[fpc-devel] 64 Bit / 32 Bit
jonas.maebe at elis.ugent.be
Thu Oct 4 13:07:20 CEST 2007
On 04 Oct 2007, at 13:00, Daniël Mantione wrote:
>> I don't think it would be a good idea to map the extended type to
>> 80 bit soft
>> float on platforms that don't support 80 bit fpu calculations in
>> Many programs use "extended" by default without actually requiring
>> 80 bit
>> precision, and mapping those all to soft float would needlessly
>> slow down such
>> I think a separate type would be more appropriate.
> Hmmm... I prefer to keep correct code that writes say, an extended
> type to
> a file working,
It won't keep it working but rather break it, since currently writing
an extended to file on virtually all platforms writes a double to the
> over keeping code that falsely uses extended precision
> fast, especially as I expect people to correct such code anyway to
> advantage of SSE performance.
I don't expect that to happen in most situations.
> In such case "extended" would also be a misleading name, since it
> get "long double" semantics. Even worse, it would be a TP compatible
> extended on i386 and some x86_64 platforms and long double on other
It's probably better to directly introduce a longdouble type with
longdouble (128 bit) semantics on all platforms. I don't think that
emulating the almost nowhere supported 80 bit type does much good.
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