Commit Graph

137 Commits

Author SHA1 Message Date
Chandler Carruth 89c45a162f [PM] Port GVN to the new pass manager, wire it up, and teach a couple of
tests to run GVN in both modes.

This is mostly the boring refactoring just like SROA and other complex
transformation passes. There is some trickiness in that GVN's
ValueNumber class requires hand holding to get to compile cleanly. I'm
open to suggestions about a better pattern there, but I tried several
before settling on this. I was trying to balance my desire to sink as
much implementation detail into the source file as possible without
introducing overly many layers of abstraction.

Much like with SROA, the design of this system is made somewhat more
cumbersome by the need to support both pass managers without duplicating
the significant state and logic of the pass. The same compromise is
struck here.

I've also left a FIXME in a doxygen comment as the GVN pass seems to
have pretty woeful documentation within it. I'd like to submit this with
the FIXME and let those more deeply familiar backfill the information
here now that we have a nice place in an interface to put that kind of
documentaiton.

Differential Revision: http://reviews.llvm.org/D18019

llvm-svn: 263208
2016-03-11 08:50:55 +00:00
Chandler Carruth 4c660f7087 [CG] Add a new pass manager printer pass for the old call graph and
actually finish wiring up the old call graph.

There were bugs in the old call graph that hadn't been caught because it
wasn't being tested. It wasn't being tested because it wasn't in the
pipeline system and we didn't have a printing pass to run in tests. This
fixes all of that.

As for why I'm still keeping the old call graph alive its so that I can
port GlobalsAA to the new pass manager with out forking it to work with
the lazy call graph. That's clearly the right eventual design, but it
seems pragmatic to defer that until its necessary. The old call graph
works just fine for GlobalsAA.

llvm-svn: 263104
2016-03-10 11:24:11 +00:00
Chandler Carruth b95def7491 [LCG] Spell the printing pass pipeline name for the lazy call graph
'lcg' instead of just 'cg'.

This makes it consistent with the analysis name of 'lcg'.

No functionality changed.

llvm-svn: 263103
2016-03-10 11:24:06 +00:00
Chandler Carruth 61440d225b [PM] Port memdep to the new pass manager.
This is a fairly straightforward port to the new pass manager with one
exception. It removes a very questionable use of releaseMemory() in
the old pass to invalidate its caches between runs on a function.
I don't think this is really guaranteed to be safe. I've just used the
more direct port to the new PM to address this by nuking the results
object each time the pass runs. While this could cause some minor malloc
traffic increase, I don't expect the compile time performance hit to be
noticable, and it makes the correctness and other aspects of the pass
much easier to reason about. In some cases, it may make things faster by
making the sets and maps smaller with better locality. Indeed, the
measurements collected by Bruno (thanks!!!) show mostly compile time
improvements.

There is sadly very limited testing at this point as there are only two
tests of memdep, and both rely on GVN. I'll be porting GVN next and that
will exercise this heavily though.

Differential Revision: http://reviews.llvm.org/D17962

llvm-svn: 263082
2016-03-10 00:55:30 +00:00
Chandler Carruth 8b5a7419b8 [PM] Wire up optimization levels and default pipeline construction APIs
in the PassBuilder.

These are really just stubs for now, but they give a nice API surface
that Clang or other tools can start learning about and enabling for
experimentation.

I've also wired up parsing various synthetic module pass names to
generate these set pipelines. This allows the pipelines to be combined
with other passes and have their order controlled, with clear separation
between the *kind* of canned pipeline, and the *level* of optimization
to be used within that canned pipeline.

The most interesting part of this patch is almost certainly the spec for
the different optimization levels. I don't think we can ever have hard
and fast rules that would make it easy to determine whether a particular
optimization makes sense at a particular level -- it will always be in
large part a judgement call. But hopefully this will outline the
expected rationale that should be used, and the direction that the
pipelines should be taken. Much of this was based on a long llvm-dev
discussion I started years ago to try and crystalize the intent behind
these pipelines, and now, at long long last I'm returning to the task of
actually writing it down somewhere that we can cite and try to be
consistent with.

