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test-suite Guide
================

Quickstart
----------

1. The lit test runner is required to run the tests. You can either use one
from an LLVM build:

```bash
% <path to llvm build>/bin/llvm-lit --version
lit 0.8.0dev
```

An alternative is installing it as a python package in a python virtual
environment:

```bash
% mkdir venv
% virtualenv -p python2.7 venv
% . venv/bin/activate
% pip install svn+http://llvm.org/svn/llvm-project/llvm/trunk/utils/lit
% lit --version
lit 0.8.0dev
```

2. Check out the `test-suite` module with:

```bash
% svn co http://llvm.org/svn/llvm-project/test-suite/trunk test-suite
```

3. Create a build directory and use CMake to configure the suite. Use the
`CMAKE_C_COMPILER` option to specify the compiler to test. Use a cache file
to choose a typical build configuration:

```bash
% mkdir test-suite-build
% cd test-suite-build
% cmake -DCMAKE_C_COMPILER=<path to llvm build>/bin/clang \
-C../test-suite/cmake/caches/O3.cmake \
../test-suite
```

4. Build the benchmarks:

```text
% make
Scanning dependencies of target timeit-target
[ 0%] Building C object tools/CMakeFiles/timeit-target.dir/timeit.c.o
[ 0%] Linking C executable timeit-target
...
```

5. Run the tests with lit:

```text
% llvm-lit -v -j 1 -o results.json .
-- Testing: 474 tests, 1 threads --
PASS: test-suite :: MultiSource/Applications/ALAC/decode/alacconvert-decode.test (1 of 474)
********** TEST 'test-suite :: MultiSource/Applications/ALAC/decode/alacconvert-decode.test' RESULTS **********
compile_time: 0.2192
exec_time: 0.0462
hash: "59620e187c6ac38b36382685ccd2b63b"
size: 83348
**********
PASS: test-suite :: MultiSource/Applications/ALAC/encode/alacconvert-encode.test (2 of 474)
...
```

6. Show and compare result files (optional):

```bash
# Make sure pandas is installed. Prepend `sudo` if necessary.
% pip install pandas
# Show a single result file:
% test-suite/utils/compare.py results.json
# Compare two result files:
% test-suite/utils/compare.py results_a.json results_b.json
```


Structure
---------

The test-suite contains benchmark and test programs. The programs come with
reference outputs so that their correctness can be checked. The suite comes
with tools to collect metrics such as benchmark runtime, compilation time and
code size.

The test-suite is divided into several directories:

- `SingleSource/`

Contains test programs that are only a single source file in size. A
subdirectory may contain several programs.

- `MultiSource/`

Contains subdirectories which entire programs with multiple source files.
Large benchmarks and whole applications go here.

- `MicroBenchmarks/`

Programs using the [google-benchmark](https://github.com/google/benchmark)
library. The programs define functions that are run multiple times until the
measurement results are statistically significant.

- `External/`

Contains descriptions and test data for code that cannot be directly
distributed with the test-suite. The most prominent members of this
directory are the SPEC CPU benchmark suites.
See [External Suites](#external-suites).

- `Bitcode/`

These tests are mostly written in LLVM bitcode.

- `CTMark/`

Contains symbolic links to other benchmarks forming a representative sample
for compilation performance measurements.

### Benchmarks

Every program can work as a correctness test. Some programs are unsuitable for
performance measurements. Setting the `TEST_SUITE_BENCHMARKING_ONLY` CMake
option to `ON` will disable them.


Configuration
-------------

The test-suite has configuration options to customize building and running the
benchmarks. CMake can print a list of them:

```bash
% cd test-suite-build
# Print basic options:
% cmake -LH
# Print all options:
% cmake -LAH
```

### Common Configuration Options

- `CMAKE_C_FLAGS`

Specify extra flags to be passed to C compiler invocations. The flags are
also passed to the C++ compiler and linker invocations. See
[https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_FLAGS.html](https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_FLAGS.html)

- `CMAKE_C_COMPILER`

Select the C compiler executable to be used. Note that the C++ compiler is
inferred automatically i.e. when specifying `path/to/clang` CMake will
automatically use `path/to/clang++` as the C++ compiler. See
[https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_COMPILER.html](https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_COMPILER.html)

- `CMAKE_BUILD_TYPE`

Select a build type like `OPTIMIZE` or `DEBUG` selecting a set of predefined
compiler flags. These flags are applied regardless of the `CMAKE_C_FLAGS`
option and may be changed by modifying `CMAKE_C_FLAGS_OPTIMIZE` etc. See
[https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html]](https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html)

- `TEST_SUITE_RUN_UNDER`

Prefix test invocations with the given tool. This is typically used to run
cross-compiled tests within a simulator tool.

