Updated VC++ build system.

[oota-llvm.git] / docs / WritingAnLLVMPass.html

diff --git a/docs/WritingAnLLVMPass.html b/docs/WritingAnLLVMPass.html
index 8f2c7af1aa4e1186d0787122e884752d7d9f4e70..58bea1a0cad4cce106158fb54808e40c73d6a012 100644 (file)
--- a/docs/WritingAnLLVMPass.html
+++ b/docs/WritingAnLLVMPass.html
@@ -262,6 +262,14 @@ href="#passtype">later</a>, but for now, know that <a
 href="#FunctionPass"><tt>FunctionPass</tt></a>'s operate a function at a
 time.</p>
 
 href="#FunctionPass"><tt>FunctionPass</tt></a>'s operate a function at a
 time.</p>
 

+<div class="doc_code"><pre>
+     static char ID;
+     Hello() : FunctionPass((intptr_t)&amp;ID) {}
+</pre></div><p>
+
+<p> This declares pass identifier used by LLVM to identify pass. This allows LLVM to
+avoid using expensive C++ runtime information.</p>
+

 <div class="doc_code"><pre>
     <b>virtual bool</b> <a href="#runOnFunction">runOnFunction</a>(Function &amp;F) {
       llvm::cerr &lt;&lt; "<i>Hello: </i>" &lt;&lt; F.getName() &lt;&lt; "\n";
 <div class="doc_code"><pre>
     <b>virtual bool</b> <a href="#runOnFunction">runOnFunction</a>(Function &amp;F) {
       llvm::cerr &lt;&lt; "<i>Hello: </i>" &lt;&lt; F.getName() &lt;&lt; "\n";


@@ -276,6 +284,13 @@ href="#FunctionPass"><tt>FunctionPass</tt></a>.  This is where we are supposed
 to do our thing, so we just print out our message with the name of each
 function.</p>
 
 to do our thing, so we just print out our message with the name of each
 function.</p>
 

+<div class="doc_code"><pre>
+  char Hello::ID = 0;
+</pre></div>
+
+<p> We initialize pass ID here. LLVM uses ID's address to identify pass so 
+initialization value is not important.</p>
+

 <div class="doc_code"><pre>
   RegisterPass&lt;Hello&gt; X("<i>hello</i>", "<i>Hello World Pass</i>");
 }  <i>// end of anonymous namespace</i>
 <div class="doc_code"><pre>
   RegisterPass&lt;Hello&gt; X("<i>hello</i>", "<i>Hello World Pass</i>");
 }  <i>// end of anonymous namespace</i>


@@ -295,12 +310,17 @@ argument "<tt>hello</tt>", and a name "<tt>Hello World Pass</tt>".</p>
 
 <b>namespace</b> {
   <b>struct Hello</b> : <b>public</b> <a href="#FunctionPass">FunctionPass</a> {
 
 <b>namespace</b> {
   <b>struct Hello</b> : <b>public</b> <a href="#FunctionPass">FunctionPass</a> {

+    
+    static char ID;
+    Hello() : FunctionPass((intptr_t)&amp;ID) {}
+

     <b>virtual bool</b> <a href="#runOnFunction">runOnFunction</a>(Function &amp;F) {
       llvm::cerr &lt;&lt; "<i>Hello: </i>" &lt;&lt; F.getName() &lt;&lt; "\n";
       <b>return false</b>;
     }
   };
   
     <b>virtual bool</b> <a href="#runOnFunction">runOnFunction</a>(Function &amp;F) {
       llvm::cerr &lt;&lt; "<i>Hello: </i>" &lt;&lt; F.getName() &lt;&lt; "\n";
       <b>return false</b>;
     }
   };
   

+  char Hello::ID = 0;

   RegisterPass&lt;Hello&gt; X("<i>hello</i>", "<i>Hello World Pass</i>");
 }
 </pre></div>
   RegisterPass&lt;Hello&gt; X("<i>hello</i>", "<i>Hello World Pass</i>");
 }
 </pre></div>


@@ -328,8 +348,8 @@ use the <tt>opt</tt> tool to access it, once loaded.</p>
 
 <p>To test it, follow the example at the end of the <a
 href="GettingStarted.html">Getting Started Guide</a> to compile "Hello World" to
 
 <p>To test it, follow the example at the end of the <a
 href="GettingStarted.html">Getting Started Guide</a> to compile "Hello World" to

