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Re: Suffix for __float128 FP constants
On Mon, Jun 18, 2007 at 07:25:06PM +0200, Uros Bizjak wrote:
> H. J. Lu wrote:
>
> >>>I was trying to load a full 128 bit constant into __float128 variable,
> >>>but
> >>>with "L" suffix, I was able to load only XFmode constant. Is there a
> >>>special
> >>>suffix for __float128 available in gcc?
> >>>
> >>No; since the x86-64 ABI is what defines the __float128 name, you could
> >>ask the associated mailing list about a standard suffix to associate with
> >>it.
> >>
> >Lack of standard for __float128 is always a problem. Suffix for
> >__float128 constant is one, scanf/printf specifier for __float128
> >is another. We also don't have a name for string to __float128
> >function.
> >
>
> While the __float128 scanf/printf specifier is part of library (and this
> way, a custom library can provide these functions), the suffix for
> constant should be covered by the compiler. Otherwise there is no
> (clear) way to load the 128bit register with a 128bit constant value.
>
> BTW: IA64 has the same issues with two FP types (long double XFmode and
> "longer double" TFmode). How is this solved for IA64?
The same as x86-64 :-(. That is there is __float128 in ia64 psABI.
But it isn't fully implemented in gcc and glibc.
H.J.