Mark Mitchell <[EMAIL PROTECTED]> writes: > http://gcc.gnu.org/projects/lto/lto.pdf
> > Section 4.2 (Executable Representation) describes the GVM as a stack > machine, and mentions load, store, duplicate, and swap operations. > But it also discusses having registers which correspond to GIMPLE > local variables. The way I put this together is that a MODIFY_EXPR > which sets a local variable, say, will be converted to something that > computes the expression using a stack and then assigns the value to a > register. It's easy to see how to convert such a MODIFY_EXPR into a > stack machine and back. But it's not easy to see why that stack > machine is going to need, e.g, a swap operation. There is no GIMPLE > swap operator. So I may still be confused about something. You are most likely correct. We either do not need a swap or do not want to encourage people to try to optimize the trees so much that they need a swap. > > Ian
