From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeffrey A Law <law@cygnus.com>
To: Jim Wilson <wilson@cygnus.com>
Cc: Joern Rennecke <amylaar@cygnus.co.uk>, tege@pdc.kth.se (Torbjorn Granlund), egcs@cygnus.com
Subject: Re: x86 failure on loop reversal 
Date: Wed, 08 Apr 1998 02:13:00 -0000
Message-id: <29422.891920176@hurl.cygnus.com>
References: <199804070310.UAA12087@rtl.cygnus.com>
X-SW-Source: 1998-04/msg00293.html

  In message < 199804070310.UAA12087@rtl.cygnus.com >you write:
  > The existing test is (FOO >= 0).  Changing that to an unsigned test doesn't
  > look very useful, as it will be always true.  I suggest we just avoid
  > reversing the loop in this case.  This is rare enough, and tricky enough,
  > that I don't think we need to handle it.
  > 
  > How about something like this?  If this is OK, I will add the testcase and
  > check in the patch at the same time.
  > 
  > Mon Apr  6 20:08:43 1998  Jim Wilson  <wilson@cygnus.com>
  > 
  > 	* loop.c (check_dbra_loop): When normalize comparison_val, add check
  > 	to verify it is non-negative.
I was going to suggest the same basic change; this is probably the
simplest/easiest way to fix the problem.

jeff