Summary:
In case two arrays share base pointers in the same invariant load equivalence
class, we canonicalize all memory accesses to the first of these arrays
(according to their order in the equivalence class).
This enables us to optimize kernels such as boost::ublas by ensuring that
different references to the C array are interpreted as accesses to the same
array. Before this change the runtime alias check for ublas would fail, as it
would assume models of the C array with differing (but identically valued) base
pointers would reference distinct regions of memory whereas the referenced
memory regions were indeed identical.
As part of this change we remove most of the MemoryAccess::get*BaseAddr
interface. We removed already all references to get*BaseAddr in previous
commits to ensure that no code relies on matching base pointers between
memory accesses and scop arrays -- except for three remaining uses where we
need the original base pointer. We document for these situations that
MemoryAccess::getOriginalBaseAddr may return a base pointer that is distinct
to the base pointer of the scop array referenced by this memory access.
Reviewers: sebpop, Meinersbur, zinob, gareevroman, pollydev, huihuiz, efriedma, jdoerfert
Reviewed By: Meinersbur
Subscribers: etherzhhb
Tags: #polly
Differential Revision: https://reviews.llvm.org/D28518
llvm-svn: 302636
Scop::init is used only during SCoP construction. Therefore ScopBuilder
seems the more appropriate place for it. We integrate it onto its only
caller ScopBuilder::buildScop where some other construction steps
already took place.
Differential Revision: https://reviews.llvm.org/D32908
llvm-svn: 302276
SCoPs with unfeasible runtime context are thrown away and therefore
do not need their uses verified.
The added test case requires a complexity limit to exceed.
Normally, error statements are removed from the SCoP and for that
reason are skipped during the verification. If there is a unfeasible
runtime context (here: because of the complexity limit being reached),
the removal of error statements and other SCoP construction steps are
skipped to not waste time. Error statements are not modeled in SCoPs
and therefore have no requirements on whether the scalars used in
them are available.
llvm-svn: 302234
If a ScopStmt references a (scalar) value, there are multiple
possibilities where this value can come. The decision about what kind of
use it is must be handled consistently at different places, which can be
error-prone. VirtualUse is meant to centralize the handling of the
different types of value uses.
This patch makes ScopBuilder and CodeGeneration use VirtualUse. This
already helps to show inconsistencies with the value handling. In order
to keep this patch NFC, exceptions to the general rules are added.
These might be fixed later if they turn to problems. Overall, this
should result in fewer post-codegen IR-verification errors, but instead
assertion failures in `getNewValue` that are closer to the actual error.
Differential Revision: https://reviews.llvm.org/D32667
llvm-svn: 302157
The AssumptionCache removal of r289756 has been reverted in
r290086/r290087. A different solution has been implemented in r291671
which keeps the AssumptionCache. We can therefore use it again in Polly.
This reverts r289791.
llvm-svn: 298089
Introduce ScopStmt::getSurroundingLoop() to replace getFirstNonBoxedLoopFor.
getSurroundingLoop() returns the precomputed surrounding/first non-boxed
loop. Except in ScopDetection, the list of boxed loops is only used to
get the surrounding loop. getFirstNonBoxedLoopFor also requires LoopInfo
at every use which is not necessarily available everywhere where we may
want to use it.
Differential Revision: https://reviews.llvm.org/D30985
llvm-svn: 297899
Move the function getFirstNonBoxedLoopFor which is used in ScopBuilder
and in ScopInfo to Support/ScopHelpers to make it reusable in other
locations. No functionality change.
Patch by Sameer Abu Asal.
Differential Revision: https://reviews.llvm.org/D28754
llvm-svn: 292168
To benefit of the type safety guarantees of C++11 typed enums, which would have
caught the type mismatch fixed in r291960, we make MemoryKind a typed enum.
