Commit Graph

15 Commits

Author SHA1 Message Date
Chandler Carruth
d984cdc17e [PM] Remove the IRUnitT typedef requirement for analysis passes.
Since the analysis managers were split into explicit function and module
analysis managers, it is now completely trivial to specify this when
building up the concept and model types explicitly, and it is impossible
to end up with a type error at run time. We instantiate a template when
registering a pass that will enforce the requirement at a type-system
level, and we produce a dynamic error on all the other query paths to
the analysis manager if the pass in question isn't registered.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195447 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 11:46:33 +00:00
Chandler Carruth
3f081983cc [PM] Fix the analysis templates' usage of IRUnitT.
This is supposed to be the whole type of the IR unit, and so we
shouldn't pass a pointer to it but rather the value itself. In turn, we
need to provide a 'Module *' as that type argument (for example). This
will become more relevant with SCCs or other units which may not be
passed as a pointer type, but also brings consistency with the
transformation pass templates.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195445 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 11:34:43 +00:00
Chandler Carruth
d793a053ad [PM] Switch analysis managers to be threaded through the run methods
rather than the constructors of passes.

This simplifies the APIs of passes significantly and removes an error
prone pattern where the *same* manager had to be given to every
different layer. With the new API the analysis managers themselves will
have to be cross connected with proxy analyses that allow a pass at one
layer to query for the analysis manager of another layer. The proxy will
both expose a handle to the other layer's manager and it will provide
the invalidation hooks to ensure things remain consistent across layers.
Finally, the outer-most analysis manager has to be passed to the run
method of the outer-most pass manager. The rest of the propagation is
automatic.

I've used SFINAE again to allow passes to completely disregard the
analysis manager if they don't need or want to care. This helps keep
simple things simple for users of the new pass manager.

Also, the system specifically supports passing a null pointer into the
outer-most run method if your pass pipeline neither needs nor wants to
deal with analyses. I find this of dubious utility as while some
*passes* don't care about analysis, I'm not sure there are any
real-world users of the pass manager itself that need to avoid even
creating an analysis manager. But it is easy to support, so there we go.

Finally I renamed the module proxy for the function analysis manager to
the more verbose but less confusing name of
FunctionAnalysisManagerModuleProxy. I hate this name, but I have no idea
what else to name these things. I'm expecting in the fullness of time to
potentially have the complete cross product of types at the proxy layer:

{Module,SCC,Function,Loop,Region}AnalysisManager{Module,SCC,Function,Loop,Region}Proxy

(except for XAnalysisManagerXProxy which doesn't make any sense)

This should make it somewhat easier to do the next phases which is to
build the upward proxy and get its invalidation correct, as well as to
make the invalidation within the Module -> Function mapping pass be more
fine grained so as to invalidate fewer fuction analyses.

After all of the proxy analyses are done and the invalidation working,
I'll finally be able to start working on the next two fun fronts: how to
adapt an existing pass to work in both the legacy pass world and the new
one, and building the SCC, Loop, and Region counterparts. Fun times!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195400 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 00:43:29 +00:00
Chandler Carruth
edd2b49134 [PM] Widen the interface for invalidate on an analysis result now that
it is completely optional, and sink the logic for handling the preserved
analysis set into it.

This allows us to implement the delegation logic desired in the proxy
module analysis for the function analysis manager where if the proxy
itself is preserved we assume the set of functions hasn't changed and we
do a fine grained invalidation by walking the functions in the module
and running the invalidate for them all at the manager level and letting
it try to invalidate any passes.

This in turn makes it blindingly obvious why we should hoist the
invalidate trait and have two collections of results. That allows
handling invalidation for almost all analyses without indirect calls and
it allows short circuiting when the preserved set is all.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195338 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-21 10:53:05 +00:00
Chandler Carruth
212226e114 [PM] Add support for using SFINAE to reflect on an analysis's result
type and detect whether or not it provides an 'invalidate' member the
analysis manager should use.

This lets the overwhelming common case of *not* caring about custom
behavior when an analysis is invalidated be the the obvious default
behavior with no code written by the author of an analysis. Only when
they write code specifically to handle invalidation does it get used.

Both cases are actually covered by tests here. The test analysis uses
the default behavior, and the proxy module analysis actually has custom
behavior on invalidation that is firing correctly. (In fact, this is the
analysis which was the primary motivation for having custom invalidation
behavior in the first place.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195332 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-21 09:10:21 +00:00
Chandler Carruth
7fac06c423 [PM] Add a module analysis pass proxy for the function analysis manager.
This proxy will fill the role of proxying invalidation events down IR
unit layers so that when a module changes we correctly invalidate
function analyses. Currently this is a very coarse solution -- any
change blows away the entire thing -- but the next step is to make
invalidation handling more nuanced so that we can propagate specific
amounts of invalidation from one layer to the next.