- `TEST_SUITE_BENCHMARKING_ONLY`

Disable tests that are unsuitable for performance measurements. The disabled
tests either run for a very short time or are dominated by I/O performance
making them unsuitable as compiler performance tests.

- `TEST_SUITE_SUBDIRS`

Semicolon-separated list of directories to include. This can be used to only
build parts of the test-suite or to include external suites. This option
does not work reliably with deeper subdirectories as it skips intermediate
`CMakeLists.txt` files which may be required.

- `TEST_SUITE_COLLECT_STATS`

Collect internal LLVM statistics. Appends `-save-stats=obj` when invocing the
compiler and makes the lit runner collect and merge the statistic files.

- `TEST_SUITE_RUN_BENCHMARKS`

If this is set to `OFF` then lit will not actually run the tests but just
collect build statistics like compile time and code size.

- `TEST_SUITE_USE_PERF`

Use the `perf` tool for time measurement instead of the `timeit` tool that
comes with the test-suite. The `perf` is usually available on linux systems.

- `TEST_SUITE_SPEC2000_ROOT`, `TEST_SUITE_SPEC2006_ROOT`, `TEST_SUITE_SPEC2017_ROOT`, ...

Specify installation directories of external benchmark suites. You can find
more information about expected versions or usage in the README files in the
`External` directory (such as `External/SPEC/README`)

### Common CMake Flags

- `-GNinja`

Generate build files for the ninja build tool.

- `-Ctest-suite/cmake/caches/<cachefile.cmake>`

Use a CMake cache. The test-suite comes with several CMake caches which
predefine common or tricky build configurations.


Displaying and Analyzing Results
--------------------------------

The `compare.py` script displays and compares result files. A result file is
produced when invoking lit with the `-o filename.json` flag.

Example usage:

- Basic Usage:

```text
% test-suite/utils/compare.py baseline.json
Warning: 'test-suite :: External/SPEC/CINT2006/403.gcc/403.gcc.test' has No metrics!
Tests: 508
Metric: exec_time
Program baseline
INT2006/456.hmmer/456.hmmer 1222.90
INT2006/464.h264ref/464.h264ref 928.70
...
baseline
count 506.000000
mean 20.563098
std 111.423325
min 0.003400
25% 0.011200
50% 0.339450
75% 4.067200
max 1222.896800
```

- Show compile_time or text segment size metrics:

```bash
% test-suite/utils/compare.py -m compile_time baseline.json
% test-suite/utils/compare.py -m size.__text baseline.json
```

- Compare two result files and filter short running tests:

```bash
% test-suite/utils/compare.py --filter-short baseline.json experiment.json
...
Program baseline experiment diff

SingleSour.../Benchmarks/Linpack/linpack-pc 5.16 4.30 -16.5%
MultiSourc...erolling-dbl/LoopRerolling-dbl 7.01 7.86 12.2%
SingleSour...UnitTests/Vectorizer/gcc-loops 3.89 3.54 -9.0%
...
```

- Merge multiple baseline and experiment result files by taking the minimum
runtime each:

```bash
% test-suite/utils/compare.py base0.json base1.json base2.json vs exp0.json exp1.json exp2.json
```

### Continuous Tracking with LNT

LNT is a set of client and server tools for continuously monitoring
performance. You can find more information at
[http://llvm.org/docs/lnt](http://llvm.org/docs/lnt). The official LNT instance
of the LLVM project is hosted at [http://lnt.llvm.org](http://lnt.llvm.org).


External Suites
---------------

External suites such as SPEC can be enabled by either

- placing (or linking) them into the `test-suite/test-suite-externals/xxx` directory (example: `test-suite/test-suite-externals/speccpu2000`)
- using a configuration option such as `-D TEST_SUITE_SPEC2000_ROOT=path/to/speccpu2000`

You can find further information in the respective README files such as
`test-suite/External/SPEC/README`.

For the SPEC benchmarks you can switch between the `test`, `train` and
`ref` input datasets via the `TEST_SUITE_RUN_TYPE` configuration option.
The `train` dataset is used by default.


Custom Suites
-------------

You can build custom suites using the test-suite infrastructure. A custom suite
has a `CMakeLists.txt` file at the top directory. The `CMakeLists.txt` will be
picked up automatically if placed into a subdirectory of the test-suite or when
setting the `TEST_SUITE_SUBDIRS` variable:

```bash
% cmake -DTEST_SUITE_SUBDIRS=path/to/my/benchmark-suite ../test-suite
```


Profile Guided Optimization
---------------------------

Profile guided optimization requires to compile and run twice. First the
benchmark should be compiled with profile generation instrumentation enabled
and setup for training data. The lit runner will merge the profile files
using `llvm-profdata` so they can be used by the second compilation run.