-LLVM.  We can now run the bytecode file (<tt>hello.bc</tt>) for the program
-through our transformation like this (or course, any bytecode file will
+LLVM.  We can now run the bitcode file (<tt>hello.bc</tt>) for the program
+through our transformation like this (or course, any bitcode file will

 work):</p>
 
 <div class="doc_code"><pre>
 work):</p>
 
 <div class="doc_code"><pre>


@@ -353,7 +373,7 @@ interesting way, we just throw away the result of <tt>opt</tt> (sending it to
 $ opt -load ../../../Debug/lib/Hello.so --help
 OVERVIEW: llvm .bc -&gt; .bc modular optimizer
 
 $ opt -load ../../../Debug/lib/Hello.so --help
 OVERVIEW: llvm .bc -&gt; .bc modular optimizer
 

-USAGE: opt [options] &lt;input bytecode&gt;
+USAGE: opt [options] &lt;input bitcode&gt;

 
 OPTIONS:
   Optimizations available:
 
 OPTIONS:
   Optimizations available:


@@ -388,7 +408,7 @@ Hello: main
   Total Execution Time: 0.02 seconds (0.0479059 wall clock)
 
    ---User Time---   --System Time--   --User+System--   ---Wall Time---  --- Pass Name ---
   Total Execution Time: 0.02 seconds (0.0479059 wall clock)
 
    ---User Time---   --System Time--   --User+System--   ---Wall Time---  --- Pass Name ---

-   0.0100 (100.0%)   0.0000 (  0.0%)   0.0100 ( 50.0%)   0.0402 ( 84.0%)  Bytecode Writer
+   0.0100 (100.0%)   0.0000 (  0.0%)   0.0100 ( 50.0%)   0.0402 ( 84.0%)  Bitcode Writer

    0.0000 (  0.0%)   0.0100 (100.0%)   0.0100 ( 50.0%)   0.0031 (  6.4%)  Dominator Set Construction
    0.0000 (  0.0%)   0.0000 (  0.0%)   0.0000 (  0.0%)   0.0013 (  2.7%)  Module Verifier
  <b>  0.0000 (  0.0%)   0.0000 (  0.0%)   0.0000 (  0.0%)   0.0033 (  6.9%)  Hello World Pass</b>
    0.0000 (  0.0%)   0.0100 (100.0%)   0.0100 ( 50.0%)   0.0031 (  6.4%)  Dominator Set Construction
    0.0000 (  0.0%)   0.0000 (  0.0%)   0.0000 (  0.0%)   0.0013 (  2.7%)  Module Verifier
  <b>  0.0000 (  0.0%)   0.0000 (  0.0%)   0.0000 (  0.0%)   0.0033 (  6.9%)  Hello World Pass</b>


@@ -466,7 +486,7 @@ refering to function bodies in no predictable order, or adding and removing
 functions.  Because nothing is known about the behavior of <tt>ModulePass</tt>
 subclasses, no optimization can be done for their execution. A module pass
 can use function level passes (e.g. dominators) using getAnalysis interface
 functions.  Because nothing is known about the behavior of <tt>ModulePass</tt>
 subclasses, no optimization can be done for their execution. A module pass
 can use function level passes (e.g. dominators) using getAnalysis interface

-<tt> getAnalysis<DominatorTree>(Function)</tt>. </p> 
+<tt> getAnalysis&lt;DominatorTree&gt;(Function)</tt>. </p> 

 
 <p>To write a correct <tt>ModulePass</tt> subclass, derive from
 <tt>ModulePass</tt> and overload the <tt>runOnModule</tt> method with the
 
 <p>To write a correct <tt>ModulePass</tt> subclass, derive from
 <tt>ModulePass</tt> and overload the <tt>runOnModule</tt> method with the


@@ -518,7 +538,7 @@ href="#BasicBlockPass">BasicBlockPass</a></tt>, you should derive from
 <li>... <em>not allowed</em> to modify any <tt>Function</tt>s that are not in
 the current SCC.</li>
 
 <li>... <em>not allowed</em> to modify any <tt>Function</tt>s that are not in
 the current SCC.</li>
 

