egcs-2.92.02 19980905 (m68k-next-nextstep3): Address of hoisted load clobbered

[Jeffrey A Law]

  In message < 19980909005126.A21382@dot.cygnus.com >you write:
  > On Tue, Sep 08, 1998 at 07:20:25PM +0200, Toon Moene wrote:
  > > An excerpt from the assmebly output, around the unrolled inner loop:
  > > 
  > >         fmoved a4@,fp1		<-- Load hoisted
  > >         movel d4,d0
  > >         movel sp@(60),a4	<-- Bleeeccchhhh
  > >         mulsl a4@,d0
  > > 	...
  > >         fmoved fp1,a4@		<-- Store sunk
  > > 
  > > which, of course, results in a Segmentation Violation.
  > 
  > I'm not sure who is at fault here, and request guidance from the 
  > gods of reload.  The problem is shared rtl.  It may be solved with
  > the following patch
  > 
  > 	* loop.c (load_mems): Copy rtx for output mem.
Can you say a little bit more about why the shared rtl is causing a
problem?  MEMs (as Mark pointed out) don't have as strict rules as
other objects.  It's hard to tell what the right thing to do is without
more information.

jeff