<li><a href="#binaryops">Binary Operations</a>
<ol>
<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
+ <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
+ <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
+ <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
<ol>
<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
- <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
- <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
- <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
- <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
</ol>
</li>
<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
see if it has been overwritten. A heuristic is used to determine if a function
needs stack protectors or not.
-<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
+<br><br>If a function that has an <tt>ssp</tt> attribute is inlined into a function
that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
-have an <tt>ssp</tt> attribute.</p></dd>
+have an <tt>ssp</tt> attribute.</dd>
<dt><tt>sspreq</tt></dt>
<dd>This attribute indicates that the function should <em>always</em> emit a
stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
function attribute.
-<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
+If a function that has an <tt>sspreq</tt> attribute is inlined into a
function that doesn't have an <tt>sspreq</tt> attribute or which has
an <tt>ssp</tt> attribute, then the resulting function will have
-an <tt>sspreq</tt> attribute.</p></dd>
+an <tt>sspreq</tt> attribute.</dd>
+
+<dt><tt>noredzone</tt></dt>
+<dd>This attribute indicates that the code generator should not use a
+red zone, even if the target-specific ABI normally permits it.
+</dd>
+
+<dt><tt>noimplicitfloat</tt></dt>
+<dd>This attributes disables implicit floating point instructions.</dd>
+
</dl>
</div>
<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
<dd>This specifies the alignment for an aggregate type of a given bit
<i>size</i>.</dd>
+ <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
+ <dd>This specifies the alignment for a stack object of a given bit
+ <i>size</i>.</dd>
</dl>
<p>When constructing the data layout for a given target, LLVM starts with a
default set of specifications which are then (possibly) overriden by the
<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
+ <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
</ul>
<p>When LLVM is determining the alignment for a given type, it uses the
following rules:</p>
<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
- <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
- <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
-
- <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
- <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
-
<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
<dd>Perform the <a href="#i_extractelement">extractelement
exception. Additionally, this is important for implementation of
'<tt>catch</tt>' clauses in high-level languages that support them.</p>
-<p>It is not valid to reference the return value of an invoke call from
-anywhere not dominated by the normal label, since an unwind does not
-provide a return value.</p>
+<p>For the purposes of the SSA form, the definition of the value
+returned by the '<tt>invoke</tt>' instruction is deemed to occur on
+the edge from the current block to the "normal" label. If the callee
+unwinds then no return value is available.</p>
<h5>Example:</h5>
<pre>
<h5>Arguments:</h5>
<p>The two arguments to the '<tt>add</tt>' instruction must be <a
- href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
- <a href="#t_vector">vector</a> values. Both arguments must have identical
- types.</p>
+ href="#t_integer">integer</a> or
+ <a href="#t_vector">vector</a> of integer 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>
+<p>The value produced is the integer sum of the two operands.</p>
-<p>If an integer sum has unsigned overflow, the result returned is the
+<p>If the sum has unsigned overflow, the result returned is the
mathematical result modulo 2<sup>n</sup>, where n is the bit width of
the result.</p>
</pre>
</div>
<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>fadd</tt>' instruction must be
+<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
+floating point values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is the floating point sum of the two operands.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ <result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="i_sub">'<tt>sub</tt>' Instruction</a>
</div>
<h5>Arguments:</h5>
<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
- href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
- or <a href="#t_vector">vector</a> values. Both arguments must have identical
- types.</p>
+ href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
+ integer 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>
+<p>The value produced is the integer difference of the two operands.</p>
-<p>If an integer difference has unsigned overflow, the result returned is the
+<p>If the difference has unsigned overflow, the result returned is the
mathematical result modulo 2<sup>n</sup>, where n is the bit width of
the result.</p>
</pre>
</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>fsub</tt>' instruction returns the difference of its two
+operands.</p>
+
+<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
+'<tt>fneg</tt>' instruction present in most other intermediate
+representations.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
+ <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
+ of floating point values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is the floating point difference of the two operands.</p>
+
+<h5>Example:</h5>
+<pre>
+ <result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
+ <result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
+</pre>
+</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="i_mul">'<tt>mul</tt>' Instruction</a>
<h5>Arguments:</h5>
<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
-href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
-or <a href="#t_vector">vector</a> values. Both arguments must have identical
-types.</p>
+href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
+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>
+<p>The value produced is the integer product of the two operands.</p>
-<p>If the result of an integer multiplication has unsigned overflow,
+<p>If the result of the multiplication has unsigned overflow,
the result returned is the mathematical result modulo
2<sup>n</sup>, where n is the bit width of the result.</p>
<p>Because LLVM integers use a two's complement representation, and the
</pre>
</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>fmul</tt>' instruction returns the product of its two
+operands.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>fmul</tt>' instruction must be
+<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
+of floating point values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is the floating point product of the two operands.</p>
+
+<h5>Example:</h5>
+<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
+</pre>
+</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
</a></div>
bytes of memory from the operating system and returns a pointer of the
appropriate type to the program. If "NumElements" is specified, it is the
number of elements allocated, otherwise "NumElements" is defaulted to be one.
