LLVM Test Suite Guide
  1. Overview
  2. Requirements
  3. Quick Start
  4. LLVM Test Suite Organization
  5. LLVM Test Suite Tree
  6. QMTest Structure
  7. llvm-test Structure
  8. Running the LLVM Tests
  9. Running the nightly tester

Written by John T. Criswell and Reid Spencer

Overview

This document is the reference manual for the LLVM test suite. It documents the structure of the LLVM test suite, the tools needed to use it, and how to add and run tests.

Requirements

In order to use the LLVM test suite, you will need all of the software required to build LLVM, plus the following:

QMTest
The LLVM test suite uses QMTest to organize and run tests. Note: you will need QMTest 2.0.3 (source tar.gz file) to be successful. The tests do not run with any other version.
Python
You will need a Python interpreter that works with QMTest. Python will need zlib and SAX support enabled.
F2C
For now, LLVM does not have a Fortran front-end, but using F2C, we can run Fortran benchmarks. F2C support must be enabled via configure if not installed in a standard place. F2C requires three items: the f2c executable, f2c.h to compile the generated code, and libf2c.a to link generated code. By default, given an F2C directory $DIR, the configure script will search $DIR/bin for f2c, $DIR/include for f2c.h, and $DIR/lib for libf2c.a. The default $DIR values are: /usr, /usr/local, /sw, and /opt. If you installed F2C in a different location, you must tell configure:
  • ./configure --with-f2c=$DIR
    This will specify a new $DIR for the above-described search process. This will only work if the binary, header, and library are in their respective subdirectories of $DIR.
  • ./configure --with-f2c-bin=/binary/path --with-f2c-inc=/include/path --with-f2c-lib=/lib/path
    This allows you to specify the F2C components separately. Note: if you choose this route, you MUST specify all three components, and you need to only specify directories where the files are located; do NOT include the filenames themselves on the configure line.
Quick Start

The tests are located in two separate CVS modules. The basic feature and regression tests are in the main "llvm" module under the directory llvm/test. A more comprehensive test suite that includes whole programs in C and C++ is in the llvm-test module. This module should be checked out to the llvm/projects directory. When you configure the llvm module, the llvm-test module will be automatically configured. Or you can do it manually.

To run all of the simple tests in LLVM, use the master Makefile in the llvm/test directory:

% gmake -C llvm/test

To run only the code fragment tests (i.e. those that do basic testing of LLVM), run the tests organized by QMTest:

% gmake -C llvm/test qmtest

To run only the basic feature tests, QMTest supports the following target:

% gmake -C llvm/test Feature.t

To run only the regression tests, QMTest supports the following target:

% gmake -C llvm/test Regression.t

To run the comprehensive test suite (tests that compile and execute whole programs), run the llvm-test tests:

% cd llvm/projects
% cvs co llvm-test
% cd llvm-test
% ./configure --with-llvmsrc=$LLVM_SRC_ROOT --with-llvmobj=$LLVM_OBJ_ROOT
% gmake
LLVM Test Suite Organization

The LLVM test suite contains two major categories of tests: code fragments and whole programs. Code fragments are in the llvm module under the directory under the llvm/test directory. The whole programs test suite are n the llvm-test module under the main directory.

Code Fragments

Code fragments are small pieces of code that test a specific feature of LLVM or trigger a specific bug in LLVM. They are usually written in LLVM assembly language, but can be written in other languages if the test targets a particular language front end.

Code fragments are not complete programs, and they are never executed to determine correct behavior.

Thes code fragment tests are located in the llvm/test/Features and llvm/test/Regression directories.

Whole Programs

Whole Programs are pieces of code which can be compiled and linked into a stand-alone program that can be executed. These programs are generally written in high level languages such as C or C++, but sometimes they are written straight in LLVM assembly.

These programs are compiled and then executed using several different methods (native compiler, LLVM C backend, LLVM JIT, LLVM native code generation, etc). The output of these programs is compared to ensure that LLVM is compiling the program correctly.

In addition to compiling and executing programs, whole program tests serve as a way of benchmarking LLVM performance, both in terms of the efficiency of the programs generated as well as the speed with which LLVM compiles, optimizes, and generates code.

All "whole program" tests are located in the llvm-test CVS module.

LLVM Test Suite Tree

Each type of test in the LLVM test suite has its own directory. The major subtrees of the test suite directory tree are as follows:

QMTest Structure

The LLVM test suite is partially driven by QMTest and partially driven by GNU Make. Specifically, the Features and Regression tests are all driven by QMTest. The llvm-test module is currently driven by a set of Makefiles.

The QMTest system needs to have several pieces of information available; these pieces of configuration information are known collectively as the "context" in QMTest parlance. Since the context for LLVM is relatively large, the master Makefile in llvm/test sets it for you.

