Merged Misha Modifications from Mainline.

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>

<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>