Commit Graph

3408 Commits

Author SHA1 Message Date
Chandler Carruth
5067929193 [LoopInfo] Add helper methods to compute two useful orderings of the
loops in a function.

These are relatively confusing to talk about and compute correctly so it
seems really good to write down their implementation in one place. I've
replaced one place we needed this in the loop PM infrastructure and
I have another place in a pending patch that wants it.

We can't quite use this for the core loop PM walk because there we're
sometimes working on a sub-forest.

I'll add the expected unittests before committing this but wanted to
make sure folks were happy with these names / comments.

Credit goes to Richard Smith for the idea for naming the order where siblings
are in reverse program order but the tree traversal remains preorder.

Differential Revision: https://reviews.llvm.org/D28932

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292569 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-20 02:41:20 +00:00
Anna Thomas
aaeaea1399 [AliasAnalysis] Fences do not modify constant memory location
Summary:
Fence instructions are currently marked as `ModRef` for all memory locations.

We can improve this for constant memory locations (such as constant globals),
since fence instructions cannot modify these locations.

This helps us to forward constant loads across fences (added test case in GVN).
There were no changes in behaviour for similar test cases in early-cse and licm.

Reviewers: dberlin, sanjoy, reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28914

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292546 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-20 00:21:33 +00:00
Easwaran Raman
d91b01bb76 Add an interface to scale the frequencies of a set of blocks.
The scaling is done with reference to the the new frequency of a reference block.

Differential Revision: https://reviews.llvm.org/D28535

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292507 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-19 18:53:16 +00:00
Hal Finkel
b1c51125dd Fix use-after-free bug in AffectedValueCallbackVH::allUsesReplacedWith
When transferring affected values in the cache from an old value, identified by
the value of the current callback, to the specified new value we might need to
insert a new entry into the DenseMap which constitutes the cache. Doing so
might delete the current callback object. Move the copying logic into a new
function, a member of the assumption cache itself, so that we don't run into UB
should the callback handle itself be removed mid-copy.

Differential Revision: https://reviews.llvm.org/D28749

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292133 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-16 15:22:01 +00:00
Xin Tong
37b9de5028 Fix typos. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292092 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-16 03:41:09 +00:00
Chandler Carruth
d97514d79a [PM] Teach the optimization remarks emitter to handle invalidation
events.

This pass sometimes has a pointer to BlockFrequencyInfo so it needs
custom invalidation logic. It is also otherwise immutable so we can
reduce the number of invalidations that happen substantially.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292058 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-15 08:20:50 +00:00
Chandler Carruth
10dd00ced5 [PM] Introduce an analysis set used to preserve all analyses over
a function's CFG when that CFG is unchanged.

This allows transformation passes to simply claim they preserve the CFG
and analysis passes to check for the CFG being preserved to remove the
fanout of all analyses being listed in all passes.

I've gone through and removed or cleaned up as many of the comments
reminding us to do this as I could.

Differential Revision: https://reviews.llvm.org/D28627

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292054 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-15 06:32:49 +00:00
Chandler Carruth
15050a4c1e [PM] The assumption cache is fundamentally designed to be self-updating,
mark it as never invalidated in the new PM.

The old PM already required this to work, and after a discussion with
Hal this seems to really be the only sensible answer. The cache
gracefully degrades as the IR is mutated, and most things which do this
should already be incrementally updating the cache.

This gets rid of a bunch of logic preserving and testing the
invalidation of this analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292039 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-15 00:26:18 +00:00
Xin Tong
2472433b47 Delete duplicate word. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291999 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-14 05:51:36 +00:00
Easwaran Raman
65d7a8cd1c Compute summary before calling extractProfTotalWeight
extractProfTotalWeight checks if the profile type is sample profile, but
before that we have to ensure that summary is available. Also expanded
the unittest to test the case where there is no summar

Differential Revision: https://reviews.llvm.org/D28708

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291982 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-14 00:32:37 +00:00
Easwaran Raman
a2090aaaf9 ProfileSummaryInfo improvements.
* Add is{Hot|Cold}CallSite methods
* Fix a bug in isHotBB where it was looking for MD_prof on a return instruction
* Use MD_prof data only if sample profiling was used to collect profiles.
* Add an unit test to ProfileSummaryInfo

