Tells the compiler that errno can be reliably tested after calls to standard math library functions.
- The compiler assumes that the program does not testerrnoafter calls to standard math library functions.
This option tells the compiler to assume that the program tests
errnoafter calls to math library functions. This restricts optimization because it causes the compiler to treat most math functions as having side effects.
-fno-math-errnotells the compiler to assume that the program does not test
errnoafter calls to math library functions. This frequently allows the compiler to generate faster code. Floating-point code that relies on IEEE exceptions instead of
errnoto detect errors can safely use this option to improve performance.