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Misha Brukman00c73d22003-11-07 19:43:14 +00004<head>
5 <title>Getting Started with LLVM System</title>
6 <link rel="stylesheet" href="llvm.css" type="text/css">
7</head>
8<body>
John Criswell85ed3612003-06-12 19:34:44 +00009
Misha Brukman00c73d22003-11-07 19:43:14 +000010<div class="doc_title">
11 Getting Started with the LLVM System
12</div>
John Criswell85ed3612003-06-12 19:34:44 +000013
Misha Brukman00c73d22003-11-07 19:43:14 +000014<ul>
15 <li><a href="#overview">Overview</a>
16 <li><a href="#quickstart">Getting Started Quickly (A Summary)</a>
17 <li><a href="#requirements">Requirements</a>
Chris Lattner96768ea2003-02-14 04:22:13 +000018 <ol>
Misha Brukman00c73d22003-11-07 19:43:14 +000019 <li><a href="#hardware">Hardware</a>
20 <li><a href="#software">Software</a>
21 </ol></li>
John Criswell7a73b802003-06-30 21:59:07 +000022
Misha Brukman00c73d22003-11-07 19:43:14 +000023 <li><a href="#starting">Getting Started with LLVM</a>
John Criswell0b459202003-07-08 20:35:59 +000024 <ol>
Misha Brukman00c73d22003-11-07 19:43:14 +000025 <li><a href="#terminology">Terminology and Notation</a>
26 <li><a href="#environment">Setting Up Your Environment</a>
27 <li><a href="#unpack">Unpacking the LLVM Archives</a>
28 <li><a href="#checkout">Checkout LLVM from CVS</a>
29 <li><a href="#installcf">Install the GCC Front End</a>
30 <li><a href="#config">Local LLVM Configuration</a>
31 <li><a href="#compile">Compiling the LLVM Suite Source Code</a>
32 <li><a href="#objfiles">The Location of LLVM Object Files</a>
33 </ol></li>
John Criswell0b459202003-07-08 20:35:59 +000034
Misha Brukman00c73d22003-11-07 19:43:14 +000035 <li><a href="#layout">Program layout</a>
36 <ol>
37 <li><a href="#cvsdir"><tt>CVS</tt> directories</a>
38 <li><a href="#include"><tt>llvm/include</tt></a>
39 <li><a href="#lib"><tt>llvm/lib</tt></a>
40 <li><a href="#runtime"><tt>llvm/runtime</tt></a>
41 <li><a href="#test"><tt>llvm/test</tt></a>
42 <li><a href="#tools"><tt>llvm/tools</tt></a>
43 <li><a href="#utils"><tt>llvm/utils</tt></a>
44 </ol></li>
John Criswell0f6d7c02003-10-27 18:18:16 +000045
Misha Brukman00c73d22003-11-07 19:43:14 +000046 <li><a href="#tutorial">An Example Using the LLVM Tool Chain</a>
47 <li><a href="#problems">Common Problems</a>
48 <li><a href="#links">Links</a>
49</ul>
50
51<p>By:
52 <a href="mailto:gshi1@uiuc.edu">Guochun Shi</a>,
53 <a href="mailto:sabre@nondot.org">Chris Lattner</a>,
54 <a href="mailto:criswell@uiuc.edu">John Criswell</a>,
55 <a href="http://misha.brukman.net">Misha Brukman</a>, and
56 <a href="http://www.cs.uiuc.edu/~vadve">Vikram Adve</a>.</p>
57
58
59<!-- *********************************************************************** -->
60<div class="doc_section">
61 <a name="overview"><b>Overview</b></a>
62</div>
63<!-- *********************************************************************** -->
64
65<div class="doc_text">
66
67<p>Welcome to LLVM! In order to get started, you first need to know some
68basic information.</p>
69
70<p>First, LLVM comes in two pieces. The first piece is the LLVM suite. This
71contains all of the tools, libraries, and header files needed to use the low
72level virtual machine. It contains an assembler, disassembler, bytecode
73analyzer, and bytecode optimizer. It also contains a test suite that can be
74used to test the LLVM tools and the GCC front end.</p>
75
76<p>The second piece is the GCC front end. This component provides a version of
77GCC that compiles C and C++ code into LLVM bytecode. Currently, the GCC front
78end is a modified version of GCC 3.4 (we track the GCC 3.4 development). Once
79compiled into LLVM bytecode, a program can be manipulated with the LLVM tools
80from the LLVM suite.</p>
81
82</div>
83
84<!-- *********************************************************************** -->
85<div class="doc_section">
86 <a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a>
87</div>
88<!-- *********************************************************************** -->
89
90<div class="doc_text">
91
92<p>Here's the short story for getting up and running quickly with LLVM:</p>
93
94<ol>
95 <li>Install the GCC front end:
96 <ol>
97 <li><tt>cd <i>where-you-want-the-C-front-end-to-live</i></tt>
98 <li><tt>gunzip --stdout cfrontend.<i>platform</i>.tar.gz | tar -xvf -</tt>
99 <li><b>Sparc Only:</b><br>
100 <tt>cd cfrontend/sparc<br>
101 ./fixheaders</tt>
102 </ol></li>
103
104 <li>Get the Source Code
105 <ul>
106 <li>With the distributed files:
107 <ol>
108 <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
109 <li><tt>gunzip --stdout llvm.tar.gz | tar -xvf -</tt>
110 <li><tt>cd llvm</tt>
111 </ol></li>
112
113 <li>With anonymous CVS access:
114 <ol>
115 <li><tt>cd <i>where-you-want-llvm-to-live</i></tt></li>
116 <li><tt>cvs -d
117 :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm login</tt></li>
118 <li>Hit the return key when prompted for the password.
119 <li><tt>cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm
120 co llvm</tt></li>
121 <li><tt>cd llvm</tt></li>
122 </ol></li>
123 </ul></li>
124
125 <li>Configure the LLVM Build Environment
126 <ol>
127 <li>Change directory to where you want to store the LLVM object
128 files and run <tt>configure</tt> to configure the Makefiles and
129 header files for the default platform. Useful options include:
130 <ul>
131 <li><tt>--with-llvmgccdir=<i>directory</i></tt>
John Criswelld000e1d2003-12-18 16:43:17 +0000132 <p>Specify the full pathname of where the LLVM GCC frontend is
133 installed.</p></li>
Misha Brukman00c73d22003-11-07 19:43:14 +0000134 <li><tt>--enable-spec2000=<i>directory</i></tt>
135 <p>Enable the SPEC2000 benchmarks for testing. The SPEC2000
136 benchmarks should be available in
137 <tt><i>directory</i></tt>.</p></li>
138 </ul>
139 </ol></li>
140
141 <li>Build the LLVM Suite:
142 <ol>
143 <li>Set your LLVM_LIB_SEARCH_PATH environment variable.
144 <li><tt>gmake -k |& tee gnumake.out
145 &nbsp;&nbsp;&nbsp;# this is csh or tcsh syntax</tt>
146 </ol>
147
148</ol>
149
150<p>Consult the <a href="starting">Getting Started with LLVM</a> section for
151detailed information on configuring and compiling LLVM. See <a
152href="#environment">Setting Up Your Environment</a> for tips that simplify
153working with the GCC front end and LLVM tools. Go to <a href="#layout">Program
154Layout</a> to learn about the layout of the source code tree.</p>
155
156</div>
157
158<!-- *********************************************************************** -->
159<div class="doc_section">
160 <a name="requirements"><b>Requirements</b></a>
161</div>
162<!-- *********************************************************************** -->
163
164<div class="doc_text">
165
166<p>Before you begin to use the LLVM system, review the requirements given below.
