This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.
Changes made:
- Removing explicit operator bool() from all the classes in the isl C++ bindings.
- Replace each call to operator bool() to method `is_null()`.
- isl-noexceptions.h has been generated by this 27396daac5
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D103976
[Polly][Isl] Removing nullptr constructor from C++ bindings. NFC.
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.
Changes made:
- Removed `std::nullptr_t` constructor from all the classes in the isl C++ bindings.
- `isl-noexceptions.h` has been generated by this a7e00bea38
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D103751
[Polly][Isl] Removing nullptr constructor from C++ bindings. NFC.
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.
Changes made:
- Removed `std::nullptr_t` constructor from all the classes in the isl C++ bindings.
- `isl-noexceptions.h` has been generated by this a7e00bea38
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D103751
ZoneAlgorithms's computePHI relies on being provided with consistent a
schedule to compute the statement prodecessors of a statement containing
PHINodes. Otherwise unexpected results such as PHI nodes with multiple
predecessors can occur which would result in problems in the
algorithms expecting consistent data.
In the added test case, statement instances are scrubbed from the
SCoP their execution would result in undefined behavior (Due to a nsw
overflow). As already being undefined behavior in LLVM-IR, neither
AssumedContext nor InvalidContext are updated, giving computePHI no
means to avoid these cases.
Intoduce a new SCoP property, the DefinedBehaviorContext, that among
the runtime-checked conditions, also tracks the assumptions not needing
a runtime check, in particular those affecting the assumed control flow.
This replaces the manual combination of the 3 other contexts that was
already done in computePHI and setNewAccessRelation. Currently, the only
additional assumption is that loop induction variables will nsw flag for
not wrap, but potentially more can be added. Use in
hasFeasibleRuntimeContext, isl::ast_build and gisting are other
potential uses.
To limit computational complexity, the DefinedBehaviorContext is not
availabe if it grows too large (atm hardcoded to 8 disjuncts).
Possible other fixes include bailing out in computePHI when
inconsistencies are detected, choose an arbitrary value for inconsistent
cases (since it is undefined behavior anyways), or make the code
receiving the result from ComputePHI handle inconsistent data. All of
them reduce the quality of implementation having to bail out more often
and disabling the ability to assert on actually wrong results.
This fixes llvm.org/PR48783.
Operand tree forwarding can cause the change of an access kind; in
particular change from a scalar kind to an array kind if the scalar
dependency is not necessary. Such an access cannot and doesn't need to
be forwarded anymore.
Fixes llvm.org/PR48034
Print to dbgs() any taken action.
Also, read-only scalars do not require any action unless
-polly-analyze-read-only-scalars=true is used. Better refect this by
using ForwardingAction::triviallyForwardable and thus not bumping the
statistics.
Recursively traversing the operand tree leads to an exponential blowup
if instructions are used multiple times due to every path leading to an
additional copy of the instructions after forwarding. This problem was
marked as a TODO in the code and was reported as a bug in llvm.org/PR47340.
Fix by caching already visited instructions and returning the cached
version when already visited. Instead of calling forwardTree() twice,
return a ForwardingAction structure that contains a lambda which will
carry-out the forwarding when requested. The lambdas are executed in
reverse-postorder to mimic the previous recursive calls unless there
is a reuse.
Fixes llvm.org/PR47340
The primary motivation is to fix an assertion failure in
isl_basic_map_alloc_equality:
isl_assert(ctx, room_for_con(bmap, 1), return -1);
Although the assertion does not occur anymore, I could not identify
which of ISL's commits fixed it.
Compared to the previous ISL version, Polly requires some changes for this update
* Since ISL commit
20d3574 "perform parameter alignment by modifying both arguments to function"
isl_*_gist_* and similar functions do not always align the paramter
list anymore. This caused the parameter lists in JScop files to
become out-of-sync. Since many regression tests use JScop files with
a fixed parameter list and order, we explicitly call align_params to
ensure a predictable parameter list.
* ISL changed some return types to isl_size, a typedef of (signed) int.