This change also allows us to drop the 'MK_' prefix and to instead use the more
descriptive full name of the enum as prefix. To reduce the amount of typing
needed, we use this opportunity to move MemoryKind from ScopArrayInfo to a
global scope, which means the ScopArrayInfo:: prefix is not needed. This move
also makes historically sense. In the beginning of Polly we had different
MemoryKind enums in both MemoryAccess and ScopArrayInfo, which were later
canonicalized to one. During this canonicalization we just choose the enum in
ScopArrayInfo, but did not consider to move this shared enum to global scope.
Reviewed-by: Michael Kruse <llvm@meinersbur.de>
Differential Revision: https://reviews.llvm.org/D28090
llvm-svn: 292030
The AssumptionCache was removed in r289756 after being replaced by the an
addtional operand list of affected values in r289755. The absence of that cache
means that we have now have to manually search for llvm.assume intrinsics as
now done by other passes (LazyValueInfo, CodeMetrics) do not take into
account an llvm::Instruction's user lists (ScalarEvolution).
llvm-svn: 289791
Commit r286294 introduced support for inaccessiblememonly and
inaccessiblemem_or_argmemonly attributes to BasicAA, which we need to
support to avoid undefined behavior. This change just refuses all calls
which are annotated with these attributes, which is conservatively correct.
In the future we may consider to model and support such function calls
in Polly.
llvm-svn: 286771
We don't actually check whether a MemoryAccess is affine in very many
places, but one important one is in checks for aliasing.
Differential Revision: https://reviews.llvm.org/D25706
llvm-svn: 285746
Under some conditions MK_Value read accessed where converted to MK_ExitPHI read
accessed. This is unexpected because MK_ExitPHI read accesses are implicit after
the scop execution. This behaviour was introduced in r265261, which fixed a
failed assertion/crash in CodeGen.
Instead, we fix this failure in CodeGen itself. createExitPHINodeMerges(),
despite its name, also handles accesses of kind MK_Value, only to skip them
because they access values that are usually not PHI nodes in the SCoP region's
exit block. Except in the situation observed in r265261.
Do not convert value accessed to ExitPHI accesses and do not handle
value accesses like ExitPHI accessed in CodeGen anymore.
llvm-svn: 284023
We do not need the size of the outermost dimension in most cases, but if we
allocate memory for newly created arrays, that size is needed.
Reviewed-by: Michael Kruse <llvm@meinersbur.de>
Differential Revision: https://reviews.llvm.org/D23991
llvm-svn: 281234
getAccessFunctions() is dead code and the 'BB' argument
of getOrCreateAccessFunctions() is not used. This patch deletes
getAccessFunctions and transforms AccFuncMap into
a std::vector<std::unique_ptr<MemoryAccess>> AccessFunctions.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: https://reviews.llvm.org/D23759
llvm-svn: 279394
Normally this is ensured when adding PHI nodes, but as PHI node dependences
do not need to be added in case all incoming blocks are within the same
non-affine region, this was missed.
This corrects an issue visible in LNT's sqlite3, in case invariant load hoisting
was disabled.
llvm-svn: 278792
Summary: LLVM adds a new value FMRB_DoesNotReadMemory in the enumeration.
Reviewers: andrew.w.kaylor, chrisj, zinob, grosser, jdoerfert
Subscribers: Meinersbur, pollydev
Differential Revision: http://reviews.llvm.org/D22109
llvm-svn: 275085
For llvm the memory accesses from nonaffine loops should be visible,
however for polly those nonaffine loops should be invisible/boxed.
This fixes llvm.org/PR28245
Cointributed-by: Huihui Zhang <huihuiz@codeaurora.org>
Differential Revision: http://reviews.llvm.org/D21591
llvm-svn: 274842
It is only used internally by the ScopInfo pass. By moving it into its
own header file we avoid it being processed that use only ScopInfo.
llvm-svn: 273983
The methods in ScopBuilder are used for the construction of a Scop,
while the remaining classes of ScopInfo are required by all passes that
use Polly's polyhedral analysis.
llvm-svn: 273982
Tobias Grosser