This flag enable the user to print debug Info from all the passes and
helpers inside polly at once. This will help a novice user as well to
work in polly without explicitly having to know which parts of polly has
actually kicked in and pass them via -debug-only.
Existing reduction detection algorithm does two types of memory checks
before marking a load store pair as reduction.
Second check is to verify there is no other memory access in ScopStmt
overlapping with the memory of load and store that forms the reduction.
Existing check misses cases where there could be probable overlap such
as
A[V] += A[P];
In the above case there is chance of overlap between A[V] and A[P] which
is missed.
This commit addresses this by removing the parameter from space before
checking for compatible space.
Part 1 of this patch :
[75297](https://github.com/llvm/llvm-project/pull/75297)
Existing reduction detection algorithm does two types of memory checks
before marking a load store pair as reduction.
First is to check if load and store are pointing to the same memory. This
check right now detects the following case as reduction. sum[0] = sum[1]
+ A[i]
This is because the check compares only base of the memory addresses
involved and not their indices. This patch addresses this issue and
introduces some debug prints. Added couple of test cases to verify the
functionality of patch as well.
This changes the AliasSetTracker to track memory locations instead of
pointers in its alias sets. The motivation for this is outlined in an RFC
posted on LLVM discourse:
https://discourse.llvm.org/t/rfc-dont-merge-memory-locations-in-aliassettracker/73336
In the data structures of the AST implementation, I made the choice to
replace the linked list of `PointerRec` entries (that had to go anyway)
with a simple flat vector of `MemoryLocation` objects, but for the
`AliasSet` objects referenced from a lookup table, I retained the
mechanism of a linked list, reference counting, forwarding, etc. The
data structures could be revised in a follow-up change.
This patch pulls out the memory checks from the base reduction detection
algorithm. This is the first one in the reduction patch series, to
reduce the difference in future patches.
D138014 restricted AST to work on immutable IR. This means it is
also safe to use a single BatchAA instance for the entire AST
lifetime, instead of only batching parts of individual queries.
The primary motivation for this is not compile-time, but rather
having a central place to control cross-iteration AA, which will
be used by D137958.
Differential Revision: https://reviews.llvm.org/D137955
Followup to D135962 to rename remaining uses of
FunctionModRefBehavior to MemoryEffects. Does not touch API names
yet, but also updates variables names FMRB/MRB to ME, to match the
new type name.
Currently, FunctionModRefBehavior tracks whether the function reads
or writes memory (ModRefInfo) and which locations it can access
(argmem, inaccessiblemem and other). This patch changes it to track
ModRef information per-location instead.
To give two examples of why this is useful:
* D117095 highlights a weakness of ModRef modelling in the presence
of operand bundles. For a memcpy call with deopt operand bundle,
we want to say that it can read any memory, but only write argument
memory. This would allow them to be treated like any other calls.
However, we currently can't express this and have to say that it
can read or write any memory.
* D127383 would ideally be modelled as a separate threadid location,
where threadid Refs outside pre-split coroutines can be ignored
(like other accesses to constant memory). The current representation
does not allow modelling this precisely.
The patch as implemented is intended to be NFC, but there are some
obvious opportunities for improvements and simplification. To fully
capitalize on this we would also want to change the way we represent
memory attributes on functions, but that's a larger change, and I
think it makes sense to separate out the FunctionModRefBehavior
refactoring.
Differential Revision: https://reviews.llvm.org/D130896
Rather than checking the bitcast pointer element types, compare
the element type of the access and the GEP result type.
The entire code is dubious due to the inspection of GEP structure,
but this at least preserves the spirit of the existing code.
Ensure that function definitions match their declrations in header
files, even if they have no effect on linking. This includes
1. Both have the same __isl_* annotations
2. Both use the same type alias
3. Remove unused declarations that have no definition
4. Use explicit polly namespace qualifier for definitions; generally,
the .cpp file should use at most an anon namespace region since
only symbols declared in the header file can be accessed from other
translation units anyway. For defintions that have been declared in
the header file, the explicit namespace qualifier ensures that both
match.
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.
In the official interface the type `isl::size` cannot be casted to an unsigned without previously having checked if it contains a valid value with the function `isl::size::is_error()`.
For this reason two helping functions have been added:
- `IslAssert`: assert that no errors are present in debug builds and just disables the mandatory error check in non-debug builds
- `unisgnedFromIslSIze`: cast the `isl::size` object to `unsigned`
Changes made:
- Add the functions `IslAssert` and `unsignedFromIslSize`
- Add the utility function `rangeIslSize()`
- Retype `MaxDisjunctsInDomain` from `int` to `unsigned`
- Retype `RunTimeChecksMaxAccessDisjuncts` from `int` to `unsigned`
- Retype `MaxDimensionsInAccessRange` from `int` to `unsigned`
- Replaced some usages of `isl_size` to `unsigned` since we aim not to use `isl_size` anymore
- `isl-noexceptions.h` has been generated by e704f73c88
No functional change intended.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D113101
As of 741fabc222f226d34d806056b804244b012853b, polly builders are
failing from this error. The signiature is slightly different and
accepts a ScalarEvolution reference instead. This should fix the polly
builders.
