Commit Graph

17 Commits

Author SHA1 Message Date
Tim Northover a009a60a91 IR: print value numbers for unnamed function arguments
For consistency with normal instructions and clarity when reading IR,
it's best to print the %0, %1, ... names of function arguments in
definitions.

Also modifies the parser to accept IR in that form for obvious reasons.

llvm-svn: 367755
2019-08-03 14:28:34 +00:00
Alexey Bataev 25d3de8a0a [OPENMP][NVPTX]Reduce number of barriers in reductions.
After the fix for the syncthreads we don't need to generate extra
barriers for the parallel reductions.

llvm-svn: 350530
2019-01-07 15:45:09 +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 29d47fcb30 [OPENMP][NVPTX]Added extra sync point to the inter-warp copy function.
The parallel reduction operation requires an extra synchronization point
in the inter-warp copy function to avoid divergence.

llvm-svn: 349525
2018-12-18 19:20:15 +00:00
Alexey Bataev ae51b96f99 [OPENMP][NVPTX]Improved interwarp copy function.
Inlined runtime with the current implementation of the interwarp copy
function leads to the undefined behavior because of the not quite
correct implementation of the barriers. Start using generic
__kmpc_barier function instead of the custom made barriers.

llvm-svn: 349192
2018-12-14 21:00:58 +00:00
Gheorghe-Teodor Bercea 2b40470c61 [OpenMP] Add a new version of the SPMD deinit kernel function
Summary: This patch adds a new runtime for the SPMD deinit kernel function which replaces the previous function. The new function takes as argument the flag which signals whether the runtime is required or not. This enables the compiler to optimize out the part of the deinit function which are not needed.

Reviewers: ABataev, caomhin

Reviewed By: ABataev

Subscribers: jholewinski, guansong, cfe-commits

Differential Revision: https://reviews.llvm.org/D54970

llvm-svn: 347915
2018-11-29 20:53:49 +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 8bcc69c054 [OPENMP][NVPTX]Extend number of constructs executed in SPMD mode.
If the statements between target|teams|distribute directives does not
require execution in master thread, like constant expressions, null
statements, simple declarations, etc., such construct can be xecuted in
SPMD mode.

llvm-svn: 346551
2018-11-09 20:03:19 +00:00
Alexey Bataev 8d8e1235ab [OPENMP][NVPTX] Add support for lightweight runtime.
If the target construct can be executed in SPMD mode + it is a loop
based directive with static scheduling, we can use lightweight runtime
support.

llvm-svn: 340953
2018-08-29 18:32:21 +00:00
Gheorghe-Teodor Bercea ad4e579407 [OpenMP] Initialize data sharing stack for SPMD case
Summary: In the SPMD case, we need to initialize the data sharing and globalization infrastructure. This covers the case when an SPMD region calls a function in a different compilation unit.

Reviewers: ABataev, carlo.bertolli, caomhin

Reviewed By: ABataev

Subscribers: Hahnfeld, jholewinski, guansong, cfe-commits

Differential Revision: https://reviews.llvm.org/D49188

llvm-svn: 337015
2018-07-13 16:18:24 +00:00
Alexey Bataev 12c62908b5 [OPENMP, NVPTX] Fix reduction of the big data types/structures.
If the shuffle is required for the reduced structures/big data type,
current code may cause compiler crash because of the loading of the
aggregate values. Patch fixes this problem.

llvm-svn: 335377
2018-06-22 19:10:38 +00:00
Alexey Bataev e372710d30 [OPENMP] Code cleanup and code improvements.
llvm-svn: 330270
2018-04-18 15:57:46 +00:00
Carlo Bertolli 79712097c7 [OpenMP] Extend NVPTX SPMD implementation of combined constructs
Differential Revision: https://reviews.llvm.org/D43852

This patch extends the SPMD implementation to all target constructs and guards this implementation under a new flag.

llvm-svn: 326368
2018-02-28 20:48:35 +00:00
Alexey Bataev b2575930b3 [OPENMP] Fix casting in NVPTX support library.
If the reduction required shuffle in the NVPTX codegen, we may need to
cast the reduced value to the integer type. This casting was implemented
incorrectly and may cause compiler crash. Patch fixes this problem.

llvm-svn: 321818
2018-01-04 20:18:55 +00:00
Arpith Chacko Jacob 101e8fb1f3 [OpenMP] Parallel reduction on the NVPTX device.
This patch implements codegen for the reduction clause on
any parallel construct for elementary data types.  An efficient
implementation requires hierarchical reduction within a
warp and a threadblock.  It is complicated by the fact that
variables declared in the stack of a CUDA thread cannot be
shared with other threads.

The patch creates a struct to hold reduction variables and
a number of helper functions.  The OpenMP runtime on the GPU
implements reduction algorithms that uses these helper
functions to perform reductions within a team.  Variables are
shared between CUDA threads using shuffle intrinsics.

An implementation of reductions on the NVPTX device is
substantially different to that of CPUs.  However, this patch
is written so that there are minimal changes to the rest of
OpenMP codegen.

The implemented design allows the compiler and runtime to be
decoupled, i.e., the runtime does not need to know of the
reduction operation(s), the type of the reduction variable(s),
or the number of reductions.  The design also allows reuse of
host codegen, with appropriate specialization for the NVPTX
device.

While the patch does introduce a number of abstractions, the
expected use case calls for inlining of the GPU OpenMP runtime.
After inlining and optimizations in LLVM, these abstractions
are unwound and performance of OpenMP reductions is comparable
to CUDA-canonical code.

Patch by Tian Jin in collaboration with Arpith Jacob

Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D29758

llvm-svn: 295333
2017-02-16 16:20:16 +00:00
Arpith Chacko Jacob bd6344c0be Revert r295319 while investigating buildbot failure.
llvm-svn: 295323
2017-02-16 14:25:35 +00:00
Arpith Chacko Jacob 8e170fc857 [OpenMP] Parallel reduction on the NVPTX device.
This patch implements codegen for the reduction clause on
any parallel construct for elementary data types.  An efficient
implementation requires hierarchical reduction within a
warp and a threadblock.  It is complicated by the fact that
variables declared in the stack of a CUDA thread cannot be
shared with other threads.

The patch creates a struct to hold reduction variables and
a number of helper functions.  The OpenMP runtime on the GPU
implements reduction algorithms that uses these helper
functions to perform reductions within a team.  Variables are
shared between CUDA threads using shuffle intrinsics.

An implementation of reductions on the NVPTX device is
substantially different to that of CPUs.  However, this patch
is written so that there are minimal changes to the rest of
OpenMP codegen.

The implemented design allows the compiler and runtime to be
decoupled, i.e., the runtime does not need to know of the
reduction operation(s), the type of the reduction variable(s),
or the number of reductions.  The design also allows reuse of
host codegen, with appropriate specialization for the NVPTX
device.

While the patch does introduce a number of abstractions, the
expected use case calls for inlining of the GPU OpenMP runtime.
After inlining and optimizations in LLVM, these abstractions
are unwound and performance of OpenMP reductions is comparable
to CUDA-canonical code.

Patch by Tian Jin in collaboration with Arpith Jacob

Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D29758

llvm-svn: 295319
2017-02-16 14:03:36 +00:00