futhark-test¶
SYNOPSIS¶
futhark test [options…] infiles…
DESCRIPTION¶
This tool is used to test Futhark programs based on input/output
datasets. If a directory is given, all contained files with a
.fut
extension are considered.
A Futhark test program is an ordinary Futhark program, with at least one test block describing input/output test cases and possibly other options. The last line must end in a newline. A test block consists of commented-out text with the following overall format:
description
==
cases...
The description
is an arbitrary (and possibly multiline)
human-readable explanation of the test program. It is separated from
the test cases by a line containing just ==
. Any comment starting
at the beginning of the line, and containing a line consisting of just
==
, will be considered a test block. The format of a test case is
as follows:
[tags { tags... }]
[entry: names...]
[compiled|nobench|random|script] input ({ values... } | @ filename)
output { values... } | auto output | error: regex
If compiled
is present before the input
keyword, this test
case will never be passed to the interpreter. This is useful for test
cases that are annoyingly slow to interpret. The nobench
keyword
is for data sets that are too small to be worth benchmarking, and only
has meaning to futhark-bench.
If input
is preceded by random
, the text between the curly
braces must consist of a sequence of Futhark types, including sizes in
the case of arrays. When futhark test
is run, a file located in a
data/
subdirectory, containing values of the indicated types and
shapes is, automatically constructed with futhark-dataset
. Apart
from sizes, integer constants (with or without type suffix), and
floating-point constants (always with type suffix) are also permitted.
If input
is preceded by script
, the text between the curly
braces is interpreted as a FutharkScript expression (see
futhark-literate), which is executed to generate the input.
It must use only functions explicitly declared as entry points. If
the expression produces an n-element tuple, it will be unpacked and
its components passed as n distinct arguments to the test function.
If input
is followed by an @
and a file name (which must not
contain any whitespace) instead of curly braces, values or
FutharkScript expression will be read from the indicated file. This
is recommended for large data sets. This notation cannot be used with
random
input.
After the input
block, the expected result of the test case is
written as either output
followed by another block of values, or
an expected run-time error, in which a regular expression can be used
to specify the exact error message expected. If no regular expression
is given, any error message is accepted. If neither output
nor
error
is given, the program will be expected to execute
succesfully, but its output will not be validated.
If output
is preceded by auto
(as in auto output
), the
expected values are automatically generated by compiling the program
with futhark-c
and recording its result for the given input (which
must not fail). This is usually only useful for testing or
benchmarking alternative compilers, and not for testing the
correctness of Futhark programs. This currently does not work for
script
inputs.
Alternatively, instead of input-output pairs, the test cases can simply be a description of an expected compile time type error:
error: regex
This is used to test the type checker.
By default, both the interpreter and compiler is run on all test cases
(except those that have specified compiled
), although this can be
changed with command-line options to futhark test
.
Tuple syntax is not supported when specifying input and output values.
Instead, you can write an N-tuple as its constituent N values. Beware
of syntax errors in the values - the errors reported by
futhark test
are very poor.
An optional tags specification is permitted in the first test block. This section can contain arbitrary tags that classify the benchmark:
tags { names... }
Tag are sequences of alphanumeric characters, dashes, and underscores,
with each tag seperated by whitespace. Any program with the
disable
tag is ignored by futhark test
.
Another optional directive is entry
, which specifies the entry
point to be used for testing. This is useful for writing programs
that test libraries with multiple entry points. Multiple entry points
can be specified on the same line by separating them with space, and
they will all be tested with the same input/output pairs. The
entry
directive affects subsequent input-output pairs in the same
comment block, and may only be present immediately preceding these
input-output pairs. If no entry
is given, main
is assumed.
See below for an example.
For many usage examples, see the tests
directory in the
Futhark source directory. A simple example can be found in
EXAMPLES
below.
OPTIONS¶
- --backend=program
The backend used when compiling Futhark programs (without leading
futhark
, e.g. justopencl
).- -c
Only run compiled code - do not run any interpreters.
- -C
Compile the programs, but do not run them.
- --concurrency=NUM
The number of tests to run concurrently. Defaults to the number of (hyper-)cores available.
- --exclude=tag
Do not run test cases that contain the given tag. Cases marked with “disable” are ignored by default, as are cases marked “no_foo”, where foo is the backend used.
- -i
Only interpret - do not run any compilers.
- -t
Type-check the programs, but do not run them.
- --futhark=program
The program used to perform operations (eg. compilation). Defaults to the binary running
futhark test
itself.- --no-terminal
Print each result on a line by itself, without line buffering.
- --no-tuning
Do not look for tuning files.
- --pass-option=opt
Pass an option to benchmark programs that are being run. For example, we might want to run OpenCL programs on a specific device:
futhark test prog.fut --backend=opencl --pass-option=-dHawaii
- --pass-compiler-option=opt
Pass an extra option to the compiler when compiling the programs.
- --runner=program
If set to a non-empty string, compiled programs are not run directly, but instead the indicated program is run with its first argument being the path to the compiled Futhark program. This is useful for compilation targets that cannot be executed directly (as with futhark-pyopencl on some platforms), or when you wish to run the program on a remote machine.
- --tuning=EXTENSION
For each program being run, look for a tuning file with this extension, which is suffixed to the name of the program. For example, given
--tuning=tuning
(the default), the programfoo.fut
will be passed the tuning filefoo.fut.tuning
if it exists.
ENVIRONMENT VARIABLES¶
TMPDIR
Directory used for temporary files such as gunzipped datasets and log files.
EXAMPLES¶
The following program tests simple indexing and bounds checking:
-- Test simple indexing of an array.
-- ==
-- tags { firsttag secondtag }
-- input { [4,3,2,1] 1i64 }
-- output { 3 }
-- input { [4,3,2,1] 5i64 }
-- error: Error*
let main (a: []i32) (i: i64): i32 =
a[i]
The following program contains two entry points, both of which are tested:
let add (x: i32) (y: i32): i32 = x + y
-- Test the add1 function.
-- ==
-- entry: add1
-- input { 1 } output { 2 }
entry add1 (x: i32): i32 = add x 1
-- Test the sub1 function.
-- ==
-- entry: sub1
-- input { 1 } output { 0 }
entry sub1 (x: i32): i32 = add x (-1)
The following program contains an entry point that is tested with randomly generated data:
-- ==
-- random input { [100]i32 [100]i32 } auto output
-- random input { [1000]i32 [1000]i32 } auto output
let main xs ys = i32.product (map2 (*) xs ys)