167This may save you some trouble by knowing ahead of time what hardware and
168software you will need.</p>
169
170</div>
171
172<!-- ======================================================================= -->
173<div class="doc_subsection">
174 <a name="hardware"><b>Hardware</b></a>
175</div>
176
177<div class="doc_text">
178
179<p>LLVM is known to work on the following platforms:</p>
180
181<ul>
182
183 <li>Linux on x86 (Pentium and above)
184 <ul>
John Criswelld000e1d2003-12-18 16:43:17 +0000185 <li>Approximately 918 MB of Free Disk Space
Misha Brukman00c73d22003-11-07 19:43:14 +0000186 <ul>
John Criswelld000e1d2003-12-18 16:43:17 +0000187 <li>Source code: 28 MB</li>
188 <li>Object code: 850 MB</li>
189 <li>GCC front end: 40 MB</li>
Misha Brukman00c73d22003-11-07 19:43:14 +0000190 </ul></li>
John Criswelld000e1d2003-12-18 16:43:17 +0000191 </ul>
192 </li>
193
Misha Brukman00c73d22003-11-07 19:43:14 +0000194 <li>Solaris on SparcV9 (Ultrasparc)
195 <ul>
John Criswelld000e1d2003-12-18 16:43:17 +0000196 <li>Approximately 1.52 GB of Free Disk Space
Misha Brukman00c73d22003-11-07 19:43:14 +0000197 <ul>
John Criswelld000e1d2003-12-18 16:43:17 +0000198 <li>Source code: 28 MB</li>
199 <li>Object code: 1470 MB</li>
200 <li>GCC front end: 50 MB</li>
Misha Brukman00c73d22003-11-07 19:43:14 +0000201 </ul></li>
John Criswelld000e1d2003-12-18 16:43:17 +0000202 </ul>
203 </li>
Misha Brukman00c73d22003-11-07 19:43:14 +0000204
John Criswelld000e1d2003-12-18 16:43:17 +0000205 <li>FreeBSD on x86 (Pentium and above)
206 <ul>
207 <li>Approximately 918 MB of Free Disk Space
208 <ul>
209 <li>Source code: 28 MB</li>
210 <li>Object code: 850 MB</li>
211 <li>GCC front end: 40 MB</li>
212 </ul></li>
213 </ul>
214 </li>
215
John Criswelld000e1d2003-12-18 16:43:17 +0000216 <li>MacOS X on PowerPC
217 <ul>
218 <li>No native code generation
219 <li>Approximately 1.20 GB of Free Disk Space
220 <ul>
221 <li>Source code: 28 MB</li>
222 <li>Object code: 1160 MB</li>
223 <li>GCC front end: 40 MB</li>
224 </ul></li>
225 </ul>
226
227 </li>
Misha Brukman00c73d22003-11-07 19:43:14 +0000228</ul>
229
230<p>The LLVM suite <i>may</i> compile on other platforms, but it is not
231guaranteed to do so. If compilation is successful, the LLVM utilities should be
232able to assemble, disassemble, analyze, and optimize LLVM bytecode. Code
233generation should work as well, although the generated native code may not work
234on your platform.</p>
235
236<p>The GCC front end is not very portable at the moment. If you want to get it
237to work on another platform, you can download a copy of the source and try to
238compile it on your platform.</p>
239
240</div>
241
242<!-- ======================================================================= -->
243<div class="doc_subsection">
244 <a name="software"><b>Software</b></a>
245</div>
246
247<div class="doc_text">
248
249<p>Compiling LLVM requires that you have several software packages
250installed:</p>
251
252<ul>
253 <li><a href="http://gcc.gnu.org">GCC 3.x with C and C++ language
254 support</a></li>
255
256 <li><a href="http://savannah.gnu.org/projects/make">GNU Make</a></li>
257
258 <li><a href="http://www.gnu.org/software/flex">Flex</a></li>
259
260 <li><a href="http://www.gnu.org/software/bison/bison.html">Bison</a></li>
261</ul>
262
263<p>There are some additional tools that you may want to have when working with
264LLVM:</p>
265
266<ul>
Brian Gaeke5c681b62004-02-08 07:49:04 +0000267 <li><A href="http://www.gnu.org/software/automake">GNU Automake</A></li>
268 <li><A href="http://www.gnu.org/software/autoconf">GNU Autoconf</A></li>
Misha Brukman00c73d22003-11-07 19:43:14 +0000269 <li><A href="http://savannah.gnu.org/projects/m4">GNU M4</A>
270
271 <p>If you want to make changes to the configure scripts, you will need GNU
272 autoconf (2.57 or higher), and consequently, GNU M4 (version 1.4 or
Brian Gaeke5c681b62004-02-08 07:49:04 +0000273 higher). You will also need automake. Any old version of
274 automake from 1.4p5 on should work; we only use aclocal from that
275 package.</p></li>
Misha Brukman00c73d22003-11-07 19:43:14 +0000276
277 <li><A href="http://www.codesourcery.com/qm/qmtest">QMTest</A></li>
278 <li><A href="http://www.python.org">Python</A>
279
280 <p>These are needed to use the LLVM test suite.</p></li>
281
282</ul>
283
Misha Brukman00c73d22003-11-07 19:43:14 +0000284<p>The remainder of this guide is meant to get you up and running with
285LLVM and to give you some basic information about the LLVM environment.
286A <a href="#starting">complete guide to installation</a> is provided in the
287next section.</p>
288
289<p>The later sections of this guide describe the <a
290href="#layout">general layout</a> of the the LLVM source tree, a <a
291href="#tutorial">simple example</a> using the LLVM tool chain, and <a
292href="#links">links</a> to find more information about LLVM or to get
293help via e-mail.</p>
294
295</div>
296
297<!-- *********************************************************************** -->
298<div class="doc_section">
299 <a name="starting"><b>Getting Started with LLVM</b></a>
300</div>
301<!-- *********************************************************************** -->
302
303<!-- ======================================================================= -->
304<div class="doc_subsection">
305 <a name="terminology">Terminology and Notation</a>
306</div>
307
308<div class="doc_text">
309
310<p>Throughout this manual, the following names are used to denote paths
311specific to the local system and working environment. <i>These are not
312environment variables you need to set but just strings used in the rest
313of this document below</i>. In any of the examples below, simply replace
314each of these names with the appropriate pathname on your local system.
315All these paths are absolute:</p>
316
Misha Brukman54111c42004-01-20 00:20:17 +0000317<dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000318 <dt>SRC_ROOT
319 <dd>
320 This is the top level directory of the LLVM source tree.
John Criswell0f6d7c02003-10-27 18:18:16 +0000321 <p>
322
Misha Brukman00c73d22003-11-07 19:43:14 +0000323 <dt>OBJ_ROOT
324 <dd>
325 This is the top level directory of the LLVM object tree (i.e. the
326 tree where object files and compiled programs will be placed. It
327 can be the same as SRC_ROOT).
328 <p>
329
330 <dt>LLVMGCCDIR
331 <dd>
332 This is the where the LLVM GCC Front End is installed.
333 <p>
334 For the pre-built GCC front end binaries, the LLVMGCCDIR is
335 <tt>cfrontend/<i>platform</i>/llvm-gcc</tt>.
336</dl>
337
338</div>
339
340<!-- ======================================================================= -->
341<div class="doc_subsection">
342 <a name="environment">Setting Up Your Environment</a>
343</div>
344
345<div class="doc_text">
346
347<p>
348In order to compile and use LLVM, you will need to set some environment
349variables. There are also some shell aliases which you may find useful.
350You can set these on the command line, or better yet, set them in your
351<tt>.cshrc</tt> or <tt>.profile</tt>.
352
Misha Brukman54111c42004-01-20 00:20:17 +0000353<dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000354 <dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt><i>LLVMGCCDIR</i>/bytecode-libs</tt>
355 <dd>
356 This environment variable helps the LLVM GCC front end find bytecode
357 libraries that it will need for compilation.
358 <p>
359
360 <dt>alias llvmgcc <i>LLVMGCCDIR</i><tt>/bin/gcc</tt>
361 <dt>alias llvmg++ <i>LLVMGCCDIR</i><tt>/bin/g++</tt>
362 <dd>
363 This alias allows you to use the LLVM C and C++ front ends without putting
364 them in your <tt>PATH</tt> or typing in their complete pathnames.
