add PTX backend info
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144711 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html
index ab83daa..036a0d2 100644
--- a/docs/ReleaseNotes.html
+++ b/docs/ReleaseNotes.html
@@ -995,6 +995,7 @@
-->
</ul>
</div>
+
<!--=========================================================================-->
<h3>
@@ -1016,7 +1017,30 @@
<li>Initial support for MIPS64 has been added.</li>
</ul>
</div>
+
+<!--=========================================================================-->
+<h3>
+ <a name="PTX">PTX Target Improvements</a>
+</h3>
+
+<div>
+ <p>
+ The PTX back-end is still experimental, but is fairly usable for compute kernels
+ in LLVM 3.0. Most scalar arithmetic is implemented, as well as intrinsics to
+ access the special PTX registers and sync instructions. The major missing
+ pieces are texture/sampler support and some vector operations.</p>
+
+ <p>That said, the backend is already being used for domain-specific languages
+ and works well with the <a href="http://www.pcc.me.uk/~peter/libclc/">libclc
+ library</a> to supply OpenCL built-ins. With it, you can use Clang to compile
+ OpenCL code into PTX and execute it by loading the resulting PTX as a binary
+ blob using the nVidia OpenCL library. It has been tested with several OpenCL
+ programs, including some from the nVidia GPU Computing SDK, and the performance
+ is on par with the nVidia compiler.</p>
+
+</div>
+
<!--=========================================================================-->
<h3>
<a name="OtherTS">Other Target Specific Improvements</a>