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Re: patch for loop combination [Re: ppc]
- To: rth at cygnus dot com (Richard Henderson)
- Subject: Re: patch for loop combination [Re: ppc]
- From: Joern Rennecke <amylaar at cygnus dot co dot uk>
- Date: Mon, 8 Feb 1999 03:04:05 +0000 (GMT)
- Cc: amylaar at cygnus dot co dot uk, law at cygnus dot com, meissner at cygnus dot com, egcs-patches at egcs dot cygnus dot com
> Comments? Shall I clean up the other places that conditionally
> initialize reg_single_use at the same time?
Does this patch actually help for the code in question?
Note that it turned out that there was actually giv combination &
derivation going on, and the biv was eliminated using a derived giv.
It seems like that giv was not only incorrect to use, but also dead,
so it would be useful to know why it was considered for biv elimination
in the first place - why hasn't the maybe_dead flag prevented this?
Was it not set, or was it ignored?