Floating-point and integer control
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 the following table, you can control trade-offs between floating-point
performance and adherence to IEEE standards.
Option name | Description |
---|---|
-fsigned-char, -funsigned-char (-qchars) | Determines whether all variables of type char are treated as either signed or unsigned. |
-qfloat | Selects different strategies for speeding up or improving the accuracy of floating-point calculations. |
-qstrict | Ensures that optimizations done by default at the -O3 and higher optimization levels, and, optionally at -O2, do not alter the semantics of a program. |
-y | Specifies the rounding mode for the compiler to use when evaluating constant floating-point expressions at compile time. |