This is the mail archive of the
gcc-help@gcc.gnu.org
mailing list for the GCC project.
Re: Scheduling and inserting NOPs
Andrew Haley writes:
> Boris Boesler writes:
> > Am 21.11.2007 um 18:07 schrieb Andrew Haley:
> >
> > > Is there some special reason you can't do this in machine dependent
> > > reorg? That seems like the obvious place. Just walk every basic
> > > block stuffing NOPs.
> >
> > The problem isn't where, it's how. The insn-list after scheduling
> > doesn't provide any information about cycles or delays, does it? How
> > do I find out before which insn I have to insert a NOP, if the
> > scheduler doesn't pass any info to me?
>
> Walk the instructions in each BB, and if you see a violation stuff a NOP.
>
> This is so simple that I'm wondering if there's something important
> that I'm failing to understand.
Ah, hold on. Is it that you don't know where sched inserted the empty
cycles, and there's no easy way to find out?
Andrew.
--
Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, UK
Registered in England and Wales No. 3798903