Differential Revision: http://reviews.llvm.org/D12826

llvm-svn: 262196
2016-02-28 22:16:03 +00:00
Chandler Carruth 470734b512 [PM] Finish removing references to fix MSVC builds. Somehow adding base
classes changed whether the decltype of these expressions was
a reference. I'm somewhat horrified why, and there may need to be
a deeper fix on MSVC, but this should at least get the bots a step
further.

llvm-svn: 262008
2016-02-26 12:30:18 +00:00
Chandler Carruth 58dde8cbc5 [PM] Speculative patch to try and fix MSVC's compilation.
No idea why r262004 triggered this, but just trying to fix somehow.

llvm-svn: 262006
2016-02-26 12:17:54 +00:00
Chandler Carruth 3a63435551 [PM] Introduce CRTP mixin base classes to help define passes and
analyses in the new pass manager.

These just handle really basic stuff: turning a type name into a string
statically that is nice to print in logs, and getting a static unique ID
for each analysis.

Sadly, the format of passes in anonymous namespaces makes using their
names in tests really annoying so I've customized the names of the no-op
passes to keep tests sane to read.

This is the first of a few simplifying refactorings for the new pass
manager that should reduce boilerplate and confusion.

llvm-svn: 262004
2016-02-26 11:44:45 +00:00
Hongbin Zheng bc53977a0d Introduce RegionInfoAnalysis, which compute Region Tree in the new PassManager. NFC
Differential Revision: http://reviews.llvm.org/D17571

llvm-svn: 261904
2016-02-25 17:54:25 +00:00
Hongbin Zheng 751337faa7 Introduce DominanceFrontierAnalysis to the new PassManager to compute DominanceFrontier. NFC
Differential Revision: http://reviews.llvm.org/D17570

llvm-svn: 261903
2016-02-25 17:54:15 +00:00
Hongbin Zheng 3f97840721 Introduce analysis pass to compute PostDominators in the new pass manager. NFC
Differential Revision: http://reviews.llvm.org/D17537

llvm-svn: 261902
2016-02-25 17:54:07 +00:00
Hongbin Zheng 66b19fbc4e Revert "Introduce analysis pass to compute PostDominators in the new pass manager. NFC"
This reverts commit a3e5cc6a51ab5ad88d1760c63284294a4e34c018.

llvm-svn: 261891
2016-02-25 16:45:53 +00:00
Hongbin Zheng ad782ce3f7 Revert "Introduce DominanceFrontierAnalysis to the new PassManager to compute DominanceFrontier. NFC"
This reverts commit 109c38b2226a87b0be73fa7a0a8c1a81df20aeb2.

llvm-svn: 261890
2016-02-25 16:45:46 +00:00
Hongbin Zheng 921fabf34b Revert "Introduce RegionInfoAnalysis, which compute Region Tree in the new PassManager. NFC"
This reverts commit 8228b4d374edeb4cc0c5fddf6e1ab876918ee126.

llvm-svn: 261889
2016-02-25 16:45:37 +00:00
Hongbin Zheng 2fa386fd6c Introduce RegionInfoAnalysis, which compute Region Tree in the new PassManager. NFC
Differential Revision: http://reviews.llvm.org/D17571

llvm-svn: 261884
2016-02-25 16:33:26 +00:00
Hongbin Zheng 237197ba63 Introduce DominanceFrontierAnalysis to the new PassManager to compute DominanceFrontier. NFC
Differential Revision: http://reviews.llvm.org/D17570

llvm-svn: 261883
2016-02-25 16:33:15 +00:00
Hongbin Zheng a0273a04f5 Introduce analysis pass to compute PostDominators in the new pass manager. NFC
Differential Revision: http://reviews.llvm.org/D17537

llvm-svn: 261882
2016-02-25 16:33:06 +00:00
Justin Bogner eecc3c826a PM: Implement a basic loop pass manager
This creates the new-style LoopPassManager and wires it up with dummy
and print passes.

This version doesn't support modifying the loop nest at all. It will
be far easier to discuss and evaluate the approaches to that with this
in place so that the boilerplate is out of the way.

llvm-svn: 261831
2016-02-25 07:23:08 +00:00
Chandler Carruth c1dc384b54 [PM/AA] Wire up TBAA to the new pass manager's registry and test it.
llvm-svn: 261411
2016-02-20 04:04:52 +00:00
Chandler Carruth d6091a0344 [PM/AA] Wire up the scoped-no-alias AA to the new pass manager's
registry and test it.

llvm-svn: 261410
2016-02-20 04:03:06 +00:00
Chandler Carruth 2b3d0446f4 [PM/AA] Wire up SCEVAA to the new pass manager's registry and test it.
llvm-svn: 261409
2016-02-20 04:01:45 +00:00
Chandler Carruth 342c671b66 [PM/AA] Wire up CFLAA to the new pass manager fully, and port one of its
tests over to exercise this code.