Example:
```bash
# Profile generation run:
% cmake -DTEST_SUITE_PROFILE_GENERATE=ON \
-DTEST_SUITE_RUN_TYPE=train \
../test-suite
% make
% llvm-lit .
# Use the profile data for compilation and actual benchmark run:
% cmake -DTEST_SUITE_PROFILE_GENERATE=OFF \
-DTEST_SUITE_PROFILE_USE=ON \
-DTEST_SUITE_RUN_TYPE=ref \
.
% make
% llvm-lit -o result.json .
```

The `TEST_SUITE_RUN_TYPE` setting only affects the SPEC benchmark suites.


Cross Compilation and External Devices
--------------------------------------

### Compilation

CMake allows to cross compile to a different target via toolchain files. More
information can be found here:

- [http://llvm.org/docs/lnt/tests.html#cross-compiling](http://llvm.org/docs/lnt/tests.html#cross-compiling)

- [https://cmake.org/cmake/help/latest/manual/cmake-toolchains.7.html](https://cmake.org/cmake/help/latest/manual/cmake-toolchains.7.html)

Cross compilation from macOS to iOS is possible with the
`test-suite/cmake/caches/target-target-*-iphoneos-internal.cmake` CMake cache
files; this requires an internal iOS SDK.

### Running

There are two ways to run the tests in a cross compilation setting:

- Via SSH connection to an external device: The `TEST_SUITE_REMOTE_HOST` option
should be set to the SSH hostname. The executables and data files need to be
transferred to the device after compilation. This is typically done via the
`rsync` make target. After this, the lit runner can be used on the host
machine. It will prefix the benchmark and verification command lines with an
`ssh` command.

Example:

```bash
% cmake -G Ninja -D CMAKE_C_COMPILER=path/to/clang \
-C ../test-suite/cmake/caches/target-arm64-iphoneos-internal.cmake \
-D TEST_SUITE_REMOTE_HOST=mydevice \
../test-suite
% ninja
% ninja rsync
% llvm-lit -j1 -o result.json .
```

- You can specify a simulator for the target machine with the
`TEST_SUITE_RUN_UNDER` setting. The lit runner will prefix all benchmark
invocations with it.


Running the test-suite via LNT
------------------------------

The LNT tool can run the test-suite. Use this when submitting test results to
an LNT instance. See
[http://llvm.org/docs/lnt/tests.html#llvm-cmake-test-suite](http://llvm.org/docs/lnt/tests.html#llvm-cmake-test-suite)
for details.

Running the test-suite via Makefiles (deprecated)
-------------------------------------------------

**Note**: The test-suite comes with a set of Makefiles that are considered
deprecated. They do not support newer testing modes like `Bitcode` or
`Microbenchmarks` and are harder to use.

Old documentation is available in the
[test-suite Makefile Guide](TestSuiteMakefileGuide).
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=====================
LLVM test-suite Guide
=====================
======================================
test-suite Makefile Guide (deprecated)
======================================

.. contents::
:local:
:local:

Overview
========

This document describes the features of the Makefile-based LLVM
test-suite as well as the cmake based replacement. This way of interacting
with the test-suite is deprecated in favor of running the test-suite using LNT,
but may continue to prove useful for some users. See the Testing
Guide's :ref:`test-suite Quickstart <test-suite-quickstart>` section for more
information.

Test suite Structure
====================

The ``test-suite`` module contains a number of programs that can be
compiled with LLVM and executed. These programs are compiled using the
native compiler and various LLVM backends. The output from the program
compiled with the native compiler is assumed correct; the results from
the other programs are compared to the native program output and pass if
they match.

When executing tests, it is usually a good idea to start out with a
subset of the available tests or programs. This makes test run times
smaller at first and later on this is useful to investigate individual
test failures. To run some test only on a subset of programs, simply
change directory to the programs you want tested and run ``gmake``
there. Alternatively, you can run a different test using the ``TEST``
variable to change what tests or run on the selected programs (see below
for more info).

In addition for testing correctness, the ``test-suite`` directory also
performs timing tests of various LLVM optimizations. It also records
compilation times for the compilers and the JIT. This information can be
used to compare the effectiveness of LLVM's optimizations and code
generation.

``test-suite`` tests are divided into three types of tests: MultiSource,
SingleSource, and External.