365</dl>
366
367</div>
368
369<!-- ======================================================================= -->
370<div class="doc_subsection">
Misha Brukman54111c42004-01-20 00:20:17 +0000371 <a name="unpack">Unpacking the LLVM Archives</a>
Misha Brukman00c73d22003-11-07 19:43:14 +0000372</div>
373
374<div class="doc_text">
375
376<p>
377If you have the LLVM distribution, you will need to unpack it before you
John Criswelld000e1d2003-12-18 16:43:17 +0000378can begin to compile it. LLVM is distributed as a set of two files: the LLVM
379suite and the LLVM GCC front end compiled for your platform. Each
Misha Brukman00c73d22003-11-07 19:43:14 +0000380file is a TAR archive that is compressed with the gzip program.
381</p>
382
John Criswelld000e1d2003-12-18 16:43:17 +0000383<p> The files are as follows:
Misha Brukman54111c42004-01-20 00:20:17 +0000384<dl>
John Criswelld000e1d2003-12-18 16:43:17 +0000385 <dt>llvm-1.1.tar.gz
Misha Brukman00c73d22003-11-07 19:43:14 +0000386 <dd>This is the source code to the LLVM suite.
387 <p>
388
John Criswelld000e1d2003-12-18 16:43:17 +0000389 <dt>cfrontend-1.1.sparc-sun-solaris2.8.tar.gz
Misha Brukman00c73d22003-11-07 19:43:14 +0000390 <dd>This is the binary release of the GCC front end for Solaris/Sparc.
391 <p>
392
John Criswelld000e1d2003-12-18 16:43:17 +0000393 <dt>cfrontend-1.1.i686-redhat-linux-gnu.tar.gz
Misha Brukman00c73d22003-11-07 19:43:14 +0000394 <dd>This is the binary release of the GCC front end for Linux/x86.
John Criswelld000e1d2003-12-18 16:43:17 +0000395 <p>
396
397 <dt>cfrontend-1.1.i386-unknown-freebsd5.1.tar.gz
398 <dd>This is the binary release of the GCC front end for FreeBSD/x86.
399 <p>
400
401 <dt>cfrontend-1.1.powerpc-apple-darwin7.0.0.tar.gz
402 <dd>This is the binary release of the GCC front end for MacOS X/PPC.
Misha Brukman00c73d22003-11-07 19:43:14 +0000403</dl>
404
405</div>
406
407<!-- ======================================================================= -->
408<div class="doc_subsection">
Misha Brukman54111c42004-01-20 00:20:17 +0000409 <a name="checkout">Checkout LLVM from CVS</a>
Misha Brukman00c73d22003-11-07 19:43:14 +0000410</div>
411
412<div class="doc_text">
413
414<p>If you have access to our CVS repository, you can get a fresh copy of
415the entire source code. All you need to do is check it out from CVS as
416follows:</p>
417
418<ul>
419<li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
420 <li><tt>cvs -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm login</tt>
421 <li>Hit the return key when prompted for the password.
422 <li><tt>cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm co
423 llvm</tt>
424</ul>
425
426<p>This will create an '<tt>llvm</tt>' directory in the current
427directory and fully populate it with the LLVM source code, Makefiles,
428test directories, and local copies of documentation files.</p>
429
Misha Brukman54111c42004-01-20 00:20:17 +0000430<p>If you want to get a specific release (as opposed to the most recent
431revision), you can specify a label. The following releases have the following
432label:</p>
433
John Criswelld000e1d2003-12-18 16:43:17 +0000434<ul>
435 <li>
436 Release 1.1: <b>RELEASE_11</b>
437 </li>
438
439 <li>
440 Release 1.0: <b>RELEASE_1</b>
441 </li>
442</ul>
John Criswelld000e1d2003-12-18 16:43:17 +0000443
Misha Brukman00c73d22003-11-07 19:43:14 +0000444<p>Note that the GCC front end is not included in the CVS repository. You
445should have downloaded the binary distribution for your platform.</p>
446
447</div>
448
449<!-- ======================================================================= -->
450<div class="doc_subsection">
Misha Brukman54111c42004-01-20 00:20:17 +0000451 <a name="installcf">Install the GCC Front End</a>
Misha Brukman00c73d22003-11-07 19:43:14 +0000452</div>
453
454<div class="doc_text">
455
456<p>Before configuring and compiling the LLVM suite, you need to extract the LLVM
457GCC front end from the binary distribution. It is used for building the
458bytecode libraries later used by the GCC front end for linking programs, and its
459location must be specified when the LLVM suite is configured.</p>
460
461<p>To install the GCC front end, do the following:</p>
462
463<ol>
464 <li><tt>cd <i>where-you-want-the-front-end-to-live</i></tt></li>
John Criswelld000e1d2003-12-18 16:43:17 +0000465 <li><tt>gunzip --stdout cfrontend-<i>version</i>.<i>platform</i>.tar.gz | tar -xvf
Misha Brukman00c73d22003-11-07 19:43:14 +0000466 -</tt></li>
467</ol>
468
John Criswelld000e1d2003-12-18 16:43:17 +0000469<p>If you are using Solaris/Sparc or MacOS X/PPC, you will need to fix the
470header files:</p>
Misha Brukman00c73d22003-11-07 19:43:14 +0000471
472<p><tt>cd cfrontend/sparc<br>
473 ./fixheaders</tt></p>
474
475<p>The binary versions of the GCC front end may not suit all of your needs. For
476example, the binary distribution may include an old version of a system header
477file, not "fix" a header file that needs to be fixed for GCC, or it may be
478linked with libraries not available on your system.</p>
479
480<p>In cases like these, you may want to try <a
481href="CFEBuildInstrs.html">building the GCC front end from source.</a> This is
482not for the faint of heart, so be forewarned.</p>
483
484</div>
485
486<!-- ======================================================================= -->
487<div class="doc_subsection">
488 <a name="config">Local LLVM Configuration</a>
489</div>
490
491<div class="doc_text">
492
493<p>Once checked out from the CVS repository, the LLVM suite source code must be
494configured via the <tt>configure</tt> script. This script sets variables in
495<tt>llvm/Makefile.config</tt> and <tt>llvm/include/Config/config.h</tt>. It
John Criswelld000e1d2003-12-18 16:43:17 +0000496also populates <i>OBJ_ROOT</i> with the Makefiles needed to begin building
497LLVM.</p>
Misha Brukman00c73d22003-11-07 19:43:14 +0000498
499<p>The following environment variables are used by the <tt>configure</tt>
500script to configure the build system:</p>
501
502<table border=1>
503 <tr>
504 <th>Variable</th>
505 <th>Purpose</th>
506 </tr>
507
508 <tr>
509 <td>CC</td>
510 <td>Tells <tt>configure</tt> which C compiler to use. By default,
511 <tt>configure</tt> will look for the first GCC C compiler in
512 <tt>PATH</tt>. Use this variable to override
513 <tt>configure</tt>'s default behavior.</td>
514 </tr>
515
516 <tr>
517 <td>CXX</td>
518 <td>Tells <tt>configure</tt> which C++ compiler to use. By default,
519 <tt>configure</tt> will look for the first GCC C++ compiler in
520 <tt>PATH</tt>. Use this variable to override
521 <tt>configure</tt>'s default behavior.</td>
522 </tr>
523</table>
524
525<p>The following options can be used to set or enable LLVM specific options:</p>
526
Misha Brukman54111c42004-01-20 00:20:17 +0000527<dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000528 <dt><i>--with-llvmgccdir=LLVMGCCDIR</i>
529 <dd>
530 Path to the location where the LLVM C front end binaries and
John Criswelld000e1d2003-12-18 16:43:17 +0000531 associated libraries were installed. This must be specified as an
532 absolute pathname.
Misha Brukman00c73d22003-11-07 19:43:14 +0000533 <p>
534 <dt><i>--enable-optimized</i>
535 <dd>
536 Enables optimized compilation by default (debugging symbols are removed
537 and GCC optimization flags are enabled). The default is to use an
538 unoptimized build (also known as a debug build).
539 <p>
540 <dt><i>--enable-jit</i>
541 <dd>
John Criswelld000e1d2003-12-18 16:43:17 +0000542 Compile the Just In Time (JIT) compiler functionality. This is not
543 available
Misha Brukman00c73d22003-11-07 19:43:14 +0000544 on all platforms. The default is dependent on platform, so it is best
545 to explicitly enable it if you want it.
