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

[David Kastrup]

Thomas Morley <address@hidden> writes:

> Am Sa., 1. Feb. 2020 um 12:39 Uhr schrieb David Kastrup <address@hidden>:
>>
>> Dan Eble <address@hidden> writes:
>>
>> > On Feb 1, 2020, at 05:05, David Kastrup <address@hidden> wrote:
>> >>
>> >> Frankly, I think that it would be better if our Windows executables just
>> >> moved to 64bit but that seems like the more complicated option yet. And
>> >> 32bit systems kept around a whole lot longer even after processors
>> >> became 64bit-capable because they tended to require less memory.
>> >
>> > You provided a lot of good information in your post, but the
>> > conclusion was not entirely clear.
>> > Are you suggesting requiring SSE2 at this time?
>>
>> Yes.  It appears to get used anyway for 64bit executables, and it seems
>> safe enough to demand it for 32bit executables.
>>
>> For SSE there would be the danger of libraries stomping over the
>> registers that share memory with the FPU stack, but I think that SSE2 is
>> not affected.
>>
>> --
>> David Kastrup
>>
>
> Well, Arnold encountered the problem (iirc he will not be online
> during the weekend) and there may several other older 32-bit OS
> around.
> What shoud those people do?

Nothing?  I am currently proposing that we compile with

-mfpmath=sse -msse2

as options which should shift arithmetic off to the SSE2 instruction set
which doesn't work with 80-bit arithmetic.  That would be a default way
of compilation.

-- 
David Kastrup