- ``test-suite/SingleSource``

The SingleSource directory contains test programs that are only a
single source file in size. These are usually small benchmark
programs or small programs that calculate a particular value. Several
such programs are grouped together in each directory.

- ``test-suite/MultiSource``

The MultiSource directory contains subdirectories which contain
entire programs with multiple source files. Large benchmarks and
whole applications go here.

- ``test-suite/External``

The External directory contains Makefiles for building code that is
external to (i.e., not distributed with) LLVM. The most prominent
members of this directory are the SPEC 95 and SPEC 2000 benchmark
suites. The ``External`` directory does not contain these actual
tests, but only the Makefiles that know how to properly compile these
programs from somewhere else. The presence and location of these
external programs is configured by the test-suite ``configure``
script.

Each tree is then subdivided into several categories, including
applications, benchmarks, regression tests, code that is strange
grammatically, etc. These organizations should be relatively self
explanatory.

Some tests are known to fail. Some are bugs that we have not fixed yet;
others are features that we haven't added yet (or may never add). In the
regression tests, the result for such tests will be XFAIL (eXpected
FAILure). In this way, you can tell the difference between an expected
and unexpected failure.

The tests in the test suite have no such feature at this time. If the
test passes, only warnings and other miscellaneous output will be
generated. If a test fails, a large <program> FAILED message will be
displayed. This will help you separate benign warnings from actual test
failures.

Running the test suite via CMake
================================

To run the test suite, you need to use the following steps:

#. The test suite uses the lit test runner to run the test-suite,
you need to have lit installed first. Check out LLVM and install lit:

.. code-block:: bash
% svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm
% cd llvm/utils/lit
% sudo python setup.py install # Or without sudo, install in virtual-env.
running install
running bdist_egg
running egg_info
writing lit.egg-info/PKG-INFO
...
% lit --version
lit 0.5.0dev
#. Check out the ``test-suite`` module with:

.. code-block:: bash
% svn co http://llvm.org/svn/llvm-project/test-suite/trunk test-suite
#. Use CMake to configure the test suite in a new directory. You cannot build
the test suite in the source tree.

.. code-block:: bash
% mkdir test-suite-build
% cd test-suite-build
% cmake ../test-suite
#. Build the benchmarks, using the makefiles CMake generated.

.. code-block:: bash
% make
Scanning dependencies of target timeit-target
[ 0%] Building C object tools/CMakeFiles/timeit-target.dir/timeit.c.o
[ 0%] Linking C executable timeit-target
[ 0%] Built target timeit-target
Scanning dependencies of target fpcmp-host
[ 0%] [TEST_SUITE_HOST_CC] Building host executable fpcmp
[ 0%] Built target fpcmp-host
Scanning dependencies of target timeit-host
[ 0%] [TEST_SUITE_HOST_CC] Building host executable timeit
[ 0%] Built target timeit-host
#. Run the tests with lit:

.. code-block:: bash
% lit -v -j 1 . -o results.json
-- Testing: 474 tests, 1 threads --
PASS: test-suite :: MultiSource/Applications/ALAC/decode/alacconvert-decode.test (1 of 474)
********** TEST 'test-suite :: MultiSource/Applications/ALAC/decode/alacconvert-decode.test' RESULTS **********
compile_time: 0.2192
exec_time: 0.0462
hash: "59620e187c6ac38b36382685ccd2b63b"
size: 83348
**********
PASS: test-suite :: MultiSource/Applications/ALAC/encode/alacconvert-encode.test (2 of 474)
Running the test suite via Makefiles (deprecated)
=================================================

First, all tests are executed within the LLVM object directory tree.
They *are not* executed inside of the LLVM source tree. This is because
the test suite creates temporary files during execution.
Expand Down Expand Up @@ -208,7 +60,7 @@ you have the suite checked out and configured, you don't need to do it
again (unless the test code or configure script changes).

Configuring External Tests
--------------------------
==========================

In order to run the External tests in the ``test-suite`` module, you
must specify *--with-externals*. This must be done during the
Expand Down Expand Up @@ -237,8 +89,8 @@ names known to LLVM include:
Others are added from time to time, and can be determined from
``configure``.

Running different tests
-----------------------
Running Different Tests
=======================

In addition to the regular "whole program" tests, the ``test-suite``
module also provides a mechanism for compiling the programs in different
Expand All @@ -257,8 +109,8 @@ LLVM research group. They may still be valuable, however, as a guide to
writing your own TEST Makefile for any optimization or analysis passes
that you develop with LLVM.