546 <p>
547 <dt><i>--enable-spec2000</i>
548 <dt><i>--enable-spec2000=&lt;<tt>directory</tt>&gt;</i>
549 <dd>
550 Enable the use of SPEC2000 when testing LLVM. This is disabled by default
551 (unless <tt>configure</tt> finds SPEC2000 installed). By specifying
552 <tt>directory</tt>, you can tell configure where to find the SPEC2000
553 benchmarks. If <tt>directory</tt> is left unspecified, <tt>configure</tt>
554 uses the default value
555 <tt>/home/vadve/shared/benchmarks/speccpu2000/benchspec</tt>.
556</dl>
557
558<p>To configure LLVM, follow these steps:</p>
559
560<ol>
561 <li>Change directory into the object root directory:
John Criswell0f6d7c02003-10-27 18:18:16 +0000562 <br>
Misha Brukman00c73d22003-11-07 19:43:14 +0000563 <tt>cd <i>OBJ_ROOT</i></tt>
John Criswell0f6d7c02003-10-27 18:18:16 +0000564 <p>
John Criswell0f6d7c02003-10-27 18:18:16 +0000565
Misha Brukman00c73d22003-11-07 19:43:14 +0000566 <li>Run the <tt>configure</tt> script located in the LLVM source tree:
567 <br>
568 <tt><i>SRC_ROOT</i>/configure</tt>
John Criswell0f6d7c02003-10-27 18:18:16 +0000569 <p>
Misha Brukman00c73d22003-11-07 19:43:14 +0000570</ol>
John Criswell85ed3612003-06-12 19:34:44 +0000571
Misha Brukman00c73d22003-11-07 19:43:14 +0000572<p>In addition to running <tt>configure</tt>, you must set the
573<tt>LLVM_LIB_SEARCH_PATH</tt> environment variable in your startup scripts.
574This environment variable is used to locate "system" libraries like
575"<tt>-lc</tt>" and "<tt>-lm</tt>" when linking. This variable should be set to
John Criswelld000e1d2003-12-18 16:43:17 +0000576the absolute path of the <tt>bytecode-libs</tt> subdirectory of the GCC front
577end, or <i>LLVMGCCDIR</i>/<tt>bytecode-libs</tt>. For example, one might set
Misha Brukman00c73d22003-11-07 19:43:14 +0000578<tt>LLVM_LIB_SEARCH_PATH</tt> to
John Criswelld000e1d2003-12-18 16:43:17 +0000579<tt>/home/vadve/lattner/local/x86/llvm-gcc/bytecode-libs</tt> for the x86
Misha Brukman00c73d22003-11-07 19:43:14 +0000580version of the GCC front end on our research machines.</p>
John Criswell7a73b802003-06-30 21:59:07 +0000581
Misha Brukman00c73d22003-11-07 19:43:14 +0000582</div>
John Criswell85ed3612003-06-12 19:34:44 +0000583
Misha Brukman00c73d22003-11-07 19:43:14 +0000584<!-- ======================================================================= -->
585<div class="doc_subsection">
586 <a name="compile">Compiling the LLVM Suite Source Code</a>
587</div>
John Criswell85ed3612003-06-12 19:34:44 +0000588
Misha Brukman00c73d22003-11-07 19:43:14 +0000589<div class="doc_text">
John Criswell0b459202003-07-08 20:35:59 +0000590
Misha Brukman00c73d22003-11-07 19:43:14 +0000591<p>Once you have configured LLVM, you can build it. There are three types of
592builds:</p>
John Criswell0b459202003-07-08 20:35:59 +0000593
Misha Brukman54111c42004-01-20 00:20:17 +0000594<dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000595 <dt>Debug Builds
John Criswellce760f62003-07-03 16:01:38 +0000596 <dd>
Misha Brukman00c73d22003-11-07 19:43:14 +0000597 These builds are the default when one types <tt>gmake</tt> (unless the
598 <tt>--enable-optimized</tt> option was used during configuration). The
599 build system will compile the tools and libraries with debugging
600 information.
601 <p>
602
603 <dt>Release (Optimized) Builds
John Criswellce760f62003-07-03 16:01:38 +0000604 <dd>
Misha Brukman00c73d22003-11-07 19:43:14 +0000605 These builds are enabled with the <tt>--enable-optimized</tt> option to
606 <tt>configure</tt> or by specifying <tt>ENABLE_OPTIMIZED=1</tt> on the
607 <tt>gmake</tt> command line. For these builds, the build system will
608 compile the tools and libraries with GCC optimizations enabled and strip
609 debugging information from the libraries and executables it generates.
610 <p>
611
612 <dt>Profile Builds
John Criswellce760f62003-07-03 16:01:38 +0000613 <dd>
Misha Brukman00c73d22003-11-07 19:43:14 +0000614 These builds are for use with profiling. They compile profiling
615 information into the code for use with programs like <tt>gprof</tt>.
616 Profile builds must be started by specifying <tt>ENABLE_PROFILING=1</tt>
617 on the <tt>gmake</tt> command line.
618</dl>
John Criswell7a73b802003-06-30 21:59:07 +0000619
Misha Brukman00c73d22003-11-07 19:43:14 +0000620<p>Once you have LLVM configured, you can build it by entering the
621<i>OBJ_ROOT</i> directory and issuing the following command:</p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000622
Misha Brukman00c73d22003-11-07 19:43:14 +0000623<p><tt>gmake</tt></p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000624
Misha Brukman00c73d22003-11-07 19:43:14 +0000625<p>If you have multiple processors in your machine, you may wish to use some of
626the parallel build options provided by GNU Make. For example, you could use the
627command:</p>
John Criswell85ed3612003-06-12 19:34:44 +0000628
Misha Brukman00c73d22003-11-07 19:43:14 +0000629<p><tt>gmake -j2</tt></p>
John Criswellce760f62003-07-03 16:01:38 +0000630
Misha Brukman00c73d22003-11-07 19:43:14 +0000631<p>There are several special targets which are useful when working with the LLVM
632source code:</p>
John Criswellce760f62003-07-03 16:01:38 +0000633
Misha Brukman54111c42004-01-20 00:20:17 +0000634<dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000635 <dt><tt>gmake clean</tt>
636 <dd>
637 Removes all files generated by the build. This includes object files,
638 generated C/C++ files, libraries, and executables.
639 <p>
John Criswellce760f62003-07-03 16:01:38 +0000640
Misha Brukman00c73d22003-11-07 19:43:14 +0000641 <dt><tt>gmake distclean</tt>
642 <dd>
643 Removes everything that <tt>gmake clean</tt> does, but also removes
644 files generated by <tt>configure</tt>. It attempts to return the
645 source tree to the original state in which it was shipped.
646 <p>
John Criswellce760f62003-07-03 16:01:38 +0000647
Misha Brukman00c73d22003-11-07 19:43:14 +0000648 <dt><tt>gmake install</tt>
649 <dd>
650 Installs LLVM files into the proper location. For the most part,
651 this does nothing, but it does install bytecode libraries into the
652 GCC front end's bytecode library directory. If you need to update
653 your bytecode libraries, this is the target to use once you've built
654 them.
