[PATCH] Fix PR rtl-optimization/32557 dataflow RTL checking ICE

[Rask Ingemann Lambertsen]

On Mon, Aug 20, 2007 at 10:58:12AM +0100, Richard Sandiford wrote:
> I don't think this is correct.  df_set_{dead,unused}_notes_for_mw are
> supposed to detect this case themselves.  I suppose the question is:
> if we have a SUBREG destination, why isn't it a DF_REF_PARTIAL definition?

   We have

(gdb) call debug_rtx(mws->mw_reg)
(subreg:DF (reg/v:DI 3 r3 [orig:327 d2 ] [327]) 0)

(gdb) print *mws
$1 = {mw_reg = 0x2b27c6a994e0, type = DF_REF_REG_USE, flags = 100,
start_regno = 3, end_regno = 4, mw_order = 207550}

   which doesn't seem partial to me. A good question is why it doesn't
simply read (reg/v:DF 3 r3 ...). Another one is why we call REGNO
(mws->mw_reg) instead of using mws->start_regno.

-- 
Rask Ingemann Lambertsen