Specifying the details of how your applications perform calculations can allow you to take better advantage of your system's floating-point performance and precision, including how to direct rounding. However, keep in mind that strictly adhering to IEEE floating-point specifications can impact the performance of your application. Using the options in Table 1, you can control trade-offs between floating-point performance and adherence to IEEE standards.
The table also lists options that allow you to control the characteristics of integer variables, values and types.
| Option | Description | C Compile | C++ Compile | IPA Link | More Information |
|---|---|---|---|---|---|
| BITFIELD | Specifies whether bit fields are signed or unsigned. | ✓ | ✓ | ✓ | See detail |
| CHARS | Determines whether all variables of type char are treated as either signed or unsigned. | ✓ | ✓ | ✓ | See detail |
| DFP | Provides support for decimal floating-point types. | ✓ | ✓ | ✓ | See detail |
| ENUMSIZE | Specifies the amount of storage occupied by enumerations. | ✓ | ✓ | ✓ | See detail |
| FLOAT | Selects different strategies for speeding up or improving the accuracy of floating-point calculations. | ✓ | ✓ | ✓ | See detail |
| ROUND | Specifies the rounding mode for the compiler to use when evaluating constant floating-point expressions at compile time. | ✓ | ✓ | ✓ | See detail |