Commit Graph

21 Commits

Author SHA1 Message Date
Johannes Doerfert ac3ec22df9 [Attributor] Use AAFunctionReachability to determine AANoRecurse
We missed out on AANoRecurse in the module pass because we had no call
graph. With AAFunctionReachability we can simply ask if the function may
reach itself.

Differential Revision: https://reviews.llvm.org/D110099
2022-02-01 01:40:44 -06:00
Johannes Doerfert a1db0e523d [Attributor][FIX] Liveness handling in the isAssumedDead helpers
This fixes a conceptual problem with our AAIsDead usage which conflated
call site liveness with call site return value liveness. Without the
fix tests would obviously miscompile as we make genericValueTraversal
more powerful (in a follow up). The effects on the tests are mixed but
mostly marginal. The most prominent one is the lack of `noreturn` for
functions. The reason is that we make entire blocks live at the same
time (for time reasons). Now that we actually look at the block
liveness, which we need to do, the return instructions are live and
will survive. As an example,  `noreturn_async.ll` has been modified
to retain the `noreturn` even with block granularity. We could address
this easily but there is little need in practice.
2022-02-01 01:18:52 -06:00
Joseph Huber 5eb49009eb [OpenMP] Add more identifier to created shared globals
Currenly we push some variables to a global constant containing shared
memory as an optimization. This generated constant had internal linkage
and should not have collided with any known identifiers in the
translation unit. However, there have been observed cases of this
optimiztaion unintentionally colliding with undocumented PTX
identifiers. This patch adds a suffix to the created globals to
hopefully bypass this.

Depends on D118059

Reviewed By: tianshilei1992

Differential Revision: https://reviews.llvm.org/D118068
2022-01-24 20:37:54 -05:00
Joseph Huber 6e220296d7 [OpenMP] Use alignment information in HeapToShared
This patch uses the return alignment attribute now present in the
`__kmpc_alloc_shared` runtime call to set the alignment of the shared
memory global created to replace it.

Depends on D115971

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D116319
2021-12-27 16:58:27 -05:00
Johannes Doerfert c690c1c977 [NVVM] Update intrinsic definitions to include more attributes
A lot of NVVM intrinsics can use the default intrinsic attributes (e.g.,
nosync, nofree, ...) as well as `speculatable`. The latter is important
if we want to recompute intrinsics results instead of communicating them
via memory.

I did use default attributes for almost all `readnone` attributes but
speculatable only where I had reasonable confidence they cannot
experience UB. That said, someone should double check.

TODO: There seem to be various intrinsics marked `Commutative` which
      should not, e.g., fma and div.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D109987
2021-11-02 23:21:57 -05:00
Johannes Doerfert 57822c3f4f [OpenMP][NFC] Repair test that contained nested kernels
The benchmark contained (partially) nested kernels, something we do not
generate nor support.
2021-09-23 00:04:29 -05:00
Shilei Tian 423d34f74a [OpenMP][Offloading] Change `bool IsSPMD` to `int8_t Mode` in `__kmpc_target_init` and `__kmpc_target_deinit`
This is a follow-up of D110029, which uses bitset to indicate execution mode. This patches makes the changes in the function call.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D110279
2021-09-22 17:16:41 -04:00
Joseph Huber fec2927e07 [OpenMP] Add NoSync attributes to alloc / free shared RTL calls
This patch adds the `nosync` attribute to the `__kmpc_alloc_shared` and
`__kmpc_free_shared` runtime library calls. This allows code analysis to
know that these functins dont contain any barriers. This will help
optimizations reason about the CFG of blocks containing these calls.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D109995
2021-09-17 19:50:13 -04:00
Giorgis Georgakoudis 29a3e3dd7b [OpenMPOpt] Expand SPMDization with guarding for target parallel regions
This patch expands SPMDization (converting generic execution mode to SPMD for target regions) by guarding code regions that should be executed only by the main thread. Specifically, it generates guarded regions, which only the main thread executes, and the synchronization with worker threads using simple barriers. For correctness, the patch aborts SPMDization for target regions if the same code executes in a parallel region, thus must be not be guarded. This check is implemented using the ParallelLevels AA.

Reviewed By: jhuber6

Differential Revision: https://reviews.llvm.org/D106892
2021-08-04 11:49:24 -07:00
Joseph Huber 754eb1c210 [OpenMP] Change `__kmpc_free_shared` to include the paired allocation size
This patch changes `__kmpc_free_shared` to take an additional argument
corresponding to the associated allocation's size. This makes it easier to
implement the allocator in the runtime.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106496
2021-07-21 20:56:21 -04:00
Johannes Doerfert d9659bf6a0 [OpenMP] Create custom state machines for generic target regions
In the spirit of TRegions [0], this patch creates a custom state
machine for a generic target region based on the potentially called
parallel regions.

The code analysis is done interprocedurally via an abstract attribute
(AAKernelInfo). All outermost parallel regions are collected and we
check if there might be unknown outermost parallel regions for which
we need an indirect call. Other AAKernelInfo extensions are expected.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

Differential Revision: https://reviews.llvm.org/D101977
2021-07-10 17:57:08 -05:00
Johannes Doerfert e2cfbfcc0c [OpenMP] Unified entry point for SPMD & generic kernels in the device RTL
In the spirit of TRegions [0], this patch provides a simpler and uniform
interface for a kernel to set up the device runtime. The OMPIRBuilder is
used for reuse in Flang. A custom state machine will be generated in the
follow up patch.