Differential Revision: https://reviews.llvm.org/D28584



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291878 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-13 01:34:00 +00:00
Chad Rosier
4afed5d5d2 TTI: Add comment clarifying the meaning of MemIntrinsicInfo::PtrVal.
Patch by Tom Stellard.
Differential Revision: https://reviews.llvm.org/D27563

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291772 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-12 16:15:10 +00:00
Piotr Padlewski
4e1eef1855 [Devirtualization] MemDep returns non-local !invariant.group dependencies
Summary:
Memory Dependence Analysis was limited to return only local dependencies
for invariant.group handling. Now it returns NonLocal when it finds it
and then by asking getNonLocalPointerDependency we get found dep.

Thanks to this we are able to devirtualize loops!

    void indirect(A &a, int n) {
      for (int i = 0 ; i < n; i++)
        a.foo();

    }
    void test(int n) {
      A a;
      indirect(a);
    }

After inlining a.foo() will be changed to direct call, even if foo and A::A()
is external (but only if vtable definition is be available).

Reviewers: nlewycky, dberlin, chandlerc, rsmith

Subscribers: mehdi_amini, davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D28137

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291762 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-12 11:33:58 +00:00
David Blaikie
ae69f7de68 Make some operator bools explicit for sanity/safety.
There are a couple left in bool-like containers (BitVector, etc) where
the implicit conversions seem more suitable - though it might be worth
considering explicitifying those too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291694 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 19:47:16 +00:00
Hal Finkel
a6e44bd635 Make processing @llvm.assume more efficient - Add affected values to the assumption cache
Here's my second try at making @llvm.assume processing more efficient. My
previous attempt, which leveraged operand bundles, r289755, didn't end up
working: it did make assume processing more efficient but eliminating the
assumption cache made ephemeral value computation too expensive. This is a
more-targeted change. We'll keep the assumption cache, but extend it to keep a
map of affected values (i.e. values about which an assumption might provide
some information) to the corresponding assumption intrinsics. This allows
ValueTracking and LVI to find assumptions relevant to the value being queried
without scanning all assumptions in the function. The fact that ValueTracking
started doing O(number of assumptions in the function) work, for every
known-bits query, has become prohibitively expensive in some cases.

As discussed during the review, this is a pragmatic fix that, longer term, will
likely be replaced by a more-principled solution (perhaps based on an extended
SSA form).

Differential Revision: https://reviews.llvm.org/D28459

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291671 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 13:24:24 +00:00
Chandler Carruth
c68d25fb58 [PM] Separate the LoopAnalysisManager from the LoopPassManager and move
the latter to the Transforms library.

While the loop PM uses an analysis to form the IR units, the current
plan is to have the PM itself establish and enforce both loop simplified
form and LCSSA. This would be a layering violation in the analysis
library.

Fundamentally, the idea behind the loop PM is to *transform* loops in
addition to running passes over them, so it really seemed like the most
natural place to sink this was into the transforms library.

We can't just move *everything* because we also have loop analyses that
rely on a subset of the invariants. So this patch splits the the loop
infrastructure into the analysis management that has to be part of the
analysis library, and the transform-aware pass manager.

This also required splitting the loop analyses' printer passes out to
the transforms library, which makes sense to me as running these will
transform the code into LCSSA in theory.

I haven't split the unittest though because testing one component
without the other seems nearly intractable.

Differential Revision: https://reviews.llvm.org/D28452

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291662 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 09:43:56 +00:00
Mohammed Agabaria
9c6b24cc3a [X86] updating TTI costs for arithmetic instructions on X86\SLM arch.
updated instructions:
pmulld, pmullw, pmulhw, mulsd, mulps, mulpd, divss, divps, divsd, divpd, addpd and subpd.

special optimization case which replaces pmulld with pmullw\pmulhw\pshuf seq. 
In case if the real operands bitwidth <= 16.

Differential Revision: https://reviews.llvm.org/D28104 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291657 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 08:23:37 +00:00
Chandler Carruth
d27a39a962 [PM] Rewrite the loop pass manager to use a worklist and augmented run
arguments much like the CGSCC pass manager.