Code outside the SCoP will be executed recardless of the code versioning
runtime check introduced by CodeGeneration. Assumption made based on
that these are never executed in Polly-optimized code does not hold.
This fixes the miscompilation of MultiSource/Applications/lambda-0.1.3
Compilation of the file insn-attrtab.c of the SPEC CPU 2017 502.gcc_r
benchmark takes excessive time (> 30min) with Polly enabled. Most time
is spent in the isErrorBlock function querying the DominatorTree.
The isErrorBlock is invoked redundantly over the course of ScopDetection
and ScopBuilder. This patch introduces a caching mechanism for its
result.
Instead of a free function, isErrorBlock is moved to ScopDetection where
its cache map resides. This also means that many functions directly or
indirectly calling isErrorBlock are not "const" anymore. The
DetectionContextMap was marked as "mutable", but IMHO it never should
have been since it stores the detection result.
502.gcc_r only takes excessive time with the new pass manager. The
reason seeams to be that it invalidates the ScopDetection analysis more
often than the legacy pass manager, for unknown reasons.
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.
With this commit we are moving from the `polly-generator` branch to the `new-polly-generator` branch that is more mantainable and is based on the official C++ interface `cpp-checked.h`.
Changes made:
- There are now many sublcasses for `isl::ast_node` representing different isl types. Use `isl::ast_node_for`, `isl::ast_node_user`, `isl::ast_node_block` and `isl::ast_node_mark` where needed.
- There are now many sublcasses for `isl::schedule_node` representing different isl types. Use `isl::schedule_node_mark`, `isl::schedule_node_extension`, `isl::schedule_node_band` and `isl::schedule_node_filter` where needed.
- Replace the `isl::*::dump` with `dumpIslObj` since the isl dump method is not exposed in the C++ interface.
- `isl::schedule_node::get_child` has been renamed to `isl::schedule_node::child`
- `isl::pw_multi_aff::get_pw_aff` has been renamed to `isl::pw_multi_aff::at`
- The constructor `isl::union_map(isl::union_pw_multi_aff)` has been replaced with the static method `isl::union_map::from()`
- Replace usages of `isl::val::add_ui` with `isl::val::add`
- `isl::union_set_list::alloc` is now a constructor
- All the `isl_size` values are now wrapped inside the class `isl::size` use `isl::size::release` to get the internal `isl_size` value where needed.
- `isl-noexceptions.h` has been generated by 73f5ed1f4d
No functional change intended.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D107225
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:
- Use `isl::union_map::unite()` instead of `isl::union_map::add_map()`
- `isl-noexceptions.h` has been generated by this 3f43ae29fa
Depends on D106059
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D106061
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:
- Stop generating `isl::union_set` and isl::union_map` from `isl::space` and instead generate them from `isl::ctx`
- Disable clang-format on `isl-noexceptions.h`
- Removed `isl::union_{set,map}` generator from `isl::space` from `isl-noexceptions.h`
- `isl-noexceptions.h` has been generated by this 87c3413b6f
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D106059
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:
- Use `isl::set::tuple_dim` instead of `isl::set::dim` and `isl::set::n_dim`
- Use `isl::map::domain_tuple_dim` instead of `isl::map::dim`
- Use `isl::map::range_tuple_dim` instead of `isl::map::dim`
- isl-noexceptions.h has been generated by this 45576e1b42
Note that not all the usage of `isl::{set,map}::dim` where replaced
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D104994
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 method `to_str()` from all the classes in the isl C++ bindings.
- Overload method `stringFromIslObj()` so it accepts isl C++ objects.
- To keep backward compatibility `stringFromIslObj()` now accepts a value that is returned if the isl C object is `null` or doesn't have a string representation (by default it's an empty string). In some cases it's better to have the string "null" instead of an empty string.
- isl-noexceptions.h has been generated by this d33ec3a3bb
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D104211
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
Make Polly look for unrolling metadata (https://llvm.org/docs/TransformMetadata.html#loop-unrolling) that is usually only interpreted by the LoopUnroll pass and apply it to the SCoP's schedule.
While not that useful by itself (there already is an unroll pass), it introduces mechanism to apply arbitrary loop transformation directives in arbitrary order to the schedule. Transformations are applied until no more directives are found. Since ISL's rescheduling would discard the manual transformations and it is assumed that when the user specifies the sequence of transformations, they do not want any other transformations to apply. Applying user-directed transformations can be controlled using the `-polly-pragma-based-opts` switch and is enabled by default.
This does not influence the SCoP detection heuristic. As a consequence, loop that do not fulfill SCoP requirements or the initial profitability heuristic will be ignored. `-polly-process-unprofitable` can be used to disable the latter.
