PR #125442 replaces the pass-based Polly architecture with a monolithic
pass consisting of phases. Reasons listed in
https://github.com/llvm/llvm-project/pull/125442.
With this change, the SCoP-passes became redundant problematic versions
of the same functionality and are removed.
Reapply of a22d1c2225543aa9ae7882f6b1a97ee7b2c95574. Using this PR for
pre-merge CI.
Instead of relying on any pass manager to schedule Polly's passes, add
Polly's own pipeline manager which is seen as a monolithic pass in
LLVM's pass manager. Polly's former passes are now phases of the new
PhaseManager component.
Relying on LLVM's pass manager (the legacy as well as the New Pass
Manager) to manage Polly's phases never was a good fit that the
PhaseManager resolves:
* Polly passes were modifying analysis results, in particular RegionInfo
and ScopInfo. This means that there was not just one unique and
"definite" analysis result, the actual result depended on which analyses
ran prior, and the pass manager was not allowed to throw away cached
analyses or prior SCoP optimizations would have been forgotten. The LLVM
pass manger's persistance of analysis results is not contractual but
designed for caching.
* Polly depends on a particular execution order of passes and regions
(e.g. regression tests, invalidation of consecutive SCoPs). LLVM's pass
manager does not guarantee any excecution order.
* Polly does not completely preserve DominatorTree, RegionInfo,
LoopInfo, or ScalarEvolution, but only as-needed for Polly's own uses.
Because the ScopDetection object stores references to those analyses, it
still had to lie to the pass manager that they would be preserved, or
the pass manager would have released and recomputed the invalidated
analysis objects that ScopDetection/ScopInfo was still referencing. To
ensure that no non-Polly pass would see these not-completely-preserved
analyses, all analyses still had to be thrown away after the
ScopPassManager, respectively with a BarrierNoopPass in case of the LPM.
* The NPM's PassInstrumentation wraps the IR unit into an `llvm::Any`
object, but implementations such as PrintIRInstrumentation call
llvm_unreachable on encountering an unknown IR unit, such as SCoPs, with
no extension points to add support. Hence LLVM crashes when dumping IR
between SCoP passes (such as `-print-before-changed` with Polly being
active).
The new PhaseManager uses some command line options that previously
belonged to Polly's legacy passes, such as `-polly-print-detect` (so the
option will continue to work). Hence the LPM support is incompatible
with the new approach and support for it is removed.
Instead of relying on any pass manager to schedule Polly's passes, add
Polly's own pipeline manager which is seen as a monolithic pass in
LLVM's pass manager. Polly's former passes are now phases of the new
PhaseManager component.
Relying on LLVM's pass manager (the legacy as well as the New Pass
Manager) to manage Polly's phases never was a good fit that the
PhaseManager resolves:
* Polly passes were modifying analysis results, in particular RegionInfo
and ScopInfo. This means that there was not just one unique and
"definite" analysis result, the actual result depended on which analyses
ran prior, and the pass manager was not allowed to throw away cached
analyses or prior SCoP optimizations would have been forgotten. The LLVM
pass manger's persistance of analysis results is not contractual but
designed for caching.
* Polly depends on a particular execution order of passes and regions
(e.g. regression tests, invalidation of consecutive SCoPs). LLVM's pass
manager does not guarantee any excecution order.
* Polly does not completely preserve DominatorTree, RegionInfo,
LoopInfo, or ScalarEvolution, but only as-needed for Polly's own uses.
Because the ScopDetection object stores references to those analyses, it
still had to lie to the pass manager that they would be preserved, or
the pass manager would have released and recomputed the invalidated
analysis objects that ScopDetection/ScopInfo was still referencing. To
ensure that no non-Polly pass would see these not-completely-preserved
analyses, all analyses still had to be thrown away after the
ScopPassManager, respectively with a BarrierNoopPass in case of the LPM.
* The NPM's PassInstrumentation wraps the IR unit into an `llvm::Any`
object, but implementations such as PrintIRInstrumentation call
llvm_unreachable on encountering an unknown IR unit, such as SCoPs, with
no extension points to add support. Hence LLVM crashes when dumping IR
between SCoP passes (such as `-print-before-changed` with Polly being
active).