This is a major redesign following the pattern establish for the CGSCC layer to
support updates to the set of loops during the traversal of the loop nest and
to support invalidation of analyses.

An additional significant burden in the loop PM is that so many passes require
access to a large number of function analyses. Manually ensuring these are
cached, available, and preserved has been a long-standing burden in LLVM even
with the help of the automatic scheduling in the old pass manager. And it made
the new pass manager extremely unweildy. With this design, we can package the
common analyses up while in a function pass and make them immediately available
to all the loop passes. While in some cases this is unnecessary, I think the
simplicity afforded is worth it.

This does not (yet) address loop simplified form or LCSSA form, but those are
the next things on my radar and I have a clear plan for them.

While the patch is very large, most of it is either mechanically updating loop
passes to the new API or the new testing for the loop PM. The code for it is
reasonably compact.

I have not yet updated all of the loop passes to correctly leverage the update
mechanisms demonstrated in the unittests. I'll do that in follow-up patches
along with improved FileCheck tests for those passes that ensure things work in
more realistic scenarios. In many cases, there isn't much we can do with these
until the loop simplified form and LCSSA form are in place.

Differential Revision: https://reviews.llvm.org/D28292

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291651 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 06:23:21 +00:00
Matt Arsenault
1f4353fb62 InstSimplify: Eliminate fabs on known positive
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291624 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 00:33:24 +00:00
Sanjay Patel
3f06747367 fix comment typos; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291447 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-09 16:27:56 +00:00
Chandler Carruth
f7babeb5d8 [PM] Teach SCEV to invalidate itself when its dependencies become
invalid.

This fixes use-after-free bugs that will arise with any interesting use
of SCEV.

I've added a dedicated test that works diligently to trigger these kinds
of bugs in the new pass manager and also checks for them explicitly as
well as triggering ASan failures when things go squirly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291426 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-09 07:44:34 +00:00
Mohammed Agabaria
6bf7471dbc Currently isLikelyComplexAddressComputation tries to figure out if the given stride seems to be 'complex' and need some extra cost for address computation handling.
This code seems to be target dependent which may not be the same for all targets.
Passed the decision whether the given stride is complex or not to the target by sending stride information via SCEV to getAddressComputationCost instead of 'IsComplex'.

Specifically at X86 targets we dont see any significant address computation cost in case of the strided access in general.

Differential Revision: https://reviews.llvm.org/D27518



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291106 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-05 14:03:41 +00:00
Chandler Carruth
4125a9aec7 [PM] Fix a typo in a comment that Davide spotted in another code review.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291066 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-05 03:10:26 +00:00
Sanjay Patel
6aec022dd7 fix comment formatting; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290980 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-04 18:16:43 +00:00
Elena Demikhovsky
c2b6a16ee9 AVX-512 Loop Vectorizer: Cost calculation for interleave load/store patterns.
X86 target does not provide any target specific cost calculation for interleave patterns.It uses the common target-independent calculation, which gives very high numbers. As a result, the scalar version is chosen in many cases. The situation on AVX-512 is even worse, since we have 3-src shuffles that significantly reduce the cost.

In this patch I calculate the cost on AVX-512. It will allow to compare interleave pattern with gather/scatter and choose a better solution (PR31426).

* Shiffle-broadcast cost will be changed in Simon's upcoming patch.

Differential Revision: https://reviews.llvm.org/D28118



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290810 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-02 10:37:52 +00:00
Sanjay Patel
c6901e1685 [ValueTracking] make dominator tree requirement explicit for isKnownNonNullFromDominatingCondition(); NFCI
I don't think this hole is currently exposed, but I crashed regression tests for
jump-threading and loop-vectorize after I added calls to isKnownNonNullAt() in
InstSimplify as part of trying to solve PR28430:
https://llvm.org/bugs/show_bug.cgi?id=28430

That's because they call into value tracking with a context instruction, but no
other parts of the query structure filled in.

