<li><a href="#general">General Information</a>
<ul>
<li><a href="#stl">The C++ Standard Template Library</a>
+<!--
+ <li>The <tt>-time-passes</tt> option
+ <li>How to use the LLVM Makefile system
+ <li>How to write a regression test
+-->
+ </ul>
+ <li><a href="#apis">Important and useful LLVM APIs</a>
+ <ul>
<li><a href="#isa">The <tt>isa<></tt>, <tt>cast<></tt> and
<tt>dyn_cast<></tt> templates</a>
+ <li><a href="#DEBUG">The <tt>DEBUG()</tt> macro &
+ <tt>-debug</tt> option</a>
+ <ul>
+ <li><a href="#DEBUG_TYPE">Fine grained debug info with
+ <tt>DEBUG_TYPE</tt> and the <tt>-debug-only</tt> option</a/>
+ </ul>
+ <li><a href="#Statistic">The <tt>Statistic</tt> template &
+ <tt>-stats</tt> option</a>
+<!--
+ <li>The <tt>InstVisitor</tt> template
+ <li>The general graph API
+-->
</ul>
<li><a href="#common">Helpful Hints for Common Operations</a>
<ul>
<li>
<li>
</ul>
- <li>Useful LLVM APIs
- <ul>
- <li>The general graph API
- <li>The <tt>InstVisitor</tt> template
- <li>The DEBUG() macro
- <li>The <tt>Statistic</tt> template
--->
- </ul>
-<!--
- <li>Useful related topics
- <ul>
- <li>The <tt>-time-passes</tt> option
- <li>How to use the LLVM Makefile system
- <li>How to write a regression test
- <li>
- </ul>
-->
</ul>
<li><a href="#coreclasses">The Core LLVM Class Hierarchy Reference</a>
Here are some useful links:<p>
<ol>
-<li><a href="http://www.dinkumware.com/htm_cpl/index.html">Dinkumware C++
+<li><a href="http://www.dinkumware.com/refxcpp.html">Dinkumware C++
Library reference</a> - an excellent reference for the STL and other parts of
-the standard C++ library.<br>
+the standard C++ library.
+
+<li><a href="http://www.tempest-sw.com/cpp/">C++ In a Nutshell</a> - This is an
+O'Reilly book in the making. It has a decent <a
+href="http://www.tempest-sw.com/cpp/ch13-libref.html">Standard Library
+Reference</a> that rivals Dinkumware's, and is actually free until the book is
+published.
<li><a href="http://www.parashift.com/c++-faq-lite/">C++ Frequently Asked
Questions</a>
to write maintainable code more than where to put your curly braces.<p>
+<!-- *********************************************************************** -->
+</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
+<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
+<a name="apis">Important and useful LLVM APIs
+</b></font></td></tr></table><ul>
+<!-- *********************************************************************** -->
+
+Here we highlight some LLVM APIs that are generally useful and good to know
+about when writing transformations.<p>
+
<!-- ======================================================================= -->
</ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0>
<tr><td> </td><td width="100%">
return true;
<i>// Otherwise, it must be an instruction...</i>
- return !L->contains(cast<<a href="#Instruction">Instruction</a>>(V)->getParent());
+ return !L->contains(cast<<a href="#Instruction">Instruction</a>>(V)->getParent());
</pre><p>
Note that you should <b>not</b> use an <tt>isa<></tt> test followed by a
<pre>
<i>// Loop over all of the phi nodes in a basic block</i>
- BasicBlock::iterator BBI = BB->begin();
- for (; <a href="#PhiNode">PHINode</a> *PN = dyn_cast<<a href="#PHINode">PHINode</a>>(&*BBI); ++BBI)
+ BasicBlock::iterator BBI = BB->begin();
+ for (; <a href="#PhiNode">PHINode</a> *PN = dyn_cast<<a href="#PHINode">PHINode</a>>(BBI); ++BBI)
cerr << *PN;
</pre><p>
lots of examples in the LLVM source base.<p>
+<!-- ======================================================================= -->
+</ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0>
+<tr><td> </td><td width="100%">
+<font color="#EEEEFF" face="Georgia,Palatino"><b>
+<a name="DEBUG">The <tt>DEBUG()</tt> macro & <tt>-debug</tt> option</a>
+</b></font></td></tr></table><ul>
+
+Often when working on your pass you will put a bunch of debugging printouts and
+other code into your pass. After you get it working, you want to remove
+it... but you may need it again in the future (to work out new bugs that you run
+across).<p>
+
+Naturally, because of this, you don't want to delete the debug printouts, but
+you don't want them to always be noisy. A standard compromise is to comment
+them out, allowing you to enable them if you need them in the future.<p>
+
+The "<tt><a href="/doxygen/Debug_8h-source.html">Support/Debug.h</a></tt>" file
+provides a macro named <tt>DEBUG()</tt> that is a much nicer solution to this
+problem. Basically, you can put arbitrary code into the argument of the
+<tt>DEBUG</tt> macro, and it is only executed if '<tt>opt</tt>' (or any other
+tool) is run with the '<tt>-debug</tt>' command line argument:
+
+<pre>
+ ...
