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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
	<head>
		<title>LLVM Test Suite Guide</title>
	</head>

	<body bgcolor=white>

	<center><h1>LLVM Test Suite Guide<br></h1></center>

	<!--===============================================================-->
	<h2><a name="overview">Overview</a><hr></h2>
	<!--===============================================================-->

	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.

	<!--===============================================================-->
	<h2><a name="Requirements">Requirements</a><hr></h2>
	<!--===============================================================-->

	In order to use the LLVM test suite, you will need all of the software
	required to build LLVM, plus the following:
	<dl compact>
		<dt><A HREF="http://www.qmtest.com">QMTest</A>
		<dd>
		The LLVM test suite uses QMTest to organize and run tests.
		<p>

		<dt><A HREF="http://www.python.org">Python</A>
		<dd>
		You will need a python interpreter that works with QMTest.
		Python will need zlib and SAX support enabled.
		<p>
	</dl>

	<!--===============================================================-->
	<h2><a name="quick">Quick Start</a><hr></h2>
	<!--===============================================================-->

	To run all of the tests in LLVM, use the Master Makefile in llvm/test:
	<p>
	<tt>
	cd test
	<br>
	make
	</tt>

	<p>

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

	<tt>
	cd test
	<br>
	make qmtest
	</tt>

	<p>

	To run only the tests that compile and execute whole programs, run the
	Programs tests:
	<p>

	<tt>
	cd test/Programs
	<br>
	make
	</tt>
	<p>

	<!--===============================================================-->
	<h2><a name="org">LLVM Test Suite Organization</a><hr></h2>
	<!--===============================================================-->

	The LLVM test suite contains two major types of tests:
	<ul>
		<li>Code Fragments<br>
		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.
		<p>
		Code fragments are not complete programs, and they are never executed
		to determine correct behavior.
		<p>
		The tests in the llvm/test/Features and llvm/test/Regression directories
		contain code fragments.

		<li>Whole Programs<br>
		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.
		<p>
		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.

		<p>
		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.

		<p>
		The test/Programs directory contains all tests which compile and
		benchmark whole programs.
	</ul>

	<!--===============================================================-->
	<h2><a name="tree">LLVM Test Suite Tree</a><hr></h2>
	<!--===============================================================-->

	The LLVM test suite is broken up into the following directory
	hierarchy:

	<ul>
		<li> Features<br>
		This directory contains sample codes that test various features
		of the LLVM language.  These pieces of sample code are run
		through various assembler, disassembler, and optimizer passes.
		<p>

		<li>Regression<br>
		This directory contains regression tests for LLVM.  When a bug
		is found in LLVM, a regression test containing just enough
		code to reproduce the problem should be written and placed
		somewhere underneath this directory.  In most cases, this
		will be a small piece of LLVM assembly language code, often
		distilled from an actual application or benchmark.
		<p>

		<li>Programs<br>
		The Programs directory contains 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.
		<p>
		In addition for testing correctness, the Programs 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.
		<p>
		The Programs directory is subdivided into several smaller
		subdirectories:
		<ul>
			<li>SingleSource<br>
			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.
			<p>

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

			<li>External<br>
			The External directory contains Makefiles for building
			code that is external to (i.e. not distributed with)
			LLVM.  The most prominent member of this directory is
			the SPEC 2000 benchmark suite.  The presence and location
			of these external programs is configured by the LLVM
			<tt>configure</tt> script.
		</ul>

		<p>

		<li>QMTest<br>
		This directory contains the QMTest information files.  Inside this
		directory are QMTest administration files and the Python code that
		implements the LLVM test and database classes.
	</ul>

	<!--===============================================================-->
	<h2><a name="qmstructure">QMTest Structure</a><hr></h2>
	<!--===============================================================-->

	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 Programs directory is currently
	driven by a set of Makefiles.
	<p>

	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.

	<p>

	The LLVM database class makes the directory tree underneath 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.

