This is the third 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 replacement of
the access relations and create empty arrays, which are steps to implement
the packing transformation. In subsequent changes we will implement copying
to created arrays.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: http://reviews.llvm.org/D22187
llvm-svn: 278666
To do so we change the way array exents are computed. Instead of the precise
set of memory locations accessed, we now compute the extent as the range between
minimal and maximal address in the first dimension and the full extent defined
by the sizes of the inner array dimensions.
We also move the computation of the may_persist region after the construction
of the arrays, as it relies on array information. Without arrays being
constructed no useful information is computed at all.
llvm-svn: 278212
Ensure the right scalar allocations are used as the host location of data
transfers. For the device code, we clear the allocation cache before device
code generation to be able to generate new device-specific allocation and
we need to make sure to add back the old host allocations as soon as the
device code generation is finished.
llvm-svn: 278126
This increases the readability of the IR and also clarifies that the GPU
inititialization is executed _after_ the scalar initialization which needs
to before the code of the transformed scop is executed.
Besides increased readability, the IR should not change. Specifically, I
do not expect any changes in program semantics due to this patch.
llvm-svn: 278125
In case some code -- not guarded by control flow -- would be emitted directly in
the start block, it may happen that this code would use uninitalized scalar
values if the scalar initialization is only emitted at the end of the start
block. This is not a problem today in normal Polly, as all statements are
emitted in their own basic blocks, but Polly-ACC emits host-to-device copy
statements into the start block.
Additional Polly-ACC test coverage will be added in subsequent changes that
improve the handling of PHI nodes in Polly-ACC.
llvm-svn: 278124
After having generated the code for a ScopStmt, we run a simple dead-code
elimination that drops all instructions that are known to be and remain unused.
Until this change, we only considered instructions for dead-code elimination, if
they have a corresponding instruction in the original BB that belongs to
ScopStmt. However, when generating code we do not only copy code from the BB
belonging to a ScopStmt, but also generate code for operands referenced from BB.
After this change, we now also considers code for dead code elimination, which
does not have a corresponding instruction in BB.
This fixes a bug in Polly-ACC where such dead-code referenced CPU code from
within a GPU kernel, which is possible as we do not guarantee that all variables
that are used in known-dead-code are moved to the GPU.
llvm-svn: 278103
The function expandRegion() frees Region* objects again when it determines that
these are not valid SCoPs. However, the DetectionContext added to the
DetectionContextMap still holds a reference. The validity is checked using the
ValidRegions lookup table. When a new Region is added to that list, it might
share the same address, such that the DetectionContext contains two
Region* associations that are in ValidRegions, but that are unrelated and of
which one has already been free.
Also remove the DetectionContext when not a valid expansion.
llvm-svn: 278062
When adding code that avoids to pass values used in isl expressions and
LLVM instructions twice, we forgot to make single variable passed to the
kernel available in the ValueMap that makes it usable for instructions that
are not replaced with isl ast expressions. This change adds the variable
that is passed to the kernel to the ValueMap to ensure it is available
for such use cases as well.
llvm-svn: 278039
There is no need to reset the position of the builder, as we can just continue
to insert code at the current position of the IRBuilder, which happens to
be precisely the location we reset the builder to.
llvm-svn: 278014
... instead of adding instructions at the end of the basic block the builder
is currently at. This makes it easier to reason about where IR is generated,
as with the IRBuilder there is just a single location that specificies where
IR is generated.
llvm-svn: 278013
The map is iterated over when generating the values escaping the SCoP. The
indeterministic iteration order of DenseMap causes the output IR to change at
every compilation, adding noise to comparisons.
Replace DenseMap by a MapVector to ensure the same iteration order at every
compilation.
llvm-svn: 277832
When entering the dependence computation and the max_operations is set, the
operations counter may have already exceeded the counter, thus aborting any ISL
computation from the start. The counter is reset at the end of the dependence
calculation such that a follow-up recomputation might succeed, ie. the success
of the first dependence calculation depends on unrelated ISL operations that
happened before, giving it a disadvantage to the following calculations.
This patch resets the operations counter at the beginning of the dependence
recalculation to not depend on previous actions. Otherwise additional
preprocessing of the Scop that aims to improve its schedulability (eg. DeLICM)
do have the effect that DependenceInfo and hence the scheduling fail more
likely, contraproductive to the goal of said preprocessing.
llvm-svn: 277810
Before this commit we generated the array type in reverse order and we also
added the outermost dimension size to the new array declaration, which is
incorrect as Polly additionally assumed an additional unsized outermost
dimension, such that we had an off-by-one error in the linearization of access
expressions.
llvm-svn: 277802
These annotations ensure that the NVIDIA PTX assembler limits the number of
registers used such that we can be certain the resulting kernel can be executed
for the number of threads in a thread block that we are planning to use.
llvm-svn: 277799
Pass the content of scalar array references to the alloca on the kernel side
and do not pass them additional as normal LLVM scalar value.
llvm-svn: 277699
Otherwise, we would try to re-optimize them with Polly-ACC and possibly even
generate kernels that try to offload themselves, which does not work as the
GPURuntime is not available on the accelerator and also does not make any
sense.
llvm-svn: 277589
Extend the jscop interface to allow the user to export arrays. It is required
that already existing arrays of the list of arrays correspond to arrays
of the SCoP. Each array that is appended to the list will be newly created.
Furthermore, we allow the user to modify access expressions to reference
any array in case it has the same element type.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: https://reviews.llvm.org/D22828
llvm-svn: 277263
Before this change we used the array index, which would result in us accessing
the parameter array out-of-bounds. This bug was visible for test cases where not
all arrays in a scop are passed to a given kernel.
llvm-svn: 276961
Adding a new pass PolyhedralInfo. This pass will be the interface to Polly.
Initially, we will provide the following interface:
- #IsParallel(Loop *L) - return a bool depending on whether the loop is
parallel or not for the given program order.
Patch by Utpal Bora <cs14mtech11017@iith.ac.in>
Differential Revision: https://reviews.llvm.org/D21486
llvm-svn: 276637
Also factor out getArraySize() to avoid code dupliciation and reorder some
function arguments to indicate the direction into which data is transferred.
llvm-svn: 276636
At the beginning of each SCoP, we allocate device arrays for all arrays
used on the GPU and we free such arrays after the SCoP has been executed.
llvm-svn: 276635
This function is currently unused and won't be used in this form again. Instead
of freeing many unrelated items at the same time, we will instead explicitly
call free function from the host-IR we generate for each object we want to free.
