Commit Graph

47 Commits

Author SHA1 Message Date
Craig Topper
273fd11da9 Use range based for loops to avoid needing to re-mention SmallPtrSet size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216351 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-24 23:23:06 +00:00
Benjamin Kramer
00e08fcaa0 Canonicalize header guards into a common format.
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)

Changes made by clang-tidy with minor tweaks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215558 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-13 16:26:38 +00:00
Craig Topper
e703fcb975 [C++] Use 'nullptr'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207083 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 06:44:33 +00:00
Craig Topper
ec0f0bc6af [C++11] More 'nullptr' conversion or in some cases just using a boolean check instead of comparing to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205831 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-09 06:08:46 +00:00
Chandler Carruth
2d74092f5f [PM] As was pointed out in review, I need to define a custom swap in
order to use the single assignment. That's probably worth doing for
a lot of these types anyways as they may have non-trivial moves and so
getting copy elision in more places seems worthwhile.

I've tried to add some tests that actually catch this mistake, and one
of the types is now well tested but the others' tests still fail to
catch this. I'll keep working on tests, but this gets the core pattern
right.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203780 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-13 10:42:18 +00:00
Chandler Carruth
04239506f1 [PM] Stop playing fast and loose with rebinding of references. However
convenient it is to imagine a world where this works, that is not C++ as
was pointed out in review. The standard even goes to some lengths to
preclude any attempt at this, for better or worse. Maybe better. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203775 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-13 09:50:31 +00:00
Chandler Carruth
87d5f1babe [PM] Cleanup formatting and namespace commenting. Mostly done with
clang-format, but with some modifications by me where it got things
wrong or got confused.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203432 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-10 01:42:03 +00:00
Chandler Carruth
209ae573e0 [PM] As Dave noticed in review, I had erroneously copied the move
constructors from the classes which only have a single reference member
to many other places. This resulted in them copying their single member
instead of moving. =/ Fix this.

There's really not a useful test to add sadly because these move
constructors are only called when something deep inside some standard
library implementation *needs* to move them. Many of the types aren't
even user-impacting types. Or, the objects are copyable anyways and so
the result was merely a performance problem rather than a correctness
problem.

Anyways, thanks for the review. And this is a great example of why
I wish I colud have the compiler write these for me.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203431 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-10 01:32:25 +00:00
Chandler Carruth
9e215b0880 [PM] Add a comment I missed and add the special members to one more
class that might (at some point) need them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203428 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-10 00:54:01 +00:00
Chandler Carruth
1bb614e8da [PM] Comment on all of the totally pointless definitions of special
members as being te workaround MSVC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203427 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-10 00:50:56 +00:00
Chandler Carruth
153ed40614 [PM] I have been educated by several folks that MSVC will never
synthesize a move constructor. Thus, for any types where move semantics
are important (yea, that's essentially every type...) you must
explicitly define the special members. Do so systematically throughout
the pass manager as the core of the design relies heavily on move
semantics.

This will hopefully fix the build with MSVC 2013. We still don't know
why MSVC 2012 accepted this code, but it almost certainly wasn't doing
the right thing.

I've also added explicit to a few single-argument constructors spotted
in passing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203426 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-10 00:35:47 +00:00
Chandler Carruth
15903b7dc5 [PM] Switch new pass manager from polymorphic_ptr to unique_ptr now that
it is available. Also make the move semantics sufficiently correct to
tolerate move-only passes, as the PassManagers *are* move-only passes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203391 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-09 11:49:53 +00:00
Craig Topper
c83e68f732 [C++11] Add 'override' keyword to virtual methods that override their base class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203345 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-08 08:27:28 +00:00
Craig Topper
c37e6c0734 [C++11] Add 'override' keyword to virtual methods that override their base class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202945 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-05 07:30:04 +00:00
Chandler Carruth
0a3eef53d7 [C++11] Switch all uses of the llvm_move macro to use std::move
directly, and remove the macro.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202612 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-02 04:08:41 +00:00
Chandler Carruth
bc1bddb4c6 [C++11] Remove the use of LLVM_HAS_RVALUE_REFERENCES from the rest of
the core LLVM libraries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202582 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-01 09:32:03 +00:00
Chandler Carruth
77b655c1c9 [PM] Don't require analysis results to be const in the new pass manager.
I think this was just over-eagerness on my part. The analysis results
need to often be non-const because they need to (in some cases at least)
be updated by the transformation pass in order to remain correct. It
also makes lazy analyses (a common case) needlessly annoying to write in
order to make their entire state mutable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200881 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-05 21:41:42 +00:00
Chandler Carruth
b56749c3b7 [PM] Add names to passes under the new pass manager, and a debug output
mode that can be used to debug the execution of everything.

No support for analyses here, that will come later. This already helps
show parts of the opt commandline integration that isn't working. Tests
of that will start using it as the bugs are fixed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199004 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-11 11:52:05 +00:00
Chandler Carruth
d55b5fe992 [PM] Somehow I missed the header guards on this file. Yikes!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199003 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-11 10:59:00 +00:00
Chandler Carruth
974a445bd9 Re-sort all of the includes with ./utils/sort_includes.py so that
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.

Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198685 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 11:48:04 +00:00
Chandler Carruth
7a46096665 [PM] Fix a stale comment after my last refactoring spoted by Joey in
review!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195757 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-26 12:00:58 +00:00
Chandler Carruth
9200d12fd5 [PM] Remove four extraneous 'typename's that Clang (in C++11 mode) is
happy with but GCC complains about. I'm assuming both compilers are
correct and these are optional in C++11 because I'm too tired to read
the standard. ;]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195748 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-26 11:31:06 +00:00
Chandler Carruth
0dd9c5f9e4 [PM] Factor the overwhelming majority of the interface boiler plate out
of the two analysis managers into a CRTP base class that can be shared
and re-used in building any analysis manager. This will in turn simplify
adding yet another analysis manager to the system.

The base class provides all of the interface sugar for the analysis
manager delegating the functionality back through DerivedT methods which
operate on simple pass IDs. It also provides the pass registration,
storage, and lookup system which is common across the various
formulations of analysis managers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195747 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-26 11:24:37 +00:00
Chandler Carruth
e510665548 [PM] Complete the cross-layer interfaces with a Module-to-Function
proxy. This lets a function pass query a module analysis manager.
However, the interface is const to indicate that only cached results can
be safely queried.

With this, I think the new pass manager is largely functionally complete
for modules and analyses. Still lots to test, and need to generalize to
SCCs and Loops, and need to build an adaptor layer to support the use of
existing Pass objects in the new managers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195538 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-23 01:25:07 +00:00
Chandler Carruth
b88831b204 [PM] Add support to the analysis managers to query explicitly for cached
results.

This is the last piece of infrastructure needed to effectively support
querying *up* the analysis layers. The next step will be to introduce
a proxy which provides access to those layers with appropriate use of
const to direct queries to the safe interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195525 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-23 00:38:42 +00:00
Chandler Carruth
4d32e85359 [PM] Switch the downward invalidation to be incremental where only the
one function's analyses are invalidated at a time. Also switch the
preservation of the proxy to *fully* preserve the lower (function)
analyses.

Combined, this gets both upward and downward analysis invalidation to
a point I'm happy with:

- A function pass invalidates its function analyses, and its parent's
  module analyses.
- A module pass invalidates all of its functions' analyses including the
  set of which functions are in the module.
- A function pass can preserve a module analysis pass.
- If all function passes preserve a module analysis pass, that
  preservation persists. If any doesn't the module analysis is
  invalidated.
- A module pass can opt into managing *all* function analysis
  invalidation itself or *none*.
- The conservative default is none, and the proxy takes the maximally
  conservative approach that works even if the set of functions has
  changed.
- If a module pass opts into managing function analysis invalidation it
  has to propagate the invalidation itself, the proxy just does nothing.

The only thing really missing is a way to query for a cached analysis or
nothing at all. With this, function passes can more safely request
a cached module analysis pass without fear of it accidentally running
part way through.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195519 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 23:38:07 +00:00
Chandler Carruth
2fd69d0fcc [PM] Remove a FIXME comment that was fixed by my recent refactorings:
now the access to the manager is via the proxy that ensures it behaves
correctly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195518 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 23:37:54 +00:00
Chandler Carruth
e1bacb886d [PM] Remove extraneous space that I left in there.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195453 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 12:26:40 +00:00
Chandler Carruth
5f347a9bd1 [PM] Teach the analysis managers to pass themselves as arguments to the
run methods of the analysis passes.

Also generalizes and re-uses the SFINAE for transformation passes so
that users can write an analysis pass and only accept an analysis
manager if that is useful to their pass.

This completes the plumbing to make an analysis manager available
through every pass's run method if desired so that passes no longer need
to be constructed around them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195451 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 12:11:02 +00:00
Chandler Carruth
1fe44e4bef [PM] Reverse the template arguments 'PassT' and 'AnalysisManagerT' in
several templates. The previous order didn't make any sense as it
separated 'IRUnitT' and 'AnalysisManagerT', the types which are
essentially paired and passed along together throughout the layers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195450 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 11:55:38 +00:00
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
ef70984795 [PM] Simplify how the SFINAE for AnalysisResultModel is applied by
factoring it out into the default template argument so clients don't
have to even think about it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195402 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-22 00:48:49 +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
a5f9e4ed39 [PM] Fix typo and trailing space.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195340 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-21 11:04:53 +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
4701c4702e Fix the header comment of the new pass manager stuff to not claim to be
the legacy stuff. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194689 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-14 10:55:14 +00:00
Chandler Carruth
429af0e0a7 Add another (perhaps better) video for Sean's talk. (Thanks Marshall!)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194549 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-13 02:49:38 +00:00
Chandler Carruth
cfe36cb02a Give folks a reference to some material on the fundamental design
pattern in use here. Addresses review feedback from Sean (thanks!) and
others.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194541 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-13 01:51:36 +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