On 7/17/20 3:23 PM, Segher Boessenkool wrote:
> On ISA 3.0B and later you can do
>
> mffscdrni %3,7
> drdpq %2,%1
> mffscdrn %3,%3
> drsp %0,%2
>
> (saving one insn, and using somewhat cheaper insns). But that is only
> on newer machines, so is this worth it at all? :-)
So something like the following?
Peter
(define_insn "trunctdsd2"
[(set (match_operand:SD 0 "gpc_reg_operand" "=d")
(float_truncate:SD (match_operand:TD 1 "gpc_reg_operand" "d")))
(clobber (match_scratch:TD 2 "=&d"))
(clobber (match_scratch:DF 3 "=&d"))]
"TARGET_DFP"
{
if (TARGET_MODULO)
return "mffscdrni %3,7\;drdpq %2,%1\;mffscdrn %3,%3\;drsp %0,%2";
else
return "mffs %3\;mtfsfi 7,7,1\;drdpq %2,%1\;mtfsf 0xff,%3,1,0\;drsp %0,%2";
}
[(set_attr "type" "dfp")
(set (attr "length")
(if_then_else
(match_test "TARGET_MODULO")
(const_string "16")
(const_string "20")))])