655 <p>
656</dl>
John Criswellce760f62003-07-03 16:01:38 +0000657
Misha Brukman00c73d22003-11-07 19:43:14 +0000658<p>It is also possible to override default values from <tt>configure</tt> by
659declaring variables on the command line. The following are some examples:</p>
John Criswellce760f62003-07-03 16:01:38 +0000660
Misha Brukman54111c42004-01-20 00:20:17 +0000661<dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000662 <dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
663 <dd>
664 Perform a Release (Optimized) build.
665 <p>
John Criswellce760f62003-07-03 16:01:38 +0000666
Misha Brukman00c73d22003-11-07 19:43:14 +0000667 <dt><tt>gmake ENABLE_PROFILING=1</tt>
668 <dd>
669 Perform a Profiling build.
670 <p>
John Criswellce760f62003-07-03 16:01:38 +0000671
Misha Brukman00c73d22003-11-07 19:43:14 +0000672 <dt><tt>gmake VERBOSE=1</tt>
673 <dd>
674 Print what <tt>gmake</tt> is doing on standard output.
675 <p>
676</dl>
John Criswellce760f62003-07-03 16:01:38 +0000677
Misha Brukman00c73d22003-11-07 19:43:14 +0000678<p>Every directory in the LLVM object tree includes a <tt>Makefile</tt> to build
679it and any subdirectories that it contains. Entering any directory inside the
680LLVM object tree and typing <tt>gmake</tt> should rebuild anything in or below
681that directory that is out of date.</p>
John Criswellce760f62003-07-03 16:01:38 +0000682
Misha Brukman00c73d22003-11-07 19:43:14 +0000683</div>
John Criswell20d2d3e2003-10-10 14:26:14 +0000684
Misha Brukman00c73d22003-11-07 19:43:14 +0000685<!-- ======================================================================= -->
686<div class="doc_subsection">
687 <a name="objfiles">The Location of LLVM Object Files</a>
688</div>
John Criswell20d2d3e2003-10-10 14:26:14 +0000689
Misha Brukman00c73d22003-11-07 19:43:14 +0000690<div class="doc_text">
John Criswellce760f62003-07-03 16:01:38 +0000691
Misha Brukman00c73d22003-11-07 19:43:14 +0000692<p>The LLVM build system is capable of sharing a single LLVM source tree among
693several LLVM builds. Hence, it is possible to build LLVM for several different
694platforms or configurations using the same source tree.</p>
John Criswellce760f62003-07-03 16:01:38 +0000695
Misha Brukman00c73d22003-11-07 19:43:14 +0000696<p>This is accomplished in the typical autoconf manner:</p>
John Criswellce760f62003-07-03 16:01:38 +0000697
Misha Brukman00c73d22003-11-07 19:43:14 +0000698<ul>
699 <li><p>Change directory to where the LLVM object files should live:</p>
John Criswellce760f62003-07-03 16:01:38 +0000700
Misha Brukman00c73d22003-11-07 19:43:14 +0000701 <p><tt>cd <i>OBJ_ROOT</i></tt></p></li>
John Criswellce760f62003-07-03 16:01:38 +0000702
Misha Brukman00c73d22003-11-07 19:43:14 +0000703 <li><p>Run the <tt>configure</tt> script found in the LLVM source
704 directory:</p>
John Criswellce760f62003-07-03 16:01:38 +0000705
Misha Brukman00c73d22003-11-07 19:43:14 +0000706 <p><tt><i>SRC_ROOT</i>/configure</tt></p></li>
707</ul>
John Criswell85ed3612003-06-12 19:34:44 +0000708
Misha Brukman00c73d22003-11-07 19:43:14 +0000709<p>The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
710named after the build type:</p>
John Criswell85ed3612003-06-12 19:34:44 +0000711
Misha Brukman54111c42004-01-20 00:20:17 +0000712<dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000713 <dt>Debug Builds
714 <dd>
Misha Brukman54111c42004-01-20 00:20:17 +0000715 <dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000716 <dt>Tools
717 <dd><tt><i>OBJ_ROOT</i>/tools/Debug</tt>
718 <dt>Libraries
719 <dd><tt><i>OBJ_ROOT</i>/lib/Debug</tt>
720 </dl>
721 <p>
John Criswell85ed3612003-06-12 19:34:44 +0000722
Misha Brukman00c73d22003-11-07 19:43:14 +0000723 <dt>Release Builds
724 <dd>
Misha Brukman54111c42004-01-20 00:20:17 +0000725 <dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000726 <dt>Tools
727 <dd><tt><i>OBJ_ROOT</i>/tools/Release</tt>
728 <dt>Libraries
729 <dd><tt><i>OBJ_ROOT</i>/lib/Release</tt>
730 </dl>
731 <p>
John Criswell85ed3612003-06-12 19:34:44 +0000732
Misha Brukman00c73d22003-11-07 19:43:14 +0000733 <dt>Profile Builds
734 <dd>
Misha Brukman54111c42004-01-20 00:20:17 +0000735 <dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000736 <dt>Tools
737 <dd><tt><i>OBJ_ROOT</i>/tools/Profile</tt>
738 <dt>Libraries
739 <dd><tt><i>OBJ_ROOT</i>/lib/Profile</tt>
740 </dl>
741</dl>
John Criswell85ed3612003-06-12 19:34:44 +0000742
Misha Brukman00c73d22003-11-07 19:43:14 +0000743</div>
Chris Lattner7fe7f812002-07-24 19:51:14 +0000744
Misha Brukman00c73d22003-11-07 19:43:14 +0000745<!-- *********************************************************************** -->
746<div class="doc_section">
747 <a name="layout"><b>Program Layout</b></a>
748</div>
749<!-- *********************************************************************** -->
John Criswell85ed3612003-06-12 19:34:44 +0000750
Misha Brukman00c73d22003-11-07 19:43:14 +0000751<div class="doc_text">
John Criswell85ed3612003-06-12 19:34:44 +0000752
Misha Brukman00c73d22003-11-07 19:43:14 +0000753<p>One useful source of information about the LLVM source base is the LLVM <a
754href="http://www.doxygen.org">doxygen</a> documentation, available at <tt><a
755href="http://llvm.cs.uiuc.edu/doxygen/">http://llvm.cs.uiuc.edu/doxygen/</a></tt>.
756The following is a brief introduction to code layout:</p>
John Criswell85ed3612003-06-12 19:34:44 +0000757
Misha Brukman00c73d22003-11-07 19:43:14 +0000758</div>
John Criswell85ed3612003-06-12 19:34:44 +0000759
Misha Brukman00c73d22003-11-07 19:43:14 +0000760<!-- ======================================================================= -->
761<div class="doc_subsection">
762 <a name="cvsdir"><tt>CVS</tt> directories</a>
763</div>
John Criswell85ed3612003-06-12 19:34:44 +0000764
Misha Brukman00c73d22003-11-07 19:43:14 +0000765<div class="doc_text">
John Criswell85ed3612003-06-12 19:34:44 +0000766
Misha Brukman00c73d22003-11-07 19:43:14 +0000767<p>Every directory checked out of CVS will contain a <tt>CVS</tt> directory; for
768the most part these can just be ignored.</p>
John Criswell85ed3612003-06-12 19:34:44 +0000769
Misha Brukman00c73d22003-11-07 19:43:14 +0000770</div>
John Criswell85ed3612003-06-12 19:34:44 +0000771
Misha Brukman00c73d22003-11-07 19:43:14 +0000772<!-- ======================================================================= -->
773<div class="doc_subsection">
774 <a name="include"><tt>llvm/include</tt></a>
775</div>
776
777<div class="doc_text">
778
779<p>This directory contains public header files exported from the LLVM
780library. The three main subdirectories of this directory are:</p>
781
782<ol>
783 <li><tt>llvm/include/llvm</tt> - This directory contains all of the LLVM
784 specific header files. This directory also has subdirectories for
785 different portions of LLVM: <tt>Analysis</tt>, <tt>CodeGen</tt>,
786 <tt>Target</tt>, <tt>Transforms</tt>, etc...</li>
787
788 <li><tt>llvm/include/Support</tt> - This directory contains generic
789 support libraries that are independent of LLVM, but are used by LLVM.
790 For example, some C++ STL utilities and a Command Line option processing
791 library store their header files here.</li>
792
793 <li><tt>llvm/include/Config</tt> - This directory contains header files
794 configured by the <tt>configure</tt> script. They wrap "standard" UNIX
795 and C header files. Source code can include these header files which
796 automatically take care of the conditional #includes that the
797 <tt>configure</tt> script generates.</li>
798</ol>
799
800</div>
801
802<!-- ======================================================================= -->
803<div class="doc_subsection">
804 <a name="lib"><tt>llvm/lib</tt></a>
805</div>
806
807<div class="doc_text">
808
809<p>This directory contains most of the source files of the LLVM system. In LLVM,
810almost all code exists in libraries, making it very easy to share code among the
811different <a href="#tools">tools</a>.</p>
812
Misha Brukman54111c42004-01-20 00:20:17 +0000813<dl>
Misha Brukman00c73d22003-11-07 19:43:14 +0000814 <dt><tt>llvm/lib/VMCore/</tt><dd> This directory holds the core LLVM
815 source files that implement core classes like Instruction and BasicBlock.
