https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92488
Peter Bergner <bergner at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |WAITING
--- Comment #1 from Peter Bergner <bergner at gcc dot gnu.org> ---
So if I look at what we generate for:
_Decimal64
truncd128 (_Decimal128 d)
{
return d;
}
and:
_Decimal32
truncd64(_Decimal64 d)
{
return d;
}
We basically just get a drdpq for the first function and a drsp for the second
function. Ie, they don't change the rounding mode at all. If I modify your
test case slightly to insert an intermediate cast to _Decimal64 like so:
_Decimal32
truncd128 (_Decimal128 d)
{
return (_Decimal64)d;
}
...then we get:
drdpq 12,2
fmr 1,12
drsp 1,1
blr
So is changing the rounding mode really required here when we go from
_Decimal128 directly to _Decimal32? If so, do the other casts also need to be
inserting rounding mode changes too? If not, why not?