These specific free functions will be added together with the corresponding
host-IR generation code.
llvm-svn: 276632
Do not process SCoPs with infeasible runtime context in the new
ScopInfoWrapperPass. Do not compute dependences for such SCoPs in the new
DependenceInfoWrapperPass.
Patch by Utpal Bora <cs14mtech11017@iith.ac.in>
Differential Revision: https://reviews.llvm.org/D22402
llvm-svn: 276631
This is the second 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 create the BLIS macro-kernel by applying a combination of tiling
and interchanging. In subsequent changes we will implement the packing
transformation.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: http://reviews.llvm.org/D21491
llvm-svn: 276627
There is no need to expose the selected device at the moment. We also pass back
pointers as return values, as this simplifies the interface.
llvm-svn: 276623
This allows the finalization routine of the IslNodeBuilder to be overwritten
by derived classes. Being here, we also drop the unnecessary 'Scop' postfix
and the unnecessary 'Scop' parameter.
llvm-svn: 276622
Before this change, the debug statements in polly_initDevice would all be
skipped, as debug-mode would only be enabled _after_ they have already been run.
llvm-svn: 276621
This functionality won't be used in the current iteration. Drop it for now to
reduce the surface of the library. We can always add it back in when we need
it again.
llvm-svn: 276611
We optimize the kernel _after_ dumping the IR we generate to make the IR we
dump easier readable and independent of possible changes in the general
purpose LLVM optimizers.
llvm-svn: 276551
Run the NVPTX backend over the GPUModule IR and write the resulting assembly
code in a string.
To work correctly, it is important to invalidate analysis results that still
reference the IR in the kernel module. Hence, this change clears all references
to dominators, loop info, and scalar evolution.
Finally, the NVPTX backend has troubles to generate code for various special
floating point types (not surprising), but also for uncommon integer types. This
commit does not resolve these issues, but pulls out problematic test cases into
separate files to XFAIL them individually and resolve them in future (not
immediate) changes one by one.
llvm-svn: 276396
This change introduces the actual compute code in the GPU kernels. To ensure
all values referenced from the statements in the GPU kernel are indeed available
we scan all ScopStmts in the GPU kernel for references to llvm::Values that
are not yet covered by already modeled outer loop iterators, parameters, or
array base pointers and also pass these additional llvm::Values to the
GPU kernel.
For arrays used in the GPU kernel we introduce a new ScopArrayInfo object, which
is referenced by the newly generated access functions within the GPU kernel and
which is used to help with code generation.
llvm-svn: 276270
This is useful for external users using IslExprBuilder, in case they cannot
embed ScopArrayInfo data into their isl_ids, because the isl_ids either already
carry other information or the isl_ids have been created and their user pointers
cannot be updated any more.
llvm-svn: 276268
This ensures that no trivially dead code is generated. This is not only cleaner,
but also avoids troubles in case code is generated in a separate function and
some of this dead code contains references to values that are not available.
This issue may happen, in case the memory access functions have been updated
and old getelementptr instructions remain in the code. With normal Polly,
a test case is difficult to draft, but the upcoming GPU code generation can
possibly trigger such problems. We will later extend this dead-code elimination
to region and vector statements.
llvm-svn: 276263
It seems the order in which we generated memory accesses changed such that
the import of these updated memory accesses failed for the 'loop3' statement
in this test case. Unfortunately, the existing CHECK lines were not strict
enough to catch this. Hence, besides fixing the order of the memory access
lines we also ensure that the memory access changes are both clearly visibly
and well checked.
llvm-svn: 276247
This makes the structure of the code clearer and reduces the size of runOnScop.
We also adjust the coding style to the latest LLVM style guide.
llvm-svn: 276246
This makes the structure of the code clearer and reduces the size of runOnScop.
We also adjust the coding style to the latest LLVM style guide.
llvm-svn: 276245
This makes the structure of the code clearer and reduces the size of runOnScop.
We also adjust the coding style to the latest LLVM style guide.
llvm-svn: 276244
This is currently not supported and will only be added later. Also update the
test cases to ensure no invariant code hoisting is applied.
llvm-svn: 275987
This simplifies the upcoming patches to add code generation for ScopStmts. Load
hoisting support will later be added in a separate commit. This commit will
be implicitly tested by the subsequent GPGPU changes.
llvm-svn: 275969
We use this opportunity to further classify the different user statements that
can arise and add TODOs for the ones not yet implemented.
llvm-svn: 275957
Create for each kernel a separate LLVM-IR module containing a single function
marked as kernel function and taking one pointer for each array referenced
by this kernel. Add debugging output to verify the kernels are generated
correctly.
llvm-svn: 275952
Initialize the list of references to a GPU array to ensure that the arrays that
need to be passed to kernel calls are computed correctly. Furthermore, the very
same information is also necessary to compute synchronization correctly. As the
functionality to compute these references is already available, what is left for
us to do is only to connect the necessary functionality to compute array
reference information.
llvm-svn: 275798
Create LLVM-IR for all host-side control flow of a given GPU AST. We implement
this by introducing a new GPUNodeBuilder class derived from IslNodeBuilder. The
IslNodeBuilder will take care of generating all general-purpose ast nodes, but
we provide our own createUser implementation to handle the different GPU
specific user statements. For now, we just skip any user statement and only
generate a host-code sceleton, but in subsequent commits we will add handling of
normal ScopStmt's performing computations, kernel calls, as well as host-device
data transfers. We will also introduce run-time check generation and LICM in
subsequent commits.
llvm-svn: 275783
This ensures that accidental calls to these functions will break loadly instead
of corrupting the stack with invalid return values.
These functions have been introduced earlier as replacement of pet and parts of
ppcg which we will never use and consequently have not been imported or compiled
into Polly.
llvm-svn: 275680
Otherwise ppcg would try to call into pet functionality that this not available,
which obviously will cause trouble. As we can easily print these statements
ourselves, we just do so.
llvm-svn: 275579
This option increases the scalability of the scheduler and allows us to remove
the 'gisting' workaround we introduced in r275565 to handle a more complicated
test case. Another benefit of using this option is also that the generated
code looks a lot more streamlined.
Thanks to Sven Verdoolaege for reminding me of this option.
llvm-svn: 275573
This works around a shortcoming of the isl scheduler, which even for some
smaller test cases does not terminate in case domain constraints are part
of the flow dependences.
llvm-svn: 275565
It seems we forgot to actually add the memory access ids to the tagged accesses,
but instead just tagged the accesses with empty isl_ids. This issue was found
by inspection and without code generation it is difficult to test just by
itself. We fix it for now without test case and expect our code generation
tests to cover this later on.
llvm-svn: 275557
We do not have them in Polly and the code to check for them is directly
referring to pet data structures which we do not have available.
