docs/HowToSubmitABug.html - platform/external/llvm - Gitiles

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   <title>How to submit an LLVM bug report</title>
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 </head>
 <body>

 <div class="doc_title">
   How to submit an LLVM bug report
 </div>

 <table class="layout" style="width: 90%" >
 <tr class="layout">
   <td class="left">
 <ol>
   <li><a href="#introduction">Introduction - Got bugs?</a></li>
   <li><a href="#crashers">Crashing Bugs</a>
     <ul>
     <li><a href="#front-end">Front-end bugs</a>
     <li><a href="#gccas">GCCAS bugs</a>
     <li><a href="#gccld">GCCLD bugs</a>
     <li><a href="#passes">Bugs in LLVM passes</a>
     </ul></li>
   <li><a href="#miscompilations">Miscompilations</a></li>
   <li><a href="#codegen">Incorrect code generation (JIT and LLC)</a></li>
 </ol>
 <div class="doc_author">
   <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a> and
                 <a href="http://misha.brukman.net">Misha Brukman</a></p>
 </div>
 </td>
 <td class="right">
   <img src="img/Debugging.gif" alt="Debugging" width="444" height="314">
 </td>
 </tr>
 </table>

 <!-- *********************************************************************** -->
 <div class="doc_section">
   <a name="introduction">Introduction - Got bugs?</a>
 </div>
 <!-- *********************************************************************** -->

 <div class="doc_text">

 <p>If you're working with LLVM and run into a bug, we definitely want to know
 about it.  This document describes what you can do to increase the odds of
 getting it fixed quickly.</p>

 <p>Basically you have to do two things at a minimum.  First, decide whether the
 bug <a href="#crashers">crashes the compiler</a> (or an LLVM pass), or if the
 compiler is <a href="#miscompilations">miscompiling</a> the program.  Based on
 what type of bug it is, follow the instructions in the linked section to narrow
 down the bug so that the person who fixes it will be able to find the problem
 more easily.</p>

 <p>Once you have a reduced test-case, go to <a
 href="http://llvm.org/bugs/enter_bug.cgi">the LLVM Bug Tracking
 System</a>, select the category in which the bug falls, and fill out the form
 with the necessary details.  The bug description should contain the following
 information:</p>

 <ul>
   <li>All information necessary to reproduce the problem.</li>
   <li>The reduced test-case that triggers the bug.</li>
   <li>The location where you obtained LLVM (if not from our CVS
   repository).</li>
 </ul>

 <p>Thanks for helping us make LLVM better!</p>

 </div>

 <!-- *********************************************************************** -->
 <div class="doc_section">
   <a name="crashers">Crashing Bugs</a>
 </div>
 <!-- *********************************************************************** -->

 <div class="doc_text">

 <p>More often than not, bugs in the compiler cause it to crash - often due to an
 assertion failure of some sort.  If you are running <tt><b>opt</b></tt> or
 <tt><b>analyze</b></tt> directly, and something crashes, jump to the section on
 <a href="#passes">bugs in LLVM passes</a>.  Otherwise, the most important
 piece of the puzzle is to figure out if it is the GCC-based front-end that is
 buggy or if it's one of the LLVM tools that has problems.</p>

 <p>To figure out which program is crashing (the front-end,
 <tt><b>gccas</b></tt>, or <tt><b>gccld</b></tt>), run the
 <tt><b>llvm-gcc</b></tt> command line as you were when the crash occurred, but
 add a <tt>-v</tt> option to the command line.  The compiler will print out a
 bunch of stuff, and should end with telling you that one of
 <tt><b>cc1</b>/<b>cc1plus</b></tt>, <tt><b>gccas</b></tt>, or
 <tt><b>gccld</b></tt> crashed.</p>

 <ul>

   <li>If <tt><b>cc1</b></tt> or <tt><b>cc1plus</b></tt> crashed, you found a
   problem with the front-end.
   Jump ahead to the section on <a href="#front-end">front-end bugs</a>.</li>

   <li>If <tt><b>gccas</b></tt> crashed, you found a bug in <a href="#gccas">one
   of the passes in <tt><b>gccas</b></tt></a>.</li>

   <li>If <tt><b>gccld</b></tt> crashed, you found a bug in <a href="#gccld">one
   of the passes in <tt><b>gccld</b></tt></a>.</li>

