<html>
<head>
<title>LLVM Assembly Language Reference Manual</title>
+ <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+ <meta name="author" content="Chris Lattner">
+ <meta name="description"
+ content="LLVM Assembly Language Reference Manual.">
<link rel="stylesheet" href="llvm.css" type="text/css">
</head>
+
<body>
+
<div class="doc_title"> LLVM Language Reference Manual </div>
<ol>
<li><a href="#abstract">Abstract</a></li>
<li><a href="#t_function">Function Type</a></li>
<li><a href="#t_pointer">Pointer Type</a></li>
<li><a href="#t_struct">Structure Type</a></li>
-<!-- <li><a href="#t_packed" >Packed Type</a> -->
+ <li><a href="#t_packed">Packed Type</a></li>
</ol>
</li>
</ol>
<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
+ <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
</ol>
</li>
<li><a href="#binaryops">Binary Operations</a>
<li><a href="#i_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
</ol>
</li>
+ <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
+ <ol>
+ <li><a href="#i_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
+ <li><a href="#i_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
+ <li><a href="#i_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
+ </ol>
+ </li>
<li><a href="#int_codegen">Code Generator Intrinsics</a>
<ol>
<li><a href="#i_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
</li>
<li><a href="#int_os">Operating System Intrinsics</a>
<ol>
- <li><a href="#i_readport">'<tt>llvm.readport</tt>' Intrinsic</a></li>
- <li><a href="#i_writeport">'<tt>llvm.writeport</tt>' Intrinsic</a></li>
+ <li><a href="#i_readport">'<tt>llvm.readport</tt>' Intrinsic</a></li>
+ <li><a href="#i_writeport">'<tt>llvm.writeport</tt>' Intrinsic</a></li>
<li><a href="#i_readio">'<tt>llvm.readio</tt>' Intrinsic</a></li>
<li><a href="#i_writeio">'<tt>llvm.writeio</tt>' Intrinsic</a></li>
</ol>
<li><a href="#i_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a></li>
<li><a href="#i_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a></li>
<li><a href="#i_memset">'<tt>llvm.memset</tt>' Intrinsic</a></li>
+ <li><a href="#i_isunordered">'<tt>llvm.isunordered</tt>' Intrinsic</a></li>
</ol>
</li>
- <li><a href="#int_debugger">Debugger intrinsics</a>
+ <li><a href="#int_debugger">Debugger intrinsics</a></li>
</ol>
</li>
</ol>
-<div class="doc_text">
-<p><b>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
-and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></b></p>
-<p> </p>
+
+<div class="doc_author">
+ <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
+ and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
</div>
+
<!-- *********************************************************************** -->
<div class="doc_section"> <a name="abstract">Abstract </a></div>
<!-- *********************************************************************** -->
+
<div class="doc_text">
<p>This document is a reference manual for the LLVM assembly language.
LLVM is an SSA based representation that provides type safety,
representation used throughout all phases of the LLVM compilation
strategy.</p>
</div>
+
<!-- *********************************************************************** -->
<div class="doc_section"> <a name="introduction">Introduction</a> </div>
<!-- *********************************************************************** -->
+
<div class="doc_text">
+
<p>The LLVM code representation is designed to be used in three
different forms: as an in-memory compiler IR, as an on-disk bytecode
representation (suitable for fast loading by a Just-In-Time compiler),
to debug and visualize the transformations. The three different forms
of LLVM are all equivalent. This document describes the human readable
representation and notation.</p>
+
<p>The LLVM representation aims to be a light-weight and low-level
while being expressive, typed, and extensible at the same time. It
aims to be a "universal IR" of sorts, by being at a low enough level
can be proven that a C automatic variable is never accessed outside of
the current function... allowing it to be promoted to a simple SSA
value instead of a memory location.</p>
+
</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
+
<div class="doc_text">
+
<p>It is important to note that this document describes 'well formed'
LLVM assembly language. There is a difference between what the parser
accepts and what is considered 'well formed'. For example, the
following instruction is syntactically okay, but not well formed:</p>
-<pre> %x = <a href="#i_add">add</a> int 1, %x<br></pre>
+
+<pre>
+ %x = <a href="#i_add">add</a> int 1, %x
+</pre>
+
<p>...because the definition of <tt>%x</tt> does not dominate all of
its uses. The LLVM infrastructure provides a verification pass that may
be used to verify that an LLVM module is well formed. This pass is
the optimizer before it outputs bytecode. The violations pointed out
by the verifier pass indicate bugs in transformation passes or input to
the parser.</p>
+
<!-- Describe the typesetting conventions here. --> </div>
+