+ DEBUG(std::cerr << "I am here!\n");
+ ...
+</pre><p>
+
+Then you can run your pass like this:<p>
+
+<pre>
+ $ opt < a.bc > /dev/null -mypass
+ <no output>
+ $ opt < a.bc > /dev/null -mypass -debug
+ I am here!
+ $
+</pre><p>
+
+Using the <tt>DEBUG()</tt> macro instead of a home-brewed solution allows you to
+now have to create "yet another" command line option for the debug output for
+your pass. Note that <tt>DEBUG()</tt> macros are disabled for optimized builds,
+so they do not cause a performance impact at all (for the same reason, they
+should also not contain side-effects!).<p>
+
+One additional nice thing about the <tt>DEBUG()</tt> macro is that you can
+enable or disable it directly in gdb. Just use "<tt>set DebugFlag=0</tt>" or
+"<tt>set DebugFlag=1</tt>" from the gdb if the program is running. If the
+program hasn't been started yet, you can always just run it with
+<tt>-debug</tt>.<p>
+
+<!-- _______________________________________________________________________ -->
+</ul><h4><a name="DEBUG_TYPE"><hr size=0>Fine grained debug info with
+ <tt>DEBUG_TYPE()</tt> and the <tt>-debug-only</tt> option</a> </h4><ul>
+
+Sometimes you may find yourself in a situation where enabling <tt>-debug</tt>
+just turns on <b>too much</b> information (such as when working on the code
+generator). If you want to enable debug information with more fine-grained
+control, you define the <tt>DEBUG_TYPE</tt> macro and the <tt>-debug</tt> only
+option as follows:<p>
+
+<pre>
+ ...
+ DEBUG(std::cerr << "No debug type\n");
+ #undef DEBUG_TYPE
+ #define DEBUG_TYPE "foo"
+ DEBUG(std::cerr << "'foo' debug type\n");
+ #undef DEBUG_TYPE
+ #define DEBUG_TYPE "bar"
+ DEBUG(std::cerr << "'bar' debug type\n");
+ #undef DEBUG_TYPE
+ #define DEBUG_TYPE ""
+ DEBUG(std::cerr << "No debug type (2)\n");
+ ...
