Commit Graph

416 Commits

Author SHA1 Message Date
Adam Nemet 01abb2c355 [LoopAccesses] Make blockNeedsPredication static
blockNeedsPredication is in LoopAccess in order to share it with the
vectorizer.  It's a utility needed by LoopAccess not strictly provided
by it but it's a good place to share it.  This makes the function static
so that it no longer required to create an LoopAccessInfo instance in
order to access it from LV.

This was actually causing problems because it would have required
creating LAI much earlier that LV::canVectorizeMemory().

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229625
2015-02-18 03:43:19 +00:00
Adam Nemet 3cf32ad6db [LoopAccesses] Cache the result of canVectorizeMemory
LAA will be an on-demand analysis pass, so we need to cache the result
of the analysis.  canVectorizeMemory is renamed to analyzeLoop which
computes the result.  canVectorizeMemory becomes the query function for
the cached result.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229624
2015-02-18 03:42:57 +00:00
Adam Nemet 5474be2c80 [LoopAccesses] Stash the report from the analysis rather than emitting it
The transformation passes will query this and then emit them as part of
their own report.  The currently only user LV is modified to do just
that.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229623
2015-02-18 03:42:50 +00:00
Adam Nemet 4f3ede5a01 [LoopAccesses] Make VectorizerParams global
As LAA is becoming a pass, we can no longer pass the params to its
constructor.  This changes the command line flags to have external
storage.  These can now be accessed both from LV and LAA.

VectorizerParams is moved out of LoopAccessInfo in order to shorten the
code to access it.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229622
2015-02-18 03:42:43 +00:00
Adam Nemet 30f16e1696 [LoopAccesses] Rename LoopAccessAnalysis to LoopAccessInfo
LoopAccessAnalysis will be used as the name of the pass.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229621
2015-02-18 03:42:35 +00:00
Elena Demikhovsky 6f5a859633 Enabled cost calculation for masked memory operations.
We already have implementation for cost calculation for
masked memory operations. I just call it from the loop vectorizer.

llvm-svn: 229290
2015-02-15 08:08:48 +00:00
Duncan P. N. Exon Smith 2c79ad974c Transforms: Canonicalize access to function attributes, NFC
Canonicalize access to function attributes to use the simpler API.

getAttributes().getAttribute(AttributeSet::FunctionIndex, Kind)
  => getFnAttribute(Kind)

getAttributes().hasAttribute(AttributeSet::FunctionIndex, Kind)
  => hasFnAttribute(Kind)

llvm-svn: 229202
2015-02-14 01:11:29 +00:00
Adam Nemet 7206d7a5d2 [LV] Move addRuntimeCheck to LoopAccessAnalysis
This will allow it to be shared with the new Loop Distribution pass.

getFirstInst is currently duplicated across LoopVectorize.cpp and
LoopAccessAnalysis.cpp.  This is a short-term work-around until we figure out
a better solution.

NFC.  (The code moved is adjusted a bit for the name of the Loop member and
that PtrRtCheck is now a reference rather than a pointer.)

llvm-svn: 228418
2015-02-06 18:31:04 +00:00
Adam Nemet 5add5d9d85 [LV] Split off memcheck block really at the first check
I've noticed this while trying to move addRuntimeCheck to LoopAccessAnalysis.

I think that the intention was to early exit from the overflow checking before
the code for the memchecks.  This is the entire reason why we compute
FirstCheckInst but then we don't use that as the splitting instruction but the
final check.  Looks like an oversight.

llvm-svn: 228056
2015-02-03 22:45:39 +00:00
Adam Nemet b60295a525 [LoopVectorize] Fix rebase glitch in r227751
LoopVectorizationLegality::{getNumLoads,getNumStores} should forward to
LoopAccessAnalysis now.

