Closed
Description
When in finite math-only mode, we issue two diagnostics for use of NAN but only one for use of INFINITY: https://godbolt.org/z/4YYhaTzx9
#include <math.h>
_Static_assert(_Generic(INFINITY, float : 1, default : 0), "");
_Static_assert(_Generic(NAN, float : 1, default : 0), "");
produces:
<source>:3:25: warning: use of infinity via a macro is undefined behavior due to the currently enabled floating-point options [-Wnan-infinity-disabled]
3 | _Static_assert(_Generic(INFINITY, float : 1, default : 0), "");
| ^
<source>:4:25: warning: use of NaN via a macro is undefined behavior due to the currently enabled floating-point options [-Wnan-infinity-disabled]
4 | _Static_assert(_Generic(NAN, float : 1, default : 0), "");
| ^
<source>:4:25: warning: use of NaN is undefined behavior due to the currently enabled floating-point options [-Wnan-infinity-disabled]
4 | _Static_assert(_Generic(NAN, float : 1, default : 0), "");
| ^~~
/usr/include/math.h:98:16: note: expanded from macro 'NAN'
98 | # define NAN (__builtin_nanf (""))
| ^~~~~~~~~~~~~~~~~~~
3 warnings generated.