<li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
<li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
<li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
- <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
<li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
<li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
<li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
<li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
<li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
<li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
+ <li><a href="#linkage_linkonce_odr_auto_hide">'<tt>linkonce_odr_auto_hide</tt>' Linkage</a></li>
<li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
<li><a href="#linkage_external">'<tt>external</tt>' Linkage</a></li>
<li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
<li><a href="#metadata">Metadata Nodes and Metadata Strings</a>
<ol>
<li><a href="#tbaa">'<tt>tbaa</tt>' Metadata</a></li>
+ <li><a href="#tbaa.struct">'<tt>tbaa.struct</tt>' Metadata</a></li>
<li><a href="#fpmath">'<tt>fpmath</tt>' Metadata</a></li>
<li><a href="#range">'<tt>range</tt>' Metadata</a></li>
- <li><a href="#alloc">'<tt>alloc</tt>' Metadata</a></li>
</ol>
</li>
</ol>
<li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
<li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
<li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_fabs">'<tt>llvm.fabs.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_floor">'<tt>llvm.floor.*</tt>' Intrinsic</a></li>
</ol>
</li>
<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
'<tt>llvm.debugtrap</tt>' Intrinsic</a></li>
<li><a href="#int_stackprotector">
'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
- <li><a href="#int_objectsize">
+
<li><a href="#int_objectsize">
'<tt>llvm.objectsize</tt>' Intrinsic</a></li>
- <li><a href="#int_expect">
+
<li><a href="#int_expect">
'<tt>llvm.expect</tt>' Intrinsic</a></li>
+ <li><a href="#int_donothing">
+ '<tt>llvm.donothing</tt>' Intrinsic</a></li>
</ol>
</li>
</ol>
linker. The symbols are removed by the linker from the final linked image
(executable or dynamic library).</dd>
- <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
- <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
- of the object is not taken. For instance, functions that had an inline
- definition, but the compiler decided not to inline it. Note,
- unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
- <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
- visibility. The symbols are removed by the linker from the final linked
- image (executable or dynamic library).</dd>
-
<dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
<dd>Similar to private, but the value shows as a local symbol
(<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
be merged with equivalent globals. These linkage types are otherwise the
same as their non-<tt>odr</tt> versions.</dd>
+ <dt><tt><b><a name="linkage_linkonce_odr_auto_hide">linkonce_odr_auto_hide</a></b></tt></dt>
+ <dd>Similar to "<tt>linkonce_odr</tt>", but nothing in the translation unit
+ takes the address of this definition. For instance, functions that had an
+ inline definition, but the compiler decided not to inline it.
+ <tt>linkonce_odr_auto_hide</tt> may have only <tt>default</tt> visibility.
+ The symbols are removed by the linker from the final linked image
+ (executable or dynamic library).</dd>
+
<dt><tt><b><a name="linkage_external">external</a></b></tt></dt>
<dd>If none of the above identifiers are used, the global is externally
visible, meaning that it participates in linkage and can be used to
<p>Global variables define regions of memory allocated at compilation time
instead of run-time. Global variables may optionally be initialized, may
have an explicit section to be placed in, and may have an optional explicit
- alignment specified. A variable may be defined as "thread_local", which
+ alignment specified.</p>
+
+<p>A variable may be defined as <tt>thread_local</tt>, which
means that it will not be shared by threads (each thread will have a
- separated copy of the variable). A variable may be defined as a global
+ separated copy of the variable). Not all targets support thread-local
+ variables. Optionally, a TLS model may be specified:</p>
+
+<dl>
+ <dt><b><tt>localdynamic</tt></b>:</dt>
+ <dd>For variables that are only used within the current shared library.</dd>
+
+ <dt><b><tt>initialexec</tt></b>:</dt>
+ <dd>For variables in modules that will not be loaded dynamically.</dd>
+
+ <dt><b><tt>localexec</tt></b>:</dt>
+ <dd>For variables defined in the executable and only used within it.</dd>
+</dl>
+
+<p>The models correspond to the ELF TLS models; see
+ <a href="http://people.redhat.com/drepper/tls.pdf">ELF
+ Handling For Thread-Local Storage</a> for more information on under which
+ circumstances the different models may be used. The target may choose a
+ different TLS model if the specified model is not supported, or if a better
+ choice of model can be made.</p>
+
+<p>A variable may be defined as a global
"constant," which indicates that the contents of the variable
will <b>never</b> be modified (enabling better optimization, allowing the
global data to be placed in the read-only section of an executable, etc).
@G = addrspace(5) constant float 1.0, section "foo", align 4
</pre>
+<p>The following example defines a thread-local global with
+ the <tt>initialexec</tt> TLS model:</p>
+
+<pre class="doc_code">
+@G = thread_local(initialexec) global i32 0, align 4
+</pre>
+
</div>
<dd>This indicates that the pointer parameter specifies the address of a
structure that is the return value of the function in the source program.