For more background, see the discussion in:
https://reviews.llvm.org/D27855


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290786 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-31 17:37:01 +00:00
Dehao Chen
ddd3bb716c Use continuous boosting factor for complete unroll.
Summary:
The current loop complete unroll algorithm checks if unrolling complete will reduce the runtime by a certain percentage. If yes, it will apply a fixed boosting factor to the threshold (by discounting cost). The problem for this approach is that the threshold abruptly. This patch makes the boosting factor a function of runtime reduction percentage, capped by a fixed threshold. In this way, the threshold changes continuously.

The patch also simplified the code by reducing one parameter in UP.

The patch only affects code-gen of two speccpu2006 benchmark:

445.gobmk binary size decreases 0.08%, no performance change.
464.h264ref binary size increases 0.24%, no performance change.

Reviewers: mzolotukhin, chandlerc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26989

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290737 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-30 00:50:28 +00:00
Craig Topper
cfa271980e [Analysis] Remove repeated text from a comment. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290723 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-29 21:48:28 +00:00
Chandler Carruth
86d536565b [PM] Introduce a devirtualization iteration layer for the new PM.
This is an orthogonal and separated layer instead of being embedded
inside the pass manager. While it adds a small amount of complexity, it
is fairly minimal and the composability and control seems worth the
cost.

The logic for this ends up being nicely isolated and targeted. It should
be easy to experiment with different iteration strategies wrapped around
the CGSCC bottom-up walk using this kind of facility.

The mechanism used to track devirtualization is the simplest one I came
up with. I think it handles most of the cases the existing iteration
machinery handles, but I haven't done a *very* in depth analysis. It
does however match the basic intended semantics, and we can tweak or
tune its exact behavior incrementally as necessary. One thing that we
may want to revisit is freshly building the value handle set on each
iteration. While I don't think this will be a significant cost (it is
strictly fewer value handles but more churn of value handes than the old
call graph), it is conceivable that we'll want a somewhat more clever
tracking mechanism. My hope is to layer that on as a follow up patch
with data supporting any implementation complexity it adds.

This code also provides for a basic count heuristic: if the number of
indirect calls decreases and the number of direct calls increases for
a given function in the SCC, we assume devirtualization is responsible.
This matches the heuristics currently used in the legacy pass manager.

Differential Revision: https://reviews.llvm.org/D23114

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290665 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-28 11:07:33 +00:00
Chandler Carruth
6fbb41e40a [PM] Teach the CGSCC's CG update utility to more carefully invalidate
analyses when we're about to break apart an SCC.

We can't wait until after breaking apart the SCC to invalidate things:
1) Which SCC do we then invalidate? All of them?
2) Even if we invalidate all of them, a newly created SCC may not have
   a proxy that will convey the invalidation to functions!

Previously we only invalidated one of the SCCs and too late. This led to
stale analyses remaining in the cache. And because the caching strategy
actually works, they would get used and chaos would ensue.

Doing invalidation early is somewhat pessimizing though if we *know*
that the SCC structure won't change. So it turns out that the design to
make the mutation API force the caller to know the *kind* of mutation in
advance was indeed 100% correct and we didn't do enough of it. So this
change also splits two cases of switching a call edge to a ref edge into
two separate APIs so that callers can clearly test for this and take the
easy path without invalidating when appropriate. This is particularly
important in this case as we expect most inlines to be between functions
in separate SCCs and so the common case is that we don't have to so
aggressively invalidate analyses.

The LCG API change in turn needed some basic cleanups and better testing
in its unittest. No interesting functionality changed there other than
more coverage of the returned sequence of SCCs.

While this seems like an obvious improvement over the current state, I'd
like to revisit the core concept of invalidating within the CG-update
layer at all. I'm wondering if we would be better served forcing the
callers to handle the invalidation beforehand in the cases that they
can handle it. An interesting example is when we want to teach the
inliner to *update and preserve* analyses. But we can cross that bridge
when we get there.

With this patch, the new pass manager an build all of the LLVM test
suite at -O3 and everything passes. =D I haven't bootstrapped yet and
I'm sure there are still plenty of bugs, but this gives a nice baseline
so I'm going to increasingly focus on fleshing out the missing
functionality, especially the bits that are just turned off right now in
order to let us establish this baseline.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290664 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-28 10:34:50 +00:00
Chandler Carruth
fad6a3fdf9 [PM] Teach MemDep to invalidate its result object when its cached
analysis handles become invalid.

