acc_is_present– Indicate whether host variable / array is present on device.
This function indicates whether the specified host address in a and a length of len bytes is present on the device. In C/C++, a non-zero value is returned to indicate the presence of the mapped memory on the device. A zero is returned to indicate the memory is not mapped on the device.
In Fortran, two (2) forms are supported. In the first form, a specifies
a contiguous array section. The second form a specifies a variable or
array element and len specifies the length in bytes. If the host
memory is mapped to device memory, then a
true is returned. Otherwise,
false is return to indicate the mapped memory is not present.
OpenACC specification v2.0, section 3.2.29.