This commit avoids undefined behavior. As such issues are difficult to
reproduce, this commit comes without a test case.
llvm-svn: 275553
Arrays with integer base type are similar to arrays with floating point types,
with the exception that LLVM's integer types can take some odd values. We
add a selection of different values to make sure we correctly round these
types when necessary.
References to scalar integer types are special, as we currently do not model
these types as array accesses as they are considered 'synthesizable' by Polly.
As a result, we do not generate explicit data-transfers for them, but instead
will need to keep track of all references to 'synthesizable' values separately.
At the current stage, this is only visible by missing host-to-device
data-transfer calls. In the future, we will also require special code generation
strategies.
llvm-svn: 275551
We currently only test that the code structure we generate for these scalar
parameters is correct and we add these types to make sure later code generation
additions have sufficient test coverage.
In case some of these types cannot be mapped due to missing hardware support
on the GPU some of these test cases may need to be updated later on.
llvm-svn: 275548
Instead of directly linking to ppcg's main source directory, we link to the
parent director. This allows us to access ppcg's include files with
'ppcg/cuda.h' and avoids a conflict with NVIDIA's cuda.h header.
Also drop an include directory that is currently not used.
llvm-svn: 275536
A sequence of CHECK lines allows additional statements to appear in the
output of the tested program without any test failures appearing. As we do
not want this to happen, switch this test case to use CHECK-NEXT.
llvm-svn: 275534
For this we need to provide an explicit list of statements as they occur in
the polly::Scop to ppcg.
We also setup basic AST printing facilities to facilitate debugging. To allow
code reuse some (minor) changes in ppcg are have been necessary.
llvm-svn: 275436
Instead of calling to a pet function that does not return anything, we pass
our own dummy implementation to ppcg that always returns a nullptr. This
ensures that the list of ast expressions always contains a nullptr and we do
not accidentally free a random (uninitalized) pointer. This resolves the
last valgrind warning we see.
We provide an implementation for this function, when the generated AST
expressions can be used and consequently can be tested.
llvm-svn: 275435
The tile size was previously uninitialized. As a result, it was often zero (aka.
no tiling), which is not what we want in general. More importantly, there was
the risk for arbitrary tile sizes to be choosen, which we did not observe, but
which still is highly problematic.
llvm-svn: 275418
This change now applies ppcg's GPU mapping on our initial schedule. For this
to work, we need to also initialize the set of all names (isl_ids) used in
the scop as well as the program context.
llvm-svn: 275396
To do so we copy the necessary information to compute an initial schedule from
polly::Scop to ppcg's scop. Most of the necessary information is directly
available and only needs to be passed on to ppcg, with the exception of 'tagged'
access relations, access relations that additionally carry information about
which memory access an access relation originates from.
We could possibly perform the construction of tagged accesses as part of
ScopInfo, but as this format is currently specific to ppcg we do not do this
yet, but keep this functionality local to our GPU code generation.
After the scop has been initialized, we compute data dependences and ask ppcg to
compute an initial schedule. Some of this functionality is already available in
polly::DependenceInfo and polly::ScheduleOptimizer, but to keep differences
to ppcg small we use ppcg's functionality here. We may later investiage if
a closer integration of these tools makes sense.
llvm-svn: 275390
At this stage, we do not yet modify the IR but just generate a default
initialized ppcg_scop and gpu_prog and free both immediately. Both will later be
filled with data from the polly::Scop and are needed to use PPCG for GPU
schedule generation. This commit does not yet perform any GPU code generation,
but ensures that the basic infrastructure has been put in place.
We also add a simple test case to ensure the new code is run and use this
opportunity to verify that GPU_CODEGEN tests are only run if GPU code generation
has been enabled in cmake.
llvm-svn: 275389
Add a new pass to serve as basis for automatic accelerator mapping in Polly.
The pass structure and the analyses preserved are copied from
CodeGeneration.cpp, as we will rely on IslNodeBuilder and IslExprBuilder for
LLVM-IR code generation.
Polly's accelerator code generation is enabled with -polly-target=gpu
I would like to use this commit as opportunity to thank Yabin Hu for his work in
the context of two Google summer of code projects during which he implemented
initial prototypes of the Polly accelerator code generation -- in parts this
code is already available in todays Polly (e.g., tools/GPURuntime). More will
come as part of the upcoming Polly ACC changes.
Reviewers: Meinersbur
Subscribers: pollydev, llvm-commits
Differential Revision: http://reviews.llvm.org/D22036
llvm-svn: 275275
ppcg will be used to provide mapping decisions for GPU code generation.
As we do not use C as input language, we do not include pet. However, we include
pet.h from pet 82cacb71 plus a set of dummy functions to ensure ppcg links
without problems.
The version of ppcg committed is unmodified ppcg-0.04 which has been well tested
in the context of LLVM. It does not provide an official library interface yet,
which means that in upcoming commits we will add minor modifications to make
necessary functionality accessible. We will aim to upstream these modifications
after we gained enough experience with GPU generation support in Polly to
propose a stable interface.
Reviewers: Meinersbur
Subscribers: pollydev, llvm-commits
Differential Revision: http://reviews.llvm.org/D22033
llvm-svn: 275274
Check not only that the compiler is not crashing, but also whether the
probablematic part (The sequence of instructions simplified to '4') is reflected
in the output.
Thanks to Tobias for the hint.
llvm-svn: 275189
An assertion in visitSDivInstruction() checked whether the divisor is constant
by checking whether the argument is a ConstantInt. However, SCEVValidator allows
the divisor to be simplified to a constant by ScalarEvolution.
We synchronize the implementation of SCEVValidator and SCEVAffinator to both
accept simplified SCEV expressions.
llvm-svn: 275174
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
Commit r275056 introduced a gcc compile failure due to us using two
types named 'Type', the first being the newly introduced member variable
'Type' the second being llvm::Type. We resolve this issue by renaming
the newly introduced member variable to AccessType.
llvm-svn: 275057
Summary:
With a struct we can use named accessors instead of generic std::get<3>()
calls. This increases readability of the source code.
Reviewers: jdoerfert
Subscribers: pollydev, llvm-commits
Differential Revision: http://reviews.llvm.org/D21955
llvm-svn: 275056
We now compute the invalid context of memory accesses only for the domain under
which the memory access is executed. Without limiting ourselves to this
restricted domain, invalid accesses outside of the domain of actually executed
statement instances may result in the execution domain of the statement to
become empty despite the fact that the statement will actually be executed. As a
result, such scops would use unitialized values for their computations which
results in incorrect computations.