This pointer must be guaranteed by the caller to be valid: loads and
- stores to the structure may be assumed by the callee to not to trap. This
- may only be applied to the first parameter. This is not a valid attribute
- for return values. </dd>
+ stores to the structure may be assumed by the callee to not to trap and
+ to be properly aligned. This may only be applied to the first parameter.
+ This is not a valid attribute for return values. </dd>
<dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
<dd>This indicates that pointer values
8-bits. If omitted, the natural stack alignment defaults to "unspecified",
which does not prevent any alignment promotions.</dd>
- <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
+ <dt><tt>p[n]:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
- <i>preferred</i> alignments. All sizes are in bits. Specifying
- the <i>pref</i> alignment is optional. If omitted, the
- preceding <tt>:</tt> should be omitted too.</dd>
+ <i>preferred</i> alignments for address space <i>n</i>. All sizes are in
+ bits. Specifying the <i>pref</i> alignment is optional. If omitted, the
+ preceding <tt>:</tt> should be omitted too. The address space,
+ <i>n</i> is optional, and if not specified, denotes the default address
+ space 0. The value of <i>n</i> must be in the range [1,2^23).</dd>
<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
<dd>This specifies the alignment for an integer type of a given bit
<ul>
<li><tt>E</tt> - big endian</li>
<li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
+ <li><tt>p1:32:32:32</tt> - 32-bit pointers with 32-bit alignment for
+ address space 1</li>
+ <li><tt>p2:16:32:32</tt> - 16-bit pointers with 32-bit alignment for
+ address space 2</li>
<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
<li>If no match is found, and the type sought is an integer type, then the
smallest integer type that is larger than the bitwidth of the sought type
is used. If none of the specifications are larger than the bitwidth then
- the the largest integer type is used. For example, given the default
+ the largest integer type is used. For example, given the default
specifications above, the i7 type will use the alignment of i8 (next
largest) while both i65 and i256 will use the alignment of i64 (largest
specified).</li>
<p>Structures may optionally be "packed" structures, which indicate that the
alignment of the struct is one byte, and that there is no padding between
the elements. In non-packed structs, padding between field types is inserted
- as defined by the TargetData string in the module, which is required to match
+ as defined by the DataLayout string in the module, which is required to match
what the underlying code generator expects.</p>
<p>Structures can either be "literal" or "identified". A literal structure is
make it fit in <tt>TYPE</tt>.</dd>
<dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
- <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
+ <dd>Convert an integer constant to a pointer constant. TYPE must be a pointer
type. CST must be of integer type. The CST value is zero extended,
truncated, or unchanged to make it fit in a pointer size. This one is
<i>really</i> dangerous!</dd>
</pre>
<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
- a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
- have:</p>
+ a <a href="#i_call"><tt>call</tt></a> or an
+ <a href="#i_invoke"><tt>invoke</tt></a> instruction.
+ Thus, typically we have:</p>
<pre class="doc_code">
%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
call void asm alignstack "eieio", ""()
</pre>
-<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
- first.</p>
+<p>Inline asms also support using non-standard assembly dialects. The assumed
+ dialect is ATT. When the '<tt>inteldialect</tt>' keyword is present, the
+ inline asm is using the Intel dialect. Currently, ATT and Intel are the
+ only supported dialects. An example is:</p>
+
+<pre class="doc_code">
+call void asm inteldialect "eieio", ""()
+</pre>
+
+<p>If multiple keywords appear the '<tt>sideeffect</tt>' keyword must come
+ first, the '<tt>alignstack</tt>' keyword second and the
+ '<tt>inteldialect</tt>' keyword last.</p>
<!--
<p>TODO: The format of the asm and constraints string still need to be
</div>
+<!-- _______________________________________________________________________ -->
+<h4>
+ <a name="tbaa.struct">'<tt>tbaa.struct</tt>' Metadata</a>
+</h4>
+
+<div>
+
+<p>The <a href="#int_memcpy"><tt>llvm.memcpy</tt></a> is often used to implement
+aggregate assignment operations in C and similar languages, however it is
+defined to copy a contiguous region of memory, which is more than strictly
+necessary for aggregate types which contain holes due to padding. Also, it
+doesn't contain any TBAA information about the fields of the aggregate.</p>
+
+<p><tt>!tbaa.struct</tt> metadata can describe which memory subregions in a memcpy
+are padding and what the TBAA tags of the struct are.</p>
+
+<p>The current metadata format is very simple. <tt>!tbaa.struct</tt> metadata nodes
+ are a list of operands which are in conceptual groups of three. For each
