Commit Graph

561 Commits

Author SHA1 Message Date
Tobias Grosser
2d58a64e7f GPGPU: Bail out of scops with hoisted invariant loads
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
2016-07-19 15:56:25 +00:00
Tobias Grosser
5260c041ea GPGPU: Emit in-kernel synchronization statements
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
2016-07-19 07:33:16 +00:00
Tobias Grosser
59ab070523 GPGPU: generate control flow within the kernel
llvm-svn: 275956
2016-07-19 07:33:11 +00:00
Tobias Grosser
c84a1995fe GPGPU: add scop parameters to kernel arguments
llvm-svn: 275955
2016-07-19 07:33:06 +00:00
Tobias Grosser
f6044bd0ef GPGPU: add host iterators to kernel arguments
llvm-svn: 275954
2016-07-19 07:32:55 +00:00
Tobias Grosser
472f9654c8 GPGPU: add intrinsic functions to obtain a kernels thread and block ids
llvm-svn: 275953
2016-07-19 07:32:44 +00:00
Tobias Grosser
32837fe313 GPGPU: create kernel function skeleton
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
2016-07-19 07:32:38 +00:00
Tobias Grosser
b9fc860a57 GPGPU: collect array references
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
2016-07-18 15:44:32 +00:00
Tobias Grosser
1fb9b64dc0 GPGPU: Pull implementation out of class definition
This will allow us to see the full class definition even after we add
non-trivial implementations of the different member functions.

llvm-svn: 275797
2016-07-18 15:44:25 +00:00
Tobias Grosser
38fc0aed08 GPGPU: Create host control flow
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
2016-07-18 11:56:39 +00:00
Tobias Grosser
2025173494 GPGPU: Format statements scheduled on the host ourselves
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
2016-07-15 17:12:41 +00:00
Tobias Grosser
2341fe9e76 GPGPU: Use schedule whole components for scheduler
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
2016-07-15 16:15:47 +00:00
Tobias Grosser
e4725437e8 GPGPU: Drop domain constraints from flow dependences
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
2016-07-15 14:43:04 +00:00
Tobias Grosser
6293ba6973 GPGPU: Add memory reference tag ids to tagged accesses
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
2016-07-15 12:44:27 +00:00
Tobias Grosser
2d010daf85 GPGPU: Make sure scops with more than one array work
We use this opportunity to add a test case containing a scalar parameter.

llvm-svn: 275547
2016-07-15 10:51:14 +00:00
Tobias Grosser
b307ed4d08 GPGPU: Free options to avoid memory leak
ppcg does not free the option structs for us. To avoid a memory leak we do this
ourselves.

llvm-svn: 275546
2016-07-15 10:32:22 +00:00
Tobias Grosser
a56f8f8e58 GPGPU: Shorten ppcg include paths to avoid conflict with cuda.h
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
2016-07-15 07:50:36 +00:00
Tobias Grosser
60f63b49f2 GPGPU: Model array access information
This allows us to derive host-device and device-host data-transfers.

llvm-svn: 275535
2016-07-15 07:05:54 +00:00
Tobias Grosser
69b4675180 GPGPU: Generate an AST for the GPU-mapped schedule
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
2016-07-14 15:51:37 +00:00
Tobias Grosser
60c6002570 GPGPU: Add dummy implementation for ast expression construction
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
2016-07-14 15:51:32 +00:00
Tobias Grosser
4eaedde530 GPGPU: Use a tile size of 32 by default
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
2016-07-14 14:14:02 +00:00
Tobias Grosser
bd81a7eebc Fix formatting
llvm-svn: 275397
2016-07-14 10:53:00 +00:00
Tobias Grosser
aef5196f75 GPGPU: Map initial schedule to GPU schedule
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
2016-07-14 10:51:52 +00:00
Tobias Grosser
681bd5688f GPGPU: Do not dump schedule by default
llvm-svn: 275395
2016-07-14 10:51:47 +00:00
Tobias Grosser
f384594d5e GPGPU: compute new schedule from polly scop
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
2016-07-14 10:22:25 +00:00
Tobias Grosser
e938517e37 GPGPU: create default initialized PPCG scop and gpu program
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
2016-07-14 10:22:19 +00:00
Tobias Grosser
9dfe4e7c05 Add accelerator code generation pass skeleton
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
2016-07-13 15:54:58 +00:00
Tobias Grosser
faef9a7667 Fix gcc compile failure
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
2016-07-11 12:27:04 +00:00
Tobias Grosser
4e2d9c45b9 InvariantEquivClassTy: Use struct instead of 4-tuple to increase readability
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
2016-07-11 12:15:10 +00:00
Justin Bogner
e2467baba8 Update for llvm r274769
llvm-svn: 274777
2016-07-07 18:03:30 +00:00
Tobias Grosser
932ec01328 isl: isl-0.17.1-164-gcbba1b6
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
2016-07-06 09:11:00 +00:00
George Burgess IV
1a046de897 Try to fix polly buildbots.
Broken by r274589.

llvm-svn: 274595
2016-07-06 02:21:00 +00:00
Tobias Grosser
29a4dd92b7 CodegenCleanup: Drop CFLAA pass from codegen cleanup sequence
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
2016-07-02 07:58:13 +00:00
Tobias Grosser
522478d2c0 clang-tidy: Add llvm namespace comments
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
2016-06-23 22:17:27 +00:00
Tobias Grosser
616449df6d Add missing copyright header
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
2016-06-22 16:29:28 +00:00
Tobias Grosser
8dd653d983 clang-tidy: apply modern-use-nullptr fixes
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
2016-06-22 16:22:00 +00:00
Michael Kruse
6b4e928285 Replace ScalarReplAggregatesPass by SROAPass.
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
2016-06-15 13:21:28 +00:00
Tobias Grosser
43de17872a Recommit: "Simplify min/max expression generation"
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
2016-06-12 04:49:41 +00:00
Tobias Grosser
3717aa5ddb This reverts recent expression type changes
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
2016-06-11 19:17:15 +00:00
Johannes Doerfert
8448071d3e Refactor division generation code
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
2016-06-06 14:56:17 +00:00
Johannes Doerfert
c0ece9b67e [NFC] Generate runtime checks after the SCoP
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
2016-06-06 13:32:52 +00:00
Johannes Doerfert
6a6a671c72 [NFC] Simplify code
llvm-svn: 271889
2016-06-06 12:13:24 +00:00
Johannes Doerfert
0767a511ba Use minimal types for generated expressions
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
2016-06-06 09:57:41 +00:00
Michael Kruse
5c527f9963 Fix modulo compared to zero.
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
2016-06-03 18:51:48 +00:00
Johannes Doerfert
6393ef135c Temporarily promote values to i64 again
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
2016-06-02 17:09:22 +00:00
Johannes Doerfert
4cf79d4ca4 [NFC] Avoid unnecessary comparison for min/max expressions
llvm-svn: 271535
2016-06-02 16:58:12 +00:00
Matthew Simpson
acae9e3b30 [Polly] Fix -Wunused-variable warnings (NFC)
llvm-svn: 271518
2016-06-02 14:26:38 +00:00
Johannes Doerfert
47f15f6d7e [NFC] Simplify min/max expression generation
llvm-svn: 271514
2016-06-02 11:20:52 +00:00
Johannes Doerfert
d36553753e Simplify the type adjustment in the IslExprBuilder
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
2016-06-02 11:15:57 +00:00
Johannes Doerfert
a91c85a5b9 [FIX] Ensure wrapping checks for unary expressions
llvm-svn: 271512
2016-06-02 11:08:43 +00:00