Use the correct data type for pointer sized integers on Windows;
"long" is always 32 bit, even on 64 bit Windows - don't use it
for the kmp_intptr_t type.
Provide the exact correct definition of the kmp_depend_info
struct - avoid the risk of mismatches (if a platform would pack
things slightly differently when things are declared differently).
Zero initialize the whole dep_info struct before filling it in;
if only setting the in/out bits, the rest of the unallocated bits
in the bitfield can have undefined values. Libomp reads the flags
in combined form as an kmp_uint8 by reading the flag field - thus,
the unused bits do need to be zeroed. (Alternatively, the flag field
could be set to zero before setting the individual bits in the
bitfield).
Use kmp_intptr_t instead of long for casting pointers to integers.
Differential Revision: https://reviews.llvm.org/D137748
The hidden helper task is only enabled on Linux (kmp_runtime.cpp
initializes __kmp_enable_hidden_helper to TRUE for linux but to
FALSE for any other OS), and the __kmp_stg_parse_use_hidden_helper
function always makes it disabled on non-Linux OSes too.
Add a lit test feature for hidden helper tasks (only made available
on Linux) and mark two tests as requiring this feature.
Disable hidden helper tasks in the test that doesn't really involve
them, for consistent behaviour across platforms.
Differential Revision: https://reviews.llvm.org/D137749
OpenMP tests that use pthread functions include this header instead.
On Unix systems, this header includes pthread.h, while it provides
minimal implementations of the used pthread functions for Windows.
Differential Revision: https://reviews.llvm.org/D137746
Add new hidden helper affinity via the environment variable,
KMP_HIDDEN_HELPER_AFFINITY, which allows users to assign thread
affinity to hidden helper threads using the same syntax as
KMP_AFFINITY. OMP_PLACES/OMP_PROC_BIND have no interaction with
KMP_HIDDEN_HELPER_AFFINITY.
Differential Revision: https://reviews.llvm.org/D135113
Before this patch task priorities were ignored, that was a valid implementation
as the task priority is a hint according to OpenMP specification.
Implemented shared list of sorted (high -> low) task deques one per task
priority value. Tasks execution changed to first check if priority tasks ready
for execution exist, and these tasks executed before others;
otherwise usual tasks execution mechanics work.
Differential Revision: https://reviews.llvm.org/D119676
The __kmp_hidden_helper_threads_num set to N+1 if user requested N threads.
Thus number of worker hidden helper threads corresponds to user request,
main thread of helper team excluded as it does not participate in actual work.
This also fixes divide-by-0 issue in the code.
Fixes#48656
Differential Revision: https://reviews.llvm.org/D119586
Eachempati.
This patch adds clang (parsing, sema, serialization, codegen) support for the 'depend' clause on the 'taskwait' directive.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D113540
The CHECK: line in the test had no effect, because the test does not
pipe to FileCheck. Since the test only checks for a single value,
encode the result in the return value of the test.
This patch allows to simplify compiler implementation on "taskwait nowait"
construct. The "taskwait nowait" is semantically equivalent to the empty task.
Instead of creating an empty routine as a task entry, compiler can just send
NULL pointer to the runtime. Then the runtime will make all the work with
dependences and return because of the absent task routine.
Differential Revision: https://reviews.llvm.org/D112015
GOMP depobjs are represented as a two intptr_t array. The first
element is the base address of the dependency and the second element
is the flag indicating the type the depobj represents.
Differential Revision: https://reviews.llvm.org/D108790
New omp_all_memory task dependence type is implemented.
Library recognizes the new type via either
(dependence_address == NULL && dependence_flag == 0x80)
or
(dependence_address == SIZE_MAX).
A task with new dependence type depends on each preceding task
with any dependence type (kind of a dependence barrier).
Differential Revision: https://reviews.llvm.org/D108574
As discussed in D107121, task wait doesn't work when a regular task T depends on
a detached task or a hidden helper task T' in a serialized team. The root cause is,
since the team is serialized, the last task will not be tracked by
`td_incomplete_child_tasks`. When T' is finished, it first releases its
dependences, and then decrements its parent counter. So far so good. For the thread
that is running task wait, if at the moment it is still spinning and trying to
execute tasks, it is fine because it can detect the new task and execute it.
However, if it happends to finish the function `flag.execute_tasks(...)`, it will
be broken because `td_incomplete_child_tasks` is 0 now.