-If a constant alignment is specified, the value result of the allocation is guaranteed to
-be aligned to at least that boundary. If not specified, or if zero, the target can
-choose to align the allocation on any convenient boundary.</p>
+If a constant alignment is specified, the value result of the allocation is
+guaranteed to be aligned to at least that boundary. If not specified, or if
+zero, the target can choose to align the allocation on any convenient boundary
+compatible with the type.</p>
<p>'<tt>type</tt>' must be a sized type.</p>
bytes of memory on the runtime stack, returning a pointer of the
appropriate type to the program. If "NumElements" is specified, it is the
number of elements allocated, otherwise "NumElements" is defaulted to be one.
-If a constant alignment is specified, the value result of the allocation is guaranteed
-to be aligned to at least that boundary. If not specified, or if zero, the target
-can choose to align the allocation on any convenient boundary.</p>
+If a constant alignment is specified, the value result of the allocation is
+guaranteed to be aligned to at least that boundary. If not specified, or if
+zero, the target can choose to align the allocation on any convenient boundary
+compatible with the type.</p>
<p>'<tt>type</tt>' may be any sized type.</p>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
-</div>
-<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
-</pre>
-<h5>Overview:</h5>
-<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
-element-wise comparison of its two integer vector operands.</p>
-<h5>Arguments:</h5>
-<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
-the condition code indicating the kind of comparison to perform. It is not
-a value, just a keyword. The possible condition code are:</p>
-<ol>
- <li><tt>eq</tt>: equal</li>
- <li><tt>ne</tt>: not equal </li>
- <li><tt>ugt</tt>: unsigned greater than</li>
- <li><tt>uge</tt>: unsigned greater or equal</li>
- <li><tt>ult</tt>: unsigned less than</li>
- <li><tt>ule</tt>: unsigned less or equal</li>
- <li><tt>sgt</tt>: signed greater than</li>
- <li><tt>sge</tt>: signed greater or equal</li>
- <li><tt>slt</tt>: signed less than</li>
- <li><tt>sle</tt>: signed less or equal</li>
-</ol>
-<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
-<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
-<h5>Semantics:</h5>
-<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
-according to the condition code given as <tt>cond</tt>. The comparison yields a
-<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
-identical type as the values being compared. The most significant bit in each
-element is 1 if the element-wise comparison evaluates to true, and is 0
-otherwise. All other bits of the result are undefined. The condition codes
-are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
-instruction</a>.</p>
-
-<h5>Example:</h5>
-<pre>
- <result> = vicmp eq <2 x i32> < i32 4, i32 0>, < i32 5, i32 0> <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
- <result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
-</pre>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
-</div>
-<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
-<h5>Overview:</h5>
-<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
-element-wise comparison of its two floating point vector operands. The output
-elements have the same width as the input elements.</p>
-<h5>Arguments:</h5>
-<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
-the condition code indicating the kind of comparison to perform. It is not
-a value, just a keyword. The possible condition code are:</p>
-<ol>
- <li><tt>false</tt>: no comparison, always returns false</li>
- <li><tt>oeq</tt>: ordered and equal</li>
- <li><tt>ogt</tt>: ordered and greater than </li>
- <li><tt>oge</tt>: ordered and greater than or equal</li>
- <li><tt>olt</tt>: ordered and less than </li>
- <li><tt>ole</tt>: ordered and less than or equal</li>
- <li><tt>one</tt>: ordered and not equal</li>
- <li><tt>ord</tt>: ordered (no nans)</li>
- <li><tt>ueq</tt>: unordered or equal</li>
- <li><tt>ugt</tt>: unordered or greater than </li>
- <li><tt>uge</tt>: unordered or greater than or equal</li>
- <li><tt>ult</tt>: unordered or less than </li>
- <li><tt>ule</tt>: unordered or less than or equal</li>
- <li><tt>une</tt>: unordered or not equal</li>
- <li><tt>uno</tt>: unordered (either nans)</li>
- <li><tt>true</tt>: no comparison, always returns true</li>
-</ol>
-<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
-<a href="#t_floating">floating point</a> typed. They must also be identical
-types.</p>
-<h5>Semantics:</h5>
-<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
-according to the condition code given as <tt>cond</tt>. The comparison yields a
-<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
-an identical number of elements as the values being compared, and each element
-having identical with to the width of the floating point elements. The most
-significant bit in each element is 1 if the element-wise comparison evaluates to
