[OpenMP] libomptarget: test correction for use with OpenMP 4.5

[sdmitriev]

Summary

Implicit data mapping rules for scalars referenced within target region have been changed from “tofrom” to “firstprivate” in OpenMP 4.5. Libomptarget tests offload_success.c and offload_success.cpp rely on “tofrom” default and thus have to be updated to work correctly with OpenMP 4.5.

This change will make tests fail due to a problem in OpenMP runtime function omp_is_iniital_device (it returns true when called from the target code executed on device), but that is a separate issue which has to be addressed in OpenMP runtime library.

[grokos]

This problem had been mentioned before, but somehow I forgot to take care of it. Thanks for the patch!

Also, it is true that omp_is_inital_device has not been implemented for the generic-elf plugin, so the runtime picks the function from libomp. I'll fix this issue.

[sdmitriev]

I think I do not have commit access, so I cannot commit this patch myself.

openmp/trunk/libomptarget/test/offloading/offloading_success.c

 // RUN: %libomptarget-compile-run-and-check-aarch64-unknown-linux-gnu
 // RUN: %libomptarget-compile-run-and-check-powerpc64-ibm-linux-gnu
 // RUN: %libomptarget-compile-run-and-check-powerpc64le-ibm-linux-gnu
 // RUN: %libomptarget-compile-run-and-check-x86_64-pc-linux-gnu
 
 #include <stdio.h>
 #include <omp.h>
 
 int main(void) {
   int isHost = -1;
 
-#pragma omp target
+#pragma omp target map(from: isHost)
   { isHost = omp_is_initial_device(); }
 
   if (isHost < 0) {
     printf("Runtime error, isHost=%d\n", isHost);
   }
 
   // CHECK: Target region executed on the device
   printf("Target region executed on the %s\n", isHost ? "host" : "device");
 
   return isHost;
 }

openmp/trunk/libomptarget/test/offloading/offloading_success.cpp

 // RUN: %libomptarget-compilexx-run-and-check-aarch64-unknown-linux-gnu
 // RUN: %libomptarget-compilexx-run-and-check-powerpc64-ibm-linux-gnu
 // RUN: %libomptarget-compilexx-run-and-check-powerpc64le-ibm-linux-gnu
 // RUN: %libomptarget-compilexx-run-and-check-x86_64-pc-linux-gnu
 
 #include <stdio.h>
 #include <omp.h>
 
 int main(void) {
   int isHost = 0;
 
-#pragma omp target
+#pragma omp target map(from: isHost)
   { isHost = omp_is_initial_device(); }
 
   if (isHost < 0) {
     printf("Runtime error, isHost=%d\n", isHost);
   }
 
   // CHECK: Target region executed on the device
   printf("Target region executed on the %s\n", isHost ? "host" : "device");
 
   return isHost;
 }