[PATCH][PR libgfortran/78314] Fix ieee_support_halting

[FX]

Hi,

> There seems to be a separate api for checking trapping support:
> ieee_support_halting, but it only checked if the exception status
> flags are available, so check trapping support too by enabling
> and disabling traps.

Thanks for the patch.

I am worried about the unnecessary operations that we’re doing here: doesn’t glibc have a way to tell you what it supports without having to do it (twice, enabling then disabling)?

Also, the glibc doc states that: "Each of the macros FE_DIVBYZERO, FE_INEXACT, FE_INVALID, FE_OVERFLOW, FE_UNDERFLOW is defined when the implementation supports handling of the corresponding exception”. It evens says:

> Each constant is defined if and only if the FPU you are compiling for supports that exception, so you can test for FPU support with ‘#ifdef’.

So it seems rather clear that compile-time tests are the recommended way to go.

FX