multiplication
Fix small issues related to characters, operators and descriptions of tests.
Differential Revision: http://reviews.llvm.org/D20806
llvm-svn: 271264
Created a new pass ScopInfoRegionPass. As name suggests, it is a
region pass and it is there to preserve compatibility with our
existing Polly passes. ScopInfoRegionPass will return a SCoP object
for a valid region while the creation of the SCoP stays in the
ScopInfo class.
Contributed-by: Utpal Bora <cs14mtech11017@iith.ac.in>
Reviewed-by: Tobias Grosser <tobias@grosser.es>,
Johannes Doerfert <doerfert@cs.uni-saarland.de>
Differential Revision: http://reviews.llvm.org/D20770
llvm-svn: 271259
This header is required to make the ISO 646 alternative operator
spellings ("and", "or" instead of "&&", "||") work. Should these
operators be replaced by the standard ones as already suggested by
Johannes, also remove this #include again.
llvm-svn: 271206
Add determination of statements that contain, in particular,
matrix multiplications and can be optimized with [1] to try to
get close-to-peak performance. It can be enabled
via polly-pm-based-opts, which is false by default.
Refs:
[1] - http://www.cs.utexas.edu/users/flame/pubs/TOMS-BLIS-Analytical.pdf
Contributed-by: Roman Gareev <gareevroman@gmail.com>
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: http://reviews.llvm.org/D20575
llvm-svn: 271128
Add a command line switch to set the
isl_options_set_schedule_outer_coincidence option. ISL then tries to
build schedules where the outer member of a band satisfies the
coincidence constraints.
In practice this allows loop skewing for more parallelism in inner
loops.
llvm-svn: 268222
We isolate full tiles from partial tiles to be able to, for example, vectorize
loops with parametric lower and/or upper bounds.
If we use -polly-vectorizer=stripmine, we can see execution-time improvements:
correlation from 1m7361s to 0m5720s (-67.05 %), covariance from 1m5561s to
0m5680s (-63.50 %), ary3 from 2m3201s to 1m2361s (-46.72 %), CrystalMk from
8m5565s to 7m4285s (-13.18 %).
The current full/partial tile separation increases compile-time more than
necessary. As a result, we see in compile time regressions, for example, for 3mm
from 0m6320s to 0m9881s (56.34%). Some of this compile time increase is expected
as we generate more IR and consequently more time is spent in the LLVM backends.
However, a first investiagation has shown that a larger portion of compile time
is unnecessarily spent inside Polly's parallelism detection and could be
eliminated by propagating existing knowledge about vector loop parallelism.
Before enabling -polly-vectorizer=stripmine by default, it is necessary to
address this compile-time issue.
Contributed-by: Roman Gareev <gareevroman@gmail.com>
Reviewers: jdoerfert, grosser
Subscribers: grosser, #polly
Differential Revision: http://reviews.llvm.org/D13779
llvm-svn: 250809
Polly can now be used as a analysis only tool as long as the code
generation is disabled. However, we do not have an alternative to the
independent blocks pass in place yet, though in the relevant cases
this does not seem to impact the performance much. Nevertheless, a
virtual alternative that allows the same transformations without
changing the input region will follow shortly.
llvm-svn: 250652
This will allow us to optimize C++ template code with Polly. This support is
mostly for debugging purpose and individual experiments. The ultimate goal is
still to run Polly later in the pass manager when inlining already happened.
llvm-svn: 250092
Helper functions in the BlockGenerators.h/cpp introduce dependences
from the frontend to the backend of Polly. As they are used in
ScopDetection, ScopInfo, etc. we move them to the ScopHelper file.
llvm-svn: 249919
The changes affect methods that are part of the Pass interface and
include:
- Comments that describe the methods purpose.
- A consistent use of the keywords override and virtual.
