46 Commits

Author SHA1 Message Date
Johannes Doerfert 1de70a724e Revert "[OpenMPOpt] ICV tracking for calls"
This commits breaks certain OpenMP codes (on power) because it expanded
the Attributor scope without telling the Attributor about the SCC
extend. See: https://reviews.llvm.org/D85544#2227611

This reverts commit b0b32e6490.
2020-08-20 00:00:35 -05:00
Hamilton Tobon Mosquera bd2fa1819b [OpenMPOpt][HideMemTransfersLatency] Moving the 'wait' counterpart of __tgt_target_data_begin_mapper
canBeMovedDownwards checks if the "wait" counterpart of __tgt_target_data_begin_mapper can be moved downwards, returning a pointer to the instruction that might require/modify the data transferred, and returning null it the movement is not possible or not worth it. The function splitTargetDataBeginRTC receives that returned instruction and instead of moving the "wait" it creates it at that point.

Differential Revision: https://reviews.llvm.org/D86155
2020-08-19 11:42:22 -05:00
sstefan1 b0b32e6490 [OpenMPOpt] ICV tracking for calls
Introduce two new AAs. AAICVTrackerFunctionReturned which checks if a
function can have a unique ICV value after it is finished, and
AAICVCallSiteReturned which checks AAICVTrackerFunctionReturned for a
call site. This enables us to check the value of a call and if it
changes the ICV. This also changes the approach in
`getReplacementValues()` to a worklist-based approach so we can explore
all relevant BBs.

Differential Revision: https://reviews.llvm.org/D85544
2020-08-19 11:43:12 +02:00
Hamilton Tobon Mosquera 496f8e5b36 [OpenMPOpt][HideMemTransfersLatency] Split __tgt_target_data_begin_mapper into its "issue" and "wait" counterparts.
WIP that tries to hide the latency of runtime calls that involve host to
device memory transfers by splitting them into their "issue" and "wait"
versions. The "issue" is moved upwards as much as possible. The "wait" is
moved downards as much as possible. The "issue" issues the memory transfer
asynchronously, returning a handle. The "wait" waits in the returned
handle for the memory transfer to finish. We still lack of the movement.
2020-08-17 20:56:10 -05:00
Roman Lebedev 351d234d86 [OpenMPOpt] Most SCC's are uninteresting, don't waste time on them (up to 16x faster)
Summary:
This seems obvious in hindsight, but the result is surprising.
I've measured compile-time of `-openmpopt` pass standalone
on RawSpeed unity build, and while there is some OpenMP stuff,
most is not OpenMP. But nonetheless the pass does a lot of costly
preparations before ever trying to look for OpenMP stuff in SCC.

Numbers (n=25): 0.094624s  ->  0.005976s, an -93.68% improvement, or ~16x

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: yaxunl, hiraditya, guansong, llvm-commits, sstefan1

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D84689
2020-07-27 23:36:34 +03:00
Giorgis Georgakoudis 694ded37b9 [OpenMPOpt] Fix preserved analyses return 2020-07-14 23:18:43 -07:00
Johannes Doerfert fec1f2109f [OpenMP] Emit remarks during GPU state machine optimization
Since D83271 we can optimize the GPU state machine to avoid spurious
call edges that increase the register usage of kernels. With this patch
we inform the user why and if this optimization is happening and when it
is not.

Reviewed By: ye-luo

Differential Revision: https://reviews.llvm.org/D83707
2020-07-14 22:33:57 -05:00
Luofan Chen 233af8958e [Attributor] Create getter function for the ID of the abstract attribute
Summary: The `getIdAddr()` function returns the address of the ID of the abstract attribute

Reviewers: jdoerfert, sstefan1, uenoku, homerdin, baziotis

Reviewed By: jdoerfert

Subscribers: okura, hiraditya, uenoku, kuter, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83172
2020-07-15 09:55:18 +08:00
Michael Liao 81db614411 Fix -Wunused-variable warnings. NFC. 2020-07-11 10:09:44 -04:00
Johannes Doerfert dce6bc18c4 [OpenMP][FIX] remove unused variable and long if-else chain
MSVC throws an error if you use "too many" if-else in a row:
  `Frontend/OpenMP/OMPKinds.def(570): fatal error C1061: compiler limit:
    blocks nested too deeply`
We work around it now...
2020-07-11 02:37:57 -05:00
Mehdi Amini c44702bcdf Remove unused variable KMPC_KERNEL_PARALLEL_WORK_FN_PTR_ARG_NO (NFC)
This fixes a compiler warning.
2020-07-11 07:17:28 +00:00
Johannes Doerfert 5b0581aedc [OpenMP] Replace function pointer uses in GPU state machine
In non-SPMD mode we create a state machine like code to identify the
parallel region the GPU worker threads should execute next. The
identification uses the parallel region function pointer as that allows
it to work even if the kernel (=target region) and the parallel region
are in separate TUs. However, taking the address of a function comes
with various downsides. With this patch we will identify the most common
situation and replace the function pointer use with a dummy global
symbol (for identification purposes only). That means, if the parallel
region is only called from a single target region (or kernel), we do not
use the function pointer of the parallel region to identify it but a new
global symbol.

