Correct the documentation for the module block header which uses the long
format instead of the short format used in other blocks.
Discrepancy noted by Robert Mykland. Thanks Robert!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15826 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/BytecodeFormat.html b/docs/BytecodeFormat.html
index 5bb5d53..76365b4 100644
--- a/docs/BytecodeFormat.html
+++ b/docs/BytecodeFormat.html
@@ -614,10 +614,13 @@
<th class="td_left"><b>Field Description</b></th>
</tr>
<tr>
- <td><a href="#block">block</a><br>
- </td>
- <td class="td_left">Module Block Identifier (0x01) and Size<br>
- </td>
+ <td><a href="#unsigned">unsigned</a><br></td>
+ <td class="td_left"><a href="#mod_header">Module Block Identifier
+ (0x01)</a></td>
+ </tr>
+ <tr>
+ <td><a href="#unsigned">unsigned</a></td>
+ <td class="td_left"><a href="#mod_header">Module Block Size</a></td>
</tr>
<tr>
<td><a href="#uint32_vbr">uint32_vbr</a></td>
@@ -646,6 +649,21 @@
</tbody>
</table>
</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"><a name="mod_header">Module Block Header</a></div>
+<div class="doc_text">
+ <p>The block header for the module block uses a longer format than the other
+ blocks in a bytecode file. Specifically, instead of encoding the type and size
+ of the block into a 32-bit integer with 5-bits for type and 27-bits for size,
+ the module block header uses two 32-bit unsigned values, one for type, and one
+ for size. While the 2<sup>27</sup> byte limit on block size is sufficient for the blocks
+ contained in the module, it isn't sufficient for the module block itself
+ because we want to ensure that bytecode files as large as 2<sup>32</sup> bytes
+ are possible. For this reason, the module block (and only the module block)
+ uses a long format header.</p>
+</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection"><a name="format">Format Information</a></div>
<div class="doc_text">