2015-12-10 Jeff Law <law@redhat.com>
PR tree-optimization/68619
* tree-ssa-dom.c (dom_opt_dom_walker::before_dom_children): Propgate
return value from optimize_stmt.
(dom_opt_dom_walker): Add new argument to dom_walker constructor.
(pass_dominator:execute): If a block has an unreachable edge,
remove all jump threads through any successor of the affected block.
(record_equivalences_from_phis): Ignore alternative if the edge
does not have EDGE_EXECUTABLE set.
(single_incoming_edge_ignoring_loop_edges): Similarly.
(optimize_stmt): If a gimple_code has a compile-time constant
condition, return the edge taken for that constant value. Also
change the condition to true/false as necessary.
* domwalk.h (dom_walker::dom_walker): Add new argument
skip_unreachable_blocks. Don't provide empty constructor body.
(dom_walker::before_dom_children): Change return type.
(dom_walker::bb_reachable): Declare new private method.
(dom_walker::propagate_unreachable_to_edges): Likewise.
(dom_walker::m_unreachable_dom): Declare new private data member.
(dom_walker::m_skip_unreachable_blocks): Likewise.
* domwalk.c: Include dumpfile.h.
(dom_walker::dom_walker): New constructor. Initialize private data
members. If needed, set EDGE_EXECUTABLE for all edges in the CFG,
extracted from tree-ssa-sccvn.c.
(dom_walker::bb_reachable): New method extracted from tree-ssa-sccvn.c
(dom_walker::propagate_unreachable_to_edges): Likewise.
(dom_walker::walk): Only call before_dom_children on reachable
blocks. If before_dom_children returns an edge, then clear
EDGE_EXECUTABLE for all other outgoing edges from the same block.
For unreachable blocks, call propagate_unreachable_to_edges.
Similarly, only call after_dom_children on reachable blocks. For
unreachable blocks, conditionally clear m_unreachable_dom.
* tree-ssa-sccvn.c (sccvn_dom_walker::unreachable_dom): Remove
private data member.
(sccvn_dom_walker::after_dom_children): Use methods from dom_walker
class.
(run_scc_vn): Likewise.
(sccvn_dom_walker::before_dom_children): Likewise. Return the taken
outgoing edge if a COND, SWITCH, or GOTO are optimized.
* compare-elim.c (find_comparison_dom_walker::before_dom_children):
Change return type to an edge. Always return NULL.
* fwprop.c (single_def_use_dom_walker::before_dom_children): Likewise.
* gimple-ssa-strength-reduction.c
(find_candidates_dom_walker::before_dom_children): Likewise.
* ipa-prop.c (analysis_dom_walker::before_dom_children): Likewise.
(ipcp_modif_dom_walker::before_dom_children): Likewise.
* tree-into-ssa.c (rewrite_dom_walker::before_dom_children): Likewise.
(rewrite_update_dom_walker::before_dom_children): Likewise.
(mark_def_dom_children::before_dom_children): Likewise.
* tree-ssa-dse.c (dse_dom_walker::before_dom_children): Likewise.
* tree-ssa-loop-im.c
(invariantness_dom_walker::before_dom_children): Likewise.
(move_computations_dom_walker::before_dom_walker): Likewise.
* tree-ssa-phiopt.c
(nontrapping_dom_walker::before_dom_children): Likewise.
* tree-ssa-pre.c
(eliminate_dom_walker::before_dom_children): Likewise.
* tree-ssa-propagate.c
(substitute_and_fold_dom_walker::before_dom_children): Likewise.
* tree-ssa-strlen.c
(strlen_dom_walker::before_dom_children): Likewise.
* tree-ssa-uncprop.c
(uncprop_dom_walker::before_dom_children): Likewise.
PR tree-optimization/68619
* gcc.dg/tree-ssa/pr68619-1.c: New test.
* gcc.dg/tree-ssa/pr68619-2.c: New test.
* gcc.dg/tree-ssa/pr68619-3.c: New test.
* gcc.dg/tree-ssa/pr68619-4.c: New test.
* gcc.dg/tree-ssa/pr68619-5.c: New test.
From-SVN: r231527