+</pre><p>
+
+Then you can run your pass like this:<p>
+
+<pre>
+ $ opt < a.bc > /dev/null -mypass
+ <no output>
+ $ opt < a.bc > /dev/null -mypass -debug
+ No debug type
+ 'foo' debug type
+ 'bar' debug type
+ No debug type (2)
+ $ opt < a.bc > /dev/null -mypass -debug-only=foo
+ 'foo' debug type
+ $ opt < a.bc > /dev/null -mypass -debug-only=bar
+ 'bar' debug type
+ $
+</pre><p>
+
+Of course, in practice, you should only set <tt>DEBUG_TYPE</tt> at the top of a
+file, to specify the debug type for the entire module (if you do this before you
+<tt>#include "Support/Debug.h"</tt>, you don't have to insert the ugly
+<tt>#undef</tt>'s). Also, you should use names more meaningful that "foo" and
+"bar", because there is no system in place to ensure that names do not conflict:
+if two different modules use the same string, they will all be turned on when
+the name is specified. This allows all, say, instruction scheduling, debug
+information to be enabled with <tt>-debug-type=InstrSched</tt>, even if the
+source lives in multiple files.<p>
+
+
+<!-- ======================================================================= -->
+</ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0>
+<tr><td> </td><td width="100%">
+<font color="#EEEEFF" face="Georgia,Palatino"><b>
+<a name="Statistic">The <tt>Statistic</tt> template & <tt>-stats</tt>
+option</a>
+</b></font></td></tr></table><ul>
+
+The "<tt><a
+href="/doxygen/Statistic_8h-source.html">Support/Statistic.h</a></tt>"
+file provides a template named <tt>Statistic</tt> that is used as a unified way
+to keeping track of what the LLVM compiler is doing and how effective various
+optimizations are. It is useful to see what optimizations are contributing to
+making a particular program run faster.<p>
+
+Often you may run your pass on some big program, and you're interested to see
+how many times it makes a certain transformation. Although you can do this with
+hand inspection, or some ad-hoc method, this is a real pain and not very useful
+for big programs. Using the <tt>Statistic</tt> template makes it very easy to
+keep track of this information, and the calculated information is presented in a
+uniform manner with the rest of the passes being executed.<p>
+
+There are many examples of <tt>Statistic</tt> users, but this basics of using it
+are as follows:<p>
+
+<ol>
+<li>Define your statistic like this:<p>
+
+<pre>
+static Statistic<> NumXForms("mypassname", "The # of times I did stuff");
+</pre><p>
+
+The <tt>Statistic</tt> template can emulate just about any data-type, but if you
+do not specify a template argument, it defaults to acting like an unsigned int
+counter (this is usually what you want).<p>
+
+<li>Whenever you make a transformation, bump the counter:<p>
+
+<pre>
+ ++NumXForms; // I did stuff
+</pre><p>
+
+</ol><p>
+
+That's all you have to do. To get '<tt>opt</tt>' to print out the statistics
+gathered, use the '<tt>-stats</tt>' option:<p>
+
+<pre>
+ $ opt -stats -mypassname < program.bc > /dev/null
+ ... statistic output ...
+</pre><p>
+
+When running <tt>gccas</tt> on a C file from the SPEC benchmark suite, it gives
+a report that looks like this:<p>
+
+<pre>
+ 7646 bytecodewriter - Number of normal instructions
+ 725 bytecodewriter - Number of oversized instructions
+ 129996 bytecodewriter - Number of bytecode bytes written
+ 2817 raise - Number of insts DCEd or constprop'd
+ 3213 raise - Number of cast-of-self removed
+ 5046 raise - Number of expression trees converted
+ 75 raise - Number of other getelementptr's formed
+ 138 raise - Number of load/store peepholes
+ 42 deadtypeelim - Number of unused typenames removed from symtab
+ 392 funcresolve - Number of varargs functions resolved
+ 27 globaldce - Number of global variables removed
+ 2 adce - Number of basic blocks removed
+ 134 cee - Number of branches revectored
+ 49 cee - Number of setcc instruction eliminated
+ 532 gcse - Number of loads removed
+ 2919 gcse - Number of instructions removed
+ 86 indvars - Number of cannonical indvars added
+ 87 indvars - Number of aux indvars removed
+ 25 instcombine - Number of dead inst eliminate
+ 434 instcombine - Number of insts combined
+ 248 licm - Number of load insts hoisted
+ 1298 licm - Number of insts hoisted to a loop pre-header
+ 3 licm - Number of insts hoisted to multiple loop preds (bad, no loop pre-header)
+ 75 mem2reg - Number of alloca's promoted
+ 1444 cfgsimplify - Number of blocks simplified
+</pre><p>
+
+Obviously, with so many optimizations, having a unified framework for this stuff
+is very nice. Making your pass fit well into the framework makes it more
+maintainable and useful.<p>
+
<!-- *********************************************************************** -->
</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
<a name="common">Helpful Hints for Common Operations
-</b></font></td></tr></table><ul>
-<!-- *********************************************************************** -->
+</b></font></td></tr></table><ul> <!--
+*********************************************************************** -->
This section describes how to perform some very simple transformations of LLVM
code. This is meant to give examples of common idioms used, showing the
<pre>
// func is a pointer to a Function instance
- for(Function::iterator i = func->begin(), e = func->end(); i != e; ++i) {
+ for (Function::iterator i = func->begin(), e = func->end(); i != e; ++i) {
// print out the name of the basic block if it has one, and then the
// number of instructions that it contains
Note that i can be used as if it were a pointer for the purposes of
invoking member functions of the <tt>Instruction</tt> class. This is
because the indirection operator is overloaded for the iterator
-classes. In the above code, the expression <tt>i->size()</tt> is
+classes. In the above code, the expression <tt>i->size()</tt> is
exactly equivalent to <tt>(*i).size()</tt> just like you'd expect.
