Merged Misha Modifications from Mainline.

llvm-svn: 22105

1 files changed, 16 insertions, 12 deletions

diff --git a/llvm/docs/WritingAnLLVMBackend.html b/llvm/docs/WritingAnLLVMBackend.html
index dcea204e47cd..c215fc62a3f3 100644
--- a/llvm/docs/WritingAnLLVMBackend.html
+++ b/llvm/docs/WritingAnLLVMBackend.html
@@ -109,15 +109,16 @@ described the instruction set with the assembly printer generator in mind, that
 step can be almost automated.</li>
 </ul>
 
-<p>Now, for static code generation you also need to write an instruction
-selector for your platform: see <tt>lib/Target/*/*ISelSimple.cpp</tt> which
-is no longer "simple" but it gives you the idea: you have to be able to create
-MachineInstrs for any given LLVM instruction using the <tt>InstVisitor</tt>
-pattern, and produce a <tt>MachineFunction</tt> with
-<tt>MachineBasicBlock</tt>s full of <tt><a
-href="CodeGenerator.html#machineinstr">MachineInstr</a></tt>s for a
-corresponding LLVM Function.  Creating an instruction selector is perhaps the
-most time-consuming part of creating a back-end.</p> 
+<p>You also need to write an instruction selector for your platform.  The
+recommended method is the <a
+href="CodeGenerator.html#instselect">pattern-matching instruction selector</a>,
+examples of which you can see in other targets:
+<tt>lib/Target/*/*ISelPattern.cpp</tt>.  The former method for writing
+instruction selectors (<b>not</b> recommended for new targets) is evident in
+<tt>lib/Target/*/*ISelSimple.cpp</tt>, which are <tt>InstVisitor</tt>-based
+translators, generating code for an LLVM instruction at a time.  Creating an
+instruction selector is perhaps the most time-consuming part of creating a
+back-end.</p>
 
 <p>To create a JIT for your platform:</p>
 
@@ -229,10 +230,13 @@ how the C backend is written.</p>
 <ul>
 <li><a href="CodeGenerator.html">Code generator</a> -
     describes some of the classes in code generation at a high level, but
-    it is not (yet) complete.</li>
+    it is not (yet) complete</li>
 <li><a href="TableGenFundamentals.html">TableGen fundamentals</a> -
-    describes how to use TableGen to describe your target information succinctly
-</li>
+    describes how to use TableGen to describe your target information
+    succinctly</li>
+<li><a href="HowToSubmitABug.html#codegen">Debugging code generation with
+    bugpoint</a> - shows bugpoint usage scenarios to simplify backend
+    development</li>
 </ul>
 
 </div>