This uncovered a few missing bits here and there in the analysis, but
nothing interesting.

llvm-svn: 261404
2016-02-20 03:52:02 +00:00
Chandler Carruth 4f846a5f15 [PM/AA] Port alias analysis evaluator to the new pass manager, and use
it to actually test the new pass manager AA wiring.

This patch was extracted from the (somewhat too large) D12357 and
rebosed on top of the slightly different design of the new pass manager
AA wiring that I just landed. With this we can start testing the AA in
a thorough way with the new pass manager.

Some minor cleanups to the code in the pass was necessitated here, but
otherwise it is a very minimal change.

Differential Revision: http://reviews.llvm.org/D17372

llvm-svn: 261403
2016-02-20 03:46:03 +00:00
Chandler Carruth 9c4ed175c2 [PM] Port the PostOrderFunctionAttrs pass to the new pass manager and
convert one test to use this.

This is a particularly significant milestone because it required
a working per-function AA framework which can be queried over each
function from within a CGSCC transform pass (and additionally a module
analysis to be accessible). This is essentially *the* point of the
entire pass manager rewrite. A CGSCC transform is able to query for
multiple different function's analysis results. It works. The whole
thing appears to actually work and accomplish the original goal. While
we were able to hack function attrs and basic-aa to "work" in the old
pass manager, this port doesn't use any of that, it directly leverages
the new fundamental functionality.

For this to work, the CGSCC framework also has to support SCC-based
behavior analysis, etc. The only part of the CGSCC pass infrastructure
not sorted out at this point are the updates in the face of inlining and
running function passes that mutate the call graph.

The changes are pretty boring and boiler-plate. Most of the work was
factored into more focused preperatory patches. But this is what wires
it all together.

llvm-svn: 261203
2016-02-18 11:03:11 +00:00
Chandler Carruth edf5996b06 [PM/AA] Teach the new pass manager to use pass-by-lambda for registering
analysis passes, support pre-registering analyses, and use that to
implement parsing and pre-registering a custom alias analysis pipeline.

With this its possible to configure the particular alias analysis
pipeline used by the AAManager from the commandline of opt. I've updated
the test to show this effectively in use to build a pipeline including
basic-aa as part of it.

My big question for reviewers are around the APIs that are used to
expose this functionality. Are folks happy with pass-by-lambda to do
pass registration? Are folks happy with pre-registering analyses as
a way to inject customized instances of an analysis while still using
the registry for the general case?

Other thoughts of course welcome. The next round of patches will be to
add the rest of the alias analyses into the new pass manager and wire
them up here so that they can be used from opt. This will require
extending the (somewhate limited) functionality of AAManager w.r.t.
module passes.

Differential Revision: http://reviews.llvm.org/D17259

llvm-svn: 261197
2016-02-18 09:45:17 +00:00
Chandler Carruth bece8d517d [PM/AA] Wire BasicAA's new pass manager class up to the pass registry.
This ensures that all of the various pieces are working. The next patch
will wire up commandline-driven alias analysis chain building and allow
BasicAA to work with the AAManager.

llvm-svn: 260838
2016-02-13 23:46:24 +00:00
Chandler Carruth 6f5770b10f [PM/AA] Actually wire the AAManager I built for the new pass manager
into the new pass manager and fix the latent bugs there.

This lets everything live together nicely, but it isn't really useful
yet. I never finished wiring the AA layer up for the new pass manager,
and so subsequent patches will change this to do that wiring and get AA
stuff more fully integrated into the new pass manager. Turns out this is
necessary even to get functionattrs ported over. =]

llvm-svn: 260836
2016-02-13 23:32:00 +00:00
Chris Bieneman e49730d4ba Remove autoconf support
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html

"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi

Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark

Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D16471

llvm-svn: 258861
2016-01-26 21:29:08 +00:00
Chandler Carruth 3a040e6d47 [attrs] Extract the pure inference of function attributes into
a standalone pass.

