futhark c [options…] <program.fut>


futhark c translates a Futhark program to sequential C code, and either compiles that C code with gcc(1) 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 GCC is invoked with -O3, -lm, and -std=c99.

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.


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.

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

-b, --binary-output

Print the program result in the binary output format. The default is human-readable text, which is very slow.

-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.

-L, --log

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

-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.

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

Print the time taken to execute the program to the indicated file, an integral number of microseconds.