Commit Graph

38 Commits

Author SHA1 Message Date
Giorgis Georgakoudis 207b08a913 [OpenMP][NFC] Refactor Clang OpenMP tests using update_cc_test_checks
This patch refactors a subset of Clang OpenMP tests, generating checklines using the update_cc_test_checks script. This refactoring facilitates updating the Clang OpenMP code generation codebase by automating test generation.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D101849
2021-05-05 20:08:38 -07:00
Giorgis Georgakoudis 78a7d8c4dd [Utils][NFC] Rename replace-function-regex in update_cc_test_checks
This patch renames the replace-function-regex to replace-value-regex to indicate that the existing regex replacement functionality can replace any IR value besides functions.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D101934
2021-05-05 14:19:30 -07:00
Giorgis Georgakoudis f016c06abb Revert "[OpenMP][NFC] Refactor Clang OpenMP tests using update_cc_test_checks"
This reverts commit 956cae2f09.
2021-05-04 17:12:32 -07:00
Giorgis Georgakoudis 956cae2f09 [OpenMP][NFC] Refactor Clang OpenMP tests using update_cc_test_checks
This patch refactors a subset of Clang OpenMP tests, generating checklines using the update_cc_test_checks script. This refactoring facilitates updating the Clang OpenMP code generation codebase by automating test generation.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D101849
2021-05-04 16:58:45 -07:00
Giorgis Georgakoudis a2dbfb6b72 [OpenMP] Simplify offloading parallel call codegen
This revision simplifies Clang codegen for parallel regions in OpenMP GPU target offloading and corresponding changes in libomptarget: SPMD/non-SPMD parallel calls are unified under a single `kmpc_parallel_51` runtime entry point for parallel regions (which will be commonized between target, host-side parallel regions), data sharing is internalized to the runtime. Tests have been auto-generated using `update_cc_test_checks.py`. Also, the revision contains changes to OpenMPOpt for remark creation on target offloading regions.

Reviewed By: jdoerfert, Meinersbur

Differential Revision: https://reviews.llvm.org/D95976
2021-04-21 18:46:07 -07:00
Johannes Doerfert 03cc8a1ba0 [OpenMP][NFC] Move the `noinline` to the parallel entry point
The `noinline` for non-SPMD parallel functions is probably not necessary
but as long as we use it we should put it on the outermost parallel
function, which is the wrapper, not the actual outlined function.

Resolves PR49752

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D99506
2021-03-30 01:12:45 -05:00
JonChesterfield 5d02ca49a2 [libomptarget][nvptx] Undef, weak shared variables
[libomptarget][nvptx] Undef, weak shared variables

Shared variables on nvptx, and LDS on amdgcn, are uninitialized at
the start of kernel execution. Therefore create the variables with
undef instead of zeros, motivated in part by the amdgcn back end
rejecting LDS+initializer.

Common is zero initialized, which seems incompatible with shared. Thus
change them to weak, following the direction of
https://reviews.llvm.org/rG7b3eabdcd215

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D90248
2020-10-28 14:25:36 +00:00
Joseph Huber 3cc1f1fc1d [OpenMP] Replace OpenMP RTL Functions With OMPIRBuilder and OMPKinds.def
Summary:
Replace the OpenMP Runtime Library functions used in CGOpenMPRuntimeGPU
for OpenMP device code generation with ones in OMPKinds.def and use
OMPIRBuilder for generating runtime calls. This allows us to
consolidate more OpenMP code generation into the OMPIRBuilder. Future
additions to the GPU runtime functions should now go in OMPKinds.def

Reviewers: jdoerfert

Subscribers: aaron.ballman cfe-commits guansong llvm-commits sstefan1 yaxunl

Tags: #OpenMP #LLVM #clang

Differential Revision: https://reviews.llvm.org/D88430
2020-10-08 14:00:22 -04:00
Joseph Huber 1b60f63e4f Revert "[OpenMP] Replace OpenMP RTL Functions With OMPIRBuilder and OMPKinds.def"
Failing tests on Arm due to the tests automatically populating
incomatible pointer width architectures. Reverting until the tests are
updated. Failing tests:

OpenMP/distribute_parallel_for_num_threads_codegen.cpp
OpenMP/distribute_parallel_for_if_codegen.cpp
OpenMP/distribute_parallel_for_simd_if_codegen.cpp
OpenMP/distribute_parallel_for_simd_num_threads_codegen.cpp
OpenMP/target_teams_distribute_parallel_for_if_codegen.cpp
OpenMP/target_teams_distribute_parallel_for_simd_if_codegen.cpp
OpenMP/teams_distribute_parallel_for_if_codegen.cpp
OpenMP/teams_distribute_parallel_for_simd_if_codegen.cpp

