C99 defines :
Long long int type values range from -(2^63-1) to 2^63-1.
When running the below testcase, PGCC executes successfully without any warning while gcc and intelc output warnings: integer constant is too large for its type. And clang report an error: integer literal is too large to be represented in any integer type. So i think it would be better for PGCC to ouput a warning message for the wrong action.
long long int NISLParameter1 = -28434685606287798005;
pgcc 19.10-0 LLVM 64-bit target on x86-64 Linux -tp skylake
output a warning then run the testcase.