	<p>

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

	<p>

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

	<ul>
		<li>Feature<br>
		These are the feature tests found in llvm/test/Feature.  They are broken
		up into the following categories:
		<ul>
			<li>ad<br>
			Assembler/Disassembler tests.  These tests verify that a piece of
			LLVM assembly language can be assembled into bytecode and then
			disassembled into the original assembly language code.
			It does this several times to ensure that assembled
			output can be disassembled and disassembler output can
			be assembled.  It also verifies that the give assembly language file
			can be assembled correctly.
			<p>

			<li>opt<br>
			Optimizer tests.  These tests verify that two of the
			optimizer passes completely optimize a program (i.e.
			after a single pass, they cannot optimize a program
			any further).
			<p>

			<li>mc<br>
			Machine code tests.  These tests verify that the LLVM assembly
			language file can be translated into native assembly code.
			<p>

			<li>cc<br>
			C code tests.  These tests verify that the specified LLVM assembly
			code can be converted into C source code using the C backend.
		</ul>

		<p>

		The LLVM database class looks at every file in llvm/test/Feature and
		creates a fake test hierarchy containing
		Feature.&lt;testtype&gt;.&lt;testname&gt;.
		So, if you add an LLVM assembly language file to llvm/test/Feature, it
		actually creates 5 news test: assembler/disassembler, assembler,
		optimizer, machine code, and C code.

		<li>Regression<br>
		These are the regression tests.  There is one suite for each directory
		in llvm/test/Regression.
		<p>

		If you add a new directory to llvm/test/Regression, you will need to
		modify llvm/test/QMTest/llvmdb.py so that it knows what sorts of tests
		are in it and how to run them.
	</ul>

	<!--===============================================================-->
	<h2><a name="progstructure">Programs Structure</a><hr></h2>
	<!--===============================================================-->
	As mentioned previously, the Programs tree in llvm/test 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.
	<p>
	In addition to the regular Programs tests, the Programs tree 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.&lt;value of TEST variable&gt;.Makefile.  This Makefile can modify
	build rules that yield different results.
	<p>
	For example, the LLVM nightly tester uses TEST.nightly.Makefile to create the
	nightly test reports.  To run the nightly tests, run <tt>gmake
	TEST=nightly</tt>.
	<p>
	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.

	<!--===============================================================-->
	<h2><a name="run">Running the LLVM Tests</a><hr></h2>
	<!--===============================================================-->

	First, all tests are executed within the LLVM object directory tree.  They
	<i>are not</i> executed inside of the LLVM source tree.  This is because
	the test suite creates temporary files during execution.

	<p>

	The master Makefile in llvm/test is capable of running both the
	QMTest driven tests and the Programs tests.  By default, it will run
	all of the tests.
	<p>
	To run only the QMTest driven tests, run <tt>make qmtest</tt> at the
	command line in llvm/tests.  To run a specific qmtest, suffix the test name
	with ".t" when running make.
	<p>
	For example, to run the Regression.LLC tests, type
	<tt>make Regression.LLC.t</tt> in llvm/tests.
	<p>
	Note that the Makefiles in llvm/test/Features and llvm/test/Regression
	are gone.  You must now use QMTest from the llvm/test directory to run them.
	<p>

	To run the Programs test, cd into the llvm/test/Programs directory
	and type <tt>make</tt>.  Alternatively, you can type <tt>make
	TEST=&lt;type&gt; test</tt> to run one of the specialized tests in
	llvm/test/Programs/TEST.&lt;type&gt;.Makefile.  For example, you could run
	the nightly tester tests using the following commands:
	<p>
	<tt>
	cd llvm/test/Programs
	<br>
	make TEST=nightly test
	</tt>

	<p>
	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.
	<p>
	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.
	<p>
	The Programs tests 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 &lt;program&gt; FAILED message will be displayed.  This will
	help you separate benign warnings from actual test failures.

	<hr>

	</body>
</html>