Leopold Toetsch <[EMAIL PROTECTED]> writes: > Piers Cawley <[EMAIL PROTECTED]> wrote: >> Leopold Toetsch <[EMAIL PROTECTED]> writes: >>> As calling conventions clearly state, that the caller has to save >>> everything, its probably up to imcc/pcc.c to insert above >>> statements, if another sub gets called from a sub. I'll fix that in >>> a minute ;-) > >> If and only if that's not a tail call of course. > > Good point. But I can imagine, that's by far more simple to detect tail > calls at the AST level then inside the flattened code parrot sees. So > the HL can emit (a TBD) flag like "tailcall" appended to the .pcc_call > sequence. > Then the call can be optimized to a C<jump> opcode. The construction of > the subroutine object (which is outside of the call sequence) will lead > to an used once LHS, which the optimizer already can get rid of.
I'm not sure you can optimize it to a jump opcode when you're tail calling another function can you? You could be tailcalling into a closure so you'll need to use invoke to do the right thing with the lexical stack etc.