816
817 <dt><tt>llvm/lib/AsmParser/</tt><dd> This directory holds the source code
818 for the LLVM assembly language parser library.
819
820 <dt><tt>llvm/lib/ByteCode/</tt><dd> This directory holds code for reading
821 and write LLVM bytecode.
822
823 <dt><tt>llvm/lib/CWriter/</tt><dd> This directory implements the LLVM to C
824 converter.
825
826 <dt><tt>llvm/lib/Analysis/</tt><dd> This directory contains a variety of
827 different program analyses, such as Dominator Information, Call Graphs,
828 Induction Variables, Interval Identification, Natural Loop Identification,
829 etc...
830
831 <dt><tt>llvm/lib/Transforms/</tt><dd> This directory contains the source
832 code for the LLVM to LLVM program transformations, such as Aggressive Dead
833 Code Elimination, Sparse Conditional Constant Propagation, Inlining, Loop
834 Invariant Code Motion, Dead Global Elimination, and many others...
835
836 <dt><tt>llvm/lib/Target/</tt><dd> This directory contains files that
837 describe various target architectures for code generation. For example,
838 the llvm/lib/Target/Sparc directory holds the Sparc machine
839 description.<br>
840
841 <dt><tt>llvm/lib/CodeGen/</tt><dd> This directory contains the major parts
842 of the code generator: Instruction Selector, Instruction Scheduling, and
843 Register Allocation.
John Criswell85ed3612003-06-12 19:34:44 +0000844
Misha Brukman00c73d22003-11-07 19:43:14 +0000845 <dt><tt>llvm/lib/Support/</tt><dd> This directory contains the source code
846 that corresponds to the header files located in
847 <tt>llvm/include/Support/</tt>.
848</dl>
John Criswell7a73b802003-06-30 21:59:07 +0000849
Misha Brukman00c73d22003-11-07 19:43:14 +0000850</div>
John Criswell85ed3612003-06-12 19:34:44 +0000851
Misha Brukman00c73d22003-11-07 19:43:14 +0000852<!-- ======================================================================= -->
853<div class="doc_subsection">
854 <a name="runtime"><tt>llvm/runtime</tt></a>
855</div>
John Criswell85ed3612003-06-12 19:34:44 +0000856
Misha Brukman00c73d22003-11-07 19:43:14 +0000857<div class="doc_text">
John Criswell85ed3612003-06-12 19:34:44 +0000858
Misha Brukman00c73d22003-11-07 19:43:14 +0000859<p>This directory contains libraries which are compiled into LLVM bytecode and
860used when linking programs with the GCC front end. Most of these libraries are
861skeleton versions of real libraries; for example, libc is a stripped down
862version of glibc.</p>
John Criswell85ed3612003-06-12 19:34:44 +0000863
Misha Brukman00c73d22003-11-07 19:43:14 +0000864<p>Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front
865end to compile.</p>
John Criswell85ed3612003-06-12 19:34:44 +0000866
Misha Brukman00c73d22003-11-07 19:43:14 +0000867</div>
John Criswell85ed3612003-06-12 19:34:44 +0000868
Misha Brukman00c73d22003-11-07 19:43:14 +0000869<!-- ======================================================================= -->
870<div class="doc_subsection">
871 <a name="test"><tt>llvm/test</tt></a>
872</div>
John Criswell85ed3612003-06-12 19:34:44 +0000873
Misha Brukman00c73d22003-11-07 19:43:14 +0000874<div class="doc_text">
John Criswell85ed3612003-06-12 19:34:44 +0000875
Misha Brukman00c73d22003-11-07 19:43:14 +0000876<p>This directory contains regression tests and source code that is used to test
877the LLVM infrastructure.</p>
John Criswell85ed3612003-06-12 19:34:44 +0000878
Misha Brukman00c73d22003-11-07 19:43:14 +0000879</div>
John Criswell85ed3612003-06-12 19:34:44 +0000880
Misha Brukman00c73d22003-11-07 19:43:14 +0000881<!-- ======================================================================= -->
882<div class="doc_subsection">
883 <a name="tools"><tt>llvm/tools</tt></a>
884</div>
John Criswell85ed3612003-06-12 19:34:44 +0000885
Misha Brukman00c73d22003-11-07 19:43:14 +0000886<div class="doc_text">
John Criswell20d2d3e2003-10-10 14:26:14 +0000887
Misha Brukman00c73d22003-11-07 19:43:14 +0000888<p>The <b>tools</b> directory contains the executables built out of the
889libraries above, which form the main part of the user interface. You can
890always get help for a tool by typing <tt>tool_name --help</tt>. The
891following is a brief introduction to the most important tools.</p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000892
Misha Brukman54111c42004-01-20 00:20:17 +0000893<dl>
894 <dt><tt><b>analyze</b></tt> <dd><tt>analyze</tt> is used to run a specific
Misha Brukman00c73d22003-11-07 19:43:14 +0000895 analysis on an input LLVM bytecode file and print out the results. It is
896 primarily useful for debugging analyses, or familiarizing yourself with
897 what an analysis does.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000898
Misha Brukman54111c42004-01-20 00:20:17 +0000899 <dt><tt><b>bugpoint</b></tt> <dd><tt>bugpoint</tt> is used to debug
Misha Brukman00c73d22003-11-07 19:43:14 +0000900 optimization passes or code generation backends by narrowing down the
901 given test case to the minimum number of passes and/or instructions that
902 still cause a problem, whether it is a crash or miscompilation. See <a
903 href="HowToSubmitABug.html">HowToSubmitABug.html</a> for more information
904 on using <tt>bugpoint</tt>.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000905
Misha Brukman54111c42004-01-20 00:20:17 +0000906 <dt><tt><b>llvm-ar</b></tt> <dd>The archiver produces an archive containing
Misha Brukman00c73d22003-11-07 19:43:14 +0000907 the given LLVM bytecode files, optionally with an index for faster
908 lookup.<p>
909
Misha Brukman54111c42004-01-20 00:20:17 +0000910 <dt><tt><b>llvm-as</b></tt> <dd>The assembler transforms the human readable
Misha Brukman00c73d22003-11-07 19:43:14 +0000911 LLVM assembly to LLVM bytecode.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000912
Misha Brukman00c73d22003-11-07 19:43:14 +0000913 <dt><tt><b>llvm-dis</b></tt><dd>The disassembler transforms the LLVM
Chris Lattner036e6392004-02-14 01:07:17 +0000914 bytecode to human readable LLVM assembly.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000915
Misha Brukman00c73d22003-11-07 19:43:14 +0000916 <dt><tt><b>llvm-link</b></tt><dd> <tt>llvm-link</tt>, not surprisingly,
917 links multiple LLVM modules into a single program.<p>
918
919 <dt><tt><b>lli</b></tt><dd> <tt>lli</tt> is the LLVM interpreter, which
920 can directly execute LLVM bytecode (although very slowly...). In addition
921 to a simple interpreter, <tt>lli</tt> also has a tracing mode (entered by
922 specifying <tt>-trace</tt> on the command line). Finally, for
923 architectures that support it (currently only x86 and Sparc), by default,
924 <tt>lli</tt> will function as a Just-In-Time compiler (if the
925 functionality was compiled in), and will execute the code <i>much</i>
926 faster than the interpreter.<p>
Misha Brukmanef0ad412003-10-06 19:23:34 +0000927
Chris Lattner036e6392004-02-14 01:07:17 +0000928 <dt><tt><b>llc</b></tt><dd> <tt>llc</tt> is the LLVM backend compiler, which
929 translates LLVM bytecode to a SPARC or x86 assembly file, or to C code (with
930 the -march=c option).<p>
Misha Brukmanef0ad412003-10-06 19:23:34 +0000931
Misha Brukman00c73d22003-11-07 19:43:14 +0000932 <dt><tt><b>llvmgcc</b></tt><dd> <tt>llvmgcc</tt> is a GCC-based C frontend
933 that has been retargeted to emit LLVM code as the machine code output. It
934 works just like any other GCC compiler, taking the typical <tt>-c, -S, -E,