In this patch, we update the rule to track children tasks a little bit. If the
task team encounters a proxy task or a hidden helper task, all following tasks
will be tracked.
Reviewed By: AndreyChurbanov
Differential Revision: https://reviews.llvm.org/D107496
Fix for https://bugs.llvm.org/show_bug.cgi?id=49723.
Eliminated references from task dependency hash to node allocated on stack,
thus eliminated accesses to stale memory. So the node now never freed.
Uncommented assertion which triggered when stale memory accessed.
Removed unneeded ref count increment for stack allocated node.
Differential Revision: https://reviews.llvm.org/D106705
This patch fixes https://bugs.llvm.org/show_bug.cgi?id=49066.
For detachable tasks, the assumption breaks that the proxy task cannot have
remaining child tasks when the proxy completes.
In stead of increment/decrement the incomplete task count, a high-order bit
is flipped to mark and wait for the incomplete proxy task.
Differential Revision: https://reviews.llvm.org/D101082
gcc 11 introduced support for depend clause, but the gomp interface of libomp
does not yet handle the information.
Also remove -fopenmp-version=50, which is no longer needed for clang, but not
supported by gcc.
Refactored code of dependence processing and added new inoutset dependence type.
Compiler can set dependence flag to 0x8 when call __kmpc_omp_task_with_deps.
All dependence flags library gets so far and corresponding dependence types:
1 - IN, 2 - OUT, 3 - INOUT, 4 - MUTEXINOUTSET, 8 - INOUTSET.
Differential Revision: https://reviews.llvm.org/D97085
This reverts commit a1f550e052543f75acac9089b760cbc61729131f.
Revert in order to fix backwards compatibility breakage
caused by type size change for task dependence flag.
Refactored code of dependence processing and added new inoutset dependence type.
Compiler can set dependence flag to 0x8 when call __kmpc_omp_task_with_deps.
Size of type of the dependence flag changed from 1 to 4 bytes in clang.
All dependence flags library gets so far and corresponding dependence types:
1 - IN, 2 - OUT, 3 - INOUT, 4 - MUTEXINOUTSET, 8 - INOUTSET.
Differential Revision: https://reviews.llvm.org/D97085
Bug 49356 (https://bugs.llvm.org/show_bug.cgi?id=49356) reports crash in
the test case `tasking/bug_taskwait_detach.cpp`, which is caused by the wrong
function declaration. `gtid` in `__kmpc_omp_task` should be `kmp_int32`.
Reviewed By: AndreyChurbanov
Differential Revision: https://reviews.llvm.org/D102584
Implement the remaining GOMP_* functions to support task reductions
in taskgroup, parallel, loop, and taskloop constructs. The unused mem
argument to many of the work-sharing constructs has to do with the
scan() directive/ inscan() modifier. If mem is set, each function
will call KMP_FATAL() and tell the user scan/inscan is unsupported. The
GOMP reduction implementation is kept separate from our implementation
because of how GOMP presents reduction data and computes the reductions.
GOMP expects the privatized copies to be present even after a #pragma
omp parallel reduction(task:...) region has ended so the data is stored
inside GOMP's uintptr_t* data pseudo-structure. This style is tightly
coupled with GCC compiler codegen. There also isn't any init(),
combiner(), fini() functions in GOMP's codegen so the two
implementations were to disparate to try to wrap GOMP's around our own.
Differential Revision: https://reviews.llvm.org/D98806
It is reported that after enabling hidden helper thread, the program
can hit the assertion `new_gtid < __kmp_threads_capacity` sometimes. The root
cause is explained as follows. Let's say the default `__kmp_threads_capacity` is
`N`. If hidden helper thread is enabled, `__kmp_threads_capacity` will be offset
to `N+8` by default. If the number of threads we need exceeds `N+8`, e.g. via
`num_threads` clause, we need to expand `__kmp_threads`. In
`__kmp_expand_threads`, the expansion starts from `__kmp_threads_capacity`, and
repeatedly doubling it until the new capacity meets the requirement. Let's
assume the new requirement is `Y`. If `Y` happens to meet the constraint
`(N+8)*2^X=Y` where `X` is the number of iterations, the new capacity is not
enough because we have 8 slots for hidden helper threads.
Here is an example.
