llvm-6502/docs/ChrisNotes.txt

* Rewrite the llvm parser/lexer in http://www.antlr.org when time permits.
  They actually do C++.  Imagine that.
* Fix DCE to elminate br <c>, %L1, %L1 so that it can optimize the main of
  fib.ll better.  Currently I have to do this to get best results:
     as < fib.ll | opt -inline -sccp -dce -sccp -dce |dis
* fix the constprop   br <x> <dst1> <dst1> case.  Must handle PHI nodes correctly
* Fix DCE to work better, so that SCCP can show it's true value.
* Implement ADCE
* Think about whether edge split SSA form would be useful to do.
* Inlining should attempt to give block names the same name in the inlined 
  method (using SymbolTable::getUniqueName)
* The dropAllReferences code can be a noop when NDEBUG!!!
* Finish xvcg output
* pred/succ iterators on basic blocks don't handle switch statements correctly
* Provide a pass that eliminates critical edges from the CFG
* I need to provide an option to the bytecode loader to ignore memory 
  dependance edges.  Instead, the VM would just treat memory operations 
  (load, store, getfield, putfield, call) as pinned instructions.
* Need a way to attach bytecode block info at various levels of asm code.
* Recognize and save comments in assembly and bytecode format
* Encode line number table in bytecode (like #line), optional table

* Encode negative relative offsets in the bytecode file

* Implement switch to switch on a constant pool array of type: 
  [{ label, int }] or [label]   (lookup vs index switch)
* Apparently bison has a %pure_parser option.  Maybe useful for Assembly/Parser

* Implement a header file that can read either assembly or bytecode, implement 
  a writer that can output either based on what is read with this reader..
* Implement the following derived types:
  * "packed format", like this:    [4 x sbyte]: Packed SIMD datatype
* Maybe 'tailcall' also?
* Include a method level bytecode block that defines a mapping between values 
  and registers that defines a minimally register allocated code.  This can
  make me finally address how to encode extensions in assembly.
* Bytecode reader should use extensions that may or may not be linked into the
  application to read blocks.  Thus an easy way to ignore symbol table info
  would be to not link in that reader into the app.