<!-- _______________________________________________________________________ -->
<pre>
// blk is a pointer to a BasicBlock instance
- for(BasicBlock::iterator i = blk->begin(), e = blk->end(); i != e; ++i)
+ for (BasicBlock::iterator i = blk->begin(), e = blk->end(); i != e; ++i)
// the next statement works since operator<<(ostream&,...)
// is overloaded for Instruction&
cerr << *i << "\n";
#include "<a href="/doxygen/InstIterator_8h-source.html">llvm/Support/InstIterator.h</a>"
...
// Suppose F is a ptr to a function
-for(inst_iterator i = inst_begin(F), e = inst_end(F); i != e; ++i)
+for (inst_iterator i = inst_begin(F), e = inst_end(F); i != e; ++i)
cerr << **i << "\n";
</pre>
<pre>Instruction* pinst = i;</pre>
-<b>Caveat emptor</b>: The above syntax works <i>only</i> when you're <i>not</i>
-working with <tt>dyn_cast</tt>. The template definition of <tt><a
-href="#isa">dyn_cast</a></tt> isn't implemented to handle this yet, so you'll
-still need the following in order for things to work properly:
-
-<pre>
-BasicBlock::iterator bbi = ...;
-<a href="#BranchInst">BranchInst</a>* b = <a href="#isa">dyn_cast</a><<a href="#BranchInst">BranchInst</a>>(&*bbi);
-</pre>
-
It's also possible to turn a class pointer into the corresponding
iterator. Usually, this conversion is quite inexpensive. The
following code snippet illustrates use of the conversion constructors
void printNextInstruction(Instruction* inst) {
BasicBlock::iterator it(inst);
++it; // after this line, it refers to the instruction after *inst.
- if(it != inst->getParent()->end()) cerr << *it << "\n";
+ if (it != inst->getParent()->end()) cerr << *it << "\n";
}
</pre>
Of course, this example is strictly pedagogical, because it'd be much
Say that you're writing a FunctionPass and would like to count all the
locations in the entire module (that is, across every
-<tt>Function</tt>) where a certain function (i.e. some
-<tt>Function</tt>*) already in scope. As you'll learn later, you may
+<tt>Function</tt>) where a certain function (i.e., some
+<tt>Function</tt>*) is already in scope. As you'll learn later, you may
want to use an <tt>InstVisitor</tt> to accomplish this in a much more
straightforward manner, but this example will allow us to explore how
you'd do it if you didn't have <tt>InstVisitor</tt> around. In
for each Function f in the Module
for each BasicBlock b in f
for each Instruction i in b
- if(i is a CallInst and calls the given function)
+ if (i is a CallInst and calls the given function)
increment callCounter
</pre>
OurFunctionPass(): callCounter(0) { }
virtual runOnFunction(Function& F) {
- for(Function::iterator b = F.begin(), be = F.end(); b != be; ++b) {
- for(BasicBlock::iterator i = b->begin(); ie = b->end(); i != ie; ++i) {
+ for (Function::iterator b = F.begin(), be = F.end(); b != be; ++b) {
+ for (BasicBlock::iterator i = b->begin(); ie = b->end(); i != ie; ++i) {
if (<a href="#CallInst">CallInst</a>* callInst = <a href="#isa">dyn_cast</a><<a href="#CallInst">CallInst</a>>(&*i)) {
// we know we've encountered a call instruction, so we
// need to determine if it's a call to the
// function pointed to by m_func or not.
