Hi,

I'm looking at the generated code for these builtins on POWER:

         add 4,3,4
         subfc 3,3,4
         subfe 3,3,3
         std 4,0(5)
         rldicl 3,3,0,63
         blr

and

         mulld 10,3,4
         mulhdu 3,3,4
         addic 9,3,-1
         std 10,0(5)
         subfe 3,9,3
         blr

The POWER architecture has variants of these instructions with builtin 
overflow checks (addo/mulldo), but these aren't listed in the .md files, 
and the builtins don't generate them either.

Is this intentional (I've found a few comments that mulldo is microcoded 
on CellBE and should be avoided there)?

    Simon