This fixes http://llvm.org/PR27944 and unbreaks the
-polly-position=before-vectorizer buildbots.
llvm-svn: 275053
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
This is a regular maintenance update to ensure the latest version of isl is
tested.
Interesting Changes:
- AST nodes and expressions are now printed as YAML
llvm-svn: 274614
There is function is currently unused and will be replaced in the future by
functions that allow to allocate memory only on the host or only on the device.
llvm-svn: 274597
When setting the POLLY_DEBUG environment variable, on calls to the run-time
library the name of the function called is printed to stderr.
llvm-svn: 274596
There is no need to specifically match for isl, but we can exclude anything in
lib/External from formatting as we assume that externally contributed code
should always match the upstream code. This simplifies the cmake script and
allows additional external projects to be added without the need to explicitly
exclude them from formatting.
llvm-svn: 274557
Since r274197 -polly-position=before-vectorizer caused various LNT failures
for example in SingleSource/Benchmarks/Linpack. These failures seem to only
occur when the CFLAA pass is scheduled in our codegen-cleanup passes, which
suggests that the way we call this AA pass is somehow problematic. As this pass
is not of high importance, we drop the pass for now to prevent these failures
from happening. At a later point, we might investigate more in-depth why this
specific usage scenario caused correctness issues.
llvm-svn: 274427
These iterators are provided to complete the interface with non-range iterators
and are useful for external users of ScopInfo. To ensure they are tested we
use them to implement the existing range iterators.
llvm-svn: 274276
This ensures that the error status set with -polly-on-isl-error-abort is
maintained even after running DependenceInfo and ScheduleOptimizer. Both
passes temporarily set the error status to CONTINUE as the dependence
analysis uses a compute-out and the scheduler may not be able to derive
a schedule. In both cases we want to not abort, but to handle the error
gracefully. Before this commit, we always set the error reporting to ABORT
after these passes. After this commit, we use the error reporting mode that was
active earlier.
This comes without a test case as this would require us to introduce (memory)
errors which would trigger the isl errors.
llvm-svn: 274272
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
This function is used by both ScopInfo and ScopBuilder. A common
location for this function is required when ScopInfo and ScopBuilder are
separated into separate files in the next commit.
llvm-svn: 273981
Reject and report regions that contains loops overlapping nonaffine region.
This situation typically happens in the presence of inifinite loops.
This addresses bug llvm.org/PR28071.
Differential Revision: http://reviews.llvm.org/D21312
Contributed-by: Huihui Zhang <huihuiz@codeaurora.org>
llvm-svn: 273905
This patch addresses:
- A new function pass to compute polyhedral dependences. This is
required to avoid the region pass manager.
- Stores a map of Scop to Dependence object for all the scops present
in a function. By default, access wise dependences are stored.
Patch by Utpal Bora <cs14mtech11017@iith.ac.in>
Differential Revision: http://reviews.llvm.org/D21105
llvm-svn: 273881
This patch adds a new function pass ScopInfoWrapperPass so that the
polyhedral description of a region, the SCoP, can be constructed and
used in a function pass.
Patch by Utpal Bora <cs14mtech11017@iith.ac.in>
Differential Revision: http://reviews.llvm.org/D20962
llvm-svn: 273856
1. SCoP object is not owned by ScopBuilder. It just creates a SCoP and
hand over ownership through getScop() method.
2. ScopInfoRegionPass owns the SCoP object for a given region.
Patch by Utpal Bora <cs14mtech11017@iith.ac.in>
Differential Revision: http://reviews.llvm.org/D20912
llvm-svn: 273855
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
This addresses warnings produced by clang's -Wextra-semi.
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: 273607
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: 273437
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: 273436
Instead of using 0 or NULL use the C++11 nullptr symbol when referencing null
pointers.
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: 273435
This is the first 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 create the BLIS micro-kernel by applying
a combination of tiling and unrolling. In subsequent changes
we will add the extraction of the BLIS macro-kernel
and implement the packing transformation.
Contributed-by: Roman Gareev <gareevroman@gmail.com>
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: http://reviews.llvm.org/D21140
llvm-svn: 273397
ScalarReplAggregatesPass was deprecated and replaced by SROAPass.
ScalarReplAggregatesPass got finally removed in LLVM commit r272737, hence this
patch is also a compile fix.
llvm-svn: 272783
As part of this simplification we pull complex logic out of the loop body and
skip the previously redundantly executed first loop iteration.
This is a partial recommit of r271514 and r271535 which where in conflict with
the revert in r272483 and consequently also had to be reverted temporarily. The
original patch was contributed by Johannes Doerfert.
This patch is mostly a NFC, but dropping the first loop iteration can sometimes
result in slightly simpler code.
llvm-svn: 272502
With this update the isl AST generation extracts disjunctive constraints early
on. As a result, code that previously resulted in two branches with (close-to)
identical code within them:
if (P <= -1) {
for (int c0 = 0; c0 < N; c0 += 1)
Stmt_store(c0);
} else if (P >= 1)
for (int c0 = 0; c0 < N; c0 += 1)
Stmt_store(c0);
results now in only a single branch body:
if (P <= -1 || P >= 1)
for (int c0 = 0; c0 < N; c0 += 1)
Stmt_store(c0);
This resolves http://llvm.org/PR27559
Besides the above change, this isl update brings better simplification of
sets/maps containing existentially quantified dimensions and fixes a bug in
isl's coalescing.
llvm-svn: 272500
As these test cases will be changed in a subsequent commit, we expand and
tighten them to make the subsequent changes to them more obvious. As part of
this we add more context to some test cases and add CHECK-NEXT lines to ensure
no intermediate lines are missed by accident.
llvm-svn: 272499
IntToPtr and PtrToInt instructions are basically no-ops that we can handle as
such. In order to generate them properly as parameters we had to improve the
ScopExpander, though the change is the first in the direction of a more
aggressive scalar synthetization.
