,...> - list of symbol names that can be reordered
--report-bad-layout=<uint> - print top <uint> functions with suboptimal code layout on input
--report-stale - print the list of functions with stale profile
--retpoline-lfence - determine if lfence instruction should exist in the retpoline
--runtime-hugify-lib=<string> - specify path of the runtime hugify library
--runtime-instrumentation-lib=<string> - specify path of the runtime instrumentation library
--runtime-lib-init-hook=<value> - Primary target for hooking runtime library initialization, used in fallback order of availabiliy in input binary (entry_point -> init -> init_array) (default: entry_point)
=entry_point - use ELF Header Entry Point
=init - use ELF DT_INIT entry
=init_array - use ELF .init_array entry
--sctc-mode=<value> - mode for simplify conditional tail calls
=always - always perform sctc
=preserve - only perform sctc when branch direction is preserved
=heuristic - use branch prediction data to control sctc
--sequential-disassembly - performs disassembly sequentially
--shorten-instructions - shorten instructions
--shrink-wrapping-threshold=<uint> - Percentage of prologue execution count to use as threshold when evaluating whether a block is cold enough to be profitable to move eligible spills there
--simplify-conditional-tail-calls - simplify conditional tail calls by removing unnecessary jumps
--simplify-rodata-loads - simplify loads from read-only sections by replacing the memory operand with the constant found in the corresponding section
--skip-funcs=<func1,func2,func3,...> - list of functions to skip
--skip-funcs-file=<string> - file with list of functions to skip
--skip-inline=<func1,func2,func3,...> - list of functions to never consider for inlining
--split-align-threshold=<uint> - when deciding to split a function, apply this alignment while doing the size comparison (see -split-threshold). Default value: 2.
--split-all-cold - outline as many cold basic blocks as possible
--split-eh - split C++ exception handling code
--split-functions - split functions into fragments
--split-strategy=<value> - strategy used to partition blocks into fragments
=profile2 - split each function into a hot and cold fragment using profiling information
=cdsplit - split each function into a hot, warm, and cold fragment using profiling information
=random2 - split each function into a hot and cold fragment at a randomly chosen split point (ignoring any available profiling information)
=randomN - split each function into N fragments at a randomly chosen split points (ignoring any available profiling information)
=all - split all basic blocks of each function into fragments such that each fragment contains exactly a single basic block
--split-threshold=<uint> - split function only if its main size is reduced by more than given amount of bytes. Default value: 0, i.e. split iff the size is reduced. Note that on some architectures the size can increase after splitting.
--stale-matching-max-func-size=<uint> - The maximum size of a function to consider for inference.
--stale-matching-min-matched-block=<uint> - Percentage threshold of matched basic blocks at which stale profile inference is executed.
--stale-threshold=<uint> - maximum percentage of stale functions to tolerate (default: 100)
--stoke - turn on the stoke analysis
--strict - trust the input to be from a well-formed source
--strip-rep-ret - strip 'repz' prefix from 'repz retq' sequence (on by default)
--tail-duplication=<value> - duplicate unconditional branches that cross a cache line
=none - do not apply
=aggressive - aggressive strategy
=moderate - moderate strategy
=cache - cache-aware duplication strategy
--tasks-per-thread=<uint> - number of tasks to be created per thread
--terminal-trap - Assume that execution stops at trap instruction
--terminal-x86-hlt - Assume that execution stops at x86 HLT instruction
--thread-count=<uint> - number of threads
--time-build - print time spent constructing binary functions
--time-opts - print time spent in each optimization
--time-rewrite - print time spent in rewriting passes
--top-called-limit=<uint> - maximum number of functions to print in top called functions section
--top-functions-for-profile-quality-check=<uint> - number of hottest functions to print aggregated profile quality stats of.
--trap-avx512 - in relocation mode trap upon entry to any function that uses AVX-512 instructions
--trap-old-code - insert traps in old function bodies (relocation mode)
--tsp-threshold=<uint> - maximum number of hot basic blocks in a function for which to use a precise TSP solution while re-ordering basic blocks
--update-branch-protection - Rewrites pac-ret DWARF CFI instructions (AArch64-only, on by default)
--update-debug-sections - update DWARF debug sections of the executable
--use-aggr-reg-reassign - use register liveness analysis to try to find more opportunities for -reg-reassign optimization
--use-compact-aligner - Use compact approach for aligning functions
--use-edge-counts - use edge count data when doing clustering
--use-gnu-stack - use GNU_STACK program header for new segment (workaround for issues with strip/objcopy)
--use-old-text - reuse space in old .text if possible (relocation mode)
-v <uint> - set verbosity level for diagnostic output
--verify-cfg - verify the CFG after every pass
--version - Display the version of this program
-w <string> - save recorded profile to a file
--x86-align-branch-boundary-hot-only - only apply branch boundary alignment in hot code
--x86-strip-redundant-address-size - Remove redundant Address-Size override prefix
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment