[Bug middle-end/50199] [4.7 Regression] wrong code with -flto -fno-merge-constants

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50199

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-08-27
                 CC|                            |hubicka at gcc dot gnu.org,
                   |                            |jsm28 at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org
   Target Milestone|---                         |4.7.0
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-27 08:20:47 UTC ---
Hmmm.  Partitioning unshares string constants and I suppose ipa-cp propagates
one of it to the callee.

Not sure if this is a well-defined testcase though.  If it is we'd probably
need to add CONST_DECLs for address-taken constants and register them with
the varpool (and disallow &"..." in gimple).

It should be possible to make a non-LTO testcase that fails similarly
by instructing the assembler/linker not to merge strings.

Joseph, does C require that a string literal "..." has a single underlying
object or would the testcase be undefined?