The "surplus" threads of the "master warp" will not exit early anymore
so we need to use non-aligned barriers. The new runtime will not have an
extra warp but also require these non-aligned barriers.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

This was in parts extracted from D59319.

Reviewed By: ABataev, JonChesterfield

Differential Revision: https://reviews.llvm.org/D101976
2021-07-10 17:53:56 -05:00
Johannes Doerfert 5ef18e2421 [Attributor] Use AAValueSimplify to simplify returned values
We should use AAValueSimplify for all value simplification, however
there was some leftover logic that predates AAValueSimplify in
AAReturnedValues. This remove the AAReturnedValues part and provides a
replacement by making AAValueSimplifyReturned strong enough to handle
all previously covered cases. Further, this improve
AAValueSimplifyCallSiteReturned to handle returned arguments.

AAReturnedValues is now much easier and the collected returned
values/instructions are now from the associated function only, making it
much more sane. We also do not have the brittle logic anymore that looks
for unresolved calls. Instead, we use AAValueSimplify to handle
recursion.

Useful code has been split into helper functions, e.g., an Attributor
interface to get a simplified value.

Differential Revision: https://reviews.llvm.org/D103860
2021-07-10 15:52:36 -05:00
Nico Weber d3e7491333 Revert Attributor patch series
Broke check-clang, see https://reviews.llvm.org/D102307#2869065
Ran `git revert -n ebbe149a6f08535ede848a531a601ae6591cfbc5..269416d41908bb670f67af689155d5ab8eea689a`
2021-07-10 16:15:55 -04:00
Johannes Doerfert f0628c6ff7 [OpenMP] Create custom state machines for generic target regions
In the spirit of TRegions [0], this patch creates a custom state
machine for a generic target region based on the potentially called
parallel regions.

The code analysis is done interprocedurally via an abstract attribute
(AAKernelInfo). All outermost parallel regions are collected and we
check if there might be unknown outermost parallel regions for which
we need an indirect call. Other AAKernelInfo extensions are expected.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

Differential Revision: https://reviews.llvm.org/D101977
2021-07-10 12:32:50 -05:00
Johannes Doerfert 1d5711c3ee [OpenMP] Unified entry point for SPMD & generic kernels in the device RTL
In the spirit of TRegions [0], this patch provides a simpler and uniform
interface for a kernel to set up the device runtime. The OMPIRBuilder is
used for reuse in Flang. A custom state machine will be generated in the
follow up patch.

The "surplus" threads of the "master warp" will not exit early anymore
so we need to use non-aligned barriers. The new runtime will not have an
extra warp but also require these non-aligned barriers.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

This was in parts extracted from D59319.

Reviewed By: ABataev, JonChesterfield

Differential Revision: https://reviews.llvm.org/D101976
2021-07-10 12:32:50 -05:00
Johannes Doerfert 374e573cfc [Attributor] Use AAValueSimplify to simplify returned values
We should use AAValueSimplify for all value simplification, however
there was some leftover logic that predates AAValueSimplify in
AAReturnedValues. This remove the AAReturnedValues part and provides a
replacement by making AAValueSimplifyReturned strong enough to handle
all previously covered cases. Further, this improve
AAValueSimplifyCallSiteReturned to handle returned arguments.

AAReturnedValues is now much easier and the collected returned
values/instructions are now from the associated function only, making it
much more sane. We also do not have the brittle logic anymore that looks
for unresolved calls. Instead, we use AAValueSimplify to handle
recursion.

Useful code has been split into helper functions, e.g., an Attributor
interface to get a simplified value.

Differential Revision: https://reviews.llvm.org/D103860
2021-07-10 12:32:50 -05:00
Joseph Huber 5ccb7424fa [OpenMP] Change OpenMPOpt to check openmp metadata
The metadata added in D102361 introduces a module flag that we can check
to determine if the module was compiled with `-fopenmp` enables. We can
now check for the precense of this instead of scanning the call graph
for OpenMP runtime functions.

Depends on D102361

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D102423
2021-06-25 16:34:22 -04:00
Joseph Huber 30e36c9b3c [Attributor] Add interface to emit remarks in Attributor
Summary:
This patch adds support for the Attributor to emit remarks on behalf of some
other pass. The attributor can now optionally take a callback function that
returns an OptimizationRemarkEmitter object when given a Function pointer. If
this is availible then a remark will be emitted for the corresponding pass
name.

Depends on D102197

Reviewed By: sstefan1 thegameg

Differential Revision: https://reviews.llvm.org/D102444
2021-06-22 14:12:46 -04:00
Joseph Huber 03d7e61c87 [OpenMP] Internalize functions in OpenMPOpt to improve IPO passes
Summary:
Currently the attributor needs to give up if a function has external linkage.
This means that the optimization introduced in D97818 will only apply to static
functions. This change uses the Attributor to internalize OpenMP device
routines by making a copy of each function with private linkage and replacing
the uses in the module with it. This allows for the optimization to be applied
to any regular function.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D102824
2021-06-22 12:38:10 -04:00
Joseph Huber 6fc51c9f7d [OpenMP] Replace GPU globalization calls with shared memory in the middle-end
Summary:
The changes introduced in D97680 create a simpler interface to code that needs
to be globalized. This interface is used to simplify the globalization calls in
the middle end. We can check any globalization call that is only called by a
single thread in the team and replace it with a static shared memory buffer.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D97818
2021-06-22 11:55:44 -04:00