There is no call graph or even interesting analysis for this part of
function attributes -- it is literally inferring attributes based on the
target library identification. As such, we can do it using a much
simpler module pass that just walks the declarations. This can also
happen much earlier in the pass pipeline which has benefits for any
number of other passes.

In the process, I've cleaned up one particular aspect of the logic which
was necessary in order to separate the two passes cleanly. It now counts
inferred attributes independently rather than just counting all the
inferred attributes as one, and the counts are more clearly explained.

The two test cases we had for this code path are both ... woefully
inadequate and copies of each other. I've kept the superset test and
updated it. We need more testing here, but I had to pick somewhere to
stop fixing everything broken I saw here.

Differential Revision: http://reviews.llvm.org/D15676

llvm-svn: 256466
2015-12-27 08:41:34 +00:00
Chandler Carruth f49f1a87ef [attrs] Split off the forced attributes utility into its own pass that
is (by default) run much earlier than FuncitonAttrs proper.

This allows forcing optnone or other widely impactful attributes. It is
also a bit simpler as the force attribute behavior needs no specific
iteration order.

I've added the pass into the default module pass pipeline and LTO pass
pipeline which mirrors where function attrs itself was being run.

Differential Revision: http://reviews.llvm.org/D15668

llvm-svn: 256465
2015-12-27 08:13:45 +00:00
Justin Bogner 21e153748a [PM] Port StripDeadPrototypes to the new pass manager
This is a really straightforward port. Also adds a test for the pass,
since it only seemed to be tested tangentially before.

llvm-svn: 251726
2015-10-30 23:28:12 +00:00
Justin Bogner 19b679963f [PM] Port ADCE to the new pass manager
llvm-svn: 251725
2015-10-30 23:13:18 +00:00
Chandler Carruth 29a18a4663 [PM] Port SROA to the new pass manager.
In some ways this is a very boring port to the new pass manager as there
are no interesting analyses or dependencies or other oddities.

However, this does introduce the first good example of a transformation
pass with non-trivial state porting to the new pass manager. I've tried
to carve out patterns here to replicate elsewhere, and would appreciate
comments on whether folks like these patterns:

- A common need in the new pass manager is to effectively lift the pass
  class and some of its state into a public header file. Prior to this,
  LLVM used anonymous namespaces to provide "module private" types and
  utilities, but that doesn't scale to cases where a public header file
  is needed and the new pass manager will exacerbate that. The pattern
  I've adopted here is to use the namespace-cased-name of the core pass
  (what would be a module if we had them) as a module-private namespace.
  Then utility and other code can be declared and defined in this
  namespace. At some point in the future, we could even have
  (conditionally compiled) code that used modules features when
  available to do the same basic thing.

- I've split the actual pass run method in two in order to expose
  a private method usable by the old pass manager to wrap the new class
  with a minimum of duplicated code. I actually looked at a bunch of
  ways to automate or generate these, but they are all quite terrible
  IMO. The fundamental need is to extract the set of analyses which need
  to cross this interface boundary, and that will end up being too
  unpredictable to effectively encapsulate IMO. This is also
  a relatively small amount of boiler plate that will live a relatively
  short time, so I'm not too worried about the fact that it is boiler
  plate.

The rest of the patch is totally boring but results in a massive diff
(sorry). It just moves code around and removes or adds qualifiers to
reflect the new name and nesting structure.

Differential Revision: http://reviews.llvm.org/D12773

llvm-svn: 247501
2015-09-12 09:09:14 +00:00
Chandler Carruth 7adc3a2b0e [PM/AA] Remove the last relics of the separate IPA library from LLVM,
folding the code into the main Analysis library.

There already wasn't much of a distinction between Analysis and IPA.
A number of the passes in Analysis are actually IPA passes, and there
doesn't seem to be any advantage to separating them.

Moreover, it makes it hard to have interactions between analyses that
are both local and interprocedural. In trying to make the Alias Analysis
infrastructure work with the new pass manager, it becomes particularly
awkward to navigate this split.

I've tried to find all the places where we referenced this, but I may
have missed some. I have also adjusted the C API to continue to be
equivalently functional after this change.