+ group of three, the first operand gives the byte offset of a field in bytes,
+ the second gives its size in bytes, and the third gives its
+ tbaa tag. e.g.:</p>
+
+<div class="doc_code">
+<pre>
+!4 = metadata !{ i64 0, i64 4, metadata !1, i64 8, i64 4, metadata !2 }
+</pre>
+</div>
+
+<p>This describes a struct with two fields. The first is at offset 0 bytes
+ with size 4 bytes, and has tbaa tag !1. The second is at offset 8 bytes
+ and has size 4 bytes and has tbaa tag !2.</p>
+
+<p>Note that the fields need not be contiguous. In this example, there is a
+ 4 byte gap between the two fields. This gap represents padding which
+ does not carry useful data and need not be preserved.</p>
+
+</div>
+
<!-- _______________________________________________________________________ -->
<h4>
<a name="fpmath">'<tt>fpmath</tt>' Metadata</a>
</pre>
</div>
</div>
-
-<!-- _______________________________________________________________________ -->
-<h4>
- <a name="alloc">'<tt>alloc</tt>' Metadata</a>
-</h4>
-
-<div>
-
-<p><tt>alloc</tt> metadata may be attached to any instruction returning a
- pointer. It can be used to express the size and offset relative to the
- beginning of the buffer pointed by.</p>
-
-<blockquote>
-
-<p>The first parameter is a function that returns the size of the buffer, and
- the second (optional) parameter is a function that returns the offset from
- the beginning of the buffer. If the second parameter is not present or null,
- the offset is assumed to be null. Both functions must be either readonly or
- readnone.</p>
-<p><tt>alloc</tt> metadata can have additional parameters, which are passed to
- the size and offset functions when they are evaluated. Therefore the size and
- offset functions must have the same signature.</p>
-
-</blockquote>
-
-
-<p>Examples:</p>
-<div class="doc_code">
-<pre>
- ; size of buffer allocated by this call is my_malloc_size(%s), and offset=0
- %a = call my_malloc(%s), !alloc !{i32 (i32)* @my_malloc_size, null, i32 %s}
-
- ; size of the buffer pointed by *ptr is size(%x), and offset=offset(%x)
- %b = load i8** %foo, !alloc !{i32 (i32)* @size, i32 (i32)* @offset, i32 %x}
-
- ; size of buffer allocated by this call is foo_size(), and offset=0
- %a = call alloc_foo(%s), !alloc !0
-...
-!0 = metadata {i32 ()* @foo_size}
-</pre>
-</div>
-</div>
-
</div>
</div>
</div>
+<!-- _______________________________________________________________________ -->
+<h4>
+ <a name="int_fabs">'<tt>llvm.fabs.*</tt>' Intrinsic</a>
+</h4>
+
+<div>
+
+<h5>Syntax:</h5>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.fabs</tt> on any
+ floating point or vector of floating point type. Not all targets support all
+ types however.</p>
+
+<pre>
+ declare float @llvm.fabs.f32(float %Val)
+ declare double @llvm.fabs.f64(double %Val)
+ declare x86_fp80 @llvm.fabs.f80(x86_fp80 %Val)
+ declare fp128 @llvm.fabs.f128(fp128 %Val)
+ declare ppc_fp128 @llvm.fabs.ppcf128(ppc_fp128 %Val)
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>llvm.fabs.*</tt>' intrinsics return the absolute value of
+ the operand.</p>
+
+<h5>Arguments:</h5>
+<p>The argument and return value are floating point numbers of the same
+ type.</p>
+
+<h5>Semantics:</h5>
+<p>This function returns the same values as the libm <tt>fabs</tt> functions
+ would, and handles error conditions in the same way.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<h4>
+ <a name="int_floor">'<tt>llvm.floor.*</tt>' Intrinsic</a>
+</h4>
+
+<div>
+
+<h5>Syntax:</h5>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.floor</tt> on any
+ floating point or vector of floating point type. Not all targets support all
+ types however.</p>
+
+<pre>
+ declare float @llvm.floor.f32(float %Val)
+ declare double @llvm.floor.f64(double %Val)
+ declare x86_fp80 @llvm.floor.f80(x86_fp80 %Val)
+ declare fp128 @llvm.floor.f128(fp128 %Val)
+ declare ppc_fp128 @llvm.floor.ppcf128(ppc_fp128 %Val)
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>llvm.floor.*</tt>' intrinsics return the floor of
+ the operand.</p>
+
+<h5>Arguments:</h5>
+<p>The argument and return value are floating point numbers of the same
+ type.</p>
+
+<h5>Semantics:</h5>
+<p>This function returns the same values as the libm <tt>floor</tt> functions
+ would, and handles error conditions in the same way.</p>
+
+</div>
+
</div>
<!-- ======================================================================= -->
<p>This intrinsic is lowered to the <tt>val</tt>.</p>
</div>
+<!-- _______________________________________________________________________ -->
+<h4>
+ <a name="int_donothing">'<tt>llvm.donothing</tt>' Intrinsic</a>
+</h4>
+
+<div>
+
+<h5>Syntax:</h5>
+<pre>
+ declare void @llvm.donothing() nounwind readnone
+</pre>
+
+<h5>Overview:</h5>
+<p>The <tt>llvm.donothing</tt> intrinsic doesn't perform any operation. It's the
+only intrinsic that can be called with an invoke instruction.</p>
+
+<h5>Arguments:</h5>
+<p>None.</p>
+
+<h5>Semantics:</h5>
+<p>This intrinsic does nothing, and it's removed by optimizers and ignored by
+codegen.</p>
+</div>
+
</div>
</div>
projects / oota-llvm.git / blobdiff