The trip count calculation was incorrect for loops with large bounds. For example,
for(int i=-2,000,000,000; i < 2,000,000,000; i+=50000000), the trip count
calculation had overflow (trying to calculate 2,000,000,000 + 2,000,000,000 with
signed integers) and wasn't giving the right value. This patch fixes this error
in the runtime by using unsigned integers instead. There is still a bug in the
clang compiler component because it warns that there is overflow in the
test case file when there isn't. This error isn't there for the Intel Compiler.
So for now, the test case is designated as XFAIL.
Differential Revision: http://reviews.llvm.org/D19078
llvm-svn: 266677
This change adds back off logic in the test and set lock for better contended
lock performance. It uses a simple truncated binary exponential back off
function. The default back off parameters are tuned for x86.
The main back off logic has a two loop structure where each is controlled by a
user-level parameter:
max_backoff - limits the outer loop number of iterations.
This parameter should be a power of 2.
min_ticks - the inner spin wait loop number of "ticks" which is system
dependent and should be tuned for your system if you so choose.
The "ticks" on x86 correspond to the time stamp counter,
but on other architectures ticks is a timestamp derived
from gettimeofday().
The user can modify these via the environment variable:
KMP_SPIN_BACKOFF_PARAMS=max_backoff[,min_ticks]
Currently, since the default user lock is a queuing lock,
one would have to also specify KMP_LOCK_KIND=tas to use the test-and-set locks.
Differential Revision: http://reviews.llvm.org/D19020
llvm-svn: 266329
This change has OMP_WAIT_POLICY=active to mean that threads will busy-wait in
spin loops and virtually never go to sleep. OMP_WAIT_POLICY=passive now means
that threads will immediately go to sleep inside a spin loop. KMP_BLOCKTIME was
the previous mechanism to specify this behavior via KMP_BLOCKTIME=0 or
KMP_BLOCKTIME=infinite, but the standard OpenMP environment variable should
also be able to specify this behavior.
Differential Revision: http://reviews.llvm.org/D18577
llvm-svn: 265339
For serialized parallel regions, wrong ids were reported. Now the same code is
used as in kmp_dispatch.cpp which emits the correct ids.
Differential Revision: http://reviews.llvm.org/D18348
llvm-svn: 264266
For non-serialized parallel regions the master thread issued two callbacks:
The first one in kmp_gsupport.c and the second in __kmp_join_call. Therefore
only trigger the callback in kmp_gsupport.c for serialized parallel regions.
Differential Revision: http://reviews.llvm.org/D16716
llvm-svn: 264264
Some basic checks next to the implementation should futher lower the
possibility to introduce regressions. (Note that this would have catched
the ordering issue fixed in rL258866 and pointed to rL263940.)
The tests are implementation dependent in one point because they assume that
thread ids are assigned in ascending order. This is not defined by the standard
but currently ensured in libomp. We have to think about another way of ordering
the threads should this ever be subject to change...
Note that this isn't aiming at replacing the implementation independent
test-suite at https://github.com/OpenMPToolsInterface/ompt-test-suite!
Differential Revision: http://reviews.llvm.org/D16715
llvm-svn: 264027
From the standard: The taskloop construct specifies that the iterations of one
or more associated loops will be executed in parallel using OpenMP tasks. The
iterations are distributed across tasks created by the construct and scheduled
to be executed.
This initial implementation uses a simple linear tasks distribution algorithm.
Later we can add other algorithms to speedup generation of huge number of tasks
(i.e., tree-like tasks generation should be faster).
This needs to be put into the OpenMP runtime library in order for the
compiler team to develop the compiler side of the implementation.
Differential Revision: http://reviews.llvm.org/D17404
llvm-svn: 262535
The maximum task priority value is read from envirable: OMP_MAX_TASK_PRIORITY.
But as of now, nothing is done with it. We just handle the environment variable
and add the new api: omp_get_max_task_priority() which returns that value or
zero if it is not set.
Differential Revision: http://reviews.llvm.org/D17411
llvm-svn: 261908
This will be used in a later patch to find additional LLVM tools for tests and
enables reusability for libomptarget that is currently under review.
Differential Revision: http://reviews.llvm.org/D16713
llvm-svn: 259876
These changes allow libhwloc to be used as the topology discovery/affinity
mechanism for libomp. It is supported on Unices. The code additions:
* Canonicalize KMP_CPU_* interface macros so bitmask operations are
implementation independent and work with both hwloc bitmaps and libomp
bitmaps. So there are new KMP_CPU_ALLOC_* and KMP_CPU_ITERATE() macros and
the like. These are all in kmp.h and appropriately placed.
* Hwloc topology discovery code in kmp_affinity.cpp. This uses the hwloc
interface to create a libomp address2os object which the rest of libomp knows
how to handle already.
* To build, use -DLIBOMP_USE_HWLOC=on and
-DLIBOMP_HWLOC_INSTALL_DIR=/path/to/install/dir [default /usr/local]. If CMake
can't find the library or hwloc.h, then it will tell you and exit.
Differential Revision: http://reviews.llvm.org/D13991
llvm-svn: 254320
Setting dynamic schedule with chunk size 0 via omp_set_schedule(dynamic,0)
and then using "schedule (runtime)" causes infinite loop because for the
chunked dynamic schedule we didn't correct zero chunk to the default (1).
llvm-svn: 252338
Add additional dependency to clang/clang-headers/FileCheck to avoid possible troubles with in-tree build/test of libomp + allow parallel testing of libomp. Also includes bugfixes for tests + improvements to avoid possible race conditions.
Differential Revision: http://reviews.llvm.org/D14055
llvm-svn: 251797
This change introduces a check-libomp target which is based upon llvm's lit
test infrastructure. Each test (generated from the University of Houston's
OpenMP testsuite) is compiled and then run. For each test, an exit status of 0
indicates success and non-zero indicates failure. This way, FileCheck is not
needed. I've added a bit of logic to generate symlinks (libiomp5 and libgomp)
in the build tree so that gcc can be tested as well. When building out-of-
tree builds, the user will have to provide llvm-lit either by specifying
-DLIBOMP_LLVM_LIT_EXECUTABLE or having llvm-lit in their PATH.
Differential Revision: http://reviews.llvm.org/D11821
llvm-svn: 248211
Jonathan Peyton