re PR tree-optimization/68619 (error: loop with header 6 not in loop tree)

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

1 files changed, 6 insertions, 5 deletions

diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index f379ea7..f96bf97 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -2245,17 +2245,18 @@ public:
   analysis_dom_walker (struct ipa_func_body_info *fbi)
     : dom_walker (CDI_DOMINATORS), m_fbi (fbi) {}
 
-  virtual void before_dom_children (basic_block);
+  virtual edge before_dom_children (basic_block);
 
 private:
   struct ipa_func_body_info *m_fbi;
 };
 
-void
+edge
 analysis_dom_walker::before_dom_children (basic_block bb)
 {
   ipa_analyze_params_uses_in_bb (m_fbi, bb);
   ipa_compute_jump_functions_for_bb (m_fbi, bb);
+  return NULL;
 }
 
 /* Release body info FBI.  */
@@ -5098,7 +5099,7 @@ public:
     : dom_walker (CDI_DOMINATORS), m_fbi (fbi), m_descriptors (descs),
       m_aggval (av), m_something_changed (sc), m_cfg_changed (cc) {}
 
-  virtual void before_dom_children (basic_block);
+  virtual edge before_dom_children (basic_block);
 
 private:
   struct ipa_func_body_info *m_fbi;
@@ -5107,7 +5108,7 @@ private:
   bool *m_something_changed, *m_cfg_changed;
 };
 
-void
+edge
 ipcp_modif_dom_walker::before_dom_children (basic_block bb)
 {
   gimple_stmt_iterator gsi;
@@ -5198,7 +5199,7 @@ ipcp_modif_dom_walker::before_dom_children (basic_block bb)
 	  && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
 	*m_cfg_changed = true;
     }
-
+  return NULL;
 }
 
 /* Update alignment of formal parameters as described in