Additionally, the printScop method is now optional and removed from
SCoP passes that do not implement it.
llvm-svn: 248685
Other passes which perform different optimizations might be interested in
also applying data-locality transformations as part of their overall
transformation.
llvm-svn: 245824
Register tiling in Polly is for now just an additional level of tiling which
is fully unrolled. It is disabled by default. To make this useful for more than
experiments, we still need a cost function as well as possibly further
optimizations that teach LLVM to actually put some of the values we got into
scalar registers.
llvm-svn: 245564
By default we only use one level of tiling for loops, but in general tiling
for multiple levels is trivial for us. Hence, we add a set of options that
allow people to play with a second level of tiling. If this is profitable for
some cases we can work on heuristics that allow us to identify these cases
and use two-level tiling for them.
llvm-svn: 245563
Polly uses 'prevectorization' to enable outer loop vectorization. When
vectorizing an outer loop, we strip-mine <number-of-prevec-dims> loop
iterations which are than interchanged to the innermost level such that LLVM's
inner loop vectorizer (or Polly's simple vectorizer) can easily vectorize this
loop. The number of loop iterations to strip-mine is now configurable with the
option -polly-prevect-width=<number-of-prevec-dims>.
This is mostly a debugging option. We should probably add a heuristic that
derives the number of prevectorization dimensions from the target data and
the data types used.
llvm-svn: 245424
The July issue of TOPLAS contains a 50 page discussion of the AST generation
techniques used in Polly. This discussion gives not only an in-depth
description of how we (re)generate an imperative AST from our polyhedral based
mathematical program description, but also gives interesting insights about:
- Schedule trees: A tree-based mathematical program description that enables us
to perform loop transformations on an abstract level, while issues like the
generation of the correct loop structure and loop bounds will be taken care of
by our AST generator.
- Polyhedral unrolling: We discuss techniques that allow the unrolling of
non-trivial loops in the context of parameteric loop bounds, complex tile
shapes and conditionally executed statements. Such unrolling support enables
the generation of predicated code e.g. in the context of GPGPU computing.
- Isolation for full/partial tile separation: We discuss native support for
handling full/partial tile separation and -- in general -- native support for
isolation of boundary cases to enable smooth code generation for core
computations.
- AST generation with modulo constraints: We discuss how modulo mappings are
lowered to efficient C/LLVM code.
- User-defined constraint sets for run-time checks We discuss how arbitrary
sets of constraints can be used to automatically create run-time checks that
ensure a set of constrainst actually hold. This feature is very useful to
verify at run-time various assumptions that have been taken program
optimization.
Polyhedral AST generation is more than scanning polyhedra
Tobias Grosser, Sven Verdoolaege, Albert Cohen
ACM Transations on Programming Languages and Systems (TOPLAS), 37(4), July 2015
llvm-svn: 245157
Summary: The splitExitBlock function is never called. Going to replace its functionality in successive patches that do not modify the IR.
Reviewers: grosser
Subscribers: pollydev
Projects: #polly
Differential Revision: http://reviews.llvm.org/D11865
llvm-svn: 244404
Schedule trees are a lot easier to work with, for both humans and machines. For
humans the more structured schedule representation is easier to reason about.
Together with the more abstract isl programming interface this can result in a
lot cleaner code (see this changeset). For machines, the structured schedule and
the fact that we now use explicit piecewise affine expressions instead of
integer maps makes it easier to generate code from this schedule tree. As a
result, we can already see a slight compile-time improvement -- for 3mm from
0m0.593s to 0m0.551s seconds (-7 %). More importantly, future optimizations such
as full-partial tile separation will most likely result in more streamlined code
to be generated.
Contributed-by: Roman Gareev <gareevroman@gmail.com>
llvm-svn: 243458
Instead of flat schedules, we now use so-called schedule trees to represent the
execution order of the statements in a SCoP. Schedule trees make it a lot easier
to analyze, understand and modify properties of a schedule, as specific nodes
in the tree can be choosen and possibly replaced.
This patch does not yet fully move our DependenceInfo pass to schedule trees,
as some additional performance analysis is needed here. (In general schedule
trees should be faster in compile-time, as the more structured representation
is generally easier to analyze and work with). We also can not yet perform the
reduction analysis on schedule trees.
For more information regarding schedule trees, please see Section 6 of
https://lirias.kuleuven.be/handle/123456789/497238
llvm-svn: 242130
This removes old code that has been disabled since several weeks and was hidden
behind the flags -disable-polly-intra-scop-scalar-to-array=false and
-polly-model-phi-nodes=false. Earlier, Polly used to translate scalars and
PHI nodes to single element arrays, as this avoided the need for their special
handling in Polly. With Johannes' patches adding native support for such scalar
references to Polly, this code is not needed any more. After this commit both
-polly-prepare and -polly-independent are now mostly no-ops. Only a couple of
simple transformations still remain, but they are scheduled for removal too.
