<dl>
<dt><tt><b>zeroext</b></tt></dt>
<dd>This indicates to the code generator that the parameter or return value
- should be zero-extended to a 32-bit value by the caller (for a parameter)
- or the callee (for a return value).</dd>
+ should be zero-extended to the extent required by the target's ABI (which
+ is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
+ parameter) or the callee (for a return value).</dd>
<dt><tt><b>signext</b></tt></dt>
<dd>This indicates to the code generator that the parameter or return value
- should be sign-extended to a 32-bit value by the caller (for a parameter)
- or the callee (for a return value).</dd>
+ should be sign-extended to the extent required by the target's ABI (which
+ is usually 32-bits) by the caller (for a parameter) or the callee (for a
+ return value).</dd>
<dt><tt><b>inreg</b></tt></dt>
<dd>This indicates that this parameter or return value should be treated in a
<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
function is using two metadata arguments.</p>
- <pre class="doc_code">
- call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
- </pre>
+<div class="doc_code">
+<pre>
+call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
+</pre>
+</div>
<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
- <pre class="doc_code">
- %indvar.next = add i64 %indvar, 1, !dbg !21
- </pre>
+<div class="doc_code">
+<pre>
+%indvar.next = add i64 %indvar, 1, !dbg !21
+</pre>
+</div>
+
</div>
<h5>Semantics:</h5>
<p>This instruction returns the <i>remainder</i> of a division (where the result
- has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
- operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
- a value. For more information about the difference,
+ is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
+ <i>modulo</i> operator (where the result is either zero or has the same sign
+ as the divisor, <tt>op2</tt>) of a value.
+ For more information about the difference,
see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Math Forum</a>. For a table of how this is implemented in various languages,
please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
type <tt>ty2</tt>.</p>
<h5>Arguments:</h5>
-<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
- be an <a href="#t_integer">integer</a> type, and a type that specifies the
- size and type of the result, which must be
- an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
- be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
- allowed.</p>
+<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
+ Both types must be of <a href="#t_integer">integer</a> types, or vectors
+ of the same number of integers.
+ The bit size of the <tt>value</tt> must be larger than
+ the bit size of the destination type, <tt>ty2</tt>.
+ Equal sized types are not allowed.</p>
<h5>Semantics:</h5>
<p>The '<tt>trunc</tt>' instruction truncates the high order bits
<h5>Example:</h5>
<pre>
- %X = trunc i32 257 to i8 <i>; yields i8:1</i>
- %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
- %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
+ %X = trunc i32 257 to i8 <i>; yields i8:1</i>
+ %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
+ %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
+ %W = trunc <2 x i16> <i16 8, i16 7> to <2 x i8> <i>; yields <i8 8, i8 7></i>
</pre>
</div>
<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
<h5>Arguments:</h5>
-<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
- <a href="#t_integer">integer</a> type, and a type to cast it to, which must
- also be of <a href="#t_integer">integer</a> type. The bit size of the
- <tt>value</tt> must be smaller than the bit size of the destination type,
+<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
+ Both types must be of <a href="#t_integer">integer</a> types, or vectors
+ of the same number of integers.
+ The bit size of the <tt>value</tt> must be smaller than
+ the bit size of the destination type,
<tt>ty2</tt>.</p>
<h5>Semantics:</h5>
<pre>
%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
%Y = sext i1 true to i32 <i>; yields i32:-1</i>
+ %Z = sext <2 x i16> <i16 8, i16 7> to <2 x i32> <i>; yields <i32 8, i32 7></i>
</pre>
</div>
<h5>Example:</h5>
<pre>
- %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
- %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
+ %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
+ %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
</pre>
</div>
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<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
- <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
+ <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Last modified: $Date$
</address>
projects / oota-llvm.git / blobdiff