A question about df - ReadList.com

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A question about df
\ Revital1 Eres (24 Oct 2007)
. \ Seongbae Park (冠己硅, 谟圜燮) (24 Oct 2007)
. . \ Revital1 Eres (24 Oct 2007)
. . . \ Seongbae Park (冠己硅, 谟圜燮) (24 Oct 2007)

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Subject:	A question about df
Group:	Gcc
From:	Revital1 Eres
Date:	24 Oct 2007

Hello,

While testing a patch for the SMS I got an ICE which seems
to be related to the fact we build def-use chains only
and not use-def chains. (removed in the following patch -
http://gcc.gnu.org/ml/gcc-patches/2006-12/msg01682.html)

The problem arises when we delete an insn from the df that contains a
use but do not update the def-use chain of it's def as we do not have
the use-def chain to reach it's def, This later causes a problem when
we try to dump the def-use chain of it's def.

So, it seems that when asking for only def-use problem and later dump
the function we should ask for use-def problem as well to avoid cases
like the above.

Thanks,
Revital