Thanks again to Johannes Doerfert for his nice work in making all this code
obsolete.
llvm-svn: 240766
This version adds small integer optimization, but is not active by
default. It will be enabled in a later commit.
The schedule-fuse=min/max option has been replaced by the
serialize-sccs option. Adapting Polly was necessary, but retaining the
name polly-opt-fusion=min/max.
Differential Revision: http://reviews.llvm.org/D10505
Reviewers: grosser
llvm-svn: 240027
Running indvar before Polly is useful as this eliminates zexts as they commonly
appear when a 32 bit induction variable (type int) was used on a 64 bit system.
These zexts confuse our delinearization and prevent for example the successful
delinearization of the nussinov kernel in polybench-c-4.1.
This fixes http://llvm.org/PR23426
Suggested-by: Xing Su <xsu.llvm@outlook.com>
llvm-svn: 238643
David Blaike suggested this as an alternative to the use of owningptr(s) for our
memory management, as value semantics allow to avoid the additional interface
complexity caused by owningptr while still providing similar memory consistency
guarantees. We could also have used a std::vector, but the use of std::vector
would yield possibly changing pointers which currently causes problems as for
example the memory accesses carry pointers to their parent statements. Such
pointers should not change.
Reviewer: jblaikie, jdoerfert
Differential Revision: http://reviews.llvm.org/D10041
llvm-svn: 238290
The feature itself has been committed by Johannes in r238070. As this is the
way forward, we now enable it to ensure we get test coverage.
Thank you Johannes for this nice work!
llvm-svn: 238088
Instead of explicitly building constraints and adding them to our maps we
now use functions like map_order_le to add the relevant information to the
maps.
llvm-svn: 237934
Upcoming revisions of isl require us to include header files explicitly, which
have previously been already transitively included. Before we add them, we sort
the existing includes.
Thanks to Chandler for sort_includes.py. A simple, but very convenient script.
llvm-svn: 236930
In Polly we used both the term 'scattering' and the term 'schedule' to describe
the execution order of a statement without actually distinguishing between them.
We now uniformly use the term 'schedule' for the execution order. This
corresponds to the terminology of isl.
History: CLooG introduced the term scattering as the generated code can be used
as a sequential execution order (schedule) or as a parallel dimension
enumerating different threads of execution (placement). In Polly and/or isl the
term placement was never used, but we uniformly refer to an execution order as a
schedule and only later introduce parallelism. When doing so we do not talk
about about specific placement dimensions.
llvm-svn: 235380
We do not have buildbots or anything that tests this functionality, hence it
most likely bitrots. People interested to use this functionality can always
recover it from svn history.
llvm-svn: 233570
Replacing the old band_tree based code with code that is based on the new
schedule tree [1] interface makes applying complex schedule transformations a lot
more straightforward. We now do not need to reason about the meaning of flat
schedules, but can use a more straightforward tree structure. We do not yet
exploit this a lot in the current code, but hopefully we will be able to do so
soon.
This change also allows us to drop some code, as isl now provides some higher
level interfaces to apply loop transformations such as tiling.
This change causes some small test case changes as isl uses a slightly different
way to perform loop tiling, but no significant functional changes are intended.
[1] http://impact.gforge.inria.fr/impact2014/papers/impact2014-verdoolaege.pdf
llvm-svn: 232911
The new Dependences struct in the DependenceInfo holds all information
that was formerly part of the DependenceInfo. It also provides the
same interface for the user to access this information.
This is another step to a more general ScopPass interface that does
allow multiple SCoPs to be "in flight".
llvm-svn: 231327
We rename the Dependences pass to DependenceInfo as a first step to a
caching pass policy. The new DependenceInfo pass will later provide
"Dependences" for a SCoP.
To keep consistency the test folder is renamed too.
llvm-svn: 231308
namespace and header rather than the top-level header and using
declarations. These helpers impede modular builds and are going away.
Migrating away from them will also be necessary to start mixing in any
usage of the new pass manager.
llvm-svn: 229091
This allows us to skip ast and code generation if we did not optimize
a SCoP and will not generate parallel or alias annotations. The
initial heuristic to exit is simple but allows improvements later on.
All failing test cases have been modified to disable early exit, thus
to keep their coverage.
Differential Revision: http://reviews.llvm.org/D7254
llvm-svn: 228851
This allows us to model PHI nodes in the polyhedral description
without demoting them. The modeling however will result in the
same accesses as the demotion would have introduced.
