This is the mail archive of the
gcc-help@gcc.gnu.org
mailing list for the GCC project.
Re: Scheduling and inserting NOPs
Boris Boesler <baembel@gmx.de> writes:
> Hi!
>
> Am 13.11.2007 um 19:14 schrieb Ian Lance Taylor:
>
> > Boris Boesler <baembel@gmx.de> writes:
> >
> >> 1) As far as I can see some levels of optimization do not schedule
> >> the code. To generate correct code I have to insert NOP-operations to
> >> fill the delays (the architecture has no interlocks),
>
> ...
>
> > gcc is weak on VLIW support. The scheduler does not insert NOPs for
> > you.
>
> VLIWs? As I mentioned above the processor does not wait till the
> operands are evaluated; this must be done by the programmer/compiler
> by inserting NOPs or other instructions.
It amounts to the same thing: you need to insert NOP instructions.
Ian