```
#include <vector>
int main(int argc, char *argv[]) {
constexpr const size_t N = 1344;
std::vector<int> data(N);
#pragma omp parallel for
for (unsigned i = 0; i < N; ++i) {
data[i] = i;
}
#pragma omp parallel for num_threads(N)
for (unsigned i = 0; i < N; ++i) {
data[i] += i;
}
return 0;
}
```
My CPU is 20C40T, then `__kmp_threads_capacity` is 160. After offset,
`__kmp_threads_capacity` becomes 168. `1344 = (160+8)*2^3`, then the assertions
hit.
Reviewed By: protze.joachim
Differential Revision: https://reviews.llvm.org/D98838
The basic design is to create an outer-most parallel team. It is not a regular team because it is only created when the first hidden helper task is encountered, and is only responsible for the execution of hidden helper tasks. We first use `pthread_create` to create a new thread, let's call it the initial and also the main thread of the hidden helper team. This initial thread then initializes a new root, just like what RTL does in initialization. After that, it directly calls `__kmpc_fork_call`. It is like the initial thread encounters a parallel region. The wrapped function for this team is, for main thread, which is the initial thread that we create via `pthread_create` on Linux, waits on a condition variable. The condition variable can only be signaled when RTL is being destroyed. For other work threads, they just do nothing. The reason that main thread needs to wait there is, in current implementation, once the main thread finishes the wrapped function of this team, it starts to free the team which is not what we want.
Two environment variables, `LIBOMP_NUM_HIDDEN_HELPER_THREADS` and `LIBOMP_USE_HIDDEN_HELPER_TASK`, are also set to configure the number of threads and enable/disable this feature. By default, the number of hidden helper threads is 8.
Here are some open issues to be discussed:
1. The main thread goes to sleeping when the initialization is finished. As Andrey mentioned, we might need it to be awaken from time to time to do some stuffs. What kind of update/check should be put here?
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D77609
The basic design is to create an outer-most parallel team. It is not a regular team because it is only created when the first hidden helper task is encountered, and is only responsible for the execution of hidden helper tasks. We first use `pthread_create` to create a new thread, let's call it the initial and also the main thread of the hidden helper team. This initial thread then initializes a new root, just like what RTL does in initialization. After that, it directly calls `__kmpc_fork_call`. It is like the initial thread encounters a parallel region. The wrapped function for this team is, for main thread, which is the initial thread that we create via `pthread_create` on Linux, waits on a condition variable. The condition variable can only be signaled when RTL is being destroyed. For other work threads, they just do nothing. The reason that main thread needs to wait there is, in current implementation, once the main thread finishes the wrapped function of this team, it starts to free the team which is not what we want.
Two environment variables, `LIBOMP_NUM_HIDDEN_HELPER_THREADS` and `LIBOMP_USE_HIDDEN_HELPER_TASK`, are also set to configure the number of threads and enable/disable this feature. By default, the number of hidden helper threads is 8.
Here are some open issues to be discussed:
1. The main thread goes to sleeping when the initialization is finished. As Andrey mentioned, we might need it to be awaken from time to time to do some stuffs. What kind of update/check should be put here?
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D77609
This patch adds new API __kmpc_taskloop_5 to accomadate strict
modifier (introduced in OpenMP 5.1) in num_tasks and grainsize
clause.
Differential Revision: https://reviews.llvm.org/D92352
This change introduces the GOMP_taskwait_depend() function. It implements
the OpenMP 5.0 feature of #pragma omp taskwait with depend() clause by
wrapping around __kmpc_omp_wait_deps().
Differential Revision: https://reviews.llvm.org/D87269
Encapsulate GOMP task dependencies in separate class and introduce the
new mutexinoutset dependency type. This separate class allows
future GOMP task APIs easier access to the task dependency functionality
and better ability to propagate new dependency types to all existing GOMP
task APIs which use task dependencies.
Differential Revision: https://reviews.llvm.org/D87267
If the compilation fails, the test is marked as unsupported.
-> This will never change for a specific version of gcc
If the linking fails, the test is marked as expected to fail.
-> This might change as LLVM/OpenMP implements the missing GOMP interface function
Reviewed by: Hahnfeld
Differential Revision: https://reviews.llvm.org/D83077
This is a follow up patch to D64534 (r365963) which removed all OMP
spec versioning within the OpenMP runtime codebase. This patch removes
REQUIRES: openmp-x.y lines from lit tests.
llvm-svn: 366341
Remove all older OMP spec versioning from the runtime and build system.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D64534
llvm-svn: 365963
