[Bug tree-optimization/55559] Marshalling double through union with inlines, incorrect behavior with -O2

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55559



Andrew Pinski <pinskia at gcc dot gnu.org> changed:



           What    |Removed                     |Added

----------------------------------------------------------------------------

           Keywords|                            |wrong-code

             Status|UNCONFIRMED                 |NEW

   Last reconfirmed|                            |2012-12-02

          Component|c++                         |tree-optimization

     Ever Confirmed|0                           |1

      Known to fail|                            |4.7.0, 4.8.0



--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-12-02 
00:09:30 UTC ---

CCP is broken:

Visiting statement:

D.1625_1 = D.1625_8;

Lattice value changed to CONSTANT -4616189618054758400.  Adding SSA edges to

worklist.



Visiting statement:

D.1631_7 = VIEW_CONVERT_EXPR<double>(D.1625_1);

which is likely CONSTANT

Lattice value changed to CONSTANT -1.0e+0.  Adding SSA edges to worklist.



Visiting statement:

D.1631_9 = D.1631_7;

Lattice value changed to CONSTANT -1.0e+0.  Adding SSA edges to worklist.



Visiting statement:

D.1631_2 = D.1631_9;

Lattice value changed to CONSTANT -1.0e+0.  Adding SSA edges to worklist.



Visiting statement:

D.1610_3 = (unsigned int) D.1631_2;

which is likely CONSTANT

Lattice value changed to CONSTANT 0.  Adding SSA edges to worklist.





I think this is a regression if the code does not use extended  initializer

lists but I have not tested it though.