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Re: -fssa is broken
- To: Andreas Jaeger <aj at suse dot de>
- Subject: Re: -fssa is broken
- From: Richard Henderson <rth at cygnus dot com>
- Date: Thu, 18 May 2000 21:01:03 -0700
- Cc: gcc-bugs at gcc dot gnu dot org, Alex Samuel <samuel at codesourcery dot com>, Ulrich Drepper <drepper at cygnus dot com>
- References: <u8em719tjz.fsf@gromit.rhein-neckar.de>
On Wed, May 17, 2000 at 03:48:16PM +0200, Andreas Jaeger wrote:
> I couldn't find a small example of this breakage. If anybody wants to
> find out what's broken, I can try to assist - but I don't know where
> to look and how to hunt this down.
Uli tracked down the point of failure for me before he went travelling.
I've forgotten in the meantime the exact details.
The problem was in the register partitioning while converting back from
SSA form. We didn't properly notice that a use of a variable in between
a PHI and an increment meant that there should have been a conflict.
The result is that the use saw the value after the increment rather
than the value before the increment.
Or something like that. Sigh. I guess I'll have to track it down again...
r~