Other than manually editing the IR, there is currently no way for the user to add loop transformations in an order other than the order in the default pipeline, or transformations other than the one supported by clang's LoopHint. See the `unroll_double.ll` test as example that clang currently is unable to emit. My own extension of `#pragma clang loop` allowing an arbitrary order and additional transformations is available here: https://github.com/meinersbur/llvm-project/tree/pragma-clang-loop. An effort to upstream this functionality as `#pragma clang transform` (because `#pragma clang loop` has an implicit transformation order defined by the loop pipeline) is D69088.
Additional transformations from my downstream pragma-clang-loop branch are tiling, interchange, reversal, unroll-and-jam, thread-parallelization and array packing. Unroll was chosen because it uses already-defined metadata and does not require correctness checks.
Reviewed By: sebastiankreutzer
Differential Revision: https://reviews.llvm.org/D97977
This reverts commit 329aeb5db43f5e69df038fb20d2def77fe6f8595,
and relands commit 61f006ac655431bd44b9e089f74c73bec0c1a48c.
This is a continuation of D89456.
As it was suggested there, now that SCEV models `PtrToInt`,
we can try to improve SCEV's pointer handling.
In particular, i believe, i will need this in the future
to further fix `SCEVAddExpr`operation type handling.
This removes special handling of `ConstantPointerNull`
from `ScalarEvolution::createSCEV()`, and add constant folding
into `ScalarEvolution::getPtrToIntExpr()`.
This way, `null` constants stay as such in SCEV's,
but gracefully become zero integers when asked.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D98147
This is a continuation of D89456.
As it was suggested there, now that SCEV models `PtrToInt`,
we can try to improve SCEV's pointer handling.
In particular, i believe, i will need this in the future
to further fix `SCEVAddExpr`operation type handling.
This removes special handling of `ConstantPointerNull`
from `ScalarEvolution::createSCEV()`, and add constant folding
into `ScalarEvolution::getPtrToIntExpr()`.
This way, `null` constants stay as such in SCEV's,
but gracefully become zero integers when asked.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D98147
Regenerate the C++ wrapper header from the current isl version's
headers.
The most notable change is that some dimension sizes are represented by
an isl_size (instead of unsigned), which is a signed int. Additionally,
some function may return -1 in case of an error which already had been
fixed in the past. The C++ may no return -1 instead of UINT_MAX which
caused the problems.
Some types in Polly had been changed from unsigned to isl_size
(that were not already auto) and some loops/comparision had to be
changed to avoid unsigned/signed comparison warnings.
This reverts commit b7d870eae7fdadcf10d0f177faa7409c2e37d776 and the
subsequent fix "[Polly] Fix build after AssumptionCache change (D96168)"
(commit e6810cab09fcbc87b6e5e4d226de0810e2f2ea38).
It caused indeterminism in the output, such that e.g. the
polly-x86_64-linux buildbot failed accasionally.
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.
ScopBuilder distributes independent instructions between statements.
Only modeled (e.g. not synthesizable) instructions are represented.
To compute independence, non-modeled instructions were used in some
parts of determining instruction independence, which could lead to the
re-introduction of non-model instructions.
In particular, required invariant loads could be added to instruction
list, which then led to redundant MemoryAccesses for such a load.
This fixes llvm.org/PR48059.
Summary:
This patch moves the getIndexExpressionsFromGEP function from polly
into ScalarEvolution so that both polly and DependenceAnalysis can
use it for the purpose of subscript delinearization when the array
sizes are not parametric.
Authored By: bmahjour
Reviewer: Meinersbur, sebpop, fhahn, dmgreen, grosser, etiotto, bollu
Reviewed By: Meinersbur
Subscribers: hiraditya, arphaman, Whitney, ppc-slack, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73995
Previously, the enums didn't account for all the possible cases, which
could cause misleading results (particularly for a "switch" on
FunctionModRefBehavior).
Fixes regression in polly from recent patch to add writeonly to memset.
While I'm here, also fix a few dubious uses of the FMRB_* enum values.
Differential Revision: https://reviews.llvm.org/D73154
Scope of changes:
1) Moved RecordedAssumptions vector to ScopBuilder. RecordedAssumptions are used only for Scop constructions.
2) Moved definition of RecordedAssumptionsTy to ScopHelper. It is required both by ScopBuilder and SCEVAffinator.
3) Add new function recordAssumption to ScopHelper. One of its argument is a reference to RecordedAssumption vector. This function is used by ScopBuilder and SCEVAffinator.
4) All RecordedAssumptions are created by ScopBuilder. isl::pw_aff
objects for corresponding SCEVs are created inside ScopBuilder. Scop
functions do not record any assumptions. Scop can use isl::pw_aff
objects which were created by ScopBuilder.
5) Removed functions for handling RecordedAssumptions from Scop class.
6) Removed constness from getScopArrayInfo functions.
7) Replaced SCEVVisitor struct from SCEVAffinator with taylored version, which allow to pass pointer to RecordedAssumptions as function argument.
Differential Revision: https://reviews.llvm.org/D68056
