This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
Re: Swap optimization pass
Jeffrey A Law writes:
>
> Yup -- this is the basic idea behind my idea of using reorg to combine
> unrelated insns after reload.
I would prefer this sort of pass to run before register allocation
otherwise the chances of combining these insns gets slim since the
register constraints are usually tighter on multi-pack insns.
> Note that introducing "foreign" insns into a libcall block tends to
> do bad things in the register allocator, and I guess this might happen
> in that case.
Well we could restrict these "foreign" insns to be moves. I'm finding
that the incoming register arguments get poorly copied to the
corresponding arguments of a nested call.
Michael.