Commit Graph

2 Commits

Author SHA1 Message Date
Alexey Bataev 9148b8b734 [OpenMP][Offloading] Fix the issue that omp_get_num_devices returns wrong number of devices, by Shiley Tian.
Summary:
This patch is to fix issue in the following simple case:

  #include <omp.h>
  #include <stdio.h>

  int main(int argc, char *argv[]) {
    int num = omp_get_num_devices();
    printf("%d\n", num);

    return 0;
  }

Currently it returns 0 even devices exist. Since this file doesn't contain any
target region, the host entry is empty so further actions like initialization
will not be proceeded, leading to wrong device number returned by runtime
function call.

Reviewers: jdoerfert, ABataev, protze.joachim

Reviewed By: ABataev

Subscribers: protze.joachim

Tags: #openmp

Differential Revision: https://reviews.llvm.org/D72576
2020-01-21 13:25:18 -05:00
Jonathan Peyton 76f3980a20 [OpenMP] Add omp_get_device_num() and update several other device API functions
Add omp_get_device_num() function for 5.0 which returns the number of the
device the current thread is running on. Currently, we are leaving it to the
compiler to handle this properly if it is called inside target.

Also, did some cleanup and updating of duplicate device API functions (in both
libomp and libomptarget) to make them into weak functions that check for the
symbol from libomptarget, and will call the version in libomptarget if it is
present. If any additional device API functions are implemented also in
libomptarget in the future, we should add the dlsym calls to the host functions.
Also, if the omp_target_* functions are to be implemented for the host (this has
been requested), they should attempt to call the libomptarget versions as well.

Patch by Terry Wilmarth

Differential Revision: https://reviews.llvm.org/D55578

llvm-svn: 350352
2019-01-03 21:14:19 +00:00