Thanks to Takumi for noticing this!

llvm-svn: 227992
2015-02-03 17:59:53 +00:00
NAKAMURA Takumi c7f8bfc5e5 Resurrect initializers for NumLoads and NumStores in LoopVectorizationLegality to suppress undefined behavior.
FIXME: Shall they be managed in LAA?
llvm-svn: 227940
2015-02-03 03:55:06 +00:00
Benjamin Kramer ad960019b0 LoopVectorize: Remove initializer list that blocks MSVC.
llvm-svn: 227766
2015-02-01 21:13:26 +00:00
Adam Nemet 0456327cfb [LoopVectorize] Move LoopAccessAnalysis to its own module
Other than moving code and adding the boilerplate for the new files, the code
being moved is unchanged.

There are a few global functions that are shared with the rest of the
LoopVectorizer.  I moved these to the new module as well (emitLoopAnalysis,
stripIntegerCast, replaceSymbolicStrideSCEV) along with the Report class used
by emitLoopAnalysis.  There is probably room for further improvement in this
area.

I kept DEBUG_TYPE "loop-vectorize" because it's used as the PassName with
emitOptimizationRemarkAnalysis.  This will obviously have to change.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

llvm-svn: 227756
2015-02-01 16:56:15 +00:00
Adam Nemet 3f737d935d [LoopVectorize] Move RuntimePointerCheck under LoopAccessAnalysis
This class needs to remain public because it's used by
LoopVectorizationLegality::addRuntimeCheck.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

llvm-svn: 227755
2015-02-01 16:56:11 +00:00
Adam Nemet c237f68fc9 [LoopVectorize] Pass parameters explicitly to MemoryDepChecker
Rather than using globals use a structure to pass parameters from the
vectorizer.  This prepares the class to be moved outside the LoopVectorizer.

It's not great how all this is passed through in LoopAccessAnalysis but this
is all expected to change once the class start servicing the Loop Distribution
pass as well where some of these parameters make no sense.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

llvm-svn: 227754
2015-02-01 16:56:09 +00:00
Adam Nemet c28ffdcf35 [LoopVectorize] Split out LoopAccessAnalysis from LoopVectorizationLegality
Move the canVectorizeMemory functionality from LoopVectorizationLegality to a
new class LoopAccessAnalysis and forward users.

Currently the collection of the symbolic stride information is kept with
LoopVectorizationLegality and it becomes an input to LoopAccessAnalysis.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

llvm-svn: 227751
2015-02-01 16:56:04 +00:00
Adam Nemet 5985971fa5 [LoopVectorize] Add accessors for Num{Stores,Loads,PredStores} in AccessAnalysis
These members are moving to LoopAccessAnalysis.  The accessors help to hide
this.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

llvm-svn: 227750
2015-02-01 16:56:02 +00:00
Adam Nemet a2abc59dac [LoopVectorize] Rename the Report class to VectorizationReport
This class will become public in the new LoopAccessAnalysis header so the name
needs to be more global.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

llvm-svn: 227749
2015-02-01 16:56:00 +00:00
Adam Nemet ac71cecdc6 [LoopVectorize] Factor out duplicated code into Report::emitAnalysis
The logic in emitAnalysis is duplicated across multiple functions.  This
splits it into a function.  Another use will be added by the patchset.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

llvm-svn: 227748
2015-02-01 16:55:58 +00:00
Adam Nemet 6854b9203a [LoopVectorize] Split out RuntimePointerCheck from LoopVectorizationLegality
RuntimePointerCheck will be used through LoopAccessAnalysis in
LoopVectorizationLegality.  Later in the patchset it will become a local class
of LoopAccessAnalysis.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

llvm-svn: 227747
2015-02-01 16:55:56 +00:00
Chandler Carruth fdb9c573f7 [multiversion] Thread a function argument through all the callers of the
getTTI method used to get an actual TTI object.

No functionality changed. This just threads the argument and ensures
code like the inliner can correctly look up the callee's TTI rather than
using a fixed one.

The next change will use this to implement per-function subtarget usage
by TTI. The changes after that should eliminate the need for FTTI as that
will have become the default.

llvm-svn: 227730
2015-02-01 12:01:35 +00:00
Chandler Carruth 705b185f90 [PM] Change the core design of the TTI analysis to use a polymorphic
type erased interface and a single analysis pass rather than an
extremely complex analysis group.

