[cft] subreg validation round 2

[Janis Johnson]

On Wed, Nov 17, 2004 at 11:18:41AM -0800, Bob Wilson wrote:
> 
> But speaking of picking up pieces after the fact....
> 
> Your change to assign_parm_setup_block() on 2004-11-13 is causing/exposing 
> a problem for Xtensa targets.  Specifically, this piece:
> 
> *************** assign_parm_setup_block (tree parm, stru
> *** 2648,2654 ****
 ...
> 
> The Xtensa FUNCTION_ARG macro is returning a BLKmode REG for a 3-byte 
> struct argument.  This used to be converted to an SImode REG, but now it 
> gets passed to gen_lowpart, which barfs on the BLKmode argument.

That change also causes several new test failures for powerpc64-linux
with -m64, which now ICE in gen_lowpart_common for a BLKmode argument.

Janis