[Bug tree-optimization/31797] [4.2/4.3 Regression] infinite loop in tree-ssa-pre or ICE

["dberlin at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #10 from dberlin at gcc dot gnu dot org  2007-05-10 19:59 -------
Ugh, so operand_equal_p claims two side-effecting component_refs are never the
same, unless they are pointer equal. For non-sideeffects ones, it checks
whether the operands are the same.

This causes PRE to continually make the value over and over again, and think
something is changing.
We only care whether they are performing the exact same operation, which they
are.

I guess i'm going to have to make expressions_equal_p that only ensures they
are the exact same operation with the same flags (IE both have side-effects,
etc).

Would any middle-end person have a problem with this?


-- 

dberlin at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu dot
                   |                            |org
         AssignedTo|unassigned at gcc dot gnu   |dberlin at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-05-07 00:22:33         |2007-05-10 19:59:11
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31797