Differential Revision: http://reviews.llvm.org/D12075

llvm-svn: 245318
2015-08-18 17:51:53 +00:00
Chandler Carruth 2f1fd1658f [PM] Port ScalarEvolution to the new pass manager.
This change makes ScalarEvolution a stand-alone object and just produces
one from a pass as needed. Making this work well requires making the
object movable, using references instead of overwritten pointers in
a number of places, and other refactorings.

I've also wired it up to the new pass manager and added a RUN line to
a test to exercise it under the new pass manager. This includes basic
printing support much like with other analyses.

But there is a big and somewhat scary change here. Prior to this patch
ScalarEvolution was never *actually* invalidated!!! Re-running the pass
just re-wired up the various other analyses and didn't remove any of the
existing entries in the SCEV caches or clear out anything at all. This
might seem OK as everything in SCEV that can uses ValueHandles to track
updates to the values that serve as SCEV keys. However, this still means
that as we ran SCEV over each function in the module, we kept
accumulating more and more SCEVs into the cache. At the end, we would
have a SCEV cache with every value that we ever needed a SCEV for in the
entire module!!! Yowzers. The releaseMemory routine would dump all of
this, but that isn't realy called during normal runs of the pipeline as
far as I can see.

To make matters worse, there *is* actually a key that we don't update
with value handles -- there is a map keyed off of Loop*s. Because
LoopInfo *does* release its memory from run to run, it is entirely
possible to run SCEV over one function, then over another function, and
then lookup a Loop* from the second function but find an entry inserted
for the first function! Ouch.

To make matters still worse, there are plenty of updates that *don't*
trip a value handle. It seems incredibly unlikely that today GVN or
another pass that invalidates SCEV can update values in *just* such
a way that a subsequent run of SCEV will incorrectly find lookups in
a cache, but it is theoretically possible and would be a nightmare to
debug.

With this refactoring, I've fixed all this by actually destroying and
recreating the ScalarEvolution object from run to run. Technically, this
could increase the amount of malloc traffic we see, but then again it is
also technically correct. ;] I don't actually think we're suffering from
tons of malloc traffic from SCEV because if we were, the fact that we
never clear the memory would seem more likely to have come up as an
actual problem before now. So, I've made the simple fix here. If in fact
there are serious issues with too much allocation and deallocation,
I can work on a clever fix that preserves the allocations (while
clearing the data) between each run, but I'd prefer to do that kind of
optimization with a test case / benchmark that shows why we need such
cleverness (and that can test that we actually make it faster). It's
possible that this will make some things faster by making the SCEV
caches have higher locality (due to being significantly smaller) so
until there is a clear benchmark, I think the simple change is best.

Differential Revision: http://reviews.llvm.org/D12063

llvm-svn: 245193
2015-08-17 02:08:17 +00:00
Chandler Carruth df397c520d [PM] Fixup for r231556 where I missed a dependency on intrinsics
generation.

llvm-svn: 231558
2015-03-07 09:08:20 +00:00
Chandler Carruth 1ff7724da5 [PM] Create a separate library for high-level pass management code.
This will provide the analogous replacements for the PassManagerBuilder
and other code long term. This code is extracted from the opt tool
currently, and I plan to extend it as I build up support for using the
new pass manager in Clang and other places.

Mailing this out for review in part to let folks comment on the terrible names
here. A brief word about why I chose the names I did.

The library is called "Passes" to try and make it clear that it is a high-level
utility and where *all* of the passes come together and are registered in
a common library. I didn't want it to be *limited* to a registry though, the
registry is just one component.

The class is a "PassBuilder" but this name I'm less happy with. It doesn't
build passes in any traditional sense and isn't a Builder-style API at all. The
class is a PassRegisterer or PassAdder, but neither of those really make a lot
of sense. This class is responsible for constructing passes for registry in an
analysis manager or for population of a pass pipeline. If anyone has a better
name, I would love to hear it. The other candidate I looked at was
PassRegistrar, but that doesn't really fit either. There is no register of all
the passes in use, and so I think continuing the "registry" analog outside of
the registry of pass *names* and *types* is a mistake. The objects themselves
are just objects with the new pass manager.

Differential Revision: http://reviews.llvm.org/D8054

llvm-svn: 231556
2015-03-07 09:02:36 +00:00