This patch was originally contributed by Johannes Doerfert in r271888, but was
in conflict with the revert in r272483. This is a recommit with some minor
adjustment to the test cases to take care of differing instruction names.
llvm-svn: 272485
The recent expression type changes still need more discussion, which will happen
on phabricator or on the mailing list. The precise list of commits reverted are:
- "Refactor division generation code"
- "[NFC] Generate runtime checks after the SCoP"
- "[FIX] Determine insertion point during SCEV expansion"
- "Look through IntToPtr & PtrToInt instructions"
- "Use minimal types for generated expressions"
- "Temporarily promote values to i64 again"
- "[NFC] Avoid unnecessary comparison for min/max expressions"
- "[Polly] Fix -Wunused-variable warnings (NFC)"
- "[NFC] Simplify min/max expression generation"
- "Simplify the type adjustment in the IslExprBuilder"
Some of them are just reverted as we would otherwise get conflicts. I will try
to re-commit them if possible.
llvm-svn: 272483
The 'Color' enum is only used for irreducible control flow detection. Johannes
already moved this enum in r270054 from ScopDetection.h to ScopDetection.cpp to
limit its scope to a single cpp file. We now move it into the only function
where this enum is needed to make clear that it is only needed locally in this
single function.
Thanks to Johannes for pointing out this cleanup opportunity.
llvm-svn: 272462
This patch refactors the code generation for divisions. This allows to
always generate a shift for a power-of-two division and to utilize
information about constant divisors in order to truncate the result
type.
llvm-svn: 271898
We now generate runtime checks __after__ the SCoP code generation and
not before, though they are still inserted at the same position int
the code. This allows to modify the runtime check during SCoP code
generation.
llvm-svn: 271894
IntToPtr and PtrToInt instructions are basically no-ops that we can handle as
such. In order to generate them properly as parameters we had to improve the
ScopExpander, though the change is the first in the direction of a more
aggressive scalar synthetization.
llvm-svn: 271888
We now use the minimal necessary bit width for the generated code. If
operations might overflow (add/sub/mul) we will try to adjust the types in
order to ensure a non-wrapping computation. If the type adjustment is not
possible, thus the necessary type is bigger than the type value of
--polly-max-expr-bit-width, we will use assumptions to verify the computation
will not wrap. However, for run-time checks we cannot build assumptions but
instead utilize overflow tracking intrinsics.
llvm-svn: 271878
In case of modulo compared to zero, we need to do signed modulo
operation as unsigned can give different results based on whether the
dividend is negative or not.
This addresses llvm.org/PR27707
Contributed-by: Chris Jenneisch <chrisj@codeaurora.org>
Reviewers: _jdoerfert, grosser, Meinersbur
Differential Revision: http://reviews.llvm.org/D20145
llvm-svn: 271707
Operands of binary operations that might overflow will be temporarily
promoted to i64 again, though that is not a sound solution for the problem.
llvm-svn: 271538
Summary:
After rL271151 (SCEV change) SCEV no longer unconditionally transfers
nuw/nsw from the increment operation to the post-inc value; this
transfer only happens if there is undefined behavior in the program if
the increment overflowed (as opposed to just generating poison).
The loops in `wraping_signed_expr_1.ll` are in non-canonical
form (they're not rotated), and that defeats LLVM's poison-is-UB
analysis. IMO the easiest fix here is to run `wraping_signed_expr_1.ll`
through `-loop-rotate` to canonicalize the loops, which is what this
patch does.
Reviewers: jdoerfert, Meinersbur, grosser
Subscribers: grosser, mcrosier, pollydev
Differential Revision: http://reviews.llvm.org/D20778
llvm-svn: 271536
We now have a simple function to adjust/unify the types of two (or three)
operands before an operation that requieres the same type for all operands.
Due to this change we will not promote parameters that are added to i64
anymore if that is not needed.
llvm-svn: 271513
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
Summary:
API-wise `apply` is a somewhat unidiomatic one-off function, and
removing the only(?) use in polly will let me remove it from SCEV's
exposed interface.
Reviewers: jdoerfert, Meinersbur, grosser
Subscribers: grosser, mcrosier, pollydev
Differential Revision: http://reviews.llvm.org/D20779
llvm-svn: 271177
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
Before this patch we bailed if a required invariant load was potentially
overwritten. However, now we will optimistically assume it is actually
invariant and, to this end, restrict the valid parameter space as well as the
execution context with regards to potential overwrites of the location.
llvm-svn: 270416
Since the base pointer of a possibly aliasing pointer might not alias
with any other pointer it (the base pointer) might not be tagged as
"required invariant". However, we need it do be in order to compare
the accessed addresses of the derived (possibly aliasing) pointer.
This patch also tries to clean up the load hoisting a little bit.
llvm-svn: 270412
So far we bailed if a required invariant load was potentially overwritten in
the SCoP. From now on we will optimistically assume it is actually invariant
and, to this end, restrict the valid parameter space.
llvm-svn: 270060
The SCoP now holds a reference to the ScopDetection::DetectionContext
which allows to simplify the type of various methods and remove code.
llvm-svn: 270053
Before this patch we only expanded valid __and__ profitable region. Therefor
we did not allow the expansion to create a profitable region from a
non-profitable one. With this patch we will remember and expand all valid
regions and check for profitability only at the end.
This patch increases the number of valid SCoPs in the LLVM-TS and SPEC
2000/2006 by 28% (from 303 to 390), including the hot loop in hmmer.
llvm-svn: 269343
This patch cleans up the rejection log handling during the
ScopDetection. It consists of two interconnected parts:
- We keep all detection contexts for a function in order to provide
more information to the user, e.g., about the rejection of
extended/intermediate regions.
- We remove the mutable "RejectLogs" member as the information is
available through the detection contexts.
llvm-svn: 269323
Truncate operations are basically modulo operations, thus we can model
them that way. However, for large types we assume the operand to fit
in the new type size instead of introducing a modulo with a very large
constant.
llvm-svn: 269300
We utilize assumptions on the input to model IR in polyhedral world.
To verify these assumptions we version the code and guard it with a
runtime-check (RTC). However, since the RTCs are themselves generated
from the polyhedral representation we generate them under the same
assumptions that they should verify. In other words, the guarantees
that we try to provide with the RTCs do not hold for the RTCs
themselves. To this end it is necessary to employ a different check
for the RTCs that will verify the assumptions did hold for them too.
Differential Revision: http://reviews.llvm.org/D20165
llvm-svn: 269299
If a profitable run is performed we will check if the SCoP seems to be
profitable after creation but before e.g., dependence are computed. This is
needed as SCoP detection only approximates the actual SCoP representation.
In the end this should allow us to be less conservative during the SCoP
detection while keeping the compile time in check.
llvm-svn: 269074
Regions with one affine loop can be profitable if the loop is
distributable. To this end we will allow them to be treated as
profitable if they contain at least two non-trivial basic blocks.
llvm-svn: 269064
The assumption attached to an llvm.assume in the SCoP needs to be
combined with the domain of the surrounding statement but can
nevertheless be used to refine the context.
