Clarify some of the differences between indexing with getelementptr and indexing...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120957 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/LangRef.html b/docs/LangRef.html
index 68d65f1a972476ffd21c044bcad89397b186111b..76fa06f49c24d0746822bad95173c69840d85dbd 100644 (file)
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -4131,6 +4131,14 @@ Instruction</a> </div>
    <a href="#t_array">array</a> type.  The operands are constant indices to
    specify which value to extract in a similar manner as indices in a
    '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
+   <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
+     <ul>
+       <li>Since the value being indexed is not a pointer, the first index is
+           omitted and assumed to be zero.</li>
+       <li>At least one index must be specified.</li>
+       <li>Not only struct indices but also array indices must be in
+           bounds.</li>
+     </ul>
 
 <h5>Semantics:</h5>
 <p>The result is the value at the position in the aggregate specified by the
@@ -4165,7 +4173,7 @@ Instruction</a> </div>
    <a href="#t_array">array</a> type.  The second operand is a first-class
    value to insert.  The following operands are constant indices indicating
    the position at which to insert the value in a similar manner as indices in a
-   '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.  The
+   '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction.  The
    value to insert must have the same type as the value identified by the
    indices.</p>