   <li>Otherwise, something really weird happened. Email the list with what you
   have at this point.</li>

 </ul>

 </div>

 <!-- ======================================================================= -->
 <div class="doc_subsection">
   <a name="front-end">Front-end bugs</a>
 </div>

 <div class="doc_text">

 <p>If the problem is in the front-end, you should re-run the same
 <tt>llvm-gcc</tt> command that resulted in the crash, but add the
 <tt>-save-temps</tt> option.  The compiler will crash again, but it will leave
 behind a <tt><i>foo</i>.i</tt> file (containing preprocessed C source code) and
 possibly <tt><i>foo</i>.s</tt> (containing LLVM assembly code), for each
 compiled <tt><i>foo</i>.c</tt> file. Send us the <tt><i>foo</i>.i</tt> file,
 along with a brief description of the error it caused. A tool that might help
 you reduce a front-end testcase to a more manageable size is
 <a href="http://delta.tigris.org/">delta</a>.
 </p>

 </div>

 <!-- ======================================================================= -->
 <div class="doc_subsection">
   <a name="gccas">GCCAS bugs</a>
 </div>

 <div class="doc_text">

 <p>If you find that a bug crashes in the <tt><b>gccas</b></tt> stage of
 compilation, compile your test-case to a <tt>.s</tt> file with the
 <tt>-save-temps</tt> option to <tt><b>llvm-gcc</b></tt>. Then run:</p>

 <div class="doc_code">
 <p><tt><b>gccas</b> -debug-pass=Arguments &lt; /dev/null -o - &gt; /dev/null</tt></p>
 </div>

 <p>... which will print a list of arguments, indicating the list of passes that
 <tt><b>gccas</b></tt> runs.  Once you have the input file and the list of
 passes, go to the section on <a href="#passes">debugging bugs in LLVM
 passes</a>.</p>

 </div>

 <!-- ======================================================================= -->
 <div class="doc_subsection">
   <a name="gccld">GCCLD bugs</a>
 </div>

 <div class="doc_text">

 <p>If you find that a bug crashes in the <tt><b>gccld</b></tt> stage of
 compilation, gather all of the <tt>.o</tt> bytecode files and libraries that are
 being linked together (the "<tt><b>llvm-gcc</b> -v</tt>" output should include
 the full list of objects linked).  Then run:</p>

 <div class="doc_code">
 <p><tt><b>llvm-as</b> &lt; /dev/null &gt; null.bc<br>
 <b>gccld</b> -debug-pass=Arguments null.bc</tt>
 </p>
 </div>

 <p>... which will print a list of arguments, indicating the list of passes that
 <tt><b>gccld</b></tt> runs.  Once you have the input files and the list of
 passes, go to the section on <a href="#passes">debugging bugs in LLVM
 passes</a>.</p>

 </div>

 <!-- ======================================================================= -->
 <div class="doc_subsection">
   <a name="passes">Bugs in LLVM passes</a>
 </div>

 <div class="doc_text">

 <p>At this point, you should have some number of LLVM assembly files or bytecode
 files and a list of passes which crash when run on the specified input.  In
 order to reduce the list of passes (which is probably large) and the input to
 something tractable, use the <tt><b>bugpoint</b></tt> tool as follows:</p>

 <div class="doc_code">
 <p><tt><b>bugpoint</b> &lt;input files&gt; &lt;list of passes&gt;</tt></p>
 </div>

 <p><tt><b>bugpoint</b></tt> will print a bunch of output as it reduces the
 test-case, but it should eventually print something like this:</p>

 <div class="doc_code">
 <p><tt>
 ...<br>
 Emitted bytecode to 'bugpoint-reduced-simplified.bc'<br>
 <br>
 *** You can reproduce the problem with: opt bugpoint-reduced-simplified.bc -licm<br>
 </tt></p>
 </div>

 <p>Once you complete this, please send the LLVM bytecode file and the command
 line to reproduce the problem to the llvmbugs mailing list.</p>

 </div>

 <!-- *********************************************************************** -->
 <div class="doc_section">
   <a name="miscompilations">Miscompilations</a>
 </div>
 <!-- *********************************************************************** -->