<!-- *********************************************************************** -->
<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
<!-- *********************************************************************** -->
+
<div class="doc_text">
+
<p>LLVM uses three different forms of identifiers, for different
purposes:</p>
+
<ol>
<li>Numeric constants are represented as you would expect: 12, -3
123.421, etc. Floating point constants have an optional hexadecimal
<p>The primitive types are the fundamental building blocks of the LLVM
system. The current set of primitive types are as follows:</p>
-<table border="0" style="align: center">
- <tbody>
- <tr>
- <td>
- <table border="1" cellspacing="0" cellpadding="4" style="align: center">
+<table class="layout">
+ <tr class="layout">
+ <td class="left">
+ <table>
<tbody>
- <tr>
- <td><tt>void</tt></td>
- <td>No value</td>
- </tr>
- <tr>
- <td><tt>ubyte</tt></td>
- <td>Unsigned 8 bit value</td>
- </tr>
- <tr>
- <td><tt>ushort</tt></td>
- <td>Unsigned 16 bit value</td>
- </tr>
- <tr>
- <td><tt>uint</tt></td>
- <td>Unsigned 32 bit value</td>
- </tr>
- <tr>
- <td><tt>ulong</tt></td>
- <td>Unsigned 64 bit value</td>
- </tr>
- <tr>
- <td><tt>float</tt></td>
- <td>32 bit floating point value</td>
- </tr>
- <tr>
- <td><tt>label</tt></td>
- <td>Branch destination</td>
- </tr>
+ <tr><th>Type</th><th>Description</th></tr>
+ <tr><td><tt>void</tt></td><td>No value</td></tr>
+ <tr><td><tt>ubyte</tt></td><td>Unsigned 8 bit value</td></tr>
+ <tr><td><tt>ushort</tt></td><td>Unsigned 16 bit value</td></tr>
+ <tr><td><tt>uint</tt></td><td>Unsigned 32 bit value</td></tr>
+ <tr><td><tt>ulong</tt></td><td>Unsigned 64 bit value</td></tr>
+ <tr><td><tt>float</tt></td><td>32 bit floating point value</td></tr>
+ <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
</tbody>
</table>
- </td>
- <td valign="top">
- <table border="1" cellspacing="0" cellpadding="4">
+ </td>
+ <td class="right">
+ <table>
<tbody>
- <tr>
- <td><tt>bool</tt></td>
- <td>True or False value</td>
- </tr>
- <tr>
- <td><tt>sbyte</tt></td>
- <td>Signed 8 bit value</td>
- </tr>
- <tr>
- <td><tt>short</tt></td>
- <td>Signed 16 bit value</td>
- </tr>
- <tr>
- <td><tt>int</tt></td>
- <td>Signed 32 bit value</td>
- </tr>
- <tr>
- <td><tt>long</tt></td>
- <td>Signed 64 bit value</td>
- </tr>
- <tr>
- <td><tt>double</tt></td>
- <td>64 bit floating point value</td>
- </tr>
+ <tr><th>Type</th><th>Description</th></tr>
+ <tr><td><tt>bool</tt></td><td>True or False value</td></tr>
+ <tr><td><tt>sbyte</tt></td><td>Signed 8 bit value</td></tr>
+ <tr><td><tt>short</tt></td><td>Signed 16 bit value</td></tr>
+ <tr><td><tt>int</tt></td><td>Signed 32 bit value</td></tr>
+ <tr><td><tt>long</tt></td><td>Signed 64 bit value</td></tr>
+ <tr><td><tt>double</tt></td><td>64 bit floating point value</td></tr>
</tbody>
</table>
- </td>
- </tr>
- </tbody>
+ </td>
+ </tr>
</table>
-
</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection"> <a name="t_classifications">Type
Classifications</a> </div>
<table border="1" cellspacing="0" cellpadding="4">
<tbody>
+ <tr><th>Classification</th><th>Types</th></tr>
<tr>
<td><a name="t_signed">signed</a></td>
<td><tt>sbyte, short, int, long, float, double</tt></td>
</tr>
<tr>
<td><a name="t_integral">integral</a></td>
- <td><tt>bool, ubyte, sbyte, ushort, short, uint, int, ulong, long</tt></td>
+ <td><tt>bool, ubyte, sbyte, ushort, short, uint, int, ulong, long</tt>
+ </td>
</tr>
<tr>
<td><a name="t_floating">floating point</a></td>
</tr>
<tr>
<td><a name="t_firstclass">first class</a></td>
- <td><tt>bool, ubyte, sbyte, ushort, short,<br>
-uint, int, ulong, long, float, double, <a href="#t_pointer">pointer</a></tt></td>
+ <td><tt>bool, ubyte, sbyte, ushort, short, uint, int, ulong, long,<br>
+ float, double, <a href="#t_pointer">pointer</a>,
+ <a href="#t_packed">packed</a></tt></td>
</tr>
</tbody>
</table>
<p>The number of elements is a constant integer value, elementtype may
be any type with a size.</p>
<h5>Examples:</h5>
-<p> <tt>[40 x int ]</tt>: Array of 40 integer values.<br>
-<tt>[41 x int ]</tt>: Array of 41 integer values.<br>
-<tt>[40 x uint]</tt>: Array of 40 unsigned integer values.</p>
-<p> </p>
+<table class="layout">
+ <tr class="layout">
+ <td class="left">
+ <tt>[40 x int ]</tt><br/>
+ <tt>[41 x int ]</tt><br/>
+ <tt>[40 x uint]</tt><br/>
+ </td>
+ <td class="left">
+ Array of 40 integer values.<br/>
+ Array of 41 integer values.<br/>
+ Array of 40 unsigned integer values.<br/>
+ </td>
+ </tr>
+</table>
<p>Here are some examples of multidimensional arrays:</p>
-
-<table border="0" cellpadding="0" cellspacing="0">
- <tbody>
- <tr>
- <td><tt>[3 x [4 x int]]</tt></td>
- <td>: 3x4 array integer values.</td>
- </tr>
- <tr>
- <td><tt>[12 x [10 x float]]</tt></td>
- <td>: 12x10 array of single precision floating point values.</td>
- </tr>
- <tr>
- <td><tt>[2 x [3 x [4 x uint]]]</tt></td>
- <td>: 2x3x4 array of unsigned integer values.</td>
- </tr>
- </tbody>
+<table class="layout">
+ <tr class="layout">
+ <td class="left">
+ <tt>[3 x [4 x int]]</tt><br/>
+ <tt>[12 x [10 x float]]</tt><br/>