Differential Revision: http://reviews.llvm.org/D7415
llvm-svn: 228433
Without updating dependences we may lose implicit transitive dependences for
which all explicit dependences have gone through the statement iterations we
have just eliminated.
No test case. We should probably implement a -verify-dependences option.
This fixes llvm.org/PR21227
llvm-svn: 224459
This commit drops the Cloog support for Polly. The scripts and
documentation are changed to only use isl as prerequisity. In the code
all Cloog specific parts have been removed and all relevant tests have
been ported to the isl backend when it was created.
llvm-svn: 223141
Polly had a copy of this pass to create the canonical induction variables
necessary for the non-scev-based code generation. As we now always use SCEV
based code generation, canonical induction variables are not needed any more.
llvm-svn: 222979
SCEV based code generation has been the default for two weeks after having
been tested for a long time. We now drop the support the non-scev-based code
generation.
llvm-svn: 222978
This prevents SCEVs to reference values not valid any more and as a consequence
solves a bug where such values reintroduced during ast generation caused the
independent blocks pass to fail validation.
http://llvm.org/PR21204
llvm-svn: 222103
This makes sure we consistently use dbgs() when printing debug output.
Previously, the code just mixed calls to isl_*_dump() with printing to dbgs()
and was relying for both methods to interact in predictable ways (same output
stream, no unexpected reordering of outputs).
llvm-svn: 220443
Arcanist (arc) will now always run linters before uploading any new
commit to Phabricator. All errors/warnings (or their absence) will be
shown in the web interface together with a explanation by the commiter
(arcanist will ask the commiter if the build was not clean).
The linters include:
- clang-format
- spelling check
- permissions check (aka. chmod)
- filename check
- merge conflict marker check
Note, that their scope is sometimes limited (see .arclint for
details).
This commit also fixes all errors and warnings these linters reported,
namely:
- spelling mistakes and typos
- executable permissions for various text files
Differential Revision: http://reviews.llvm.org/D4916
llvm-svn: 215871
Remove the PoCC and ScopLib support from Polly as we do not have a
user/maintainer for it.
Differential Revision: http://reviews.llvm.org/D4871
llvm-svn: 215563
We move back to a simple approach where the liveout is the last must-write
statement for a data-location plus all may-write statements. The previous
approach did not work out. We would have to consider per-data-access
dependences, instead of per-statement dependences to correct it. As this adds
complexity and it seems we would not gain anything over the simpler approach
that we implement in this commit, I moved us back to the old approach of
computing the liveout, but enhanced it to also add may-write accesses.
We also fix the test case and explain why we can not perform dead code
elimination in this case.
llvm-svn: 212925
+ Collect reduction dependences
+ Introduced TYPE_RED in Dependences.h which can be used to obtain the
reduction dependences
+ Used TYPE_RED to prevent parallelization while we do not have a privatizing
code generation
+ Relax the dependences for non-parallel code generation
+ Add privatization dependences to ensure correctness
+ 12 Test cases to check for reduction and privatization dependences
llvm-svn: 211369
+ CL-option --polly-tile-sizes=<int,...,int>
The i'th value is used as a tile size for dimension i, if
there is no i'th value, the value of --polly-default-tile-size is
used
+ CL-option --polly-default-tile-size=int
Used if no tile size is given for a dimension i
+ 3 Simple testcases
llvm-svn: 209753
SVN r209103 removed the OwningPtr variant of the MemoryBuffer APIs. Switch to
the equivalent std::unique_ptr versions. This should clear up the build bots.
llvm-svn: 209104
definition below all of the header #include lines, Polly edition.
If you want to know more details about this, you can see the recent
commits to Debug.h in LLVM. This is just the Polly segment of a cleanup
I'm doing globally for this macro.
llvm-svn: 206852
During code preperation trivial PHI nodes (mainly introduced by lcssa) are
deleted to decrease the number of introduced allocas (==> dependences). However
simply replacing them by their only incoming value would cause the independent
block pass to introduce new allocas. To prevent this we try to share stack slots
during code preperarion, hence to reuse a already created alloca 'to demote' the
trivial PHI node. This works if we know that the value stored in this alloca
will be the incoming value of the trivial PHI at the end of the predecessor
block of this trivial PHI.
Contributed-by: Johannes Doerfert <doerfert@cs.uni-saarland.de>
llvm-svn: 205320
Roman Gareev