I didn't give the full details of the instruction but for example a max instruction which gets an array and returns both the max value and its index in the array will need to return more than one argument.
2010/10/26 Ian Lance Taylor <i...@google.com>: > roy rosen <roy.1ro...@gmail.com> writes: > >> I am trying to demonstrate my port capabilities. >> I am writing an application which needs to use instructions like max >> a,b,c,d,e,f where a,b,c are inputs and d,e,f are outputs. >> Is that possible to write an intrinsic function for that? >> I think not because that means that I need to pass d,e,f by reference >> which means that they would be in memory and not in a register as >> meant by the instruction. > > That is correct. An intrinsic function is a normal function. If you > want it to have multiple outputs, you need to pass in addresses, or you > need to have it return a struct. > > I'm a bit curious as to why a function named max would have multiple > outputs. > >> Is there any port with such an example? > > Not to my knowledge. I wrote a private port in which some intrinsics > returned a struct, and to keep everything out of memory I added > additional intrinsics to retrieve elements of the struct. It's awkward > to use but the resulting code is fine. > >> So, I thought of implementing that with inline assembly but here I >> encounter a different problem: The compiler does not understand the >> instruction given in inline assembly and therefore it does not >> parallelize it with other insns. > > Yes. > >> Is there any other solution for that which I don't see? > > I can't think of anything. > > Ian >