+ <tt>[2 x [3 x [4 x uint]]]</tt><br/>
+ </td>
+ <td class="left">
+ 3x4 array integer values.<br/>
+ 12x10 array of single precision floating point values.<br/>
+ 2x3x4 array of unsigned integer values.<br/>
+ </td>
+ </tr>
</table>
-
</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
<div class="doc_text">
</p>
<h5>Syntax:</h5>
<pre> <returntype> (<parameter list>)<br></pre>
-<p>Where '<tt><parameter list></tt>' is a comma-separated list of
-type specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
+<p>Where '<tt><parameter list></tt>' is a comma-separated list of type
+specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
which indicates that the function takes a variable number of arguments.
Variable argument functions can access their arguments with the <a
href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
<h5>Examples:</h5>
-
-<table border="0" cellpadding="0" cellspacing="0">
- <tbody>
- <tr>
- <td><tt>int (int)</tt></td>
- <td>: function taking an <tt>int</tt>, returning an <tt>int</tt></td>
- </tr>
- <tr>
- <td><tt>float (int, int *) *</tt></td>
- <td>: <a href="#t_pointer">Pointer</a> to a function that takes
-an <tt>int</tt> and a <a href="#t_pointer">pointer</a> to <tt>int</tt>,
-returning <tt>float</tt>.</td>
- </tr>
- <tr>
- <td><tt>int (sbyte *, ...)</tt></td>
- <td>: A vararg function that takes at least one <a
- href="#t_pointer">pointer</a> to <tt>sbyte</tt> (signed char in C),
-which returns an integer. This is the signature for <tt>printf</tt>
-in LLVM.</td>
- </tr>
- </tbody>
+<table class="layout">
+ <tr class="layout">
+ <td class="left">
+ <tt>int (int)</tt> <br/>
+ <tt>float (int, int *) *</tt><br/>
+ <tt>int (sbyte *, ...)</tt><br/>
+ </td>
+ <td class="left">
+ function taking an <tt>int</tt>, returning an <tt>int</tt><br/>
+ <a href="#t_pointer">Pointer</a> to a function that takes an
+ <tt>int</tt> and a <a href="#t_pointer">pointer</a> to <tt>int</tt>,
+ returning <tt>float</tt>.<br/>
+ A vararg function that takes at least one <a href="#t_pointer">pointer</a>
+ to <tt>sbyte</tt> (signed char in C), which returns an integer. This is
+ the signature for <tt>printf</tt> in LLVM.<br/>
+ </td>
+ </tr>
</table>
</div>
<h5>Syntax:</h5>
<pre> { <type list> }<br></pre>
<h5>Examples:</h5>
-
-<table border="0" cellpadding="0" cellspacing="0">
- <tbody>
- <tr>
- <td><tt>{ int, int, int }</tt></td>
- <td>: a triple of three <tt>int</tt> values</td>
- </tr>
- <tr>
- <td><tt>{ float, int (int) * }</tt></td>
- <td>: A pair, where the first element is a <tt>float</tt> and the
-second element is a <a href="#t_pointer">pointer</a> to a <a
- href="t_function">function</a> that takes an <tt>int</tt>, returning
-an <tt>int</tt>.</td>
- </tr>
- </tbody>
+<table class="layout">
+ <tr class="layout">
+ <td class="left">
+ <tt>{ int, int, int }</tt><br/>
+ <tt>{ float, int (int) * }</tt><br/>
+ </td>
+ <td class="left">
+ a triple of three <tt>int</tt> values<br/>
+ A pair, where the first element is a <tt>float</tt> and the second element
+ is a <a href="#t_pointer">pointer</a> to a <a href="#t_function">function</a>
+ that takes an <tt>int</tt>, returning an <tt>int</tt>.<br/>
+ </td>
+ </tr>
</table>
-
</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
<div class="doc_text">
<h5>Syntax:</h5>
<pre> <type> *<br></pre>
<h5>Examples:</h5>
-
-<table border="0" cellpadding="0" cellspacing="0">
- <tbody>
- <tr>
- <td><tt>[4x int]*</tt></td>
- <td>: <a href="#t_pointer">pointer</a> to <a href="#t_array">array</a>
-of four <tt>int</tt> values</td>
- </tr>
- <tr>
- <td><tt>int (int *) *</tt></td>
- <td>: A <a href="#t_pointer">pointer</a> to a <a
- href="t_function">function</a> that takes an <tt>int</tt>, returning
-an <tt>int</tt>.</td>
- </tr>
- </tbody>
+<table class="layout">
+ <tr class="layout">
+ <td class="left">
+ <tt>[4x int]*</tt><br/>
+ <tt>int (int *) *</tt><br/>
+ </td>
+ <td class="left">
+ A <a href="#t_pointer">pointer</a> to <a href="#t_array">array</a> of
+ four <tt>int</tt> values<br/>
+ A <a href="#t_pointer">pointer</a> to a <a
+ href="#t_function">function</a> that takes an <tt>int</tt>, returning an
+ <tt>int</tt>.<br/>
+ </td>
+ </tr>
</table>
-
-</div>
-<!-- _______________________________________________________________________ --><!--
-<div class="doc_subsubsection">
- <a name="t_packed">Packed Type</a>
</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_packed">Packed Type</a> </div>
<div class="doc_text">
-
-Mention/decide that packed types work with saturation or not. Maybe have a packed+saturated type in addition to just a packed type.<p>
-
-Packed types should be 'nonsaturated' because standard data types are not saturated. Maybe have a saturated packed type?<p>
-
+<h5>Overview:</h5>
+<p>A packed type is a simple derived type that represents a vector
+of elements. Packed types are used when multiple primitive data
+are operated in parallel using a single instruction (SIMD).
+A packed type requires a size (number of
+elements) and an underlying primitive data type. Packed types are
