On Tue, 2023-08-08 at 10:24 +0800, Xi Ruoyao wrote:
And I think this way to implement these functions (using libgcc calls)
is not the best.
On 64-bit LoongArch a __float128 is stored in a pair of GPR, so
operations like copysignq and absq can be implemented much more
efficiently by expanding them using bstrins and bstrpick instructions in
the compiler. For example:
__float128
absq (__float128 val)
{
return __builtin_absq (val);
}
should be compiled to:
bstrins.d $a1, $zero, 63, 63
jr $ra
Instead of
b __fabstf2
(perhaps, unless -Os).
> > +__float128 nanq (const char * str)
Using "nanq" as the symbol name is unacceptable as well. Use "__nanq"
or something. "nanq" is not reserved for implementation, so it may
cause a conflict in the future if "nanq" finally become a standard
function or the users defines their own "nanq" function.
>
--
Xi Ruoyao <xry...@xry111.site>
School of Aerospace Science and Technology, Xidian University
