http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52134
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-03-13 22:08:12 UTC --- CCP could also remove the &: Visiting statement: D.1713_2 = t_1(D) * 4; which is likely CONSTANT Lattice value changed to CONSTANT Lattice value changed to CONSTANT 0x00000000000000000 (0x000000000fffffffc). Adding SSA edges to worklist. Visiting statement: D.1712_3 = D.1713_2 & 4294967292; which is likely CONSTANT Lattice value changed to CONSTANT Lattice value changed to CONSTANT 0x00000000000000000 (0x000000000fffffffc). Adding SSA edges to worklist. .. Visiting statement: D.1710_2 = t_1(D) * 4; which is likely CONSTANT Lattice value changed to CONSTANT Lattice value changed to CONSTANT 0x00000000000000000 (0xfffffffffffffffffffffffffffffffc). Adding SSA edges to worklist. Visiting statement: D.1709_3 = D.1710_2 & -4; which is likely CONSTANT Lattice value changed to CONSTANT Lattice value changed to CONSTANT 0x00000000000000000 (0xfffffffffffffffffffffffffffffffc). Adding SSA edges to worklist. See how the lattice's already have its last 3 bits unset. In fact I think we should only do this in the ccp/vrp passes to remove the & rather than fold.