-<li>... <em>allowed</em> to inspect any Function's other than those in the
+<li>... <em>not allowed</em> to inspect any Function's other than those in the

 current SCC and the direct callees of the SCC.</li>
 
 <li>... <em>required</em> to preserve the current CallGraph object, updating it
 current SCC and the direct callees of the SCC.</li>
 
 <li>... <em>required</em> to preserve the current CallGraph object, updating it


@@ -727,7 +747,7 @@ program, or false if they didn't. </p>
   <b>virtual bool</b> doInitialization(Loop *, LPPassManager &amp;LPM);
 </pre></div>
 
   <b>virtual bool</b> doInitialization(Loop *, LPPassManager &amp;LPM);
 </pre></div>
 

-The <tt>doInitialization</tt> method is designed to do simple initialization 
+<p>The <tt>doInitialization</tt> method is designed to do simple initialization 

 type of stuff that does not depend on the functions being processed.  The 
 <tt>doInitialization</tt> method call is not scheduled to overlap with any 
 other pass executions (thus it should be very fast). LPPassManager 
 type of stuff that does not depend on the functions being processed.  The 
 <tt>doInitialization</tt> method call is not scheduled to overlap with any 
 other pass executions (thus it should be very fast). LPPassManager 


@@ -1140,7 +1160,7 @@ For example:</p>
    }
 </pre></div>
 
    }
 </pre></div>
 

-In above example, runOnFunction for DominatorTree is called by pass manager
+<p>In above example, runOnFunction for DominatorTree is called by pass manager

 before returning a reference to the desired pass.</p>
 
 <p>
 before returning a reference to the desired pass.</p>
 
 <p>


@@ -1289,8 +1309,9 @@ no problem.</p>
 <p>Here we show how the default implementation is specified (using the extra
 argument to the <tt>RegisterAnalysisGroup</tt> template).  There must be exactly
 one default implementation available at all times for an Analysis Group to be
 <p>Here we show how the default implementation is specified (using the extra
 argument to the <tt>RegisterAnalysisGroup</tt> template).  There must be exactly
 one default implementation available at all times for an Analysis Group to be

-used.  Here we declare that the <tt><a
-href="http://llvm.org/doxygen/structBasicAliasAnalysis.html">BasicAliasAnalysis</a></tt>
+used.  Only default implementation can derive from <tt>ImmutablePass</tt>. 
+Here we declare that the
+ <tt><a href="http://llvm.org/doxygen/structBasicAliasAnalysis.html">BasicAliasAnalysis</a></tt>

 pass is the default implementation for the interface.</p>
 
 </div>
 pass is the default implementation for the interface.</p>
 
 </div>


@@ -1393,8 +1414,8 @@ Module Pass Manager
     Module Verifier
 --  Dominator Set Construction
 --  Module Verifier
     Module Verifier
 --  Dominator Set Construction
 --  Module Verifier

-  Bytecode Writer
---Bytecode Writer
+  Bitcode Writer
+--Bitcode Writer

 </pre></div>
 
 <p>This output shows us when passes are constructed and when the analysis
 </pre></div>
 
 <p>This output shows us when passes are constructed and when the analysis


@@ -1434,8 +1455,8 @@ Module Pass Manager
     Module Verifier
 --  Dominator Set Construction
 --  Module Verifier
     Module Verifier
 --  Dominator Set Construction
 --  Module Verifier

-  Bytecode Writer
---Bytecode Writer
+  Bitcode Writer
+--Bitcode Writer

 Hello: __main
 Hello: puts
 Hello: main
 Hello: __main
 Hello: puts
 Hello: main


@@ -1474,8 +1495,8 @@ Module Pass Manager
     Module Verifier
 --  Dominator Set Construction
 --  Module Verifier
     Module Verifier
 --  Dominator Set Construction
 --  Module Verifier

-  Bytecode Writer
---Bytecode Writer
+  Bitcode Writer
+--Bitcode Writer

 Hello: __main
 Hello: puts
 Hello: main
 Hello: __main
 Hello: puts
 Hello: main


@@ -1778,6 +1799,8 @@ places (for global resources).  Although this is a simple extension, we simply
 haven't had time (or multiprocessor machines, thus a reason) to implement this.
 Despite that, we have kept the LLVM passes SMP ready, and you should too.</p>
 
 haven't had time (or multiprocessor machines, thus a reason) to implement this.
 Despite that, we have kept the LLVM passes SMP ready, and you should too.</p>
 

+</div>
+

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