[Bug bootstrap/61078] [5 Regression] ESA mode bootstrap failure since r209897

[krebbel at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61078

Andreas Krebbel <krebbel at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-08-25
     Ever confirmed|0                           |1

--- Comment #2 from Andreas Krebbel <krebbel at gcc dot gnu.org> ---
The bash crash comes from using a miscompiled libgcc_s.so during gcc build.
There are "la r15,0(r15)" instructions everywhere in the code used for
decrementing the stack pointer where 0 is wrongly used as displacement. This in
turn is the result of being compiled by a miscompiled cc1plus. The following
negation of  the frame size value in s390_emit_prologue function is wrongly
split by the negdi2_31 splitter.

...
  if (cfun_frame_layout.frame_size > 0)
    {
      rtx frame_off = GEN_INT (-cfun_frame_layout.frame_size);
...