+considered <a href="#t_firstclass">first class</a>.</p>
+<h5>Syntax:</h5>
+<pre> < <# elements> x <elementtype> ><br></pre>
+<p>The number of elements is a constant integer value, elementtype may
+be any integral or floating point type.</p>
+<h5>Examples:</h5>
+<table class="layout">
+ <tr class="layout">
+ <td class="left">
+ <tt><4 x int></tt><br/>
+ <tt><8 x float></tt><br/>
+ <tt><2 x uint></tt><br/>
+ </td>
+ <td class="left">
+ Packed vector of 4 integer values.<br/>
+ Packed vector of 8 floating-point values.<br/>
+ Packed vector of 2 unsigned integer values.<br/>
+ </td>
+ </tr>
+</table>
</div>
---><!-- *********************************************************************** -->
+<!-- *********************************************************************** -->
<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
-<!-- *********************************************************************** --><!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="modulestructure">Module Structure</a> </div>
+<!-- *********************************************************************** -->
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
+</div>
<div class="doc_text">
<p>LLVM programs are composed of "Module"s, each of which is a
translation unit of the input programs. Each module consists of
<p>There are five different terminator instructions: the '<a
href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
-the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, and the '<a
- href="#i_unwind"><tt>unwind</tt></a>' instruction.</p>
+the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
+ href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
+ href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
<h5>Semantics:</h5>
<p>When the '<tt>ret</tt>' instruction is executed, control flow
returns back to the calling function's context. If the caller is a "<a
- href="#i_call"><tt>call</tt></a> instruction, execution continues at
+ href="#i_call"><tt>call</tt></a>" instruction, execution continues at
the instruction after the call. If the caller was an "<a
href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
at the beginning "normal" of the destination block. If the instruction
<p>The <tt>switch</tt> instruction specifies a table of values and
destinations. When the '<tt>switch</tt>' instruction is executed, this
-table is searched for the given value. If the value is found, the
-corresponding destination is branched to, otherwise the default value
-it transfered to.</p>
+table is searched for the given value. If the value is found, control flow is
+transfered to the corresponding destination; otherwise, control flow is
+transfered to the default destination.</p>
<h5>Implementation:</h5>
<p>Depending on properties of the target machine and the particular
<tt>switch</tt> instruction, this instruction may be code generated in different
-ways, for example as a series of chained conditional branches, or with a lookup
-table.</p>
+ways. For example, it could be generated as a series of chained conditional
+branches or with a lookup table.</p>
<h5>Example:</h5>
<pre> %retval = invoke int %Test(int 15)<br> to label %Continue<br> except label %TestCleanup <i>; {int}:retval set</i>
</pre>
</div>
+
+
<!-- _______________________________________________________________________ -->
+
<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
Instruction</a> </div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> unwind<br></pre>
+<pre>
+ unwind
+</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing
-control flow at the first callee in the dynamic call stack which used
-an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the
-call. This is primarily used to implement exception handling.</p>
+
+<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
+at the first callee in the dynamic call stack which used an <a
+href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
+primarily used to implement exception handling.</p>
+
<h5>Semantics:</h5>
-<p>The '<tt>unwind</tt>' intrinsic causes execution of the current
-function to immediately halt. The dynamic call stack is then searched
-for the first <a href="#i_invoke"><tt>invoke</tt></a> instruction on
-the call stack. Once found, execution continues at the "exceptional"
-destination block specified by the <tt>invoke</tt> instruction. If
-there is no <tt>invoke</tt> instruction in the dynamic call chain,
-undefined behavior results.</p>
+
+<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
+immediately halt. The dynamic call stack is then searched for the first <a
+href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
+execution continues at the "exceptional" destination block specified by the
+<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
+dynamic call chain, undefined behavior results.</p>
</div>
+
+<!-- _______________________________________________________________________ -->
+
+<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
+Instruction</a> </div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ unreachable