- if(callInst->getCalledFunction() == targetFunc)
+ if (callInst->getCalledFunction() == targetFunc)
++callCounter;
}
}
<pre>
Function* F = ...;
-for(Value::use_iterator i = F->use_begin(), e = F->use_end(); i != e; ++i) {
- if(Instruction* Inst = dyn_cast<Instruction>(*i)) {
+for (Value::use_iterator i = F->use_begin(), e = F->use_end(); i != e; ++i) {
+ if (Instruction *Inst = dyn_cast<Instruction>(*i)) {
cerr << "F is used in instruction:\n";
cerr << *Inst << "\n";
}
<pre>
Instruction* pi = ...;
-for(User::op_iterator i = pi->op_begin(), e = pi->op_end(); i != e; ++i) {
+for (User::op_iterator i = pi->op_begin(), e = pi->op_end(); i != e; ++i) {
Value* v = *i;
...
}
we wish to insert before <tt>*pi</tt>, we do the following:
<pre>
-BasicBlock* pb = ...;
-Instruction* pi = ...;
-Instruction* newInst = new Instruction(...);
-pb->getInstList().insert(pi, newInst); // inserts newInst before pi in pb
+ BasicBlock *pb = ...;
+ Instruction *pi = ...;
+ Instruction *newInst = new Instruction(...);
+ pb->getInstList().insert(pi, newInst); // inserts newInst before pi in pb
</pre>
</p>
Thus, we could have accomplished the same thing as the above code
without being given a <tt>BasicBlock</tt> by doing:
<pre>
-Instruction* pi = ...;
-Instruction* newInst = new Instruction(...);
-pi->getParent()->getInstList().insert(pi, newInst);
+ Instruction *pi = ...;
+ Instruction *newInst = new Instruction(...);
+ pi->getParent()->getInstList().insert(pi, newInst);
</pre>
In fact, this sequence of steps occurs so frequently that the
<tt>Instruction</tt> class and <tt>Instruction</tt>-derived classes
<p><i>Replacing individual instructions</i></p>
<p>
Including "<a
-href="/doxygen/BasicBlockUtils_8h-source.html">llvm/Transforms/Utils/BasicBlockUtils.h
-</a>" permits use of two very useful replace functions:
+href="/doxygen/BasicBlockUtils_8h-source.html">llvm/Transforms/Utils/BasicBlockUtils.h</a>" permits use of two very useful replace functions:
<tt>ReplaceInstWithValue</tt> and <tt>ReplaceInstWithInst</tt>.
<ul>
<pre>
AllocaInst* instToReplace = ...;
-ReplaceInstWithValue(*instToReplace->getParent(), instToReplace,
+BasicBlock::iterator ii(instToReplace);
+ReplaceInstWithValue(instToReplace->getParent()->getInstList(), ii,
Constant::getNullValue(PointerType::get(Type::IntTy)));
</pre>
<pre>
AllocaInst* instToReplace = ...;
-ReplaceInstWithInst(*instToReplace->getParent(), instToReplace,
- new AllocaInst(Type::IntTy, 0, "ptrToReplacedInt");
+BasicBlock::iterator ii(instToReplace);
+ReplaceInstWithInst(instToReplace->getParent()->getInstList(), ii,
+ new AllocaInst(Type::IntTy, 0, "ptrToReplacedInt"));
</pre>
</ul>
Returns the <a href="#BasicBlock"><tt>BasicBlock</tt></a> that this
<tt>Instruction</tt> is embedded into.<p>
-<li><tt>bool
hasSideEffects()</tt><p>
+<li><tt>bool
mayWriteToMemory()</tt><p>
-Returns true if the instruction has side effects, i.e. it is a <tt>call</tt>,
+Returns true if the instruction writes to memory, i.e. it is a <tt>call</tt>,
<tt>free</tt>, <tt>invoke</tt>, or <tt>store</tt>.<p>
<li><tt>unsigned getOpcode()</tt><p>
\end{itemize}
<li>LoadInst, StoreInst, GetElemPtrInst : These subclasses represent load, store and getelementptr instructions in LLVM.