This reverts commit 90eaedda9b.
2020-09-30 15:12:21 -04:00
Joseph Huber 90eaedda9b [OpenMP] Replace OpenMP RTL Functions With OMPIRBuilder and OMPKinds.def
Summary:
Replace the OpenMP Runtime Library functions used in CGOpenMPRuntimeGPU
for OpenMP device code generation with ones in OMPKinds.def and use
OMPIRBuilder for generating runtime calls. This allows us to consolidate
more OpenMP code generation into the OMPIRBuilder. This patch also
invalidates specifying target architectures with conflicting pointer
sizes.

Reviewers: jdoerfert

Subscribers: aaron.ballman cfe-commits guansong llvm-commits sstefan1 yaxunl

Tags: #OpenMP #Clang #LLVM

Differential Revision: https://reviews.llvm.org/D88430
2020-09-30 14:00:01 -04:00
Johannes Doerfert c98699582a [OpenMP][NFC] Remove unused (always fixed) arguments
There are various runtime calls in the device runtime with unused, or
always fixed, arguments. This is bad for all sorts of reasons. Clean up
two before as we match them in OpenMPOpt now.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D83268
2020-07-11 00:51:51 -05:00
Alexey Bataev 32ea3397be [OPENMP]Dynamic globalization for parallel target regions.
Summary:
Added support for dynamic memory allocation for globalized variables in
case if execution of target regions in parallel is required.

Reviewers: jdoerfert

Subscribers: jholewinski, yaxunl, guansong, sstefan1, cfe-commits, caomhin

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82324
2020-06-25 08:25:24 -04:00
Eli Friedman 62f3ef2b53 [CGCall] Annotate references with "align" attribute.
If we're going to assume references are dereferenceable, we should also
assume they're aligned: otherwise, we can't actually dereference them.

See also D80072.

Differential Revision: https://reviews.llvm.org/D80166
2020-05-19 20:21:30 -07:00
Matt Arsenault 56a503bdba OpenMP: Add convergent to more runtime functions
Several of these other functions are probably also convergent, but
these two seem obviously convergent.
2019-10-27 21:26:55 -07:00
Alexey Bataev 2cd7fafc11 [OPENMP][NVPTX]Fix critical region codegen.
Summary:
Previously critical regions were emitted with the barrier making it a
worksharing construct though it is not. Also, it leads to incorrect
behavior in Cuda9+. Patch fixes this problem.

Reviewers: ABataev, jdoerfert

Subscribers: jholewinski, guansong, cfe-commits, grokos

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66673

llvm-svn: 369946
2019-08-26 19:07:48 +00:00
Alexey Bataev a44b216036 [OPENMP][NVPTX]Mark barrier functions calls as convergent.
Added convergent attribute to the barrier functions calls for correct
optimizations.

llvm-svn: 366437
2019-07-18 13:49:24 +00:00
Alexey Bataev 8c5555c39a [OPENMP][NVPTX]Mark more functions as always_inline for better
performance.

Internally generated functions must be marked as always_inlines in most
cases. Patch marks some extra reduction function + outlined parallel
functions as always_inline for better performance, but only if the
optimization is requested.

llvm-svn: 361269
2019-05-21 15:11:58 +00:00
Alexey Bataev 8e009036c9 [OPENMP][NVPTX]Use new functions from the runtime library.
Updated codegen to use the new functions from the runtime library.

llvm-svn: 350415
2019-01-04 17:25:09 +00:00
Alexey Bataev a3924b517e [OPENMP][NVPTX]Use __kmpc_barrier_simple_spmd(nullptr, 0) instead of
nvvm_barrier0.

Use runtime functions instead of the direct call to the nvvm intrinsics.
It allows to prevent some dangerous LLVM optimizations, that breaks the
code for the NVPTX target.

llvm-svn: 350328
2019-01-03 16:25:35 +00:00
Alexey Bataev 6a1b06bcd4 [OPENMP][NVPTX]Emit shared memory buffer for reduction as 128 bytes
buffer.

