Provided by: binaryen_120-4_amd64 
NAME
wasm-split - Split a module into a primary module and a secondary module, or instrument a
DESCRIPTION
================================================================================ wasm-split INFILES
Split a module into a primary module and a secondary module, or instrument a module to gather a profile
that can inform future splitting, or manage such profiles. Options that are only accepted in particular
modes are marked with the accepted "[<modes>]" in their descriptions.
================================================================================
wasm-split options: -------------------
--split
Split an input module into two output modules. The default mode.
--multi-split
Split an input module into an arbitrary number of output modules.
--instrument
Instrument an input module to allow it to generate a profile that can be used to guide splitting.
--merge-profiles
Merge multiple profiles for the same module into a single profile.
--print-profile
[print-profile] Print profile contents in a human-readable format.
--profile
[split] The profile to use to guide splitting.
--keep-funcs
[split] Comma-separated list of functions to keep in the primary module. The rest will be split
out. Can be used alongside --profile and --split-funcs. You can also pass a file with one function
per line by passing @filename.
--split-funcs
[split] Comma-separated list of functions to split out to the secondary module. The rest will be
kept. Can be used alongside --profile and --keep-funcs. This takes precedence over other split
options. You can also pass a file with one function per line by passing @filename.
--manifest
[multi-split] File describing the functions to be split into each module. Each section separated
by a blank line begins with the base name of an output module, which is followed by a list of
functions to place in that module, one per line.
--out-prefix
[multi-split] Prefix prepended to module names in the manifest file to create output file names.
--primary-output,-o1
[split] Output file for the primary module.
--secondary-output,-o2
[split] Output file for the secondary module.
--symbolmap
[split] Write a symbol map file for each of the output modules.
--no-placeholders
[split] Do not import placeholder functions. Calls to secondary functions will fail before the
secondary module has been instantiated.
--placeholdermap
[split] Write a file mapping placeholder indices to the function names.
--import-namespace
[split, instrument] When provided as an option for module splitting, the namespace from which to
import objects from the primary module into the secondary module. In instrument mode, refers to
the namespace from which to import the secondary memory, if any.
--placeholder-namespace
[split] The namespace from which to import placeholder functions into the primary module.
--jspi [split] Transform the module to support asynchronously loading the secondary module before any
placeholder functions have been called.
--export-prefix
[split] An identifying prefix to prepend to new export names created by module splitting.
--profile-export
[instrument] The export name of the function the embedder calls to write the profile into memory.
Defaults to `__write_profile`.
--in-memory
[instrument] Store profile information in memory (starting at address 0 and taking one byte per
function) rather than globals (the default) so that it can be shared between multiple threads.
Users are responsible for ensuring that the module does not use the initial memory region for
anything else.
--in-secondary-memory
[instrument] Store profile information in a separate memory, rather than in module main memory or
globals (the default). With this option, users do not need to reserve the initial memory region
for profile data and the data can be shared between multiple threads.
--secondary-memory-name
[instrument] The name of the secondary memory created to store profile information.
--emit-module-names
[split, instrument] Emit module names, even if not emitting the rest of the names section. Can
help differentiate the modules in stack traces. This option will be removed once simpler ways of
naming modules are widely available. See https://bugs.chromium.org/p/v8/issues/detail?id=11808.
--initial-table
[split, instrument] A hack to ensure the split and instrumented modules have the same table size
when using Emscripten's SPLIT_MODULE mode with dynamic linking. TODO: Figure out a more elegant
solution for that use case and remove this.
--emit-text,-S
[split, instrument] Emit text instead of binary for the output file or files.
--debuginfo,-g
[split, multi-split, instrument] Emit names section in wasm binary (or full debuginfo in wast)
--output,-o
[instrument, merge-profiles, multi-split] Output file.
--unescape,-u
Un-escape function names (in print-profile output)
--verbose,-v
Verbose output mode. Prints the functions that will be kept and split out when splitting a module.
Tool options: -------------
--mvp-features,-mvp
Disable all non-MVP features
--all-features,-all
Enable all features
--detect-features
(deprecated - this flag does nothing)
--quiet,-q
Emit less verbose output and hide trivial warnings.
--experimental-poppy
Parse wast files as Poppy IR for testing purposes.
--enable-sign-ext
Enable sign extension operations
--disable-sign-ext
Disable sign extension operations
--enable-threads
Enable atomic operations
--disable-threads
Disable atomic operations
--enable-mutable-globals
Enable mutable globals
--disable-mutable-globals
Disable mutable globals
--enable-nontrapping-float-to-int
Enable nontrapping float-to-int operations
--disable-nontrapping-float-to-int
Disable nontrapping float-to-int operations
--enable-simd
Enable SIMD operations and types
--disable-simd
Disable SIMD operations and types
--enable-bulk-memory
Enable bulk memory operations
--disable-bulk-memory
Disable bulk memory operations
--enable-exception-handling
Enable exception handling operations
--disable-exception-handling
Disable exception handling operations
--enable-tail-call
Enable tail call operations
--disable-tail-call
Disable tail call operations
--enable-reference-types
Enable reference types
--disable-reference-types
Disable reference types
--enable-multivalue
Enable multivalue functions
--disable-multivalue
Disable multivalue functions
--enable-gc
Enable garbage collection
--disable-gc
Disable garbage collection
--enable-memory64
Enable memory64
--disable-memory64
Disable memory64
--enable-relaxed-simd
Enable relaxed SIMD
--disable-relaxed-simd
Disable relaxed SIMD
--enable-extended-const
Enable extended const expressions
--disable-extended-const
Disable extended const expressions
--enable-strings
Enable strings
--disable-strings
Disable strings
--enable-multimemory
Enable multimemory
--disable-multimemory
Disable multimemory
--enable-typed-continuations
Enable typed continuations
--disable-typed-continuations
Disable typed continuations
--enable-shared-everything
Enable shared-everything threads
--disable-shared-everything
Disable shared-everything threads
--enable-fp16
Enable float 16 operations
--disable-fp16
Disable float 16 operations
--enable-typed-function-references
Deprecated compatibility flag
--disable-typed-function-references
Deprecated compatibility flag
--no-validation,-n
Disables validation, assumes inputs are correct
--pass-arg,-pa
An argument passed along to optimization passes being run. Must be in the form KEY@VALUE. If KEY
is the name of a pass then it applies to the closest instance of that pass before us. If KEY is
not the name of a pass then it is a global option that applies to all pass instances that read it.
--closed-world,-cw
Assume code outside of the module does not inspect or interact with GC and function references,
even if they are passed out. The outside may hold on to them and pass them back in, but not
inspect their contents or call them.
--preserve-type-order
Preserve the order of types from the input (useful for debugging and testing)
--generate-stack-ir
generate StackIR during writing
--optimize-stack-ir
optimize StackIR during writing
--print-stack-ir
print StackIR during writing
General options: ----------------
--version
Output version information and exit
--help,-h
Show this help message and exit
--debug,-d
Print debug information to stderr
wasm-split 120 April 2025 WASM-SPLIT(1)