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
+instruction is used to inform the optimizer that a particular portion of the
+code is not reachable. This can be used to indicate that the code after a
+no-return function cannot be reached, and other facts.</p>
+
+<h5>Semantics:</h5>
+
+<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
+</div>
+
+
+
<!-- ======================================================================= -->
<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
<div class="doc_text">
<p>Binary operators are used to do most of the computation in a
program. They require two operands, execute an operation on them, and
-produce a single value. The result value of a binary operator is not
+produce a single value. Although, that single value might represent
+multiple data, as is the case with the <a href="#t_packed">packed</a> data type.
+The result value of a binary operator is not
necessarily the same type as its operands.</p>
<p>There are several different binary operators:</p>
</div>
<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
<h5>Arguments:</h5>
<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
- href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+ href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
+ This instruction can also take <a href="#t_packed">packed</a> versions of the values.
+Both arguments must have identical types.</p>
<h5>Semantics:</h5>
<p>The value produced is the integer or floating point sum of the two
operands.</p>
<h5>Arguments:</h5>
<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+values.
+This instruction can also take <a href="#t_packed">packed</a> versions of the values.
+Both arguments must have identical types.</p>
<h5>Semantics:</h5>
<p>The value produced is the integer or floating point difference of
the two operands.</p>
<h5>Arguments:</h5>
<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+values.
+This instruction can also take <a href="#t_packed">packed</a> versions of the values.
+Both arguments must have identical types.</p>
<h5>Semantics:</h5>
<p>The value produced is the integer or floating point product of the
two operands.</p>
<h5>Arguments:</h5>
<p>The two arguments to the '<tt>div</tt>' instruction must be either <a
href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+values.
+This instruction can also take <a href="#t_packed">packed</a> versions of the values.
+Both arguments must have identical types.</p>
<h5>Semantics:</h5>
<p>The value produced is the integer or floating point quotient of the
two operands.</p>
<h5>Arguments:</h5>
<p>The two arguments to the '<tt>rem</tt>' instruction must be either <a
href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+values.
+This instruction can also take <a href="#t_packed">packed</a> versions of the values.
+Both arguments must have identical types.</p>
<h5>Semantics:</h5>
<p>This returns the <i>remainder</i> of a division (where the result
has the same sign as the divisor), not the <i>modulus</i> (where the
<h5>Arguments:</h5>
<p>The argument to the '<tt>load</tt>' instruction specifies the memory
address to load from. The pointer must point to a <a
- href="t_firstclass">first class</a> type. If the <tt>load</tt> is
+ href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
marked as <tt>volatile</tt> then the optimizer is not allowed to modify
the number or order of execution of this <tt>load</tt> with other
volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
%RT = type { sbyte, [10 x [20 x int]], sbyte }
%ST = type { int, double, %RT }
- int* "foo"(%ST* %s) {
- %reg = getelementptr %ST* %s, int 1, uint 2, uint 1, int 5, int 13<br>
+ implementation
+
+ int* %foo(%ST* %s) {
+ entry:
+ %reg = getelementptr %ST* %s, int 1, uint 2, uint 1, int 5, int 13
ret int* %reg
}
</pre>
<h5>Semantics:</h5>
<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
-on the pointer type that is being index into. <a href="t_pointer">Pointer</a>
-and <a href="t_array">array</a> types require <tt>uint</tt>, <tt>int</tt>,
-<tt>ulong</tt>, or <tt>long</tt> values, and <a href="t_struct">structure</a>
+on the pointer type that is being index into. <a href="#t_pointer">Pointer</a>
+and <a href="#t_array">array</a> types require <tt>uint</tt>, <tt>int</tt>,
+<tt>ulong</tt>, or <tt>long</tt> values, and <a href="#t_struct">structure</a>
types require <tt>uint</tt> <b>constants</b>.</p>
<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
<h5>Example:</h5>
<pre> %retval = call int %test(int %argc)<br> call int(sbyte*, ...) *%printf(sbyte* %msg, int 12, sbyte 42);<br></pre>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_vanext">'<tt>vanext</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="i_vanext">'<tt>vanext</tt>' Instruction</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <resultarglist> = vanext <va_list> <arglist>, <argty><br></pre>
+
+<pre>
+ <resultarglist> = vanext <va_list> <arglist>, <argty>
+</pre>
+
<h5>Overview:</h5>
+
<p>The '<tt>vanext</tt>' instruction is used to access arguments passed
