[Bug rtl-optimization/64081] [5/6/7 Regression] r217827 prevents RTL loop unroll

[aldyh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64081

--- Comment #34 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
(In reply to David Edelsohn from comment #32)
> How far are you going back in the bisection effort?  You may be earlier than
> the point at which GCC on AIX generated stab strings continuation lines.  At
> worst you manually can apply the continuation code from gcc/xcoffout.h
> 
> /* XCOFF32 maximum length is 64K; XLC limits to 16K.  */
> #define DBX_CONTIN_LENGTH 16384
> 
> /* XLC uses '?' as continuation character.  */
> #define DBX_CONTIN_CHAR '?'

David, thanks for your input here, BTW.

Same problem, even if I add your above two lines to rs6000.h.

I am starting with r219827 as suggested here:

https://gcc.gnu.org/ml/gcc-patches/2016-02/msg00451.html

The aforementioned revision gets us around January 18, 2015, which is around
the time y'all were discussing the bootstrap failure.

My tree contains:

1. The rtl patch being discussed
2. A patch for r233572 to get GCC 6.x to build GCC 5.x (see BZ#69959).
3. Your suggested changes for xcoff continuation.

I am attaching the changes to r219827 that still exhibit STABSTRING ERROR
problems while bootstrapping.  These are in comment 33.  Any tips greatly
appareciated.