Seems to me, nvlink has a bug with the proper support of the weakly
linked symbols. It does not allow to define several shared memory buffer
with the different sizes even with the weak linkage. Instead we always
use 128 bytes buffer to prevent nvlink from the error message emission.

llvm-svn: 349540
2018-12-18 21:01:42 +00:00
Alexey Bataev 2c1ff9dda7 [OPENMP][NVPTX]Fixed emission of the critical region.
Critical regions in NVPTX are the constructs, which, generally speaking,
are not supported by the NVPTX target. Instead we're using special
technique to handle the critical regions. Currently they are supported
only within the loop and all the threads in the loop must execute the
same critical region.
Inside of this special regions the regions still must be emitted as
critical, to avoid possible data races between the teams +
synchronization must use __kmpc_barrier functions.

llvm-svn: 348272
2018-12-04 15:25:01 +00:00
Alexey Bataev c3028cac24 [OPENMP][NVPTX]Mark __kmpc_barrier functions as convergent.
__kmpc_barrier runtime functions must be marked as convergent to prevent
some dangerous optimizations. Also, for NVPTX target all barriers must
be emitted as simple barriers.

llvm-svn: 348271
2018-12-04 15:03:25 +00:00
Alexey Bataev f2f39be9ed [OPENMP][NVPTX]Emit correct reduction code for teams/parallel
reductions.

Fixed previously committed code for the reduction support in
teams/parallel constructs taking into account new design of the NVPTX
support in the compiler. Teams reduction are not fully functional yet,
it is going to be fixed in the following patches.

llvm-svn: 347081
2018-11-16 19:38:21 +00:00
Alexey Bataev 09c9eea78f [OPENMP][NVPTX]Allow to use shared memory for the
target|teams|distribute variables.

If the total size of the variables, declared in target|teams|distribute
regions, is less than the maximal size of shared memory available, the
buffer is allocated in the shared memory.

llvm-svn: 346507
2018-11-09 16:18:04 +00:00
Alexey Bataev e40901806f [OPENMP][NVPTX]Improve emission of the globalized variables for
target/teams/distribute regions.

Target/teams/distribute regions exist for all the time the kernel is
executed. Thus, if the variable is declared in their context and then
escape it, we can allocate global memory statically instead of
allocating it dynamically.
Patch captures all the globalized variables in target/teams/distribute
contexts, merges them into the records, one per each target region.
Those records are then joined into the union, one per compilation unit
(to save the global memory). Those units are organized into
2 x dimensional arrays, where the first dimension is
the number of blocks per SM and the second one is the number of SMs.
Runtime functions manage this global memory space between the executing
teams.

llvm-svn: 345978
2018-11-02 14:54:07 +00:00
Alexey Bataev 4ac58d1a4b [OPENMP][NVPTX]Reduce memory usage in target region.
Additional reduction of the global memory usage in the target regions
without parallel regions.

llvm-svn: 344413
2018-10-12 20:19:59 +00:00
Alexey Bataev 9ea3c38597 [OPENMP][NVPTX] Support memory coalescing for globalized variables.
Added support for memory coalescing for better performance for
globalized variables. From now on all the globalized variables are
represented as arrays of 32 elements and each thread accesses these
elements using `tid & 31` as index.

llvm-svn: 344049
2018-10-09 14:49:00 +00:00
Alexey Bataev 4065b9ae48 [OPENMP, NVPTX] Fix globalization of the variables passed to orphaned
parallel region.

If the current construct requires sharing of the local variable in the
inner parallel region, this variable must be globalized to avoid
runtime crash.

llvm-svn: 335285
2018-06-21 20:26:33 +00:00
Alexey Bataev bf5c84861c [OPENMP, NVPTX] Initial support for L2 parallelism in SPMD mode.
Added initial support for L2 parallelism in SPMD mode. Note, though,
that the orphaned parallel directives are not currently supported in
SPMD mode.

llvm-svn: 332016
2018-05-10 18:32:08 +00:00
Alexey Bataev c661186cca [OPENMP, NVPTX] Small test fix, NFC.
llvm-svn: 331654
2018-05-07 17:38:13 +00:00
Alexey Bataev 504fc2d0cd [OPENMP, NVPTX] Codegen for critical construct.
Added correct codegen for the critical construct on NVPTX devices.

llvm-svn: 331652
2018-05-07 17:23:05 +00:00
Alexey Bataev 18fa2323b6 [OPENMP] Emit names of the globals depending on target.
Some symbols are not allowed to be used as names on some targets. Patch
ries to unify the emission of the names of LLVM globals so they could be
used on different targets.

llvm-svn: 331358
2018-05-02 14:20:50 +00:00
Alexey Bataev e290ec02c7 [OPENMP, NVPTX] Fix codegen for the teams reduction.
Added NUW flags for all the add|mul|sub operations + replaced sdiv by udiv
as we operate on unsigned values only (addresses, converted to integers)

llvm-svn: 329411
2018-04-06 16:03:36 +00:00
Gheorghe-Teodor Bercea d3dcf2f05d [OpenMP] Add OpenMP data sharing infrastructure using global memory
Summary:
This patch handles the Clang code generation phase for the OpenMP data sharing infrastructure.

