[Bug tree-optimization/56448] [4.8 Regression] cc1 hangs on volatile array with -O or above

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56448

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-25 22:40:42 UTC ---
Created attachment 29536
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29536
gcc48-pr56448.patch

Untested fix.
For OEP_CONSTANT_ADDRESS_OF, we should ignore side-effects of the reference
from which the address is taken, they change the value, not its address.
OEP_CONSTANT_ADDRESS_OF in flags is fine to propagate to the first operand of
some references, so e.g. &a.b[0].c[9] is constant, even when c and b arrays are
volatile, but not the other arguments (e.g. array indexes, etc.), but for
*MEM_REF not even the first argument should get that.