Incorrect DFA scheduling of output dependency.

[Steven Bosscher]

On Dec 06, 2004 12:29 PM, Daniel Towner <daniel.towner@picochip.com> wrote:

> Any ideas?

You're not making this easy because you haven't told anything about:
1) what target you're working on (apparently something that is not
   in the FSF GCC tree);
2) what your DFA description looks like (did you tell the scheduler
   that those two instructions are issued in parallel?); and
3) what version of GCC you are working with.

Anyway, I'll assume you work from mainline.  If you use a recent
snapshot: There was a bug last week where REG notes were being
removed in pairs when they shouldn't.  That bug had been there for
about two weeks.  Perhaps your REG_DEP_OUTPUT note was incorrectly
being removed.  In that case, try a newer shapshot.

But first look at the scheduler dumps (-dS and -dR) to see if the
output dependency is there, of course...

Gr.
Steven