 <div class="doc_text">

 <p>A miscompilation occurs when a pass does not correctly transform a program,
 thus producing errors that are only noticed during execution. This is different
 from producing invalid LLVM code (i.e., code not in SSA form, using values
 before defining them, etc.) which the verifier will check for after a pass
 finishes its run.</p>

 <p>If it looks like the LLVM compiler is miscompiling a program, the very first
 thing to check is to make sure it is not using undefined behavior.  In
 particular, check to see if the program <a
 href="http://valgrind.kde.org/">valgrind</a>s clean, passes purify, or some
 other memory checker tool.  Many of the "LLVM bugs" that we have chased down
 ended up being bugs in the program being compiled, not LLVM.</p>

 <p>Once you determine that the program itself is not buggy, you should choose
 which code generator you wish to compile the program with (e.g. C backend, the
 JIT, or LLC) and optionally a series of LLVM passes to run.  For example:</p>

 <div class="doc_code">
 <p><tt>
 <b>bugpoint</b> -run-cbe [... optzn passes ...] file-to-test.bc --args -- [program arguments]</tt></p>
 </div>

 <p><tt>bugpoint</tt> will try to narrow down your list of passes to the one pass
 that causes an error, and simplify the bytecode file as much as it can to assist
 you. It will print a message letting you know how to reproduce the resulting
 error.</p>

 </div>

 <!-- *********************************************************************** -->
 <div class="doc_section">
   <a name="codegen">Incorrect code generation</a>
 </div>
 <!-- *********************************************************************** -->

 <div class="doc_text">

 <p>Similarly to debugging incorrect compilation by mis-behaving passes, you can
 debug incorrect code generation by either LLC or the JIT, using
 <tt>bugpoint</tt>. The process <tt>bugpoint</tt> follows in this case is to try
 to narrow the code down to a function that is miscompiled by one or the other
 method, but since for correctness, the entire program must be run,
 <tt>bugpoint</tt> will compile the code it deems to not be affected with the C
 Backend, and then link in the shared object it generates.</p>

 <p>To debug the JIT:</p>

 <div class="doc_code">
 <pre>
 bugpoint -run-jit -output=[correct output file] [bytecode file]  \
          --tool-args -- [arguments to pass to lli]               \
          --args -- [program arguments]
 </pre>
 </div>

 <p>Similarly, to debug the LLC, one would run:</p>

 <div class="doc_code">
 <pre>
 bugpoint -run-llc -output=[correct output file] [bytecode file]  \
          --tool-args -- [arguments to pass to llc]               \
          --args -- [program arguments]
 </pre>
 </div>

 <p><b>Special note:</b> if you are debugging MultiSource or SPEC tests that
 already exist in the <tt>llvm/test</tt> hierarchy, there is an easier way to
 debug the JIT, LLC, and CBE, using the pre-written Makefile targets, which
 will pass the program options specified in the Makefiles:</p>

 <div class="doc_code">
 <p><tt>
 cd llvm/test/../../program<br>
 make bugpoint-jit
 </tt></p>
 </div>

 <p>At the end of a successful <tt>bugpoint</tt> run, you will be presented
 with two bytecode files: a <em>safe</em> file which can be compiled with the C
 backend and the <em>test</em> file which either LLC or the JIT
 mis-codegenerates, and thus causes the error.</p>

 <p>To reproduce the error that <tt>bugpoint</tt> found, it is sufficient to do
 the following:</p>

 <ol>

 <li><p>Regenerate the shared object from the safe bytecode file:</p>

 <div class="doc_code">
 <p><tt>
 <b>llc</b> -march=c safe.bc -o safe.c<br>
 <b>gcc</b> -shared safe.c -o safe.so
 </tt></p>
 </div></li>

 <li><p>If debugging LLC, compile test bytecode native and link with the shared
     object:</p>

 <div class="doc_code">
 <p><tt>
 <b>llc</b> test.bc -o test.s -f<br>
 <b>gcc</b> test.s safe.so -o test.llc<br>
 ./test.llc [program options]
 </tt></p>
 </div></li>

 <li><p>If debugging the JIT, load the shared object and supply the test
     bytecode:</p>

 <div class="doc_code">
 <p><tt><b>lli</b> -load=safe.so test.bc [program options]</tt></p>
 </div></li>

