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5 <title>LLVM Test Suite Guide</title>
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10 <div class="doc_title">
15 <li><a href="#overview">Overview</a></li>
16 <li><a href="#Requirements">Requirements</a></li>
17 <li><a href="#quick">Quick Start</a></li>
18 <li><a href="#org">LLVM Test Suite Organization</a>
20 <li><a href="#codefragments">Code Fragments</a></li>
21 <li><a href="#wholeprograms">Whole Programs</a></li>
23 <li><a href="#tree">LLVM Test Suite Tree</a></li>
24 <li><a href="#qmstructure">QMTest Structure</a></li>
25 <li><a href="#progstructure">Programs Structure</a></li>
26 <li><a href="#run">Running the LLVM Tests</a></li>
29 <div class="doc_author">
30 <p>Written by John T. Criswell</p>
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34 <div class="doc_section"><a name="overview">Overview</a></div>
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37 <div class="doc_text">
39 <p>This document is the reference manual for the LLVM test suite. It documents
40 the structure of the LLVM test suite, the tools needed to use it, and how to add
45 <!--===============================================================-->
46 <div class="doc_section"><a name="Requirements">Requirements</a></div>
47 <!--===============================================================-->
49 <div class="doc_text">
51 <p>In order to use the LLVM test suite, you will need all of the software
52 required to build LLVM, plus the following:</p>
55 <dt><a href="http://www.qmtest.com">QMTest</A></dt>
56 <dd>The LLVM test suite uses QMTest to organize and run tests.</dd>
58 <dt><a href="http://www.python.org">Python</A></dt>
59 <dd>You will need a Python interpreter that works with QMTest. Python will
60 need zlib and SAX support enabled.</dd>
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66 <div class="doc_section"><a name="quick">Quick Start</a></div>
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69 <div class="doc_text">
71 <p> The tests are located in the LLVM source tree under the directory
72 <tt>llvm/test</tt>. To run all of the tests in LLVM, use the Master Makefile in
79 <p>To run only the code fragment tests (i.e. those that do basic testing of
80 LLVM), run the tests organized by QMTest:</p>
83 % gmake -C llvm/test qmtest
86 <p>To run only the tests that compile and execute whole programs, run the
90 % gmake -C llvm/test/Programs
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96 <div class="doc_section"><a name="org">LLVM Test Suite Organization</a></div>
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99 <div class="doc_text">
101 <p>The LLVM test suite contains two major categories of tests: code
102 fragments and whole programs.</p>
106 <div class="doc_subsection"><a name="codefragments">Code Fragments</a>
109 <div class="doc_text">
111 <p>Code fragments are small pieces of code that test a specific feature of LLVM
112 or trigger a specific bug in LLVM. They are usually written in LLVM assembly
113 language, but can be written in other languages if the test targets a particular
114 language front end.</p>
116 <p>Code fragments are not complete programs, and they are never executed to
117 determine correct behavior.</p>
119 <p>The tests in the Features and Regression directories contain code
124 <div class="doc_subsection"><a name="wholeprograms">Whole Programs</a></div>
126 <div class="doc_text">
128 <p>Whole Programs are pieces of code which can be compiled and linked into a
129 stand-alone program that can be executed. These programs are generally written
130 in high level languages such as C or C++, but sometimes they are written
131 straight in LLVM assembly.</p>
133 <p>These programs are compiled and then executed using several different
134 methods (native compiler, LLVM C backend, LLVM JIT, LLVM native code generation,
135 etc). The output of these programs is compared to ensure that LLVM is compiling
136 the program correctly.</p>
138 <p>In addition to compiling and executing programs, whole program tests serve as
139 a way of benchmarking LLVM performance, both in terms of the efficiency of the
140 programs generated as well as the speed with which LLVM compiles, optimizes, and
143 <p>The Programs directory contains all tests which compile and benchmark whole
148 <!--===============================================================-->
149 <div class="doc_section"><a name="tree">LLVM Test Suite Tree</a></div>
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152 <div class="doc_text">
154 <p>Each type of test in the LLVM test suite has its own directory. The major
155 subtrees of the test suite directory tree are as follows:</p>
159 <p>This directory contains sample codes that test various features of the
160 LLVM language. These pieces of sample code are run through various
161 assembler, disassembler, and optimizer passes.</p>
164 <p>This directory contains regression tests for LLVM. When a bug is found
165 in LLVM, a regression test containing just enough code to reproduce the
166 problem should be written and placed somewhere underneath this directory.