The test is extended to place a module pass between two function pass
managers each of which have preserved function analyses which get
correctly invalidated by the module pass that might have changed what
functions are even in the module.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195304 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-21 02:11:31 +00:00
Chandler Carruth
c49e7e6aee [PM] Add the preservation system to the new pass manager.
This adds a new set-like type which represents a set of preserved
analysis passes. The set is managed via the opaque PassT::ID() void*s.
The expected convenience templates for interacting with specific passes
are provided. It also supports a symbolic "all" state which is
represented by an invalid pointer in the set. This state is nicely
saturating as it comes up often. Finally, it supports intersection which
is used when finding the set of preserved passes after N different
transforms.

The pass API is then changed to return the preserved set rather than
a bool. This is much more self-documenting than the previous system.
Returning "none" is a conservatively correct solution just like
returning "true" from todays passes and not marking any passes as
preserved. Passes can also be dynamically preserved or not throughout
the run of the pass, and whatever gets returned is the binding state.
Finally, preserving "all" the passes is allowed for no-op transforms
that simply can't harm such things.

Finally, the analysis managers are changed to instead of blindly
invalidating all of the analyses, invalidate those which were not
preserved. This should rig up all of the basic preservation
functionality. This also correctly combines the preservation moving up
from one IR-layer to the another and the preservation aggregation across
N pass runs. Still to go is incrementally correct invalidation and
preservation across IR layers incrementally during N pass runs. That
will wait until we have a device for even exposing analyses across IR
layers.

While the core of this change is obvious, I'm not happy with the current
testing, so will improve it to cover at least some of the invalidation
that I can test easily in a subsequent commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195241 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-20 11:31:50 +00:00
Chandler Carruth
d14894059f [PM] Make the function pass manager more regular.
The FunctionPassManager is now itself a function pass. When run over
a function, it runs all N of its passes over that function. This is the
1:N mapping in the pass dimension only. This allows it to be used in
either a ModulePassManager or potentially some other manager that
works on IR units which are supersets of Functions.

This commit also adds the obvious adaptor to map from a module pass to
a function pass, running the function pass across every function in the
module.

The test has been updated to use this new pattern.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195192 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-20 04:39:16 +00:00
Chandler Carruth
523d929368 [PM] Split the analysis manager into a function-specific interface and
a module-specific interface. This is the first of many steps necessary
to generalize the infrastructure such that we can support both
a Module-to-Function and Module-to-SCC-to-Function pass manager
nestings.

After a *lot* of attempts that never worked and didn't even make it to
a committable state, it became clear that I had gotten the layering
design of analyses flat out wrong. Four days later, I think I have most
of the plan for how to correct this, and I'm starting to reshape the
code into it. This is just a baby step I'm afraid, but starts separating
the fundamentally distinct concepts of function analysis passes and
module analysis passes so that in subsequent steps we can effectively
layer them, and have a consistent design for the eventual SCC layer.

As part of this, I've started some interface changes to make passes more
regular. The module pass accepts the module in the run method, and some
of the constructor parameters are gone. I'm still working out exactly
where constructor parameters vs. method parameters will be used, so
I expect this to fluctuate a bit.

This actually makes the invalidation less "correct" at this phase,
because now function passes don't invalidate module analysis passes, but
that was actually somewhat of a misfeature. It will return in a better
factored form which can scale to other units of IR. The documentation
has gotten less verbose and helpful.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195189 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-20 04:01:38 +00:00
Chandler Carruth
8417e85781 [PM] Completely remove support for explicit 'require' methods on the
AnalysisManager. All this method did was assert something and we have
a perfectly good way to trigger that assert from the query path.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194947 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-17 03:18:05 +00:00
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
Chandler Carruth
ea9988447c [PM] Start sketching out the new module and function pass manager.
This is still just a skeleton. I'm trying to pull together the
experimentation I've done into committable chunks, and this is the first
coherent one. Others will follow in hopefully short order that move this
more toward a useful initial implementation. I still expect the design
to continue evolving in small ways as I work through the different
requirements and features needed here though.

Keep in mind, all of this is off by default.

Currently, this mostly exercises the use of a polymorphic smart pointer
and templates to hide the polymorphism for the pass manager from the
pass implementation. The next step will be more significant, adding the
first framework of analysis support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194325 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-09 13:09:08 +00:00
Chandler Carruth
49837ef811 Move the old pass manager infrastructure into a legacy namespace and
give the files a legacy prefix in the right directory. Use forwarding
headers in the old locations to paper over the name change for most
clients during the transitional period.

No functionality changed here! This is just clearing some space to
reduce renaming churn later on with a new system.

Even when the new stuff starts to go in, it is going to be hidden behind
a flag and off-by-default as it is still WIP and under development.

This patch is specifically designed so that very little out-of-tree code
has to change. I'm going to work as hard as I can to keep that the case.
Only direct forward declarations of the PassManager class are impacted
by this change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194324 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-09 12:26:54 +00:00
Rafael Espindola
c143c7573b Merge CallGraph and BasicCallGraph.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193734 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-31 03:03:55 +00:00
Chandler Carruth
c779e96158 Rename the VMCore unittest tree to IR. Somehow was missed when doing the
library rename.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171747 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 15:35:46 +00:00