 </ol>

 </div>

 <!-- *********************************************************************** -->
 <hr>
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   <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
   <a href="http://llvm.org">The LLVM Compiler Infrastructure</a>
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   Last modified: $Date$
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 </body>
 </html>
	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
	"http://www.w3.org/TR/html4/strict.dtd">
	<html>
	<head>
	<title>How to submit an LLVM bug report</title>
	<link rel="stylesheet" href="llvm.css" type="text/css">
	</head>
	<body>

	<div class="doc_title">
	How to submit an LLVM bug report
	</div>

	<table class="layout" style="width: 90%" >
	<tr class="layout">
	<td class="left">
	<ol>
	<li><a href="#introduction">Introduction - Got bugs?</a></li>
	<li><a href="#crashers">Crashing Bugs</a>
	<ul>
	<li><a href="#front-end">Front-end bugs</a>
	<li><a href="#gccas">GCCAS bugs</a>
	<li><a href="#gccld">GCCLD bugs</a>
	<li><a href="#passes">Bugs in LLVM passes</a>
	</ul></li>
	<li><a href="#miscompilations">Miscompilations</a></li>
	<li><a href="#codegen">Incorrect code generation (JIT and LLC)</a></li>
	</ol>
	<div class="doc_author">
	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a> and
	<a href="http://misha.brukman.net">Misha Brukman</a></p>
	</div>
	</td>
	<td class="right">
	<img src="img/Debugging.gif" alt="Debugging" width="444" height="314">
	</td>
	</tr>
	</table>

	<!-- *********************************************************************** -->
	<div class="doc_section">
	<a name="introduction">Introduction - Got bugs?</a>
	</div>
	<!-- *********************************************************************** -->

	<div class="doc_text">

	<p>If you're working with LLVM and run into a bug, we definitely want to know
	about it. This document describes what you can do to increase the odds of
	getting it fixed quickly.</p>

	<p>Basically you have to do two things at a minimum. First, decide whether the
	bug <a href="#crashers">crashes the compiler</a> (or an LLVM pass), or if the
	compiler is <a href="#miscompilations">miscompiling</a> the program. Based on
	what type of bug it is, follow the instructions in the linked section to narrow
	down the bug so that the person who fixes it will be able to find the problem
	more easily.</p>

	<p>Once you have a reduced test-case, go to <a
	href="http://llvm.org/bugs/enter_bug.cgi">the LLVM Bug Tracking
	System</a>, select the category in which the bug falls, and fill out the form
	with the necessary details. The bug description should contain the following
	information:</p>

	<ul>
	<li>All information necessary to reproduce the problem.</li>
	<li>The reduced test-case that triggers the bug.</li>
	<li>The location where you obtained LLVM (if not from our CVS
	repository).</li>
	</ul>

	<p>Thanks for helping us make LLVM better!</p>

	</div>

	<!-- *********************************************************************** -->
	<div class="doc_section">
	<a name="crashers">Crashing Bugs</a>
	</div>
	<!-- *********************************************************************** -->

	<div class="doc_text">

	<p>More often than not, bugs in the compiler cause it to crash - often due to an
	assertion failure of some sort. If you are running <tt><b>opt</b></tt> or
	<tt><b>analyze</b></tt> directly, and something crashes, jump to the section on
	<a href="#passes">bugs in LLVM passes</a>. Otherwise, the most important
	piece of the puzzle is to figure out if it is the GCC-based front-end that is
	buggy or if it's one of the LLVM tools that has problems.</p>

	<p>To figure out which program is crashing (the front-end,
	<tt><b>gccas</b></tt>, or <tt><b>gccld</b></tt>), run the
	<tt><b>llvm-gcc</b></tt> command line as you were when the crash occurred, but
	add a <tt>-v</tt> option to the command line. The compiler will print out a
	bunch of stuff, and should end with telling you that one of
	<tt><b>cc1</b>/<b>cc1plus</b></tt>, <tt><b>gccas</b></tt>, or
	<tt><b>gccld</b></tt> crashed.</p>

	<ul>

	<li>If <tt><b>cc1</b></tt> or <tt><b>cc1plus</b></tt> crashed, you found a
	problem with the front-end.
	Jump ahead to the section on <a href="#front-end">front-end bugs</a>.</li>

	<li>If <tt><b>gccas</b></tt> crashed, you found a bug in <a href="#gccas">one
	of the passes in <tt><b>gccas</b></tt></a>.</li>

