Dm6437 intrinsic mpyu4

I am working on DM6437. I want to perform multiply operation using intrinsic "_mpyu4". It is specified in the file c6x.h that the intrinsic is deprecated. Another intrinsic "_mpyu4ll" is available that provides long long output but I am not able to access that in my source file. Other intrinsics of the file like "_ext, " are easily accessible but this one is not accessed in the .c file.... Not able to identify the issue. Kindly help