167 In most cases, this will be a small piece of LLVM assembly language code,
168 often distilled from an actual application or benchmark.</p>
171 <p>The Programs directory contains programs that can be compiled with LLVM
172 and executed. These programs are compiled using the native compiler and
173 various LLVM backends. The output from the program compiled with the native
174 compiler is assumed correct; the results from the other programs are
175 compared to the native program output and pass if they match. </p>
177 <p> In addition for testing correctness, the Programs directory also
178 performs timing tests of various LLVM optimizations. It also records
179 compilation times for the compilers and the JIT. This information can be
180 used to compare the effectiveness of LLVM's optimizations and code
183 <p>The Programs directory is subdivided into several smaller subdirectories:
187 <li>Programs/SingleSource
188 <p>The SingleSource directory contains test programs that are only a
189 single source file in size. These are usually small benchmark programs
190 or small programs that calculate a particular value. Several such
191 programs are grouped together in each directory.</p></li>
193 <li>Programs/MultiSource
194 <p>The MultiSource directory contains subdirectories which contain
195 entire programs with multiple source files. Large benchmarks and whole
196 applications go here.</p></li>
198 <li>Programs/External
199 <p>The External directory contains Makefiles for building code that is
200 external to (i.e. not distributed with) LLVM. The most prominent member
201 of this directory is the SPEC 2000 benchmark suite. The presence and
202 location of these external programs is configured by the LLVM
203 <tt>configure</tt> script.</p></li>
208 <p>This directory contains the QMTest information files. Inside this
209 directory are QMTest administration files and the Python code that
210 implements the LLVM test and database classes.</p>
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217 <div class="doc_section"><a name="qmstructure">QMTest Structure</a></div>
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220 <div class="doc_text">
222 <p>The LLVM test suite is partially driven by QMTest and partially
223 driven by GNU Make. Specifically, the Features and Regression tests
224 are all driven by QMTest. The Programs directory is currently
225 driven by a set of Makefiles.</p>
227 <p>The QMTest system needs to have several pieces of information
228 available; these pieces of configuration information are known
229 collectively as the "context" in QMTest parlance. Since the context
230 for LLVM is relatively large, the master Makefile in llvm/test
233 <p>The LLVM database class makes the subdirectories of llvm/test a
234 QMTest test database. For each directory that contains tests driven by
235 QMTest, it knows what type of test the source file is and how to run it.</p>
237 <p>Hence, the QMTest namespace is essentially what you see in the
238 Feature and Regression directories, but there is some magic that
239 the database class performs (as described below).</p>
241 <p>The QMTest namespace is currently composed of the following tests and test
247 These are the feature tests found in the Feature directory.
248 They are broken up into the following categories:
252 <p>Assembler/Disassembler tests. These tests verify that a piece of LLVM
253 assembly language can be assembled into bytecode and then disassembled
254 into the original assembly language code. It does this several times to
255 ensure that assembled output can be disassembled and disassembler output
256 can be assembled. It also verifies that the give assembly language file
257 can be assembled correctly.</p></li>
260 <p>Optimizer tests. These tests verify that two of the optimizer passes
261 completely optimize a program (i.e. after a single pass, they cannot
262 optimize a program any further).</p></li>
265 <p> Machine code tests. These tests verify that the LLVM assembly
266 language file can be translated into native assembly code.</p></li>
269 <p>C code tests. These tests verify that the specified LLVM assembly
270 code can be converted into C source code using the C backend.</p></li>
273 <p>The LLVM database class looks at every file in the Feature directory and
274 creates a fake test hierarchy containing
275 <tt>Feature.<testtype>.<testname></tt>. So, if you add an LLVM
276 assembly language file to the Feature directory, it actually creates 5 new
277 tests: assembler/disassembler, assembler, optimizer, machine code, and C code.