	<li>If <tt><b>gccld</b></tt> crashed, you found a bug in <a href="#gccld">one
	of the passes in <tt><b>gccld</b></tt></a>.</li>

	<li>Otherwise, something really weird happened. Email the list with what you
	have at this point.</li>

	</ul>

	</div>

	<!-- ======================================================================= -->
	<div class="doc_subsection">
	<a name="front-end">Front-end bugs</a>
	</div>

	<div class="doc_text">

	<p>If the problem is in the front-end, you should re-run the same
	<tt>llvm-gcc</tt> command that resulted in the crash, but add the
	<tt>-save-temps</tt> option. The compiler will crash again, but it will leave
	behind a <tt><i>foo</i>.i</tt> file (containing preprocessed C source code) and
	possibly <tt><i>foo</i>.s</tt> (containing LLVM assembly code), for each
	compiled <tt><i>foo</i>.c</tt> file. Send us the <tt><i>foo</i>.i</tt> file,
	along with a brief description of the error it caused. A tool that might help
	you reduce a front-end testcase to a more manageable size is
	<a href="http://delta.tigris.org/">delta</a>.
	</p>

	</div>

	<!-- ======================================================================= -->
	<div class="doc_subsection">
	<a name="gccas">GCCAS bugs</a>
	</div>

	<div class="doc_text">

	<p>If you find that a bug crashes in the <tt><b>gccas</b></tt> stage of
	compilation, compile your test-case to a <tt>.s</tt> file with the
	<tt>-save-temps</tt> option to <tt><b>llvm-gcc</b></tt>. Then run:</p>

	<div class="doc_code">
	<p><tt><b>gccas</b> -debug-pass=Arguments < /dev/null -o - > /dev/null</tt></p>
	</div>

	<p>... which will print a list of arguments, indicating the list of passes that
	<tt><b>gccas</b></tt> runs. Once you have the input file and the list of
	passes, go to the section on <a href="#passes">debugging bugs in LLVM
	passes</a>.</p>

	</div>

	<!-- ======================================================================= -->
	<div class="doc_subsection">
	<a name="gccld">GCCLD bugs</a>
	</div>

	<div class="doc_text">

	<p>If you find that a bug crashes in the <tt><b>gccld</b></tt> stage of
	compilation, gather all of the <tt>.o</tt> bytecode files and libraries that are
	being linked together (the "<tt><b>llvm-gcc</b> -v</tt>" output should include
	the full list of objects linked). Then run:</p>

	<div class="doc_code">
	<p><tt><b>llvm-as</b> < /dev/null > null.bc<br>
	<b>gccld</b> -debug-pass=Arguments null.bc</tt>
	</p>
	</div>

	<p>... which will print a list of arguments, indicating the list of passes that
	<tt><b>gccld</b></tt> runs. Once you have the input files and the list of
	passes, go to the section on <a href="#passes">debugging bugs in LLVM
	passes</a>.</p>

	</div>

	<!-- ======================================================================= -->
	<div class="doc_subsection">
	<a name="passes">Bugs in LLVM passes</a>
	</div>

	<div class="doc_text">

	<p>At this point, you should have some number of LLVM assembly files or bytecode
	files and a list of passes which crash when run on the specified input. In
	order to reduce the list of passes (which is probably large) and the input to
	something tractable, use the <tt><b>bugpoint</b></tt> tool as follows:</p>

	<div class="doc_code">
	<p><tt><b>bugpoint</b> <input files> <list of passes></tt></p>
	</div>

	<p><tt><b>bugpoint</b></tt> will print a bunch of output as it reduces the
	test-case, but it should eventually print something like this:</p>

	<div class="doc_code">
	<p><tt>
	...<br>
	Emitted bytecode to 'bugpoint-reduced-simplified.bc'<br>
	<br>
	*** You can reproduce the problem with: opt bugpoint-reduced-simplified.bc -licm<br>
	</tt></p>
	</div>

	<p>Once you complete this, please send the LLVM bytecode file and the command
	line to reproduce the problem to the llvmbugs mailing list.</p>

	</div>

	<!-- *********************************************************************** -->
	<div class="doc_section">
	<a name="miscompilations">Miscompilations</a>
	</div>
	<!-- *********************************************************************** -->

