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Document llvm.umul.with.overflow indicating that it's badly broken and not intended for use. 

llvm-svn: 64104
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Bill Wendling 2009-02-08 23:00:09 +00:00
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llvm/docs/LangRef.html
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@ -216,6 +216,7 @@
<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
</ol>
</li>
<li><a href="#int_debugger">Debugger intrinsics</a></li>
@ -6170,6 +6171,59 @@ overflow.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
on any integer bit width.</p>
<pre>
declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
</pre>
<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>
<h5>Arguments:</h5>
<p>The arguments (%a and %b) and the first element of the result structure may
be of integer types of any bit width, but they must have the same bit width. The
second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
and <tt>%b</tt> are the two values that will undergo unsigned
multiplication.</p>
<h5>Semantics:</h5>
<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
an unsigned multiplication of the two arguments. They return a structure &mdash;
the first element of which is the multiplication, and the second element of
which is a bit specifying if the unsigned multiplication resulted in an
overflow.</p>
<h5>Examples:</h5>
<pre>
%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
%sum = extractvalue {i32, i1} %res, 0
%obit = extractvalue {i32, i1} %res, 1
br i1 %obit, label %overflow, label %normal
</pre>
</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="int_debugger">Debugger Intrinsics</a>