through the "variable argument" area of a function call. It is used to
implement the <tt>va_arg</tt> macro in C.</p>
+
<h5>Arguments:</h5>
-<p>This instruction takes a <tt>valist</tt> value and the type of the
-argument. It returns another <tt>valist</tt>.</p>
+
+<p>This instruction takes a <tt>va_list</tt> value and the type of the
+argument. It returns another <tt>va_list</tt>. The actual type of
+<tt>va_list</tt> may be defined differently for different targets. Most targets
+use a <tt>va_list</tt> type of <tt>sbyte*</tt> or some other pointer type.</p>
+
<h5>Semantics:</h5>
-<p>The '<tt>vanext</tt>' instruction advances the specified <tt>valist</tt>
+
+<p>The '<tt>vanext</tt>' instruction advances the specified <tt>va_list</tt>
past an argument of the specified type. In conjunction with the <a
href="#i_vaarg"><tt>vaarg</tt></a> instruction, it is used to implement
the <tt>va_arg</tt> macro available in C. For more information, see
the variable argument handling <a href="#int_varargs">Intrinsic
Functions</a>.</p>
+
<p>It is legal for this instruction to be called in a function which
does not take a variable number of arguments, for example, the <tt>vfprintf</tt>
function.</p>
+
<p><tt>vanext</tt> is an LLVM instruction instead of an <a
- href="#intrinsics">intrinsic function</a> because it takes an type as
-an argument.</p>
+href="#intrinsics">intrinsic function</a> because it takes a type as an
+argument. The type refers to the current argument in the <tt>va_list</tt>, it
+tells the compiler how far on the stack it needs to advance to find the next
+argument</p>
+
<h5>Example:</h5>
+
<p>See the <a href="#int_varargs">variable argument processing</a>
section.</p>
+
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_vaarg">'<tt>vaarg</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="i_vaarg">'<tt>vaarg</tt>' Instruction</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <resultval> = vaarg <va_list> <arglist>, <argty><br></pre>
+
+<pre>
+ <resultval> = vaarg <va_list> <arglist>, <argty>
+</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>vaarg</tt>' instruction is used to access arguments passed
-through the "variable argument" area of a function call. It is used to
-implement the <tt>va_arg</tt> macro in C.</p>
+
+<p>The '<tt>vaarg</tt>' instruction is used to access arguments passed through
+the "variable argument" area of a function call. It is used to implement the
+<tt>va_arg</tt> macro in C.</p>
+
<h5>Arguments:</h5>
-<p>This instruction takes a <tt>valist</tt> value and the type of the
-argument. It returns a value of the specified argument type.</p>
+
+<p>This instruction takes a <tt>va_list</tt> value and the type of the
+argument. It returns a value of the specified argument type. Again, the actual
+type of <tt>va_list</tt> is target specific.</p>
+
<h5>Semantics:</h5>
-<p>The '<tt>vaarg</tt>' instruction loads an argument of the specified
-type from the specified <tt>va_list</tt>. In conjunction with the <a
- href="#i_vanext"><tt>vanext</tt></a> instruction, it is used to
-implement the <tt>va_arg</tt> macro available in C. For more
-information, see the variable argument handling <a href="#int_varargs">Intrinsic
-Functions</a>.</p>
-<p>It is legal for this instruction to be called in a function which
-does not take a variable number of arguments, for example, the <tt>vfprintf</tt>
+
+<p>The '<tt>vaarg</tt>' instruction loads an argument of the specified type from
+the specified <tt>va_list</tt>. In conjunction with the <a
+href="#i_vanext"><tt>vanext</tt></a> instruction, it is used to implement the
+<tt>va_arg</tt> macro available in C. For more information, see the variable
+argument handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
+
+<p>It is legal for this instruction to be called in a function which does not
+take a variable number of arguments, for example, the <tt>vfprintf</tt>
function.</p>
+
<p><tt>vaarg</tt> is an LLVM instruction instead of an <a
- href="#intrinsics">intrinsic function</a> because it takes an type as
-an argument.</p>
+href="#intrinsics">intrinsic function</a> because it takes an type as an
+argument.</p>
+
<h5>Example:</h5>
-<p>See the <a href="#int_varargs">variable argument processing</a>
-section.</p>
+
+<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
+
</div>
<!-- *********************************************************************** -->
</div>
<div class="doc_text">
+
<p>Variable argument support is defined in LLVM with the <a
href="#i_vanext"><tt>vanext</tt></a> instruction and these three
intrinsic functions. These functions are related to the similarly
named macros defined in the <tt><stdarg.h></tt> header file.</p>
+
<p>All of these functions operate on arguments that use a
target-specific value type "<tt>va_list</tt>". The LLVM assembly
language reference manual does not define what this type is, so all
transformations should be prepared to handle intrinsics with any type
used.</p>
+
<p>This example shows how the <a href="#i_vanext"><tt>vanext</tt></a>
instruction and the variable argument handling intrinsic functions are