The LLVM database class makes the subdirectories of llvm/test a QMTest test database. For each directory that contains tests driven by QMTest, it knows what type of test the source file is and how to run it.

Hence, the QMTest namespace is essentially what you see in the Feature and Regression directories, but there is some magic that the database class performs (as described below).

The QMTest namespace is currently composed of the following tests and test suites:

llvm-test Structure

As mentioned previously, the llvm-test module provides three types of tests: MultiSource, SingleSource, and External. 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.

In addition to the regular "whole program" tests, the llvm-test module also provides a mechanism for compiling the programs in different ways. If the variable TEST is defined on the gmake command line, the test system will include a Makefile named TEST.<value of TEST variable>.Makefile. This Makefile can modify build rules to yield different results.

For example, the LLVM nightly tester uses TEST.nightly.Makefile to create the nightly test reports. To run the nightly tests, run gmake TEST=nightly.

There are several TEST Makefiles available in the tree. Some of them are designed for internal LLVM research and will not work outside of the 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.

Running the LLVM Tests

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.

The master Makefile in llvm/test is capable of running only the QMTest driven tests. By default, it will run all of these tests.

To run only the QMTest driven tests, run gmake qmtest at the command line in llvm/tests. To run a specific qmtest, suffix the test name with ".t" when running gmake.

For example, to run the Regression.LLC tests, type gmake Regression.LLC.t in llvm/tests.

Note that there are no Makefiles in llvm/test/Features and llvm/test/Regression. You must use QMTest from the llvm/test directory to run them.

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

  1. cd into the llvm/projects directory
  2. check out the llvm-test module with:
    cvs -d :pserver:anon@llvm.cs.uiuc.edu:/var/cvs/llvm co -PR llvm-test
    This will get the test suite into llvm/projects/llvm-test
  3. configure the test suite. You can do this one of two ways:
    1. Use the regular llvm configure:
      cd $LLVM_OBJ_ROOT ; $LLVM_SRC_ROOT/configure
      This will ensure that the projects/llvm-test directory is also properly configured.
    2. Use the configure script found in the llvm-test source directory:
      $BUILD_SRC_DIR/configure --with-llvmsrc=$LLVM_SRC_ROOT --with-llvmobj=$LLVM_OBJ_ROOT
  4. gmake

Note that the second and third steps only need to be done once. After you have the suite checked out and configured, you don't need to do it again (unless the test code or configure script changes).

To make a specialized test (use one of the llvm-test/TEST.<type>.Makefiles), just run:
gmake TEST=<type> test
For example, you could run the nightly tester tests using the following commands:

 % cd llvm/projects/llvm-test
 % gmake TEST=nightly test

Regardless of which test you're running, the results are printed on standard output and standard error. You can redirect these results to a file if you choose.

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 QMTest, 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 llvm-test have no such feature as of 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 nightly tester

The LLVM Nightly Testers automatically check out an LLVM tree, build it, run the "nightly" program test (described above), run all of the feature and regression tests, and then delete the checked out tree. This tester is designed to ensure that programs don't break as well as keep track of LLVM's progress over time.

If you'd like to set up an instance of the nightly tester to run on your machine, take a look at the comments at the top of the utils/NightlyTester.pl file. We usually run it from a crontab entry that looks ilke this:

5 3 * * *       LLVM_LIB_SEARCH_PATH=.../llvm-gcc/bytecode-libs $HOME/llvm/utils/NightlyTest.pl -parallel -enable-linscan ...CVSREPOSTRING... $HOME/buildtest-X86 $HOME/cvs/testresults-X86

Or, you can create a shell script to encapsulate the running of the script. The optimized x86 Linux nightly test is run from just such a script:

#!/bin/bash
BASE=/proj/work/llvm/nightlytest
export CVSROOT=:pserver:anon@llvm.cs.uiuc.edu:/var/cvs/llvm
export BUILDDIR=$BASE/build 
export WEBDIR=$BASE/testresults 
export LLVMGCCDIR=/proj/work/llvm/cfrontend/install
export PATH=/proj/install/bin:$LLVMGCCDIR/bin:$PATH
export LD_LIBRARY_PATH=/proj/install/lib
export LLVM_LIB_SEARCH_PATH=/proj/work/llvm/cfrontend/install/bytecode-libs
cd $BASE
cp /proj/work/llvm/llvm/utils/NightlyTest.pl .
nice ./NightlyTest.pl -nice -release -verbose -parallel -enable-linscan -noexternals

Take a look at the NightlyTest.pl file to see what all of the flags and strings do. If you start running the nightly tests, please let us know and we'll link your page to the global tester page. Thanks!


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