Merge pull request #10735 from seiko2plus:coreYieldPPC

modules/core/src/parallel_impl.cpp

@@ -55,6 +55,8 @@ DECLARE_CV_PAUSE
 #   define CV_PAUSE(v) do { for (int __delay = (v); __delay > 0; --__delay) { asm volatile("yield" ::: "memory"); } } while (0)
 # elif defined __GNUC__ && defined __arm__
 #   define CV_PAUSE(v) do { for (int __delay = (v); __delay > 0; --__delay) { asm volatile("" ::: "memory"); } } while (0)
+# elif defined __GNUC__ && defined __PPC64__
+#   define CV_PAUSE(v) do { for (int __delay = (v); __delay > 0; --__delay) { asm volatile("or 27,27,27" ::: "memory"); } } while (0)
 # else
 #   warning "Can't detect 'pause' (CPU-yield) instruction on the target platform. Specify CV_PAUSE() definition via compiler flags."
 #   define CV_PAUSE(...) do { /* no-op: works, but not effective */ } while (0)