\begin{itemize}
- <li><tt>Value * getPointerOperand ()</tt>: Returns the Pointer Operand which is typically the 0th operand.
+ <li><tt>Value * getPointerOperand()</tt>: Returns the Pointer Operand which is typically the 0th operand.
\end{itemize}
<li>BranchInst : This is a subclass of TerminatorInst and defines the interface for conditional and unconditional branches in LLVM.
\begin{itemize}
<li><tt>Function::BasicBlockListType &getBasicBlockList()</tt><p>
Returns the list of <a href="#BasicBlock"><tt>BasicBlock</tt></a>s. This is
-neccesary to use when you need to update the list or perform a complex action
+necessary to use when you need to update the list or perform a complex action
that doesn't have a forwarding method.<p>
<li><tt>Function::ArgumentListType &getArgumentList()</tt><p>
Returns the list of <a href="#Argument"><tt>Argument</tt></a>s. This is
-neccesary to use when you need to update the list or perform a complex action
+necessary to use when you need to update the list or perform a complex action
that doesn't have a forwarding method.<p>
and returns the return type of the function, or the <a
href="#FunctionType"><tt>FunctionType</tt></a> of the actual function.<p>
-
-<li><tt>bool hasSymbolTable() const</tt><p>
-
-Return true if the <tt>Function</tt> has a symbol table allocated to it and if
-there is at least one entry in it.<p>
-
<li><tt><a href="#SymbolTable">SymbolTable</a> *getSymbolTable()</tt><p>
Return a pointer to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for this
-<tt>Function</tt> or a null pointer if one has not been allocated (because there
-are no named values in the function).<p>
-
-<li><tt><a href="#SymbolTable">SymbolTable</a> *getSymbolTableSure()</tt><p>
-
-Return a pointer to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for this
-<tt>Function</tt> or allocate a new <a
-href="#SymbolTable"><tt>SymbolTable</tt></a> if one is not already around. This
-should only be used when adding elements to the <a
-href="#SymbolTable"><tt>SymbolTable</tt></a>, so that empty symbol tables are
-not left laying around.<p>
+<tt>Function</tt>.<p>
<li><tt>Module::FunctionListType &getFunctionList()</tt><p>
Returns the list of <a href="#Function"><tt>Function</tt></a>s. This is
-neccesary to use when you need to update the list or perform a complex action
+necessary to use when you need to update the list or perform a complex action
that doesn't have a forwarding method.<p>
<!-- Global Variable -->
<li><tt>Module::GlobalListType &getGlobalList()</tt><p>
Returns the list of <a href="#GlobalVariable"><tt>GlobalVariable</tt></a>s.
-This is neccesary to use when you need to update the list or perform a complex
+This is necessary to use when you need to update the list or perform a complex
action that doesn't have a forwarding method.<p>
<!-- Symbol table stuff -->
<hr size=0>
-<li><tt>bool hasSymbolTable() const</tt><p>
-
-Return true if the <tt>Module</tt> has a symbol table allocated to it and if
-there is at least one entry in it.<p>
-
<li><tt><a href="#SymbolTable">SymbolTable</a> *getSymbolTable()</tt><p>
-Return a pointer to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for this
-<tt>Module</tt> or a null pointer if one has not been allocated (because there
-are no named values in the function).<p>
-
-<li><tt><a href="#SymbolTable">SymbolTable</a> *getSymbolTableSure()</tt><p>
-
-Return a pointer to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for this
-<tt>Module</tt> or allocate a new <a
-href="#SymbolTable"><tt>SymbolTable</tt></a> if one is not already around. This
-should only be used when adding elements to the <a
-href="#SymbolTable"><tt>SymbolTable</tt></a>, so that empty symbol tables are
-not left laying around.<p>
+Return a reference to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for
+this <tt>Module</tt>.<p>
<!-- Convenience methods -->
<li><tt>bool isConstantExpr()</tt>: Returns true if it is a ConstantExpr
+<hr>
+Important Subclasses of Constant<p>
-
-\subsection{Important Subclasses of Constant}
-\begin{itemize}
+<ul>
<li>ConstantSInt : This subclass of Constant represents a signed integer constant.