281 <p>These are the regression tests. There is one suite for each
282 subdirectory of the Regression directory. If you add a new subdirectory
283 there, you will need to modify, at least, the <tt>RegressionMap</tt>
284 variable in <tt>QMTest/llvmdb.py</tt> so that QMTest knows how to run the
285 tests in the new subdirectory.</p>
291 <!--===============================================================-->
292 <div class="doc_section"><a name="progstructure">Programs Structure</a></div>
293 <!--===============================================================-->
295 <div class="doc_text">
297 <p>As mentioned previously, the Programs tree in llvm/test provides three types
298 of tests: MultiSource, SingleSource, and External. Each tree is then subdivided
299 into several categories, including applications, benchmarks, regression tests,
300 code that is strange grammatically, etc. These organizations should be
301 relatively self explanatory.</p>
303 <p>In addition to the regular Programs tests, the Programs tree also provides a
304 mechanism for compiling the programs in different ways. If the variable TEST is
305 defined on the gmake command line, the test system will include a Makefile named
306 <tt>TEST.<value of TEST variable>.Makefile</tt>. This Makefile can modify
307 build rules to yield different results.</p>
309 <p>For example, the LLVM nightly tester uses <tt>TEST.nightly.Makefile</tt> to
310 create the nightly test reports. To run the nightly tests, run <tt>gmake
311 TEST=nightly</tt>.</p>
313 <p>There are several TEST Makefiles available in the tree. Some of them are
314 designed for internal LLVM research and will not work outside of the LLVM
315 research group. They may still be valuable, however, as a guide to writing your
316 own TEST Makefile for any optimization or analysis passes that you develop with
321 <!--===============================================================-->
322 <div class="doc_section"><a name="run">Running the LLVM Tests</a></div>
323 <!--===============================================================-->
325 <div class="doc_text">
327 <p>First, all tests are executed within the LLVM object directory tree. They
328 <i>are not</i> executed inside of the LLVM source tree. This is because the
329 test suite creates temporary files during execution. </p>
331 <p>The master Makefile in llvm/test is capable of running both the QMTest driven
332 tests and the Programs tests. By default, it will run all of the tests.</p>
334 <p>To run only the QMTest driven tests, run <tt>gmake qmtest</tt> at the
335 command line in llvm/tests. To run a specific qmtest, suffix the test name with
336 ".t" when running gmake.</p>
338 <p>For example, to run the Regression.LLC tests, type <tt>gmake
339 Regression.LLC.t</tt> in llvm/tests.</p>
341 <p>Note that the Makefiles in llvm/test/Features and llvm/test/Regression are
342 gone. You must now use QMTest from the llvm/test directory to run them.</p>
344 <p>To run the Programs test, cd into the llvm/test/Programs directory and type
345 <tt>gmake</tt>. Alternatively, you can type <tt>gmake TEST=<type>
346 test</tt> to run one of the specialized tests in
347 llvm/test/Programs/TEST.<type>.Makefile. For example, you could run the
348 nightly tester tests using the following commands:</p>
351 % cd llvm/test/Programs
352 % gmake TEST=nightly test
355 <p>Regardless of which test you're running, the results are printed on standard
356 output and standard error. You can redirect these results to a file if you
359 <p>Some tests are known to fail. Some are bugs that we have not fixed yet;
360 others are features that we haven't added yet (or may never add). In QMTest,
361 the result for such tests will be XFAIL (eXpected FAILure). In this way, you
362 can tell the difference between an expected and unexpected failure.</p>
364 <p>The Programs tests have no such feature as of this time. If the test passes,
365 only warnings and other miscellaneous output will be generated. If a test
366 fails, a large <program> FAILED message will be displayed. This will help
367 you separate benign warnings from actual test failures.</p>
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