This fixes the problems mentioned in PR27067.
llvm-svn: 269060
This patches makes the propagation of complexity problems during
domain generation consistent. Additionally, it makes it less likely to
encounter ill-formed domains later, e.g., during schedule generation.
llvm-svn: 269055
Before this patch we generated error-restrictions only for
error-blocks, thus blocks (or regions) containing a not represented
function call. However, the same reasoning is needed if the invalid
domain of a statement subsumes its actual domain. To this end we move
the generation of error-restrictions after the propagation of the
invalid domains. Consequently, error-statements are now defined more
general as statements that are assumed to be not executed.
Additionally, we do not record an empty domain for such statements but
a nullptr instead. This allows to distinguish between error-statements
and dead-statements.
llvm-svn: 269053
We now use context information to simplify the domains and access
functions of the SCoP instead of just aligning them with the parameter
space.
llvm-svn: 269048
Previously we checked the number of pieces to decide whether or not a
invariant load was to complex to be generated. However, there are
cases when e.g., divisions cause the complexity to spike regardless of
the number of pieces. To this end we now check the number of totally
involved dimensions which will increase with the number of pieces but
also the number of divisions.
llvm-svn: 269045
This exposes the functionality to interpret a SCEV, or better the
piece-wise function created from the SCEV, as an unsigned value
instead of a signed one.
llvm-svn: 269044
Min/max expressions are easier to read and can in some cases also result in
more concise IR that is generated as the min/max --- when lowered to a
cmp+select pattern -- commonly has a simpler condition then the ternary
condition isl would normally generate.
llvm-svn: 268855
This release includes sevaral improvments compared to the previous
version isl-0.16.1-145-g243bf7c (from the ISL 0.17 announcement):
- optionally combine SCCs incrementally in scheduler
- optionally maximize coincidence in scheduler
- optionally avoid loop coalescing in scheduler
- minor AST generator improvements
- improve support for expansions in schedule trees
llvm-svn: 268500
The check for complexity compares the number of polyhedra in a set,
which are combined by disjunctions (union, "OR"),
not conjunctions (intersection, "AND").
llvm-svn: 268223
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
After zero-extend operations and unsigned comparisons we now allow
unsigned divisions. The handling is basically the same as for signed
division, except the interpretation of the operands. As the divisor
has to be constant in both cases we can simply interpret it as an
unsigned value without additional complexity in the representation.
For the dividend we could choose from the different representation
schemes introduced for zero-extend operations but for now we will
simply use an assumption.
llvm-svn: 268032
For debugging it is often convenient to not abort at the very first memory
management error. This option allows to control this behavior at run-time.
llvm-svn: 268030
It does not suffice to take a global assumptions for unsigned comparisons but
we also need to adjust the invalid domain of the statements guarded by such
an assumption. To this end we allow to specialize the getPwAff call now in
order to indicate unsigned interpretation.
llvm-svn: 268025
When we materialize parameter SCEVs we did so without considering the
side effects they might have, e.g., both division and modulo are
undefined if the right hand side is zero. This is a problem because we
potentially extended the domain under which we evaluate parameters,
thus we might have introduced such undefined behaviour. To prevent
that from happening we will now guard divisions and modulo operations
in the parameters with a compare and select.
llvm-svn: 268023
Assumptions and restrictions can both be simplified with the domain of a
statement but not the same way. After this patch we will correctly
distinguish them.
llvm-svn: 267885
Instead of matching for %6, we use a regexp to match for the result strings.
This test case caused unrelated noise in http://reviews.llvm.org/D15722.
llvm-svn: 267875
If the base pointer of an invariant load is is loaded conditionally, that
condition needs to hold for the invariant load too. The structure of the
program will imply this for domain constraints but not for imprecisions in
the modeling. To this end we will propagate the execution context of base
pointers during code generation and thus ensure the derived pointer does
not access an invalid base pointer.
llvm-svn: 267707
With this patch we will optimistically assume that the result of an unsigned
comparison is the same as the result of the same comparison interpreted as
signed.
llvm-svn: 267559
Additive expressions can have constant factors too that we can extract
and thereby simplify the internal representation. For now we do
compute the gcd of all constant factors but only extract the same
(possibly negated) factor if there is one.
llvm-svn: 267445
Before, we checked all GEPs in a statement in order to derive
out-of-bound assumptions. However, this can not only introduce new
parameters but it is also not clear what we can learn from GEPs that
are not immediately used in a memory accesses inside the SCoP. As this
case is very rare, no actual change in the behaviour is expected.
llvm-svn: 267442
Before, assumptions derived from llvm.assume could reference new
parameters that were not known to the SCoP before. These were neither
beneficial to the representation nor to the user that reads the
emitted remark. Now we project them out and keep only user assumptions
on known parameters. Nevertheless, the new parameters are still part
of the SCoPs parameter space as the SCEVAffinator currently adds them
on demand.
llvm-svn: 267441
The new handling is consistent with the remaining code, e.g., we do
not create a new parameter id for each lookup call but copy an
existing one. Additionally, we now use the implicit order defined by
the Parameters set instead of an explicit one defined in a map.
llvm-svn: 267423
A zero-extended value can be interpreted as a piecewise defined signed
value. If the value was non-negative it stays the same, otherwise it
is the sum of the original value and 2^n where n is the bit-width of
the original (or operand) type. Examples:
zext i8 127 to i32 -> { [127] }
zext i8 -1 to i32 -> { [256 + (-1)] } = { [255] }
zext i8 %v to i32 -> [v] -> { [v] | v >= 0; [256 + v] | v < 0 }
However, LLVM/Scalar Evolution uses zero-extend (potentially lead by a
truncate) to represent some forms of modulo computation. The left-hand side
of the condition in the code below would result in the SCEV
"zext i1 <false, +, true>for.body" which is just another description
of the C expression "i & 1 != 0" or, equivalently, "i % 2 != 0".
for (i = 0; i < N; i++)
if (i & 1 != 0 /* == i % 2 */)
/* do something */
If we do not make the modulo explicit but only use the mechanism described
above we will get the very restrictive assumption "N < 3", because for all
values of N >= 3 the SCEVAddRecExpr operand of the zero-extend would wrap.
Alternatively, we can make the modulo in the operand explicit in the
resulting piecewise function and thereby avoid the assumption on N. For the
example this would result in the following piecewise affine function:
{ [i0] -> [(1)] : 2*floor((-1 + i0)/2) = -1 + i0;
[i0] -> [(0)] : 2*floor((i0)/2) = i0 }
To this end we can first determine if the (immediate) operand of the
zero-extend can wrap and, in case it might, we will use explicit modulo
semantic to compute the result instead of emitting non-wrapping assumptions.
