Developer Guide and Reference

Contents

fmath-errno

Tells the compiler that errno can be reliably tested after calls to standard math library functions.

Syntax

Linux:
-fmath-errno
-fno-math-errno
macOS:
-fmath-errno
-fno-math-errno
Windows:
None
Arguments
None
Default
-fno-math-errno
The compiler assumes that the program does not test
errno
after calls to standard math library functions.
Description
This option tells the compiler to assume that the program tests
errno
after calls to math library functions. This restricts optimization because it causes the compiler to treat most math functions as having side effects.
Option
-fno-math-errno
tells the compiler to assume that the program does not test
errno
after calls to math library functions. This frequently allows the compiler to generate faster code. Floating-point code that relies on IEEE exceptions instead of
errno
to detect errors can safely use this option to improve performance.
Alternate Options
None