Generating test output
----------------------
Generating Test Output
======================

There are a number of ways to run the tests and generate output. The
most simple one is simply running ``gmake`` with no arguments. This will
Expand All @@ -283,8 +135,8 @@ running with ``TEST=<type>``). The ``report`` also generate a file
called ``report.<type>.raw.out`` containing the output of the entire
test run.

Writing custom tests for the test suite
---------------------------------------
Writing Custom Tests for the test-suite
=======================================

Assuming you can run the test suite, (e.g.
"``gmake TEST=nightly report``" should work), it is really easy to run
Expand Down
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Expand Up @@ -8,6 +8,7 @@ LLVM Testing Infrastructure Guide
.. toctree::
:hidden:

TestSuiteGuide
TestSuiteMakefileGuide

Overview
Expand All @@ -25,11 +26,7 @@ In order to use the LLVM testing infrastructure, you will need all of the
software required to build LLVM, as well as `Python <http://python.org>`_ 2.7 or
later.

If you intend to run the :ref:`test-suite <test-suite-overview>`, you will also
need a development version of zlib (zlib1g-dev is known to work on several Linux
distributions).

LLVM testing infrastructure organization
LLVM Testing Infrastructure Organization
========================================

The LLVM testing infrastructure contains two major categories of tests:
Expand Down Expand Up @@ -77,6 +74,8 @@ LLVM compiles, optimizes, and generates code.

The test-suite is located in the ``test-suite`` Subversion module.

See the :doc:`TestSuiteGuide` for details.

Debugging Information tests
---------------------------

Expand All @@ -96,9 +95,8 @@ regressions tests are in the main "llvm" module under the directory
``llvm/test`` (so you get these tests for free with the main LLVM tree).
Use ``make check-all`` to run the regression tests after building LLVM.

The more comprehensive test suite that includes whole programs in C and C++
is in the ``test-suite`` module. See :ref:`test-suite Quickstart
<test-suite-quickstart>` for more information on running these tests.
The ``test-suite`` module contains more comprehensive tests including whole C
and C++ programs. See the :doc:`TestSuiteGuide` for details.

Regression tests
----------------
Expand Down Expand Up @@ -585,65 +583,3 @@ the last RUN: line. This has two side effects:

(b) it speeds things up for really big test cases by avoiding
interpretation of the remainder of the file.

.. _test-suite-overview:

``test-suite`` Overview
=======================

The ``test-suite`` module contains a number of programs that can be
compiled and executed. The ``test-suite`` includes reference outputs for
all of the programs, so that the output of the executed program can be
checked for correctness.

``test-suite`` tests are divided into three types of tests: MultiSource,
SingleSource, and External.

- ``test-suite/SingleSource``

The SingleSource directory contains test programs that are only a
single source file in size. These are usually small benchmark
programs or small programs that calculate a particular value. Several
such programs are grouped together in each directory.

- ``test-suite/MultiSource``

The MultiSource directory contains subdirectories which contain
entire programs with multiple source files. Large benchmarks and
whole applications go here.

- ``test-suite/External``

The External directory contains Makefiles for building code that is
external to (i.e., not distributed with) LLVM. The most prominent
members of this directory are the SPEC 95 and SPEC 2000 benchmark
suites. The ``External`` directory does not contain these actual
tests, but only the Makefiles that know how to properly compile these
programs from somewhere else. When using ``LNT``, use the
``--test-externals`` option to include these tests in the results.

.. _test-suite-quickstart:

``test-suite`` Quickstart
-------------------------

The modern way of running the ``test-suite`` is focused on testing and
benchmarking complete compilers using the
`LNT <http://llvm.org/docs/lnt>`_ testing infrastructure.

For more information on using LNT to execute the ``test-suite``, please
see the `LNT Quickstart <http://llvm.org/docs/lnt/quickstart.html>`_
documentation.

``test-suite`` Makefiles
------------------------

Historically, the ``test-suite`` was executed using a complicated setup
of Makefiles. The LNT based approach above is recommended for most
users, but there are some testing scenarios which are not supported by
the LNT approach. In addition, LNT currently uses the Makefile setup
under the covers and so developers who are interested in how LNT works
under the hood may want to understand the Makefile based setup.

For more information on the ``test-suite`` Makefile setup, please see
the :doc:`Test Suite Makefile Guide <TestSuiteMakefileGuide>`.
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Expand Up @@ -145,6 +145,9 @@ representation.
:doc:`LLVM Testing Infrastructure Guide <TestingGuide>`
A reference manual for using the LLVM testing infrastructure.

:doc:`TestSuiteGuide`
Describes how to compile and run the test-suite benchmarks.

`How to build the C, C++, ObjC, and ObjC++ front end`__
Instructions for building the clang front-end from source.

Expand Down