Re: Inline assembler fallback for _FPU_SETCW() missing in MINGW libraries (issue 577450043 by address@hidden)

[David Kastrup]

Dan Eble <address@hidden> writes:

> On Jan 31, 2020, at 08:31, David Kastrup <address@hidden> wrote:
>>       -fexcess-precision=style
>>           This option allows further control over excess precision on
>>           machines where floating-point operations occur in a format
>>           with more precision or range than the IEEE standard and
>>           interchange floating-point types.  By default,
>>           -fexcess-precision=fast is in effect; this means that
>>           operations may be carried out in a wider precision than the
>>           types specified in the source if that would result in faster
>>           code, and it is unpredictable when rounding to the types
>>           specified in the source code takes place.
>
> This sounds promising.
>
>>           -fexcess-precision=standard is not implemented for languages
>>           other than C.
>
> Never mind.

Hm.  Maybe

-mfpmath=sse

instead?  The problem with switching the whole FPU to reduced precision
is that some library functions might not expect that, so it is making me
queasy.  On the other hand, using SSE might have a negative performance?
I just don't have a good idea what we are dealing with here.

-- 
David Kastrup