PR tree-optimization/29738
* tree-ssa-ccp.c: Remove UNKNOWN_VAL from comments.
(ccp_lattice_t): Remove UNKNOWN_VAL.
(dump_lattice_value, ccp_lattice_meet, ccp_visit_phi_node):
Do not handle UNKNOWN_VAL.
(get_default_value): Set initial value of virtual operands to
VARYING.
(get_value): Always use get_default_value on uninitialized
operands.
(set_value_varying, surely_varying_stmt_p): New functions.
(set_lattice_value): Do not pass argument to get_value.
Do not handle UNKNOWN_VAL.
(likely_value): Follow the semantics described in the comment.
(ccp_initialize): Use surely_varying_stmt_p. Do not mark
phi nodes DONT_SIMULATE_AGAIN.
(ccp_fold): Do not pass argument to get_value.
(fold_const_aggregate_ref, visit_assignment): Ditto. Do not
handle UNKNOWN_VAL.
* gcc.dg/tree-ssa/ssa-ccp-14.c: New test.
* gcc.dg/tree-ssa/ssa-ccp-15.c: New test.
From-SVN: r118602