935 -o</tt> options that are typically used. The source code for the
936 <tt>llvmgcc</tt> tool is currently not included in the LLVM CVS tree
937 because it is quite large and not very interesting.<p>
Misha Brukmanef0ad412003-10-06 19:23:34 +0000938
Misha Brukman54111c42004-01-20 00:20:17 +0000939 <blockquote>
940 <dl>
941 <dt><tt><b>gccas</b></tt> <dd>This tool is invoked by the
Misha Brukman00c73d22003-11-07 19:43:14 +0000942 <tt>llvmgcc</tt> frontend as the "assembler" part of the compiler. This
943 tool actually assembles LLVM assembly to LLVM bytecode,
944 performs a variety of optimizations, and outputs LLVM bytecode. Thus
945 when you invoke <tt>llvmgcc -c x.c -o x.o</tt>, you are causing
946 <tt>gccas</tt> to be run, which writes the <tt>x.o</tt> file (which is
947 an LLVM bytecode file that can be disassembled or manipulated just like
948 any other bytecode file). The command line interface to <tt>gccas</tt>
949 is designed to be as close as possible to the <b>system</b>
950 `<tt>as</tt>' utility so that the gcc frontend itself did not have to be
951 modified to interface to a "weird" assembler.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000952
Misha Brukman54111c42004-01-20 00:20:17 +0000953 <dt><tt><b>gccld</b></tt> <dd><tt>gccld</tt> links together several LLVM
Misha Brukman00c73d22003-11-07 19:43:14 +0000954 bytecode files into one bytecode file and does some optimization. It is
955 the linker invoked by the GCC frontend when multiple .o files need to be
956 linked together. Like <tt>gccas</tt>, the command line interface of
957 <tt>gccld</tt> is designed to match the system linker, to aid
Misha Brukman54111c42004-01-20 00:20:17 +0000958 interfacing with the GCC frontend.</dl><p>
959 </blockquote>
John Criswell85ed3612003-06-12 19:34:44 +0000960
Misha Brukman00c73d22003-11-07 19:43:14 +0000961 <dt><tt><b>opt</b></tt><dd> <tt>opt</tt> reads LLVM bytecode, applies a
962 series of LLVM to LLVM transformations (which are specified on the command
963 line), and then outputs the resultant bytecode. The '<tt>opt --help</tt>'
964 command is a good way to get a list of the program transformations
Misha Brukman54111c42004-01-20 00:20:17 +0000965 available in LLVM.
John Criswell85ed3612003-06-12 19:34:44 +0000966
Misha Brukman00c73d22003-11-07 19:43:14 +0000967</dl>
John Criswell85ed3612003-06-12 19:34:44 +0000968
Misha Brukman00c73d22003-11-07 19:43:14 +0000969</div>
John Criswell85ed3612003-06-12 19:34:44 +0000970
Misha Brukman00c73d22003-11-07 19:43:14 +0000971<!-- ======================================================================= -->
972<div class="doc_subsection">
973 <a name="utils"><tt>llvm/utils</tt></a>
974</div>
John Criswell85ed3612003-06-12 19:34:44 +0000975
Misha Brukman00c73d22003-11-07 19:43:14 +0000976<div class="doc_text">
John Criswell85ed3612003-06-12 19:34:44 +0000977
Misha Brukman00c73d22003-11-07 19:43:14 +0000978<p>This directory contains utilities for working with LLVM source code, and some
979of the utilities are actually required as part of the build process because they
980are code generators for parts of LLVM infrastructure.</p>
John Criswell85ed3612003-06-12 19:34:44 +0000981
Misha Brukman54111c42004-01-20 00:20:17 +0000982<dl>
983 <dt><tt><b>Burg/</b></tt> <dd><tt>Burg</tt> is an instruction selector
Misha Brukman00c73d22003-11-07 19:43:14 +0000984 generator -- it builds trees on which it then performs pattern-matching to
985 select instructions according to the patterns the user has specified. Burg
986 is currently used in the Sparc V9 backend.<p>
John Criswell0b459202003-07-08 20:35:59 +0000987
Misha Brukman54111c42004-01-20 00:20:17 +0000988 <dt><tt><b>codegen-diff</b></tt> <dd><tt>codegen-diff</tt> is a script
Misha Brukman00c73d22003-11-07 19:43:14 +0000989 that finds differences between code that LLC generates and code that LLI
990 generates. This is a useful tool if you are debugging one of them,
991 assuming that the other generates correct output. For the full user
992 manual, run <tt>`perldoc codegen-diff'</tt>.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +0000993
Misha Brukman54111c42004-01-20 00:20:17 +0000994 <dt><tt><b>cvsupdate</b></tt> <dd><tt>cvsupdate</tt> is a script that will
Misha Brukman00c73d22003-11-07 19:43:14 +0000995 update your CVS tree, but produce a much cleaner and more organized output
996 than simply running <tt>`cvs -z3 up -dP'</tt> will. For example, it will group
997 together all the new and updated files and modified files in separate
998 sections, so you can see at a glance what has changed. If you are at the
999 top of your LLVM CVS tree, running <tt>utils/cvsupdate</tt> is the
1000 preferred way of updating the tree.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +00001001
Misha Brukman54111c42004-01-20 00:20:17 +00001002 <dt><tt><b>emacs/</b></tt> <dd>The <tt>emacs</tt> directory contains
Misha Brukman00c73d22003-11-07 19:43:14 +00001003 syntax-highlighting files which will work with Emacs and XEmacs editors,
1004 providing syntax highlighting support for LLVM assembly files and TableGen
1005 description files. For information on how to use the syntax files, consult
1006 the <tt>README</tt> file in that directory.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +00001007
Misha Brukman54111c42004-01-20 00:20:17 +00001008 <dt><tt><b>getsrcs.sh</b></tt> <dd>The <tt>getsrcs.sh</tt> script finds
Misha Brukman00c73d22003-11-07 19:43:14 +00001009 and outputs all non-generated source files, which is useful if one wishes
1010 to do a lot of development across directories and does not want to
1011 individually find each file. One way to use it is to run, for example:
1012 <tt>xemacs `utils/getsources.sh`</tt> from the top of your LLVM source
1013 tree.<p>
1014
Misha Brukman54111c42004-01-20 00:20:17 +00001015 <dt><tt><b>makellvm</b></tt> <dd>The <tt>makellvm</tt> script compiles all
Misha Brukman00c73d22003-11-07 19:43:14 +00001016 files in the current directory and then compiles and links the tool that
1017 is the first argument. For example, assuming you are in the directory
1018 <tt>llvm/lib/Target/Sparc</tt>, if <tt>makellvm</tt> is in your path,
1019 simply running <tt>makellvm llc</tt> will make a build of the current
1020 directory, switch to directory <tt>llvm/tools/llc</tt> and build it,
1021 causing a re-linking of LLC.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +00001022
Misha Brukman00c73d22003-11-07 19:43:14 +00001023 <dt><tt><b>NightlyTest.pl</b></tt> and
Misha Brukman54111c42004-01-20 00:20:17 +00001024 <tt><b>NightlyTestTemplate.html</b></tt> <dd>These files are used in a
Misha Brukman00c73d22003-11-07 19:43:14 +00001025 cron script to generate nightly status reports of the functionality of
1026 tools, and the results can be seen by following the appropriate link on
1027 the <a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a>.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +00001028
Misha Brukman54111c42004-01-20 00:20:17 +00001029 <dt><tt><b>TableGen/</b></tt> <dd>The <tt>TableGen</tt> directory contains
Misha Brukman00c73d22003-11-07 19:43:14 +00001030 the tool used to generate register descriptions, instruction set
1031 descriptions, and even assemblers from common TableGen description
1032 files.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +00001033