The new PhaseManager uses some command line options that previously
belonged to Polly's legacy passes, such as `-polly-print-detect` (so the
option will continue to work). Hence the LPM support is incompatible
with the new approach and support for it is removed.
This make is obivious that a class was not intended to be derived from.
NPM analysis pass can unfortunately not marked as final because they are
derived from a llvm::Checker<T> template internally by the NPM.
Also normalize the use of classes/structs
* NPM passes are structs
* Legacy passes are classes
* structs that have methods and are not a visitor pattern are classes
* structs have public inheritance by default, remove "public" keyword
* Use typedef'ed type instead of inline forward declaration
This removes unused includes (and forward declarations) as
suggested by include-what-you-use. If a transitive include of a removed
include is required to compile a file, I added the required header (or
forward declaration if suggested by include-what-you-use).
This should reduce compilation time and reduce the number of iterative
recompilations when a header was changed.
llvm-svn: 357209
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
This pass is a small and self-contained example of a piece of code that was
written with the isl C interface. The diff of this change nicely shows how the
C++ bindings can improve the readability of the code by avoiding the long C
function names and by avoiding any need for memory management.
As you will see, no calls to isl_*_copy or isl_*_free are needed anymore.
Instead the C++ interface takes care of automatically managing the objects.
This may introduce internally additional copies, but due to the isl reference
counting, such copies are expected to be cheap. For performance critical
operations, we will later exploit move semantics to eliminate unnecessary
copies that have shown to be costly.
Below we give a set of examples that shows the benefit of the C++ interface vs.
the pure C interface.
Check properties
----------------
Before:
if (isl_aff_is_zero(aff) || isl_aff_is_one(aff))
return true;
After:
if (Aff.is_zero() || Aff.is_one())
return true;
Type conversion
---------------
Before:
isl_union_pw_multi_aff *UPMA = isl_union_pw_multi_aff_from_union_map(umap);
After:
isl::union_pw_multi_aff UPMA = UMap;
Type construction
-----------------
Before:
auto *Empty = isl_union_map_empty(space);
After:
auto Empty = isl::union_map::empty(Space);
Operations
----------
Before:
set = isl_union_set_intersect(set, set2);
After:
Set = Set.intersect(Set2);
The use of isl::boolean in return types also adds an increases the robustness
of Polly, as on conversion to true or false, we verify that no isl_bool_error
has been returned and assert in case an error was returned. Before this change
we would have just ignored the error and proceeded with (some) exection path.
Tags: #polly
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D30619
llvm-svn: 297466
This is the fourth patch to apply the BLIS matmul optimization pattern on matmul
kernels (http://www.cs.utexas.edu/users/flame/pubs/TOMS-BLIS-Analytical.pdf).
BLIS implements gemm as three nested loops around a macro-kernel, plus two
packing routines. The macro-kernel is implemented in terms of two additional
loops around a micro-kernel. The micro-kernel is a loop around a rank-1
(i.e., outer product) update. In this change we perform copying to created
arrays, which is the last step to implement the packing transformation.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: https://reviews.llvm.org/D23260
llvm-svn: 281441
LLVM's coding guideline suggests to not use @brief for one-sentence doxygen
comments to improve readability. Switch this once and for all to ensure people
do not copy @brief comments from other parts of Polly, when writing new code.
llvm-svn: 280468
llvm commonly adds a comment to the closing brace of a namespace to indicate
which namespace is closed. clang-tidy provides with llvm-namespace-comment
a handy tool to check for this habit. We use it to ensure we consitently use
namespace comments in Polly.
There are slightly different styles in how namespaces are closed in LLVM. As
there is no large difference between the different comment styles we go for the
style clang-tidy suggests by default.
To reproduce this fix run:
for i in `ls tools/polly/lib/*/*.cpp`; \
clang-tidy -checks='-*,llvm-namespace-comment' -p build $i -fix \
-header-filter=".*"; \
done
This cleanup was suggested by Eugene Zelenko <eugene.zelenko@gmail.com> in
http://reviews.llvm.org/D21488 and was split out to increase readability.
llvm-svn: 273621
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
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
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
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
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
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