This caused some issues where the return type was unsigned int before:
- No overload for std::max(unsigned,isl_size)
- It cause additional 'mixed signed/unsigned comparison' warnings.
Since they do not break compilation, and sizes larger than 2^31
were never supported, I am going to fix it separately.
* With the change to isl_size, commit
57d547 "isl_*_list_size: return isl_size"
also changed the return value in case of an error from 0 to -1. This
caused undefined looping over isl_iterator since the 'end iterator'
got index -1, never reached from the 'begin iterator' with index 0.
* Some internal changes in ISL caused the number of operations to
increase when determining access ranges to determine aliasing
overlaps. In one test, this caused exceeding the default limit of
800000. The operations-limit was disabled for this test.
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.
I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
recompiles touches affected_files header
342380 95 3604 llvm/include/llvm/ADT/STLExtras.h
314730 234 1345 llvm/include/llvm/InitializePasses.h
307036 118 2602 llvm/include/llvm/ADT/APInt.h
213049 59 3611 llvm/include/llvm/Support/MathExtras.h
170422 47 3626 llvm/include/llvm/Support/Compiler.h
162225 45 3605 llvm/include/llvm/ADT/Optional.h
158319 63 2513 llvm/include/llvm/ADT/Triple.h
140322 39 3598 llvm/include/llvm/ADT/StringRef.h
137647 59 2333 llvm/include/llvm/Support/Error.h
131619 73 1803 llvm/include/llvm/Support/FileSystem.h
Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.
Reviewers: bkramer, asbirlea, bollu, jdoerfert
Differential Revision: https://reviews.llvm.org/D70211
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368935
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
Move the optimized getDefToTarget() from ForwardOpTree to ZoneAlgo such
that it can be used by makeValInst.
This reduces the compile time of GrTestUtils of the aosp buildbot from
2m46s to 21s, which should fix the timeout issue.
Differential Revision: https://reviews.llvm.org/D48579
llvm-svn: 335606
In case the schedule has not changed and the operand tree root uses a
value defined in an ancestor loop, the def-to-target mapping is trivial.
For instance, the SCoP
for (int i < 0; i < N; i+=1) {
DefStmt:
D = ...;
for (int j < 0; j < N; j+=1) {
TargetStmt:
use(D);
}
}
has DefStmt-to-TargetStmt mapping of
{ DefStmt[i] -> TargetStmt[i,j] }
This should apply on the majority of def-to-target mappings.
This patch detects this case and directly constructs the expected
mapping. It assumes that the mapping never crosses the loop header
DefStmt is in, which ForwardOpTree does not support at the moment
anyway.
Differential Revision: https://reviews.llvm.org/D47752
llvm-svn: 334134
The aosp-O3-polly-before-vectorizer-unprofitable buildbot currently
fails in ZoneAlgorithm::isNormalized, presumably because an
out-of-quota happens in that function.
Modify ZoneAlgorithm::isNormalized to return an isl::boolean such
it can report an error.
In the failing case, it was called in an assertion in ForwardOpTree.
Allow to pass the assertion in an out-of-quota event, a condition that
is later checked before forwarding an operand tree.
llvm-svn: 333709
When forwarding a LoadInst to another statement, a map that translates
their domain is needed. Before this patch, is was computed by appending
the def-to-use map to the def-to-target of the operand tree's target.
This patch lets the new method getDefToTarget do this. This is
computationally less expensive due to:
* Caching of the result such that it can be used for multiple operands
tree to the same target.
* The map is only computed when there is a LoadInst that needs it.
* It is only computed for the statement requiring the translator map,
instead of having an intermediate result for every edge in the
operand tree.
The downside is that this scheme cannot handle forwarding from a
previous loop iteration (which would require the entire path from
statement to target). Since ForwardOpTree currently does not support
forwarding across loop iterations (SCEV expressions would need to be
transformed), this was not needed anyway.