Misha Brukman54111c42004-01-20 00:20:17 +00001034 <dt><tt><b>vim/</b></tt> <dd>The <tt>vim</tt> directory contains
Misha Brukman00c73d22003-11-07 19:43:14 +00001035 syntax-highlighting files which will work with the VIM editor, providing
1036 syntax highlighting support for LLVM assembly files and TableGen
1037 description files. For information on how to use the syntax files, consult
1038 the <tt>README</tt> file in that directory.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +00001039
Misha Brukman00c73d22003-11-07 19:43:14 +00001040</dl>
Misha Brukmanc103adf2003-08-11 18:45:46 +00001041
Misha Brukman00c73d22003-11-07 19:43:14 +00001042</div>
Misha Brukmanc103adf2003-08-11 18:45:46 +00001043
Misha Brukman00c73d22003-11-07 19:43:14 +00001044<!-- *********************************************************************** -->
1045<div class="doc_section">
1046 <a name="tutorial">An Example Using the LLVM Tool Chain</a>
1047</div>
1048<!-- *********************************************************************** -->
Misha Brukmanc103adf2003-08-11 18:45:46 +00001049
Misha Brukman00c73d22003-11-07 19:43:14 +00001050<div class="doc_text">
John Criswell85ed3612003-06-12 19:34:44 +00001051
Misha Brukman00c73d22003-11-07 19:43:14 +00001052<ol>
1053 <li>First, create a simple C file, name it 'hello.c':
John Criswell85ed3612003-06-12 19:34:44 +00001054 <pre>
1055 #include &lt;stdio.h&gt;
1056 int main() {
1057 printf("hello world\n");
1058 return 0;
1059 }
Misha Brukman00c73d22003-11-07 19:43:14 +00001060 </pre></li>
John Criswell85ed3612003-06-12 19:34:44 +00001061
Misha Brukman00c73d22003-11-07 19:43:14 +00001062 <li><p>Next, compile the C file into a LLVM bytecode file:</p>
1063 <p><tt>% llvmgcc hello.c -o hello</tt></p>
John Criswell85ed3612003-06-12 19:34:44 +00001064
Misha Brukman00c73d22003-11-07 19:43:14 +00001065 <p>This will create two result files: <tt>hello</tt> and
John Criswell85ed3612003-06-12 19:34:44 +00001066 <tt>hello.bc</tt>. The <tt>hello.bc</tt> is the LLVM bytecode that
1067 corresponds the the compiled program and the library facilities that it
1068 required. <tt>hello</tt> is a simple shell script that runs the bytecode
Misha Brukman00c73d22003-11-07 19:43:14 +00001069 file with <tt>lli</tt>, making the result directly executable.</p></li>
John Criswell85ed3612003-06-12 19:34:44 +00001070
Misha Brukman00c73d22003-11-07 19:43:14 +00001071 <li><p>Run the program. To make sure the program ran, execute one of the
1072 following commands:</p>
John Criswell8df90e02003-06-11 20:46:40 +00001073
Misha Brukman00c73d22003-11-07 19:43:14 +00001074 <p><tt>% ./hello</tt></p>
John Criswell85ed3612003-06-12 19:34:44 +00001075
Misha Brukman00c73d22003-11-07 19:43:14 +00001076 <p>or</p>
John Criswell85ed3612003-06-12 19:34:44 +00001077
Misha Brukman00c73d22003-11-07 19:43:14 +00001078 <p><tt>% lli hello.bc</tt></p></li>
John Criswell85ed3612003-06-12 19:34:44 +00001079
Misha Brukman00c73d22003-11-07 19:43:14 +00001080 <li><p>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
1081 code:</p>
John Criswell85ed3612003-06-12 19:34:44 +00001082
Misha Brukman00c73d22003-11-07 19:43:14 +00001083 <p><tt>% llvm-dis &lt; hello.bc | less</tt><p></li>
John Criswell85ed3612003-06-12 19:34:44 +00001084
Misha Brukman00c73d22003-11-07 19:43:14 +00001085 <li><p>Compile the program to native Sparc assembly using the code
1086 generator (assuming you are currently on a Sparc system):</p>
John Criswell85ed3612003-06-12 19:34:44 +00001087
Misha Brukman00c73d22003-11-07 19:43:14 +00001088 <p><tt>% llc hello.bc -o hello.s</tt></p>
John Criswell85ed3612003-06-12 19:34:44 +00001089
Misha Brukman00c73d22003-11-07 19:43:14 +00001090 <li><p>Assemble the native sparc assemble file into a program:</p>
John Criswell85ed3612003-06-12 19:34:44 +00001091
Misha Brukman00c73d22003-11-07 19:43:14 +00001092 <p><tt>% /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.sparc</tt></p>
John Criswell85ed3612003-06-12 19:34:44 +00001093
Misha Brukman00c73d22003-11-07 19:43:14 +00001094 <li><p>Execute the native sparc program:</p>
John Criswell85ed3612003-06-12 19:34:44 +00001095
Misha Brukman00c73d22003-11-07 19:43:14 +00001096 <p><tt>% ./hello.sparc</tt></p></li>
John Criswell85ed3612003-06-12 19:34:44 +00001097
Misha Brukman00c73d22003-11-07 19:43:14 +00001098</ol>
John Criswell85ed3612003-06-12 19:34:44 +00001099
Misha Brukman00c73d22003-11-07 19:43:14 +00001100</div>
John Criswell85ed3612003-06-12 19:34:44 +00001101
Misha Brukman00c73d22003-11-07 19:43:14 +00001102<!-- *********************************************************************** -->
1103<div class="doc_section">
1104 <a name="problems">Common Problems</a>
1105</div>
1106<!-- *********************************************************************** -->
John Criswellce760f62003-07-03 16:01:38 +00001107
Misha Brukman00c73d22003-11-07 19:43:14 +00001108<div class="doc_text">
John Criswellce760f62003-07-03 16:01:38 +00001109
Misha Brukman00c73d22003-11-07 19:43:14 +00001110<p>If you are having problems building or using LLVM, or if you have any other
1111general questions about LLVM, please consult the <a href="FAQ.html">Frequently
1112Asked Questions</a> page.</p>
John Criswell85ed3612003-06-12 19:34:44 +00001113
Misha Brukman00c73d22003-11-07 19:43:14 +00001114</div>
John Criswell85ed3612003-06-12 19:34:44 +00001115
Misha Brukman00c73d22003-11-07 19:43:14 +00001116<!-- *********************************************************************** -->
1117<div class="doc_section">
1118 <a name="links">Links</a>
1119</div>
1120<!-- *********************************************************************** -->
John Criswell85ed3612003-06-12 19:34:44 +00001121
Misha Brukman00c73d22003-11-07 19:43:14 +00001122<div class="doc_text">
John Criswell85ed3612003-06-12 19:34:44 +00001123
Misha Brukman00c73d22003-11-07 19:43:14 +00001124<p>This document is just an <b>introduction</b> to how to use LLVM to do
1125some simple things... there are many more interesting and complicated things
1126that you can do that aren't documented here (but we'll gladly accept a patch
1127if you want to write something up!). For more information about LLVM, check
1128out:</p>
John Criswell85ed3612003-06-12 19:34:44 +00001129
Misha Brukman00c73d22003-11-07 19:43:14 +00001130<ul>
1131 <li><a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a></li>
1132 <li><a href="http://llvm.cs.uiuc.edu/doxygen/">LLVM doxygen tree</a></li>
1133 <li><a href="http://llvm.cs.uiuc.edu/docs/Projects.html">Starting a Project
1134 that Uses LLVM</a></li>
1135</ul>
1136
1137</div>
1138
1139<!-- *********************************************************************** -->
1140
1141<hr>
Misha Brukman142207b2003-11-22 01:30:01 +00001142<address>
Misha Brukman54111c42004-01-20 00:20:17 +00001143 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
1144 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
1145 <a href="http://validator.w3.org/check/referer"><img
1146 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
1147
Misha Brukman142207b2003-11-22 01:30:01 +00001148 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
1149 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman00c73d22003-11-07 19:43:14 +00001150 Last modified: $Date$
Misha Brukman142207b2003-11-22 01:30:01 +00001151</address>
Misha Brukman00c73d22003-11-07 19:43:14 +00001152
1153</body>
Guochun Shif4688a82002-07-17 23:05:56 +00001154</html>