Note that operands with large bit-widths are less likely to be negative
because it would result in a very large access offset or loop bound after the
zero-extend. To this end one can optimistically assume the operand to be
positive and avoid the piecewise definition if the bit-width is bigger than
some threshold (here MaxZextSmallBitWidth).
We choose to go with a hybrid solution of all modeling techniques described
above. For small bit-widths (up to MaxZextSmallBitWidth) we will model the
wrapping explicitly and use a piecewise defined function. However, if the
bit-width is bigger than MaxZextSmallBitWidth we will employ overflow
assumptions and assume the "former negative" piece will not exist.
llvm-svn: 267408
Memory accesses can have non-precisely modeled access functions that
would cause us to build incorrect execution context for hoisted loads.
This is the same issue that occurred during the domain construction for
statements and it is dealt with the same way.
llvm-svn: 267289
The SCEVAffinator will now produce not only the isl representaiton of
a SCEV but also the domain under which it is invalid. This is used to
record possible overflows that can happen in the statement domains in
the statements invalid domain. The result is that invalid loads have
an accurate execution contexts with regards to the validity of their
statements domain. While the SCEVAffinator currently is only taking
"no-wrapping" assumptions, we can add more withouth worrying about the
execution context of loads that are optimistically hoisted.
llvm-svn: 267288
The invalid context is not enough to describe the parameter constraints under
which a statement is not modeled precisely. The reason is that during the
domain construction the bounds on the induction variables are not known but
needed to check if e.g., an overflow can actually happen. To this end we
replace the invalid context of a statement with an invalid domain. It is
initialized during domain construction and intersected with the domain once
it was completely build. Later this invalid domain allows to eliminate
falsely assumed wrapping cases and other falsely assumed mismatches in the
modeling.
llvm-svn: 267286
As discussed in the Polly weekly phone call and reviews.llvm.org/D18878,
the assumed contexts changed (widen) due to D18878/r265942. Also check
these contexts in the tests affected by that change.
llvm-svn: 266323
We used checks to minimize the number of remarks we present to a user
but these checks can become expensive, especially since all wrapping
assumptions are emitted separately. Because there is not benefit for a
"headless" run we put these checks under a command line flag. Thus, if
the flag is not given we will emit "non-effective" remarks, e.g.,
duplicates and revert to the old behaviour if it is given. As this
also changes the internal representation of some sets we set the flag
by default for our unit tests.
llvm-svn: 266087
Utilizing the record option for assumptions we can simplify the wrapping
assumption generation a lot. Additionally, we can now report locations
together with wrapping assumptions, though they might not be accurate yet.
llvm-svn: 266069
There are three reasons why we want to record assumptions first before we
add them to the assumed/invalid context:
1) If the SCoP is not profitable or otherwise invalid without the
assumed/invalid context we do not have to compute it.
2) Information about the context are gathered rather late in the SCoP
construction (basically after we know all parameters), thus the user
might see overly complicated assumptions to be taken while they would
have been simplified later on.
3) Currently we cannot take assumptions at any point but have to wait,
e.g., for the domain generation to finish. This makes wrapping
assumptions much more complicated as they need to be and it will
have a similar effect on "signed-unsigned" assumptions later.
llvm-svn: 266068
Collect the error domain contexts (formerly in the ErrorDomainCtxMap)
for each statement in the new InvalidContext member variable. While
this commit is basically a [NFC] it is a first step to make hoisting
sound by allowing a more fine grained record of invalid contexts,
e.g., here on statement level.
llvm-svn: 266053
Allow overflow of indices into the next higher dimension if it has
constant size. E.g.
float A[32][2];
((float*)A)[5];
is effectively the same as
A[2][1];
This can happen since r265379 as a side effect if ScopDetection
recognizes an access as affine, but ScopInfo rejects the GetElementPtr.
Differential Revision: http://reviews.llvm.org/D18878
llvm-svn: 265942
MSVC warns with:
warning C4239: nonstandard extension used: 'initializing': conversion from 'llvm::DebugLoc' to 'llvm::DebugLoc &'
note: A non-const reference may only be bound to an lvalue
Change the reference to a const reference.
llvm-svn: 265937
In r247147 we disabled pointer expressions because the IslExprBuilder did not
fully support them. This patch reintroduces them by simply treating them as
integers. The only special handling for pointers that is left detects the
comparison of two address_of operands and uses an unsigned compare.
llvm-svn: 265894
This reverts commit 2879c53e80e05497f408f21ce470d122e9f90f94.
Additionally, it adds SDiv and SRem instructions to the set of values
discovered by the findValues function even if we add the operands to
be able to recompute the SCEVs. In subfunctions we do not want to
recompute SDiv and SRem instructions but pass them instead as they
might have been created through the IslExprBuilder and are more
complicated than simple SDiv/SRem instructions in the code.
llvm-svn: 265873
Static libraries where installed into "lib${LLVM_LIBDIR_SUFFIX}" while
shared ones into "lib". I found no justification for this behaviour.
This patch changes both types of libraries to be install into
"lib${LLVM_LIBDIR_SUFFIX}". LLVM and clang use the same behaviour.
This fixes llvm.org/PR27305.
llvm-svn: 265872
We verify the optimized function now for a long time and it helped to track
down bugs early. This will now also happen for all parallel subfunctions we
generate.
llvm-svn: 265823
The way to get the elements size with getPrimitiveSizeInBits() is not
the same as used in other parts of Polly which should use
DataLayout::getTypeAllocSize(). Its use only queries the size of the
pointer and getPrimitiveSizeInBits returns 0 for types that require a
DataLayout object such as pointers.
Together with r265379, this should fix PR27195.
llvm-svn: 265795
If we build the domains for error blocks and later remove them we lose
the information that they are not executed. Thus, in the SCoP it looks
like the control will always reach the statement S:
for (i = 0 ... N)
if (*valid == 0)
doSth(&ptr);
S: A[i] = *ptr;
Consequently, we would have assumed "ptr" to be always accessed and
preloaded it unconditionally. However, only if "*valid != 0" we would
execute the optimized version of the SCoP. Nevertheless, we would have
hoisted and accessed "ptr"regardless of "*valid". This changes the
semantic of the program as the value of "*valid" can cause a change of
"ptr" and control if it is executed or not.
To fix this problem we adjust the execution context of hoisted loads
wrt. error domains. To this end we introduce an ErrorDomainCtxMap that
maps each basic block to the error context under which it might be
executed. Thus, to the context under which it is executed but an error
block would have been executed to. To fill this map one traversal of
the blocks in the SCoP suffices. During this traversal we do also
"remove" error statements and those that are only reachable via error
statements. This was previously done by the removeErrorBlockDomains
function which is therefor not needed anymore.