used.</p>
+
<pre>
int %test(int %X, ...) {
; Initialize variable argument processing
<div class="doc_text">
<h5>Syntax:</h5>
-<pre> call va_list ()* %llvm.va_start()<br></pre>
+<pre> call <va_list> ()* %llvm.va_start()<br></pre>
<h5>Overview:</h5>
<p>The '<tt>llvm.va_start</tt>' intrinsic returns a new <tt><arglist></tt>
for subsequent use by the variable argument intrinsics.</p>
<div class="doc_text">
<h5>Syntax:</h5>
-<pre> call void (va_list)* %llvm.va_end(va_list <arglist>)<br></pre>
+<pre> call void (<va_list>)* %llvm.va_end(<va_list> <arglist>)<br></pre>
<h5>Overview:</h5>
<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt><arglist></tt>
which has been initialized previously with <tt><a href="#i_va_start">llvm.va_start</a></tt>
</div>
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> call va_list (va_list)* %llvm.va_copy(va_list <destarglist>)<br></pre>
+
+<pre>
+ call <va_list> (<va_list>)* %llvm.va_copy(<va_list> <destarglist>)
+</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument
-position from the source argument list to the destination argument list.</p>
+
+<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
+from the source argument list to the destination argument list.</p>
+
<h5>Arguments:</h5>
+
<p>The argument is the <tt>va_list</tt> to copy.</p>
+
<h5>Semantics:</h5>
+
<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
-macro available in C. In a target-dependent way, it copies the source <tt>va_list</tt>
-element into the returned list. This intrinsic is necessary because the <tt><a
- href="i_va_start">llvm.va_start</a></tt> intrinsic may be arbitrarily
-complex and require memory allocation, for example.</p>
+macro available in C. In a target-dependent way, it copies the source
+<tt>va_list</tt> element into the returned list. This intrinsic is necessary
+because the <tt><a href="#i_va_start">llvm.va_start</a></tt> intrinsic may be
+arbitrarily complex and require memory allocation, for example.</p>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
+</div>
+
+<div class="doc_text">
+
+<p>
+LLVM support for <a href="GarbageCollection.html">Accurate Garbage
+Collection</a> requires the implementation and generation of these intrinsics.
+These intrinsics allow identification of <a href="#i_gcroot">GC roots on the
+stack</a>, as well as garbage collector implementations that require <a
+href="#i_gcread">read</a> and <a href="#i_gcwrite">write</a> barriers.
+Front-ends for type-safe garbage collected languages should generate these
+intrinsics to make use of the LLVM garbage collectors. For more details, see <a
+href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
+</p>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ call void (<ty>**, <ty2>*)* %llvm.gcroot(<ty>** %ptrloc, <ty2>* %metadata)
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existance of a GC root to
+the code generator, and allows some metadata to be associated with it.</p>
+
+<h5>Arguments:</h5>
+
+<p>The first argument specifies the address of a stack object that contains the
+root pointer. The second pointer (which must be either a constant or a global
+value address) contains the meta-data to be associated with the root.</p>
+
+<h5>Semantics:</h5>
+
+<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
+location. At compile-time, the code generator generates information to allow
+the runtime to find the pointer at GC safe points.
+</p>
+
+</div>
+
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ call sbyte* (sbyte**)* %llvm.gcread(sbyte** %Ptr)
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
+locations, allowing garbage collector implementations that require read
+barriers.</p>
+
+<h5>Arguments:</h5>
+
+<p>The argument is the address to read from, which should be an address
+allocated from the garbage collector.</p>
+
+<h5>Semantics:</h5>
+
+<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
+instruction, but may be replaced with substantially more complex code by the
+garbage collector runtime, as needed.</p>
+
+</div>
+
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ call void (sbyte*, sbyte**)* %llvm.gcwrite(sbyte* %P1, sbyte** %P2)
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
+locations, allowing garbage collector implementations that require write
+barriers (such as generational or reference counting collectors).</p>
+
+<h5>Arguments:</h5>
+
+<p>The first argument is the reference to store, and the second is the heap
+location to store to.</p>
+
+<h5>Semantics:</h5>
+
+<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
+instruction, but may be replaced with substantially more complex code by the
+garbage collector runtime, as needed.</p>
+
+</div>
+
+
+
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="int_codegen">Code Generator Intrinsics</a>
<h5>Arguments:</h5>
<p>
-The first argument to this intrinsic indicates the hardware I/O address to
-which data should be written. The address is in the hardware I/O address
-namespace (as opposed to being a memory location for memory mapped I/O).