Add a test case for its invalidation logic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290620 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-27 19:33:04 +00:00
Chandler Carruth
b09bd97491 [PM] Teach BasicAA how to invalidate its result object.
This requires custom handling because BasicAA caches handles to other
analyses and so it needs to trigger indirect invalidation.

This fixes one of the common crashes when using the new PM in real
pipelines. I've also tweaked a regression test to check that we are at
least handling the most immediate case.

I'm going to work at re-structuring this test some to both scale better
(rather than all being in one file) and check more invalidation paths in
a follow-up commit, but I wanted to get the basic bug fix in place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290603 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-27 10:30:45 +00:00
Chandler Carruth
2b572a2941 [PM] Teach the AAManager and AAResults layer (the worst offender for
inter-analysis dependencies) to use the new invalidation infrastructure.

This teaches it to invalidate itself when any of the peer function
AA results that it uses become invalid. We do this by just tracking the
originating IDs. I've kept it in a somewhat clunky API since some users
of AAResults are outside the new PM right now. We can clean this API up
if/when those users go away.

Secondly, it uses the registration on the outer analysis manager proxy
to trigger deferred invalidation when a module analysis result becomes
invalid.

I've included test cases that specifically try to trigger use-after-free
in both of these cases and they would crash or hang pretty horribly for
me even without ASan. Now they work nicely.

The `InvalidateAnalysis` utility pass required some tweaking to be
useful in this context and it still is pretty garbage. I'd like to
switch it back to the previous implementation and teach the explicit
invalidate method on the AnalysisManager to take care of correctly
triggering indirect invalidation, but I wanted to go ahead and send this
out so folks could see how all of this stuff works together in practice.
And, you know, that it does actually work. =]

Differential Revision: https://reviews.llvm.org/D27205

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290595 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-27 08:44:39 +00:00
Chandler Carruth
0fc446723e [PM] Introduce the facilities for registering cross-IR-unit dependencies
that require deferred invalidation.

This handles the other real-world invalidation scenario that we have
cases of: a function analysis which caches references to a module
analysis. We currently do this in the AA aggregation layer and might
well do this in other places as well.

Since this is relative rare, the technique is somewhat more cumbersome.
Analyses need to register themselves when accessing the outer analysis
manager's proxy. This proxy is already necessarily present to allow
access to the outer IR unit's analyses. By registering here we can track
and trigger invalidation when that outer analysis goes away.

To make this work we need to enhance the PreservedAnalyses
infrastructure to support a (slightly) more explicit model for "sets" of
analyses, and allow abandoning a single specific analyses even when
a set covering that analysis is preserved. That allows us to describe
the scenario of preserving all Function analyses *except* for the one
where deferred invalidation has triggered.

We also need to teach the invalidator API to support direct ID calls
instead of always going through a template to dispatch so that we can
just record the ID mapping.

I've introduced testing of all of this both for simple module<->function
cases as well as for more complex cases involving a CGSCC layer.

Much like the previous patch I've not tried to fully update the loop
pass management layer because that layer is due to be heavily reworked
to use similar techniques to the CGSCC to handle updates. As that
happens, we'll have a better testing basis for adding support like this.

Many thanks to both Justin and Sean for the extensive reviews on this to
help bring the API design and documentation into a better state.

Differential Revision: https://reviews.llvm.org/D27198

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290594 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-27 08:40:39 +00:00
Chandler Carruth
3f4d13dbf2 [LCG] Teach the LazyCallGraph to handle visiting the blockaddress
constant expression and to correctly form function reference edges
through them without crashing because one of the operands (the
`BasicBlock` isn't actually a constant despite being an operand of
a constant).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290581 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-27 05:00:45 +00:00
Piotr Padlewski
9c8f573921 [MemDep] NFC changes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290428 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-23 13:13:32 +00:00
Chandler Carruth
4ed09f06aa [PM] Remove now-dead extern template and explicit instantiation
declarations.

