IEEE decimal floating-point introduction

Starting with z/OS® V1R8, including the Language Environment® and C/C++ components, support has been added for IEEE decimal floating-point as defined by the ANSI/IEEE Standard P754/D0.15.3, IEEE Standard for Floating-Point Arithmetic.

Note:

You must have z/OS V1R8 or higher to use IEEE decimal floating-point, the hardware must have the Decimal Floating Point Facility installed, and the __STDC_WANT_DEC_FP__ feature test macro must be defined.
The abbreviation DFP refers to IEEE decimal floating-point.
IEEE decimal floating-point is fully supported in a CICS® environment only if CICS TS Version 4 or later is in use.

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.