add the ability for TargetData to return information about legal integer
datatypes on a given CPU.  This is intended to allow instcombine and other
transformations to avoid converting big sequences of operations to an
inconvenient width, and will help clean up after SRoA.  See also "Adding 
legal integer sizes to TargetData" on Feb 1, 2009 on llvmdev, and PR3451.

Comments welcome.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86370 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LangRef.html b/docs/LangRef.html
index 7032a19..eea1f03 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -1215,6 +1215,13 @@
   <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>
+
+  <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
+  <dd>This specifies a set of native integer widths for the target CPU
+      in bits.  For example, it might contain "n32" for 32-bit PowerPC,
+      "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64.  Elements of
+      this set are considered to support most general arithmetic 
+      operations efficiently.</dd>
 </dl>
 
 <p>When constructing the data layout for a given target, LLVM starts with a