Fixes PR46450.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D83271
2020-07-11 01:44:00 -05:00
Johannes Doerfert 624d34afff [OpenMP] Compute a proper module slice for the CGSCCC pass
The module slice describes which functions we can analyze and transform
while working on an SCC as part of the CGSCC OpenMPOpt pass. So far, we
simply restricted it to the SCC. In a follow up we will need to have a
bigger scope which is why this patch introduces a proper identification
of the module slice. In short, everything that has a transitive
reference to a function in the SCC or is transitively referenced by one
is fair game.

Reviewed By: sstefan1

Differential Revision: https://reviews.llvm.org/D83270
2020-07-11 01:44:00 -05:00
Johannes Doerfert e8039ad4de [OpenMP] Identify GPU kernels (aka. OpenMP target regions)
We now identify GPU kernels, that is entry points into the GPU code.
These kernels (can) correspond to OpenMP target regions. With this patch
we identify and on request print them via remarks.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D83269
2020-07-11 01:44:00 -05:00
Johannes Doerfert 54bd3751ce [OpenMP][NFC] Add convenient helper and early exit check 2020-07-11 00:51:51 -05:00
Johannes Doerfert b726c55709 [OpenMP][NFC] Fix some typos 2020-07-11 00:51:51 -05:00
sstefan1 b8235d2bd8 Reland "[OpenMPOpt] ICV Tracking"
This reverts commit 1d542f0ca8.

`recollectUses()` is added to prevent looking at dead uses after
Attributor run.

This is the first and most basic ICV Tracking implementation. For this
first version, we only support deduplication within the same BB.

Reviewers: jdoerfert, JonChesterfield, hamax97, jhuber6, uenoku,
baziotis, lebedev.ri

Differential Revision: https://reviews.llvm.org/D81788
2020-07-11 02:25:57 +02:00
Roman Lebedev 1d542f0ca8 Revert "[OpenMPOpt] ICV Tracking"
There appears to be some kind of memory corruption/use-after-free/etc
going on here. In particular, in `OpenMPOpt::deleteParallelRegions()`,
in `DeleteCallCB()`, `CI` is garbage.

WIll post reproducer in the original review.

This reverts commit 6c4a5e9257.
2020-07-10 19:00:15 +03:00
sstefan1 6aab27ba85 [OpenMPIRBuilder][Fix] Move llvm::omp::types to OpenMPIRBuilder.
Summary:
D82193 exposed a problem with global type definitions in
`OMPConstants.h`. This causes a race when running in thinLTO mode.
Types now live inside of OpenMPIRBuilder to prevent this from happening.

Reviewers: jdoerfert

Subscribers: yaxunl, hiraditya, guansong, dexonsmith, aaron.ballman, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D83176
2020-07-08 17:23:55 +02:00
sstefan1 6c4a5e9257 [OpenMPOpt] ICV Tracking
This is the first and most basic ICV Tracking implementation. For this
first version, we only support deduplication within the same BB.

Reviewers: jdoerfert, JonChesterfield, hamax97, jhuber6, uenoku,
baziotis

Differential Revision: https://reviews.llvm.org/D81788
2020-07-04 23:31:50 +02:00
sstefan1 61238d2690 [OpenMPOpt][Fix] Remove double initialization of omp::types. 2020-07-02 19:51:54 +02:00
sstefan1 951e43f357 [OpenMPOpt][NFC] Change ICV macros for initial value
This fixes build breaks when system headers are difining FALSE.
2020-06-26 15:34:43 +00:00
sstefan1 0f426935bb [OpenMPOpt] ICV macro definitions
Summary:
This defines some basic information about ICVs in `OMPKinds.def`.
We also emit remarks with initial values for each function (which are default for now)
as a way to test this.

Reviewers: jdoerfert, JonChesterfield, hamax97, jhuber6

Subscribers: yaxunl, hiraditya, guansong, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82193
2020-06-24 13:43:35 +02:00
Mehdi Amini 77b79d79c0 Remove "unused" member ModuleSlice from struct OpenMPOpt
This is fixing warning from clang:

 warning: private field 'ModuleSlice' is not used [-Wunused-private-field]
  SmallPtrSetImpl<Function *> &ModuleSlice;
                               ^

Differential Revision: https://reviews.llvm.org/D82027
2020-06-18 03:02:26 +00:00
Eric Christopher a8dad30388 Revert "Remove unused class variable ModuleSlice." as it was
used in debug only code.

This reverts commit 07a1749081.
2020-06-17 14:45:17 -07:00