Differential Revision: https://reviews.llvm.org/D47385
llvm-svn: 333426
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
Differential Revision: https://reviews.llvm.org/D44978
llvm-svn: 332352
Summary:
Most changes are mechanical, but in one place I changed the program semantics
by fixing a likely bug:
In `Scop::hasFeasibleRuntimeContext()`, I'm now explicitely handling the
error-case. Before, when the call to `addNonEmptyDomainConstraints()`
returned a null set, this (probably) accidentally worked because
isl_bool_error converts to true. I'm checking for nullptr now.
Reviewers: grosser, Meinersbur, bollu
Reviewed By: Meinersbur
Subscribers: nemanjai, kbarton, pollydev, llvm-commits
Differential Revision: https://reviews.llvm.org/D39971
llvm-svn: 318632
Put the analysis part of reloadKnownContent under an isl
max-operations quota scope, as has already been done for
forwardKnownLoad.
This should fix the aosp timeout of "GrTestUtils.cpp".
llvm-svn: 317495
Represent PHIs by their incoming values instead of an opaque value of
themselves. This allows ForwardOpTree to "look through" the PHIs and
forward the incoming values since forwardings PHIs is currently not
supported.
This is particularly useful to cope with PHIs inserted by GVN LoadPRE.
The incoming values all resolve to a load from a single array element
which then can be forwarded.
It should in theory also reduce spurious conflicts in value mapping
(DeLICM), but I have not yet found a profitable case yet, so it is
not included here.
To avoid transitive closure and potentially necessary overapproximations
of those, PHIs that may reference themselves are excluded from
normalization and keep their opaque self-representation.
Differential Revision: https://reviews.llvm.org/D39333
llvm-svn: 317008
For scalar accesses, change the access target to an array element that
is known to contain the same value.
This may become an alternative to forwardKnownLoad which creates new
loads (and therefore closer to forwarding speculatives). Reloading does
not require the known value originating from a load, but can be a store
as well.
Differential Revision: https://reviews.llvm.org/D39325
llvm-svn: 316766
Computing the reaching definition in forwardTree() can take a long time
if the coefficients are large. When the forwarding is
carried-out (doIt==true), forwardTree() must execute entirely or not at
all to get a consistent output, which means we cannot just allow
out-of-quota errors to happen in the middle of the processing.
We introduce the class IslQuotaScope which allows to opt-in code that is
conformant and has been tested with out-of-quota events. In case of
ForwardOpTree, out-of-quota is allowed during the operand tree
examination, but not during the transformation. The same forwardTree()
recursion is used for examination and execution, meaning that the
reaching definition has already been computed in the examination tree
walk and cached for reuse in the transformation tree walk.
This should fix the time-out of grtestutils.ll of the asop buildbot. If
the compilation still takes too long, we can reduce the max-operations
allows for -polly-optree.
Differential Revision: https://reviews.llvm.org/D37984
llvm-svn: 313690
cl::opt<unsigned long> is not specialized and hence the option
-polly-optree-max-ops impossible to use.
Replace by supported option cl::opt<unsigned>.
Also check for an error state when computing the written value, which
happens when the quota runs out.
llvm-svn: 313546
Before this patch, OpTree did not consider forwarding an operand tree consisting
of only single LoadInst as useful. The motivation was that, like an access to a
read-only variable, it would just replace one MemoryAccess by another. However,
in contrast to read-only accesses, this would replace a scalar access by an
array access, which is something worth doing.
In addition, leaving scalar MemoryAccess is problematic in that VirtualUse
prioritizes inter-Stmt use over intra-Stmt. It was possible that the same LLVM
value has a MemoryAccess for accessing the remote Stmt's LoadInst as well as
having the same LoadInst in its own instruction list (due to being forwarded
from another operand tree).
With this patch we ensure that if a LoadInst is forwarded is any operand tree,
also the operand tree containing just the LoadInst is forwarded as well, which
effectively removes the scalar MemoryAccess such that only the array access
remains, not both.
Thanks Michael for the detailed explanation.