+The first argument is the value to write to the I/O port.
</p>
<p>
-The second argument is the value to write to the I/O port.
+The second argument indicates the hardware I/O address to which data should be
+written. The address is in the hardware I/O address namespace (as opposed to
+being a memory location for memory mapped I/O).
</p>
<h5>Semantics:</h5>
<h5>Syntax:</h5>
<pre>
- call <integer type> (<integer type>)* %llvm.readio (<integer type> <address>)
+ call <result> (<ty>*)* %llvm.readio (<ty> * <pointer>)
</pre>
<h5>Overview:</h5>
<h5>Arguments:</h5>
<p>
-The argument to this intrinsic indicates the memory address from which to read
-the data.
+The argument to this intrinsic is a pointer indicating the memory address from
+which to read the data. The data must be a
+<a href="#t_firstclass">first class</a> type.
</p>
<h5>Semantics:</h5>
<p>
The '<tt>llvm.readio</tt>' intrinsic reads data from a memory mapped I/O
-location specified by <i>address</i> and returns the value. The address and
-return value must be integers, but the size allowed for each is dependent upon
-the platform upon which the program is code generated.
+location specified by <i>pointer</i> and returns the value. The argument must
+be a pointer, and the return value must be a
+<a href="#t_firstclass">first class</a> type. However, certain architectures
+may not support I/O on all first class types. For example, 32 bit processors
+may only support I/O on data types that are 32 bits or less.
</p>
<p>
-This intrinsic ensures that the I/O data read occurs in instruction order in
-relation to other I/O data reads and writes (as opposed to a normal load, where
-hardware scheduling can re-arrange the actual memory accesses to occur out of
-order).
+This intrinsic enforces an in-order memory model for llvm.readio and
+llvm.writeio calls on machines that use dynamic scheduling. Dynamically
+scheduled processors may execute loads and stores out of order, re-ordering at
+run time accesses to memory mapped I/O registers. Using these intrinsics
+ensures that accesses to memory mapped I/O registers occur in program order.
</p>
</div>
<h5>Syntax:</h5>
<pre>
- call void (<integer type>, <integer type>)* %llvm.writeio (<integer type> <value>, <integer type> <address>)
+ call void (<ty1>, <ty2>*)* %llvm.writeio (<ty1> <value>, <ty2> * <pointer>)
</pre>
<h5>Overview:</h5>
<h5>Arguments:</h5>
<p>
-The first argument to this intrinsic indicates the memory address to which data
-should be written.
-</p>
-
-<p>
-The second argument is the value to write to the memory mapped I/O location.
+The first argument is the value to write to the memory mapped I/O location.
+The second argument is a pointer indicating the memory address to which the
+data should be written.
</p>
<h5>Semantics:</h5>
<p>
The '<tt>llvm.writeio</tt>' intrinsic writes <i>value</i> to the memory mapped
-I/O address specified by <i>address</i>. The address and value must be
-integers, but the size is dependent upon the platform upon which the program is
-code generated.
+I/O address specified by <i>pointer</i>. The value must be a
+<a href="#t_firstclass">first class</a> type. However, certain architectures
+may not support I/O on all first class types. For example, 32 bit processors
+may only support I/O on data types that are 32 bits or less.
</p>
<p>
-This intrinsic ensures that the I/O data write occurs in instruction order in
-relation to other I/O data reads and writes (as opposed to a normal store,
-where hardware scheduling can re-arrange the actual memory accesses to occur
-out of order).
+This intrinsic enforces an in-order memory model for llvm.readio and
+llvm.writeio calls on machines that use dynamic scheduling. Dynamically
+scheduled processors may execute loads and stores out of order, re-ordering at
+run time accesses to memory mapped I/O registers. Using these intrinsics
+ensures that accesses to memory mapped I/O registers occur in program order.
</p>
</div>
-
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="int_libc">Standard C Library Intrinsics</a>
</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_isunordered">'<tt>llvm.isunordered</tt>' Intrinsic</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ call bool (<float or double>, <float or double>)* %llvm.isunordered(<float or double> Val1,
+ <float or double> Val2)
+</pre>
+
+<h5>Overview:</h5>
+
+<p>
+The '<tt>llvm.isunordered</tt>' intrinsic returns true if either or both of the
+specified floating point values is a NAN.
+</p>
+
+<h5>Arguments:</h5>
+
+<p>
+The arguments are floating point numbers of the same type.
+</p>
+
+<h5>Semantics:</h5>
+
+<p>
+If either or both of the arguments is a SNAN or QNAN, it returns true, otherwise
+false.
+</p>
+</div>
+
+
+
+
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="int_debugger">Debugger Intrinsics</a>
projects / oota-llvm.git / blobdiff