-true, and is 0 otherwise. All other bits of the result are undefined. The
-condition codes are evaluated identically to the
-<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
-
-<h5>Example:</h5>
-<pre>
- <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
- <result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
-
- <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
- <result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
-</pre>
-</div>
-
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="i_phi">'<tt>phi</tt>' Instruction</a>
block and the PHI instructions: i.e. PHI instructions must be first in
a basic block.</p>
+<p>For the purposes of the SSA form, the use of each incoming value is
+deemed to occur on the edge from the corresponding predecessor block
+to the current block (but after any definition of an '<tt>invoke</tt>'
+instruction's return value on the same edge).</p>
+
<h5>Semantics:</h5>
<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
</p>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
-on any integer bit width.</p>
-<pre>
- declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
- declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
-</pre>
-
-<h5>Overview:</h5>
-<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
-range of bits from an integer value and returns them in the same bit width as
-the original value.</p>
-
-<h5>Arguments:</h5>
-<p>The first argument, <tt>%val</tt> and the result may be integer types of
-any bit width but they must have the same bit width. The second and third
-arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
-
-<h5>Semantics:</h5>
-<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
-of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
-<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
-operates in forward mode.</p>
-<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
-right by <tt>%loBit</tt> bits and then ANDing it with a mask with
-only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
-<ol>
- <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
- by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
- <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
- to determine the number of bits to retain.</li>
- <li>A mask of the retained bits is created by shifting a -1 value.</li>
- <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
-</ol>
-<p>In reverse mode, a similar computation is made except that the bits are
-returned in the reverse order. So, for example, if <tt>X</tt> has the value
-<tt>i16 0x0ACF (101011001111)</tt> and we apply
-<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
-<tt>i16 0x0026 (000000100110)</tt>.</p>
-</div>
-
-<div class="doc_subsubsection">
- <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
-on any integer bit width.</p>
-<pre>
- declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
- declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
-</pre>
-
-<h5>Overview:</h5>
-<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
-of bits in an integer value with another integer value. It returns the integer
-with the replaced bits.</p>
-
-<h5>Arguments:</h5>
-<p>The first argument, <tt>%val</tt>, and the result may be integer types of
-any bit width, but they must have the same bit width. <tt>%val</tt> is the value
-whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
-integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
-type since they specify only a bit index.</p>
-
-<h5>Semantics:</h5>
-<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
-of operation: forwards and reverse. If <tt>%lo</tt> is greater than
-<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
-operates in forward mode.</p>
-
-<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
-truncating it down to the size of the replacement area or zero extending it
-up to that size.</p>
-
-<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
-are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
-in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
-to the <tt>%hi</tt>th bit.</p>
-
-<p>In reverse mode, a similar computation is made except that the bits are
-reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
-<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
-
-<h5>Examples:</h5>
-
-<pre>
- llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
- llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
- llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
- llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
- llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
-</pre>
-
-</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
<h5>Overview:</h5>
-<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
-actively being fixed, but it should not currently be used!</i></p>
-
<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
a unsigned multiplication of the two arguments, and indicate whether an overflow
occurred during the unsigned multiplication.</p>