- \begin{itemize}
- <li><tt>int64_t getValue () const</tt>: Returns the underlying value of this constant.
- \end{itemize}
+<ul>
+ <li><tt>int64_t getValue() const</tt>: Returns the underlying value of this constant.
+</ul>
<li>ConstantUInt : This class represents an unsigned integer.
- \begin{itemize}
- <li><tt>uint64_t getValue () const</tt>: Returns the underlying value of this constant.
- \end{itemize}
+<ul>
+ <li><tt>uint64_t getValue() const</tt>: Returns the underlying value of this constant.
+</ul>
<li>ConstantFP : This class represents a floating point constant.
- \begin{itemize}
- <li><tt>double getValue () const</tt>: Returns the underlying value of this constant.
- \end{itemize}
+<ul>
+ <li><tt>double getValue() const</tt>: Returns the underlying value of this constant.
+</ul>
<li>ConstantBool : This represents a boolean constant.
- \begin{itemize}
- <li><tt>bool getValue () const</tt>: Returns the underlying value of this constant.
- \end{itemize}
+<ul>
+ <li><tt>bool getValue() const</tt>: Returns the underlying value of this constant.
+</ul>
<li>ConstantArray : This represents a constant array.
- \begin{itemize}
- <li><tt>const std::vector<Use> &getValues() const</tt>: Returns a Vecotr of component constants that makeup this array.
- \end{itemize}
+<ul>
+ <li><tt>const std::vector<Use> &getValues() const</tt>: Returns a Vecotr of component constants that makeup this array.
+</ul>
<li>ConstantStruct : This represents a constant struct.
- \begin{itemize}
- <li><tt>const std::vector<Use> &getValues() const</tt>: Returns a Vecotr of component constants that makeup this array.
- \end{itemize}
+<ul>
+ <li><tt>const std::vector<Use> &getValues() const</tt>: Returns a Vecotr of component constants that makeup this array.
+</ul>
<li>ConstantPointerRef : This represents a constant pointer value that is initialized to point to a global value, which lies at a constant fixed address.
- \begin{itemize}
+<ul>
<li><tt>GlobalValue *getValue()</tt>: Returns the global value to which this pointer is pointing to.
- \end{itemize}
-\end{itemize}
+</ul>
+</ul>
<!-- ======================================================================= -->
<!-- _______________________________________________________________________ -->
</ul><h4><a name="m_Value"><hr size=0>Important Public Methods</h4><ul>
-<li><tt>PrimitiveID getPrimitiveID () const</tt>: Returns the base type of the type.
-<li><tt> bool isSigned () const</tt>: Returns whether an integral numeric type is signed. This is true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for Float and Double.
-<li><tt>bool isUnsigned () const</tt>: Returns whether a numeric type is unsigned. This is not quite the complement of isSigned... nonnumeric types return false as they do with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and ULongTy.
-<li><tt> bool isInteger () const</tt>: Equilivent to isSigned() || isUnsigned(), but with only a single virtual function invocation.
-<li><tt>bool isIntegral () const</tt>: Returns true if this is an integral type, which is either Bool type or one of the Integer types.
+<li><tt>PrimitiveID getPrimitiveID() const</tt>: Returns the base type of the type.
+<li><tt> bool isSigned() const</tt>: Returns whether an integral numeric type is signed. This is true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for Float and Double.
+<li><tt>bool isUnsigned() const</tt>: Returns whether a numeric type is unsigned. This is not quite the complement of isSigned... nonnumeric types return false as they do with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and ULongTy.
