[Bug debug/83758] ICE building gccgo on powerpc64le --with-cpu=power8

[boger at us dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83758

--- Comment #21 from boger at us dot ibm.com ---
(In reply to Alexandre Oliva from comment #19)
> I was copied, presumably because the problem occurred in var-tracking.
> 
> I've tried to duplicate the problem on gcc112.  I bootstrapped the trunk
> (without any --with-cpu flag), and then build attachment 43208 [details]
> with stage3:
> 
> $ ./gccgo -B./ -I../../libgo/go -I../powerpc64le-unknown-linux-gnu/libgo
> -I../powerpc64le-unknown-linux-gnu/libgo/go -O2 -g t.go -mcpu=power8 -c
> [success]
> 
> Given this, I conclude that the problem only occurs if the compiler is
> bootstrapped --with-cpu=power[89].  This suggests to me that, although the
> ICE is triggered in var-tracking, the problem is unlikely to be there: the
> compiler is getting miscompiled.  I suppose that, by now, you already knew
> that ;-)

The problem only occurs when configuring --with-cpu=power8 or 9 AND compiling
for split stack. If you are on a system where glibc is 2.17 or older then split
stack is not enabled and you won't see the failure even with --with-cpu=power8
or 9.