[patch, ia64] Patch for PR36898 & PR43760, predicated reg conflict warning

[Jim Wilson]

On Mon, 2010-10-04 at 14:37 -0700, Steve Ellcey wrote:
> After trying to fix this by having GCC put out better '.pred.mutex' 
> psuedo-ops to tell the assembler that the usages aren't conflicting and
> not having much success, I wondered if it would be easier to just not
> use (possibly) conflicting registers in the same instruction bundle
> and make GCC more conservative in it's instruction bundling.

It seems like a reasonable short term workaround, though it would be
better if the comments actually explained why we are doing the wrong
thing here.  It isn't a good idea to disable an optimization without
documenting why it has been disabled.

FYI I have left CodeSourcery and am Cisco now, so you will have to use
my tuliptree.org email address for now.  I probably won't be able to do
much until I am settle in at Cisco.  I'm busy dealing with the job
change and related activities.

Jim