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From: "ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug middle-end/51994] [4.6/4.7 Regression] git-1.7.8.3 miscompiled due to negative bitpos from get_inner_reference
Date: Wed, 25 Jan 2012 12:02:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51994

--- Comment #4 from Uros Bizjak <ubizjak at gmail dot com> 2012-01-25 11:39:11 UTC ---
(In reply to comment #2)

> > What should happen instead is that store_field needs to adjust the address
> > to properly point before the bitfield for calling store_bit_field.  Or the
> > latter needs to take signed arguments for bitpos and do the adjustment
> > itself.
> > 
> > Does simply changing the store_bit_field[_1] prototype work for you?
> 
> It might also be interesting to find out why we have a negative bitpos here.

gcc passes (&buf - 1) to get_innter_reference, so it returns *pbitpos = -8.