TODO: add a more detailed description.

Reviewers: ABataev, carlo.bertolli, caomhin, hfinkel, Hahnfeld

Reviewed By: ABataev

Subscribers: jholewinski, guansong, cfe-commits

Differential Revision: https://reviews.llvm.org/D43660

llvm-svn: 327513
2018-03-14 14:17:45 +00:00
Gheorghe-Teodor Bercea 7d80da15a0 [OpenMP] Remove implicit data sharing code gen that aims to use device shared memory
Summary: Remove this scheme for now since it will be covered by another more generic scheme using global memory. This code will be worked into an optimization for the generic data sharing scheme. Removing this completely and then adding it via future patches will make all future data sharing patches cleaner.

Reviewers: ABataev, carlo.bertolli, caomhin

Reviewed By: ABataev

Subscribers: jholewinski, guansong, cfe-commits

Differential Revision: https://reviews.llvm.org/D43625

llvm-svn: 326948
2018-03-07 21:59:50 +00:00
Jonas Hahnfeld 891c7fb19d [OpenMP] Adjust arguments of nvptx runtime functions
In the future the compiler will analyze whether the OpenMP
runtime needs to be (fully) initialized and avoid that overhead
if possible. The functions already take an argument to transfer
that information to the runtime, so pass in the default value 1.
(This is needed for binary compatibility with libomptarget-nvptx
currently being upstreamed.)

Differential Revision: https://reviews.llvm.org/D40354

llvm-svn: 318836
2017-11-22 14:46:49 +00:00
Gheorghe-Teodor Bercea eb89b1d46f [OpenMP] Add implicit data sharing support when offloading to NVIDIA GPUs using OpenMP device offloading
Summary:
This patch is part of the development effort to add support in the current OpenMP GPU offloading implementation for implicitly sharing variables between a target region executed by the team master thread and the worker threads within that team.

This patch is the first of three required for successfully performing the implicit sharing of master thread variables with the worker threads within a team. The remaining two patches are:
- Patch D38978 to the LLVM NVPTX backend which ensures the lowering of shared variables to an device memory which allows the sharing of references;
- Patch (coming soon) is a patch to libomptarget runtime library which ensures that a list of references to shared variables is properly maintained.

A simple code snippet which illustrates an implicit data sharing situation is as follows:

```
#pragma omp target
{
   // master thread only
   int v;
   #pragma omp parallel
   {
      // worker threads
      // use v
   }
}
```

Variable v is implicitly shared from the team master thread which executes the code in between the target and parallel directives. The worker threads must operate on the latest version of v, including any updates performed by the master.

The code generated in this patch relies on the LLVM NVPTX patch (mentioned above) which prevents v from being lowered in the thread local memory of the master thread thus making the reference to this variable un-shareable with the workers. This ensures that the code generated by this patch is correct.
Since the parallel region is outlined the passing of arguments to the outlined regions must preserve the original order of arguments. The runtime therefore maintains a list of references to shared variables thus ensuring their passing in the correct order. The passing of arguments to the outlined parallel function is performed in a separate function which the data sharing infrastructure constructs in this patch. The function is inlined when optimizations are enabled.

Reviewers: hfinkel, carlo.bertolli, arpith-jacob, Hahnfeld, ABataev, caomhin

Reviewed By: ABataev

Subscribers: cfe-commits, jholewinski

Differential Revision: https://reviews.llvm.org/D38976

llvm-svn: 318773
2017-11-21 15:54:54 +00:00
Arpith Chacko Jacob bb36fe8dba [OpenMP] Basic support for a parallel directive in a target region on an NVPTX device
Summary:

This patch introduces support for the execution of parallel constructs in a target
region on the NVPTX device.  Parallel regions must be in the lexical scope of the
target directive.

The master thread in the master warp signals parallel work for worker threads in worker
warps on encountering a parallel region.

Note: The patch does not yet support capture of arguments in a parallel region so
the test cases are simple.

Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D28145

llvm-svn: 291565
2017-01-10 15:42:51 +00:00