This fixes bug PR26683 and thereby several SPEC miscompiles.
Differential Revision: http://reviews.llvm.org/D18822
llvm-svn: 265778
If ScalarEvolution cannot look through some expression but we do, it
might happen that a multiplication will arrive at the
SCEVAffinator::visitMulExpr. While we could always try to improve the
extractConstantFactor function we might still miss something, thus we
reintroduce the code to generate multiplicative piecewise-affine
functions as a fall-back.
llvm-svn: 265777
The findValues() function did not look through div & srem instructions
that were part of the argument SCEV. However, in different other
places we already look through it. This mismatch caused us to preload
values in the wrong order.
llvm-svn: 265775
If all exiting blocks of a SCoP are error blocks and therefor not
represented we will not generate accesses and consequently no SAI
objects for exit PHIs. However, they are needed in the code generation
to generate the merge PHIs between the original and optimized region.
With this patch we enusre that the SAI objects for exit PHIs exist
even if all exiting blocks turn out to be eror blocks.
This fixes the crash reported in PR27207.
llvm-svn: 265393
We currently only consider the first GEP when delinearizing access functions,
which makes us loose information about additional index expression offsets,
which results in our SCoP model to be incorrect. With this patch we now
compare the base pointers used to ensure we do not miss any additional offsets.
This fixes llvm.org/PR27195.
We may consider supporting nested GEP in our delinearization heuristics in
the future.
llvm-svn: 265379
Even before we build the domain the branch condition can become very
complex, especially if we have to build the complement of a lot of
equality constraints. With this patch we bail if the branch condition
has a lot of basic sets and parameters.
After this patch we now successfully compile
External/SPEC/CINT2000/186_crafty/186_crafty
with "-polly-process-unprofitable -polly-position=before-vectorizer".
llvm-svn: 265286
As a CFG is often structured we can simplify the steps performed during
domain generation. When we push domain information we can utilize the
information from a block A to build the domain of a block B, if A dominates B
and there is no loop backede on a path from A to B. When we pull domain
information we can use information from a block A to build the domain of a
block B if B post-dominates A. This patch implements both ideas and thereby
simplifies domains that were not simplified by isl. For the FINAL basic block
in test/ScopInfo/complex-successor-structure-3.ll we used to build a universe
set with 81 basic sets. Now it actually is represented as universe set.
While the initial idea to utilize the graph structure depended on the
dominator and post-dominator tree we can use the available region
information as a coarse grained replacement. To this end we push the
region entry domain to the region exit and pull it from the region
entry for the region exit if applicable.
With this patch we now successfully compile
External/SPEC/CINT2006/400_perlbench/400_perlbench
and
SingleSource/Benchmarks/Adobe-C++/loop_unroll.
Differential Revision: http://reviews.llvm.org/D18450
llvm-svn: 265285
If a loop has no exiting blocks the region covering we use during
schedule genertion might not cover that loop properly. For now we bail
out as we would not optimize these loops anyway.
llvm-svn: 265280
If an exit PHI is written and also read in the SCoP we should not create two
SAI objects but only one. As the read is only modeled to ensure OpenMP code
generation knows about it we can simply use the EXIT_PHI MemoryKind for both
accesses.
llvm-svn: 265261
If a loop has no exiting blocks the region covering we use during
schedule genertion might not cover that loop properly. For now we bail
out as we would not optimize these loops anyway.
llvm-svn: 265260
If a non-affine region PHI is generated we should not move the insert
point prior to the synthezised value in the same block as we might
split that block at the insert point later on. Only if the incoming
value should be placed in a different block we should change the
insertion point.
llvm-svn: 265132
... instead of hardcoding something that has been free at some point. This fixes
a crash triggered by r265084, where the diagnostic IDs have been shifted in a
way that resulted our hardcode ID to not be assigned any implementation. Our ID
was likely already wrong earlier on, but this time we really crashed nicely.
llvm-svn: 265114
These caused LNT failures due to new assertions when running with
-polly-position=before-vectorizer -polly-process-unprofitable for:
FAIL: clamscan.compile_time
FAIL: cjpeg.compile_time
FAIL: consumer-jpeg.compile_time
FAIL: shapes.compile_time
FAIL: clamscan.execution_time
FAIL: cjpeg.execution_time
FAIL: consumer-jpeg.execution_time
FAIL: shapes.execution_time
The failures have been introduced by r264782, but r264789 had to be reverted
as it depended on the earlier patch.
llvm-svn: 264885
As a CFG is often structured we can simplify the steps performed
during domain generation. When we push domain information we can
utilize the information from a block A to build the domain of a
block B, if A dominates B. When we pull domain information we can
use information from a block A to build the domain of a block B
if B post-dominates A. This patch implements both ideas and thereby
simplifies domains that were not simplified by isl. For the FINAL
basic block in
test/ScopInfo/complex-successor-structure-3.ll .
we used to build a universe set with 81 basic sets. Now it actually is
represented as universe set.
While the initial idea to utilize the graph structure depended on the
dominator and post-dominator tree we can use the available region
information as a coarse grained replacement. To this end we push the
region entry domain to the region exit and pull it from the region
entry for the region exit.
Differential Revision: http://reviews.llvm.org/D18450
llvm-svn: 264789
Instead of waiting for the domain construction to finish we will now
bail as early as possible in case a complexity problem is encountered.
This might save compile time but more importantly it makes the "abort"
explicit. While we can always check if we invalidated the assumed
context we can simply propagate the result of the construction back.
This also removes the HasComplexCFG flag that was used for the very
same reason.
Differential Revision: http://reviews.llvm.org/D18504
llvm-svn: 264775
Ensure the length of the header underline matches the length of the header.
This prevents SPHINX from erroring on this file and consequently not updating
the documentation.
Also, make this its own point not belonging to the 'increased applicability'
section.
llvm-svn: 264592
This patch applies the restrictions on the number of domain conjuncts
also to the domain parts of piecewise affine expressions we generate.
To this end the wording is change slightly. It was needed to support
complex additions featuring zext-instructions but it also fixes PR27045.
lnt profitable runs reports only little changes that might be noise:
Compile Time:
Polybench/[...]/2mm +4.34%
SingleSource/[...]/stepanov_container -2.43%
Execution Time:
External/[...]/186_crafty -2.32%
External/[...]/188_ammp -1.89%
External/[...]/473_astar -1.87%
llvm-svn: 264514
Roman Gareev