On Mon, 2009-08-10 at 15:09 +0200, Steven Bosscher wrote: > On Mon, Aug 10, 2009 at 1:16 PM, Ramana > Radhakrishnan<ramana.radhakrish...@arm.com> wrote: > > I wonder if the best way to fix this is to teach ifcvt.c to handle > > conditional returns. > > Yes. This is a bug in the middle-end. I can only guess why you are > the first to run into this (the ia64 return instruction is not > predicable?) but clearly the assert is bogus if the conditional branch > of the IF-block is actually a conditional return.
I did try to see what happened with the ia64 port - The ia64 return insn is predicable but th port doesn't like to conditionalize the return for this particular case because current_frame_info.r[reg_save_b0] is 32 and not 0 as required. Not knowing enough about the ia64 backend I gave up at this point assuming that the port was DTRT. > > > Should I be fixing this inside ifcvt.c by handling > > conditional returns specially > > I think you should fix this inside ifcvt.c, but try to make the > handing of cond_return not too specially ;-) > > Alternatively, you could add a conditional call pattern and a > post-reload splitter to the ARM backend, and disallow the > EXIT_BLOCK_PTR as the JOIN-block in ifcvt.c. I have added a conditional call pattern by saying that the call pattern is predicable - I don't see what else you mean here. What do you want to split here ? The conditional return + call into a cond_call + return or conditional return into a conditional branch and return ... ( both of which are impossible really ! ) I don't see how one can fix this without special casing for a return here. Either fix it inside ifcvt.c as a special case or look for a way of doing this from the hooks that ifcvt appears to provide . Thanks, Ramana > > Ciao! > Steven
