[Bug tree-optimization/51760] [4.7 Regression] ICE in set_lattice_value, at tree-ssa-ccp.c:456

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51760

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-05 11:48:28 UTC ---
This is because likely_value says VARYING for __builtin___memmove_chk (&a, b_1,
0, D.1724_7) if b_1 is not already CONSTANT.  But we evaluate it with

            /* These builtins return their first argument, unmodified.  */
            case BUILT_IN_MEMCPY:
            case BUILT_IN_MEMMOVE:

anyway, so likely_value should return CONSTANT if the first arg of these
builtins is constant.