+<li><tt> bool isInteger() const</tt>: Equilivent to isSigned() || isUnsigned(), but with only a single virtual function invocation.
+<li><tt>bool isIntegral() const</tt>: Returns true if this is an integral type, which is either Bool type or one of the Integer types.
-<li><tt>bool isFloatingPoint ()</tt>: Return true if this is one of the two floating point types.
-<li><tt>bool isRecursive () const</tt>: Returns rue if the type graph contains a cycle.
+<li><tt>bool isFloatingPoint()</tt>: Return true if this is one of the two floating point types.
+<li><tt>bool isRecursive() const</tt>: Returns rue if the type graph contains a cycle.
<li><tt>isLosslesslyConvertableTo (const Type *Ty) const</tt>: Return true if this type can be converted to 'Ty' without any reinterpretation of bits. For example, uint to int.
-<li><tt>bool isPrimitiveType () const</tt>: Returns true if it is a primitive type.
-<li><tt>bool isDerivedType () const</tt>: Returns true if it is a derived type.
+<li><tt>bool isPrimitiveType() const</tt>: Returns true if it is a primitive type.
+<li><tt>bool isDerivedType() const</tt>: Returns true if it is a derived type.
<li><tt>const Type * getContainedType (unsigned i) const</tt>:
This method is used to implement the type iterator. For derived types, this returns the types 'contained' in the derived type, returning 0 when 'i' becomes invalid. This allows the user to iterate over the types in a struct, for example, really easily.
-<li><tt>unsigned getNumContainedTypes () const</tt>: Return the number of types in the derived type.
+<li><tt>unsigned getNumContainedTypes() const</tt>: Return the number of types in the derived type.
+<p>
+<hr>
+Derived Types<p>
-\subsection{Derived Types}
-\begin{itemize}
+<ul>
<li>SequentialType : This is subclassed by ArrayType and PointerType
- \begin{itemize}
- <li><tt>const Type * getElementType () const</tt>: Returns the type of each of the elements in the sequential type.
- \end{itemize}
+<ul>
+ <li><tt>const Type * getElementType() const</tt>: Returns the type of each of the elements in the sequential type.
+</ul>
<li>ArrayType : This is a subclass of SequentialType and defines interface for array types.
- \begin{itemize}
- <li><tt>unsigned getNumElements () const</tt>: Returns the number of elements in the array.
- \end{itemize}
+<ul>
+ <li><tt>unsigned getNumElements() const</tt>: Returns the number of elements in the array.
+</ul>
<li>PointerType : Subclass of SequentialType for pointer types.
<li>StructType : subclass of DerivedTypes for struct types
<li>FunctionType : subclass of DerivedTypes for function types.
- \begin{itemize}
+
+<ul>
- <li><tt>bool isVarArg () const</tt>: Returns true if its a vararg function
- <li><tt> const Type * getReturnType () const</tt>: Returns the return type of the function.
- <li><tt> const ParamTypes &getParamTypes () const</tt>: Returns a vector of parameter types.
+ <li><tt>bool isVarArg() const</tt>: Returns true if its a vararg function
+ <li><tt> const Type * getReturnType() const</tt>: Returns the return type of the function.
+ <li><tt> const ParamTypes &getParamTypes() const</tt>: Returns a vector of parameter types.
<li><tt>const Type * getParamType (unsigned i)</tt>: Returns the type of the ith parameter.
- <li><tt> const unsigned getNumParams () const</tt>: Returns the number of formal parameters.
- \end{itemize}
-\end{itemize}
+ <li><tt> const unsigned getNumParams() const</tt>: Returns the number of formal parameters.
+</ul>
+</ul>
<a href="mailto:sabre@nondot.org">Chris Lattner</a></address>
<!-- Created: Tue Aug 6 15:00:33 CDT 2002 -->
<!-- hhmts start -->
-Last modified: Tue Sep 17 22:16:24 CDT 2002
+Last modified: Tue Aug 5 17:53:43 CDT 2003
<!-- hhmts end -->
</font></body></html>
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