We're using a custom class here instead of the helper template, these
bits just didn't get deleted when the other bits did get deleted. This
was found by a really nice MSVC warning about explicitly instantiating
a template where some member functions aren't defined and thus can't be
instantiatied.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290327 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-22 07:14:33 +00:00
Chandler Carruth
2ffea51042 [PM] Introduce a reasonable port of the main per-module pass pipeline
from the old pass manager in the new one.

I'm not trying to support (initially) the numerous options that are
currently available to customize the pass pipeline. If we end up really
wanting them, we can add them later, but I suspect many are no longer
interesting. The simplicity of omitting them will help a lot as we sort
out what the pipeline should look like in the new PM.

I've also documented to the best of my ability *why* each pass or group
of passes is used so that reading the pipeline is more helpful. In many
cases I think we have some questionable choices of ordering and I've
left FIXME comments in place so we know what to come back and revisit
going forward. But for now, I've left it as similar to the current
pipeline as I could.

Lastly, I've had to comment out several places where passes are not
ported to the new pass manager or where the loop pass infrastructure is
not yet ready. I did at least fix a few bugs in the loop pass
infrastructure uncovered by running the full pipeline, but I didn't want
to go too far in this patch -- I'll come back and re-enable these as the
infrastructure comes online. But I'd like to keep the comments in place
because I don't want to lose track of which passes need to be enabled
and where they go.

One thing that seemed like a significant API improvement was to require
that we don't build pipelines for O0. It seems to have no real benefit.

I've also switched back to returning pass managers by value as at this
API layer it feels much more natural to me for composition. But if
others disagree, I'm happy to go back to an output parameter.

I'm not 100% happy with the testing strategy currently, but it seems at
least OK. I may come back and try to refactor or otherwise improve this
in subsequent patches but I wanted to at least get a good starting point
in place.

Differential Revision: https://reviews.llvm.org/D28042

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290325 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-22 06:59:15 +00:00
George Burgess IV
1ced44b92a [Analysis] Centralize objectsize lowering logic.
We're currently doing nearly the same thing for @llvm.objectsize in
three different places: two of them are missing checks for overflow,
and one of them could subtly break if InstCombine gets much smarter
about removing alloc sites. Seems like a good idea to not do that.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290214 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-20 23:46:36 +00:00
Chandler Carruth
54cffa1811 [PM] Provide an initial, minimal port of the inliner to the new pass manager.
This doesn't implement *every* feature of the existing inliner, but
tries to implement the most important ones for building a functional
optimization pipeline and beginning to sort out bugs, regressions, and
other problems.

Notable, but intentional omissions:
- No alloca merging support. Why? Because it isn't clear we want to do
  this at all. Active discussion and investigation is going on to remove
  it, so for simplicity I omitted it.
- No support for trying to iterate on "internally" devirtualized calls.
  Why? Because it adds what I suspect is inappropriate coupling for
  little or no benefit. We will have an outer iteration system that
  tracks devirtualization including that from function passes and
  iterates already. We should improve that rather than approximate it
  here.
- Optimization remarks. Why? Purely to make the patch smaller, no other
  reason at all.

The last one I'll probably work on almost immediately. But I wanted to
skip it in the initial patch to try to focus the change as much as
possible as there is already a lot of code moving around and both of
these *could* be skipped without really disrupting the core logic.

A summary of the different things happening here:

1) Adding the usual new PM class and rigging.

2) Fixing minor underlying assumptions in the inline cost analysis or
   inline logic that don't generally hold in the new PM world.

3) Adding the core pass logic which is in essence a loop over the calls
   in the nodes in the call graph. This is a bit duplicated from the old
   inliner, but only a handful of lines could realistically be shared.
   (I tried at first, and it really didn't help anything.) All told,
   this is only about 100 lines of code, and most of that is the
   mechanics of wiring up analyses from the new PM world.

4) Updating the LazyCallGraph (in the new PM) based on the *newly
   inlined* calls and references. This is very minimal because we cannot
   form cycles.

5) When inlining removes the last use of a function, eagerly nuking the
   body of the function so that any "one use remaining" inline cost
   heuristics are immediately refined, and queuing these functions to be
   completely deleted once inlining is complete and the call graph
   updated to reflect that they have become dead.

