llvm/unittests
Chandler Carruth f348c9782c Introduce an AnalysisManager which is like a pass manager but with a lot
more smarts in it. This is where most of the interesting logic that used
to live in the implicit-scheduling-hackery of the old pass manager will
live.

Like the previous commits, note that this is a very early prototype!
I expect substantial changes before this is ready to use.

The core of the design is the following:

- We have an AnalysisManager which can be used across a series of
  passes over a module.
- The code setting up a pass pipeline registers the analyses available
  with the manager.
- Individual transform passes can check than an analysis manager
  provides the analyses they require in order to fail-fast.
- There is *no* implicit registration or scheduling.
- Analysis passes are different from other passes: they produce an
  analysis result that is cached and made available via the analysis
  manager.
- Cached results are invalidated automatically by the pass managers.
- When a transform pass requests an analysis result, either the analysis
  is run to produce the result or a cached result is provided.

There are a few aspects of this design that I *know* will change in
subsequent commits:
- Currently there is no "preservation" system, that needs to be added.
- All of the analysis management should move up to the analysis library.
- The analysis management needs to support at least SCC passes. Maybe
  loop passes. Living in the analysis library will facilitate this.
- Need support for analyses which are *both* module and function passes.
- Need support for pro-actively running module analyses to have cached
  results within a function pass manager.
- Need a clear design for "immutable" passes.
- Need support for requesting cached results when available and not
  re-running the pass even if that would be necessary.
- Need more thorough testing of all of this infrastructure.

There are other aspects that I view as open questions I'm hoping to
resolve as I iterate a bit on the infrastructure, and especially as
I start writing actual passes against this.
- Should we have separate management layers for function, module, and
  SCC analyses? I think "yes", but I'm not yet ready to switch the code.
  Adding SCC support will likely resolve this definitively.
- How should the 'require' functionality work? Should *that* be the only
  way to request results to ensure that passes always require things?
- How should preservation work?
- Probably some other things I'm forgetting. =]

Look forward to more patches in shorter order now that this is in place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194538 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-13 01:12:08 +00:00
..
ADT Switch to allow implicit construction. In many cases, we're wrapping 2013-11-09 05:55:03 +00:00
Analysis Fix an oversight in isPotentiallyReachable where we wouldn't do any CFG-walking 2013-08-13 00:03:47 +00:00
Bitcode llvm/unittests: Use OwningPtr to fix --vg-leak. 2013-01-23 08:33:13 +00:00
CodeGen DIEHash: Summary hashing of member functions 2013-10-25 20:04:25 +00:00
DebugInfo DWARF parser: propery handle DW_FORM_ref_sig8 and fix Windows build. 2013-10-29 16:32:19 +00:00
ExecutionEngine Removing unnecessary link component for MCJIT unittests 2013-10-21 22:35:06 +00:00
IR Introduce an AnalysisManager which is like a pass manager but with a lot 2013-11-13 01:12:08 +00:00
MC Fix MCDataAtom never calling remap when adding data. 2013-10-16 18:26:16 +00:00
Object Update incorrect file headers. 2013-08-01 18:42:28 +00:00
Option Option parsing: support case-insensitive option matching. 2013-08-28 20:04:31 +00:00
Support Simplify ErrorOr. 2013-11-05 00:28:01 +00:00
Transforms Introduce SpecialCaseList::isIn overload for GlobalAliases. 2013-08-19 19:00:35 +00:00
CMakeLists.txt Fix MCDataAtom never calling remap when adding data. 2013-10-16 18:26:16 +00:00
Makefile Revert "Move copying of global initializers below the cloning of functions." 2013-11-09 00:43:18 +00:00
Makefile.unittest build/unittests: Fix llvm-config names for gtest libraries, and bring Makefile 2011-12-15 23:35:08 +00:00