futhark c [options…] <program.fut>


futhark c translates a Futhark program to sequential C code, and either compiles that C code with a C compiler (see below) to an executable binary program, or produces a .h and .c file that can be linked with other code.. The standard Futhark optimisation pipeline is used, and

The resulting program will read the arguments to the entry point (main by default) from standard input and print its return value on standard output. The arguments are read and printed in Futhark syntax.



Print help text to standard output and exit.

--entry-point NAME

Treat this top-level function as an entry point.


Generate a library instead of an executable. Appends .c/.h to the name indicated by the -o option to determine output file names.

-o outfile

Where to write the result. If the source program is named foo.fut, this defaults to foo.


Ignore unsafe in program and perform safety checks unconditionally.


Generate a server-mode executable that reads commands from stdin.

-v verbose

Enable debugging output. If compilation fails due to a compiler error, the result of the last successful compiler step will be printed to standard error.


Print version information on standard output and exit.


Do not print any warnings.


Treat warnings as errors.



The C compiler used to compile the program. Defaults to cc if unset.


Space-separated list of options passed to the C compiler. Defaults to -O3 -std=c99 if unset.


The following options are accepted by executables generated by futhark c.

-h, --help

Print help text to standard output and exit.

-b, --binary-output

Print the program result in the binary output format. The default is human-readable text, which is very slow. Not accepted by server-mode executables.


Store any reusable initialisation data in this file, possibly speeding up subsequent launches.

-D, --debugging

Perform possibly expensive internal correctness checks and verbose logging. Implies -L.

-e, --entry-point=FUN

The entry point to run. Defaults to main. Not accepted by server-mode executables.

-L, --log

Print various low-overhead logging information to stderr while running.

-n, --no-print-result

Do not print the program result. Not accepted by server-mode executables.

-P, --profile

Gather profiling data during execution. Mostly interesting in --server mode. Implied by -D.


Set a tuning parameter to the given value. ASSIGNMENT must be of the form NAME=INT Use --print-params to see which names are available.


Print all tuning parameters that can be set with --param or --tuning.

-r, --runs=NUM

Perform NUM runs of the program. With -t, the runtime for each individual run will be printed. Additionally, a single leading warmup run will be performed (not counted). Only the final run will have its result written to stdout. Not accepted by server-mode executables.

-t, --write-runtime-to=FILE

Print the time taken to execute the program to the indicated file, an integral number of microseconds. Not accepted by server-mode executables.


Read size=value assignments from the given file.


futhark-opencl, futhark-cuda, futhark-test