[Bug middle-end/69454] [6 Regression] ix86_expand_prologue internal compiler error: Segmentation fault

["ienkovich at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69454

--- Comment #26 from Ilya Enkovich <ienkovich at gcc dot gnu.org> ---
(In reply to H.J. Lu from comment #25)
> Please add -mpreferred-stack-boundary=2 to your tests.  Otherwise,
> you just remove a nop.

Here is a test which crashes LRA with the path you proposed.  Crash happens
because LRA requests a stack slot aligned by 8 and stack is aligned by 4.  So
Jakub's patch looks the safest option for now, but probably use 64 requirement
instead of 128.

>cat test.i
long long a, b;
fn1() {
  long long c = a;
  a = b ^ a;
  fn2();
  a = c;
}
>gcc test.i -O2 -m32 -mpreferred-stack-boundary=2
test.i: In function 'fn1':
test.i:5:3: warning: implicit declaration of function 'fn2'
[-Wimplicit-function-declaration]
   fn2();
   ^~~

test.i:7:1: internal compiler error: in assign_stack_local_1, at function.c:409