	<div class="doc_text">

	<p>A miscompilation occurs when a pass does not correctly transform a program,
	thus producing errors that are only noticed during execution. This is different
	from producing invalid LLVM code (i.e., code not in SSA form, using values
	before defining them, etc.) which the verifier will check for after a pass
	finishes its run.</p>

	<p>If it looks like the LLVM compiler is miscompiling a program, the very first
	thing to check is to make sure it is not using undefined behavior. In
	particular, check to see if the program <a
	href="http://valgrind.kde.org/">valgrind</a>s clean, passes purify, or some
	other memory checker tool. Many of the "LLVM bugs" that we have chased down
	ended up being bugs in the program being compiled, not LLVM.</p>

	<p>Once you determine that the program itself is not buggy, you should choose
	which code generator you wish to compile the program with (e.g. C backend, the
	JIT, or LLC) and optionally a series of LLVM passes to run. For example:</p>

	<div class="doc_code">
	<p><tt>
	<b>bugpoint</b> -run-cbe [... optzn passes ...] file-to-test.bc --args -- [program arguments]</tt></p>
	</div>

	<p><tt>bugpoint</tt> will try to narrow down your list of passes to the one pass
	that causes an error, and simplify the bytecode file as much as it can to assist
	you. It will print a message letting you know how to reproduce the resulting
	error.</p>

	</div>

	<!-- *********************************************************************** -->
	<div class="doc_section">
	<a name="codegen">Incorrect code generation</a>
	</div>
	<!-- *********************************************************************** -->

	<div class="doc_text">

	<p>Similarly to debugging incorrect compilation by mis-behaving passes, you can
	debug incorrect code generation by either LLC or the JIT, using
	<tt>bugpoint</tt>. The process <tt>bugpoint</tt> follows in this case is to try
	to narrow the code down to a function that is miscompiled by one or the other
	method, but since for correctness, the entire program must be run,
	<tt>bugpoint</tt> will compile the code it deems to not be affected with the C
	Backend, and then link in the shared object it generates.</p>

	<p>To debug the JIT:</p>

	<div class="doc_code">
	<pre>
	bugpoint -run-jit -output=[correct output file] [bytecode file] \
	--tool-args -- [arguments to pass to lli] \
	--args -- [program arguments]
	</pre>
	</div>

	<p>Similarly, to debug the LLC, one would run:</p>

	<div class="doc_code">
	<pre>
	bugpoint -run-llc -output=[correct output file] [bytecode file] \
	--tool-args -- [arguments to pass to llc] \
	--args -- [program arguments]
	</pre>
	</div>

	<p><b>Special note:</b> if you are debugging MultiSource or SPEC tests that
	already exist in the <tt>llvm/test</tt> hierarchy, there is an easier way to
	debug the JIT, LLC, and CBE, using the pre-written Makefile targets, which
	will pass the program options specified in the Makefiles:</p>

	<div class="doc_code">
	<p><tt>
	cd llvm/test/../../program<br>
	make bugpoint-jit
	</tt></p>
	</div>

	<p>At the end of a successful <tt>bugpoint</tt> run, you will be presented
	with two bytecode files: a <em>safe</em> file which can be compiled with the C
	backend and the <em>test</em> file which either LLC or the JIT
	mis-codegenerates, and thus causes the error.</p>

	<p>To reproduce the error that <tt>bugpoint</tt> found, it is sufficient to do
	the following:</p>

	<ol>

	<li><p>Regenerate the shared object from the safe bytecode file:</p>

	<div class="doc_code">
	<p><tt>
	<b>llc</b> -march=c safe.bc -o safe.c<br>
	<b>gcc</b> -shared safe.c -o safe.so
	</tt></p>
	</div></li>

	<li><p>If debugging LLC, compile test bytecode native and link with the shared
	object:</p>

	<div class="doc_code">
	<p><tt>
	<b>llc</b> test.bc -o test.s -f<br>
	<b>gcc</b> test.s safe.so -o test.llc<br>
	./test.llc [program options]
	</tt></p>
	</div></li>

	<li><p>If debugging the JIT, load the shared object and supply the test
	bytecode:</p>

	<div class="doc_code">
	<p><tt><b>lli</b> -load=safe.so test.bc [program options]</tt></p>
	</div></li>

	</ol>

	</div>

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	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a>
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