6) After all the inlining for a particular function, updating the
   LazyCallGraph and the CGSCC pass manager to reflect the
   function-local simplifications that are done immediately and
   internally by the inline utilties. These are the exact same
   fundamental set of CG updates done by arbitrary function passes.

7) Adding a bunch of test cases to specifically target CGSCC and other
   subtle aspects in the new PM world.

Many thanks to the careful review from Easwaran and Sanjoy and others!

Differential Revision: https://reviews.llvm.org/D24226

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290161 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-20 03:15:32 +00:00
Daniel Jasper
47d6abcc05 Add files I seem to have dropped in my revert (r290086).
Sorry!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290087 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-19 08:32:13 +00:00
Daniel Jasper
8de3a54f07 Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290086 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-19 08:22:17 +00:00
Hal Finkel
bffeba468d Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289756 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-15 03:02:15 +00:00
Hal Finkel
fe647d2183 Make processing @llvm.assume more efficient by using operand bundles
There was an efficiency problem with how we processed @llvm.assume in
ValueTracking (and other places). The AssumptionCache tracked all of the
assumptions in a given function. In order to find assumptions relevant to
computing known bits, etc. we searched every assumption in the function. For
ValueTracking, that means that we did O(#assumes * #values) work in InstCombine
and other passes (with a constant factor that can be quite large because we'd
repeat this search at every level of recursion of the analysis).

Several of us discussed this situation at the last developers' meeting, and
this implements the discussed solution: Make the values that an assume might
affect operands of the assume itself. To avoid exposing this detail to
frontends and passes that need not worry about it, I've used the new
operand-bundle feature to add these extra call "operands" in a way that does
not affect the intrinsic's signature. I think this solution is relatively
clean. InstCombine adds these extra operands based on what ValueTracking, LVI,
etc. will need and then those passes need only search the users of the values
under consideration. This should fix the computational-complexity problem.

At this point, no passes depend on the AssumptionCache, and so I'll remove
that as a follow-up change.

Differential Revision: https://reviews.llvm.org/D27259

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289755 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-15 02:53:42 +00:00
Sanjoy Das
9b021f22ef Re-land "[SCEVExpander] Use llvm data structures; NFC"
This change re-lands r289215, by reverting r289482.  The underlying
issue that caused it to be reverted has been fixed by Tim Northover in
r289496.

Original commit message for r289215:

[SCEVExpander] Use llvm data structures; NFC

Original commit message for r289482:

Revert "[SCEVExpander] Use llvm data structures; NFC"

This reverts r289215 (git SHA1 cb7b86a1).  It breaks the ubsan build
because a DenseMap that keys off of `AssertingVH<T>` will hit UB when it
tries to cast the empty and tombstone keys to `T *` (due to insufficient
alignment).

This is the relevant stack trace (thanks to Mike Aizatsky):

    #0 0x25cf100 in llvm::AssertingVH<llvm::PHINode>::getValPtr() const llvm/include/llvm/IR/ValueHandle.h:212:39
    #1 0x25cea20 in llvm::AssertingVH<llvm::PHINode>::operator=(llvm::AssertingVH<llvm::PHINode> const&) llvm/include/llvm/IR/ValueHandle.h:234:19
    #2 0x25d0092 in llvm::DenseMapBase<llvm::DenseMap<llvm::AssertingVH<llvm::PHINode>, llvm::detail::DenseSetEmpty, llvm::DenseMapInfo<llvm::AssertingVH<llvm::PHINode> >, llvm::detail::DenseSetPair<llvm::AssertingVH<llvm::PHINode> > >, llvm::AssertingVH<llvm::PHINode>, llvm::detail::DenseSetEmpty, llvm::DenseMapInfo<llvm::AssertingVH<llvm::PHINode> >, llvm::detail::DenseSetPair<llvm::AssertingVH<llvm::PHINode> > >::clear() llvm/include/llvm/ADT/DenseMap.h:113:23

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289602 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-13 22:04:58 +00:00
Sanjoy Das
e55942613d Revert "[SCEVExpander] Use llvm data structures; NFC"
This reverts r289215 (git SHA1 cb7b86a1).  It breaks the ubsan build
because a DenseMap that keys off of `AssertingVH<T>` will hit UB when it
tries to cast the empty and tombstone keys to `T *` (due to insufficient
alignment).