The end result is that the TTI analysis can contain a type erased
implementation that supports the polymorphic TTI interface. We can build
one from a target-specific implementation or from a dummy one in the IR.

I've also factored all of the code into "mix-in"-able base classes,
including CRTP base classes to facilitate calling back up to the most
specialized form when delegating horizontally across the surface. These
aren't as clean as I would like and I'm planning to work on cleaning
some of this up, but I wanted to start by putting into the right form.

There are a number of reasons for this change, and this particular
design. The first and foremost reason is that an analysis group is
complete overkill, and the chaining delegation strategy was so opaque,
confusing, and high overhead that TTI was suffering greatly for it.
Several of the TTI functions had failed to be implemented in all places
because of the chaining-based delegation making there be no checking of
this. A few other functions were implemented with incorrect delegation.
The message to me was very clear working on this -- the delegation and
analysis group structure was too confusing to be useful here.

The other reason of course is that this is *much* more natural fit for
the new pass manager. This will lay the ground work for a type-erased
per-function info object that can look up the correct subtarget and even
cache it.

Yet another benefit is that this will significantly simplify the
interaction of the pass managers and the TargetMachine. See the future
work below.

The downside of this change is that it is very, very verbose. I'm going
to work to improve that, but it is somewhat an implementation necessity
in C++ to do type erasure. =/ I discussed this design really extensively
with Eric and Hal prior to going down this path, and afterward showed
them the result. No one was really thrilled with it, but there doesn't
seem to be a substantially better alternative. Using a base class and
virtual method dispatch would make the code much shorter, but as
discussed in the update to the programmer's manual and elsewhere,
a polymorphic interface feels like the more principled approach even if
this is perhaps the least compelling example of it. ;]

Ultimately, there is still a lot more to be done here, but this was the
huge chunk that I couldn't really split things out of because this was
the interface change to TTI. I've tried to minimize all the other parts
of this. The follow up work should include at least:

1) Improving the TargetMachine interface by having it directly return
   a TTI object. Because we have a non-pass object with value semantics
   and an internal type erasure mechanism, we can narrow the interface
   of the TargetMachine to *just* do what we need: build and return
   a TTI object that we can then insert into the pass pipeline.
2) Make the TTI object be fully specialized for a particular function.
   This will include splitting off a minimal form of it which is
   sufficient for the inliner and the old pass manager.
3) Add a new pass manager analysis which produces TTI objects from the
   target machine for each function. This may actually be done as part
   of #2 in order to use the new analysis to implement #2.
4) Work on narrowing the API between TTI and the targets so that it is
   easier to understand and less verbose to type erase.
5) Work on narrowing the API between TTI and its clients so that it is
   easier to understand and less verbose to forward.
6) Try to improve the CRTP-based delegation. I feel like this code is
   just a bit messy and exacerbating the complexity of implementing
   the TTI in each target.

Many thanks to Eric and Hal for their help here. I ended up blocked on
this somewhat more abruptly than I expected, and so I appreciate getting
it sorted out very quickly.

Differential Revision: http://reviews.llvm.org/D7293

llvm-svn: 227669
2015-01-31 03:43:40 +00:00
Reid Kleckner f0d389c139 Silence "not all paths return a value" warning in MSVC
llvm-svn: 227614
2015-01-30 21:30:57 +00:00
Chandler Carruth 6b1aa9be6a Fix a warning introduced by r227557 due to a default label in a fully
covering switch.

llvm-svn: 227575
2015-01-30 13:30:43 +00:00
Hao Liu 8de4f8b1b5 [LoopVectorize] Induction variables: support arbitrary constant step.
Previously, only -1 and +1 step values are supported for induction variables. This patch extends LV to support
arbitrary constant steps.
Initial patch by Alexey Volkov. Some bug fixes are added in the following version.

Differential Revision: http://reviews.llvm.org/D6051 and http://reviews.llvm.org/D7193

llvm-svn: 227557
2015-01-30 05:02:21 +00:00