Painful problems with -fpic implementation on powerpc-sysv

[Jeffrey A Law]

  In message < 19980826122503.D1747@dot.cygnus.com >you write:
  > On Wed, Aug 26, 1998 at 01:11:02AM -0600, Jeffrey A Law wrote:
  > > This could work for cases where one is trying to build up a constant,
  > > but would not work if (for example) reload decided try and put
  > > (const (plus (symbol_ref) (offset)) into the constant pool.  Yes, this
  > > does really happen and it is painful.
  > 
  > If this happens, it is a bug.  With -fpic, a symbol_ref is not a
  > constant, and will result in a run-time relocation to .rodata.
  > Not good.
Certainly not good.  But it happens.

Consider a target where it is impossible to synthesize the sequence
at reload time.  It can (and does) happen on the PA.  It has to go into
memory.  Of course, we don't want it in readonly memory because of
shared library issues, so we arrange to get it into the normal data
segment.

jeff