Re: [PATCH v2 0/3] MR7748: ucrtbase: Add cexp() implementation.

[Piotr Caban (＠piotr)]

Piotr Caban (@piotr) commented about libs/musl/src/complex/cexp.c:
> -
>
> +#include "complex_impl.h"
> -
>
> +static const uint32_t
> +exp_ovfl  = 0x40862e42,  /* high bits of MAX_EXP * ln2 ~= 710 */
> +cexp_ovfl = 0x4096b8e4;  /* (MAX_EXP - MIN_DENORM_EXP) * ln2 */
> -
>
> +extern double __cdecl __exp(double x, matherr_t matherr);
> -
>
> +static double cexp_callback( int type, const char *name, double arg1, double arg2, double retval )
> +{
> - switch (type) {
> -
>    case _UNDERFLOW:
> -
>    case _OVERFLOW:
> -
>        errno = ERANGE;
> -
>        break;

Should `errno` be set on undeflow? It's probably better to copy switch cases ffrom `dlls/msvcrt/math.c -> math_error()`:
```c
case _DOMAIN:
    errno = EDOM;
    break;
case _SING:
case _OVERFLOW:
    errno = ERANGE;
    break;
```