This is the relevant stack trace (thanks to Mike Aizatsky):

    #0 0x25cf100 in llvm::AssertingVH<llvm::PHINode>::getValPtr() const llvm/include/llvm/IR/ValueHandle.h:212:39
    #1 0x25cea20 in llvm::AssertingVH<llvm::PHINode>::operator=(llvm::AssertingVH<llvm::PHINode> const&) llvm/include/llvm/IR/ValueHandle.h:234:19
    #2 0x25d0092 in llvm::DenseMapBase<llvm::DenseMap<llvm::AssertingVH<llvm::PHINode>, llvm::detail::DenseSetEmpty, llvm::DenseMapInfo<llvm::AssertingVH<llvm::PHINode> >, llvm::detail::DenseSetPair<llvm::AssertingVH<llvm::PHINode> > >, llvm::AssertingVH<llvm::PHINode>, llvm::detail::DenseSetEmpty, llvm::DenseMapInfo<llvm::AssertingVH<llvm::PHINode> >, llvm::detail::DenseSetPair<llvm::AssertingVH<llvm::PHINode> > >::clear() llvm/include/llvm/ADT/DenseMap.h:113:23

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289482 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-12 23:00:12 +00:00
Chandler Carruth
8bf2780092 [PM] Support invalidation of inner analysis managers from a pass over the outer IR unit.
Summary:
This never really got implemented, and was very hard to test before
a lot of the refactoring changes to make things more robust. But now we
can test it thoroughly and cleanly, especially at the CGSCC level.

The core idea is that when an inner analysis manager proxy receives the
invalidation event for the outer IR unit, it needs to walk the inner IR
units and propagate it to the inner analysis manager for each of those
units. For example, each function in the SCC needs to get an
invalidation event when the SCC gets one.

The function / module interaction is somewhat boring here. This really
becomes interesting in the face of analysis-backed IR units. This patch
effectively handles all of the CGSCC layer's needs -- both invalidating
SCC analysis and invalidating function analysis when an SCC gets
invalidated.

However, this second aspect doesn't really handle the
LoopAnalysisManager well at this point. That one will need some change
of design in order to fully integrate, because unlike the call graph,
the entire function behind a LoopAnalysis's results can vanish out from
under us, and we won't even have a cached API to access. I'd like to try
to separate solving the loop problems into a subsequent patch though in
order to keep this more focused so I've adapted them to the API and
updated the tests that immediately fail, but I've not added the level of
testing and validation at that layer that I have at the CGSCC layer.

An important aspect of this change is that the proxy for the
FunctionAnalysisManager at the SCC pass layer doesn't work like the
other proxies for an inner IR unit as it doesn't directly manage the
FunctionAnalysisManager and invalidation or clearing of it. This would
create an ever worsening problem of dual ownership of this
responsibility, split between the module-level FAM proxy and this
SCC-level FAM proxy. Instead, this patch changes the SCC-level FAM proxy
to work in terms of the module-level proxy and defer to it to handle
much of the updates. It only does SCC-specific invalidation. This will
become more important in subsequent patches that support more complex
invalidaiton scenarios.

Reviewers: jlebar

Subscribers: mehdi_amini, mcrosier, mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D27197

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289317 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-10 06:34:44 +00:00
Sanjoy Das
96d56a0bcf [SCEVExpander] Remove \brief, reflow comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289216 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-09 14:42:14 +00:00
Sanjoy Das
cb7b86a1e4 [SCEVExpander] Use llvm data structures; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289215 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-09 14:42:11 +00:00
Chandler Carruth
410e7953c3 [LCG] Minor cleanup to the LCG walk over a function, NFC.
This just hoists the check for declarations up a layer which allows
various sets used in the walk to be smaller. Also moves the relevant
comments to match, and catches a few other cleanups in this code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289163 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-09 00:46:44 +00:00