The z/OS XL C/C++ compiler provides a DFP option to include support for IEEE decimal floating-point numbers. For details on the z/OS XL C/C++ support, see the description of the DFP option in z/OS XL C/C++ User's Guide.
New C/C++ runtime library interfaces, which support IEEE decimal floating-point numbers have been added for z/OS V1R8, and other existing interfaces have been updated to support DFP. These interfaces are documented in z/OS XL C/C++ Runtime Library Reference.
The primary documentation for the IEEE decimal floating-point support is contained in z/Architecture® Principles of Operation, SA22-7832 and z/OS XL C/C++ User's Guide.
Reference information for IEEE floating-point can also be found in z/OS XL C/C++ Language Reference.