[Bug target/100693] PPC: missing 64-bit addg6s

["willschm at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100693

Will Schmidt <willschm at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |willschm at gcc dot gnu.org

--- Comment #2 from Will Schmidt <willschm at gcc dot gnu.org> ---
(In reply to Segher Boessenkool from comment #1)
> Confirmed.  The define_insn for it is for SImode only as well.

I see the SImode for the define as mentioned

(define_insn "addg6s"
  [(set (match_operand:SI 0 "register_operand" "=r")
        (unspec:SI [(match_operand:SI 1 "register_operand" "r")
                    (match_operand:SI 2 "register_operand" "r")]
                   UNSPEC_ADDG6S))]
  "TARGET_POPCNTD"
  "addg6s %0,%1,%2"
  [(set_attr "type" "integer")])


But.. a simple testcase with unsigned long long parms builds ok.   (both gcc 11
and older gcc 9).  


unsigned long long bcd_arith_longlong (unsigned long long a, unsigned long long
b)
{
        return __builtin_addg6s (a, b); 
}

Expand shows.. this instruction is using a subset, erm, subreg of the inputs. 
Is this expected behavior?

(insn 11 10 12 2 (set (reg:SI 128)
        (unspec:SI [
                (subreg/s/v:SI (reg:DI 121 [ _1 ]) 0)
                (subreg/s/v:SI (reg:DI 122 [ _2 ]) 0)
            ] UNSPEC_ADDG6S)) "./addg6s.c":11:16 -1
     (nil))