Reviewers: Meinersbur, bellu, singam-sanjay, gareevroman
Subscribers: hfinkel, pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D37424
llvm-svn: 312456
Summary:
After region statements now also have instruction lists, this is a
straightforward extension.
Reviewers: Meinersbur, bollu, singam-sanjay, gareevroman
Reviewed By: Meinersbur
Subscribers: hfinkel, pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D37298
llvm-svn: 312249
ZoneAlgo used to bail out for the complete SCoP if it encountered
something violating its assumption. This meant the neither OpTree can
forward any load nor DeLICM do anything in such cases, even if their
transformations are unrelated to the violations.
This patch adds a list of compatible elements (currently with the
granularity of entire arrays) that can be used for analysis. OpTree
and DeLICM can then check whether their transformations only concern
compatible elements, and skip non-compatible ones.
This will be useful for e.g. Polybench's benchmarks covariance,
correlation, bicg, doitgen, durbin, gramschmidt, adi that have
assumption violation, but which are not necessarily relevant
for all transformations.
Differential Revision: https://reviews.llvm.org/D37219
llvm-svn: 311929
Add statistics about
- Which optimizations are applied
- Number of loops in Scops at various stages
- Number of scalar/singleton writes at various stages representative
for scalar false dependencies
- Number of parallel loops
These will be useful to find regressions due to moving Polly further
down of LLVM's pass pipeline.
Differential Revision: https://reviews.llvm.org/D37049
llvm-svn: 311553
We are working towards removing uses of Scop::getStmtFor(BB). In this
patch, we remove dependency of Scop::getStmtFor(Inst) on getStmtFor(BB).
To do so, we introduce a map of instructions to their corresponding scop
statements and use it to get the instructions' statement.
Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>
Differential Revision: https://reviews.llvm.org/D35663
llvm-svn: 310494
The previous value of "polly-delicm" was forgotten to to be changed when
ForwardOpTree was split from DeLICM.
Thanks to Tobias for noticing!
llvm-svn: 310465
This is an addition to the -polly-optree pass that reuses the array
content analysis from DeLICM to find array elements that contain the
same value as the value loaded when the target statement instance
is executed.
The analysis is now enabled by default.
The known content analysis could also be used to rematerialize any
llvm::Value that was written to some array element, but currently
only loads are forwarded.
Differential Revision: https://reviews.llvm.org/D36380
llvm-svn: 310279
The method forwardSpeculatable forwards speculatively executable
instructions and is currently the only way to forward an
instruction.
In the future we intend to add more methods.
llvm-svn: 310056
Commit r309730 moved the call to canForwardTree into an assert(), even
though this function has side-effects if its DoIt parameter is true. To
avoid a warning in release builds, do an (void)Execution of its result
instead.
To avoid such confusion in the future, rename
canForwardTree() to forwardTree().
llvm-svn: 309753
This allows -polly-optree to move instructions that depend on
synthesizable values.
The difficulty for synthesizable values is that their value depends on
the location. When it is moved over a loop header, and the SCEV
expression depends on the loop induction variable (SCEVAddRecExpr), it
would use the current induction variable instead of the last one.
At the moment we cannot forward PHI nodes such that crossing the header
of loops referenced by SCEVAddRecExpr is not possible (assuming the loop
header has at least two incoming blocks: for entering the loop and the
backedge, such any instruction to be forwarded must have a phi between
use and definition).
A remaining issue is when the forwarded value is used after the loop,
but is only synthesizable inside the loop. This happens e.g. if
ScalarEvolution is unable to determine the number of loop iterations or
the initial loop value. We do not forward in this situation.
Differential Revision: https://reviews.llvm.org/D36102
llvm-svn: 309609
Read-only values (values defined before the SCoP) require special
handing with -polly-analyze-read-only-scalars=true (which is the
default). If active, each use of a value requires a read access.
When a copied value uses a read-only value, we must also ensure that
such a MemoryAccess is available or is created.
Differential Revision: https://reviews.llvm.org/D35764
llvm-svn: 308876
patacca