re PR tree-optimization/27548 (ICE: SSA corruption - Conflict across an abnormal edge)

	PR tree-optimization/27548
	* tree-scalar-evolution.c (scev_const_prop): Do not prolong life
	range of ssa names that appear on abnormal edges.
	* tree-ssa-loop-ivopts.c (contains_abnormal_ssa_name_p): Export.
	* tree-flow.h (contains_abnormal_ssa_name_p): Declare.

From-SVN: r113853

gcc/ChangeLog

+2006-05-17  Zdenek Dvorak <dvorakz@suse.cz>
+
+	PR tree-optimization/27548
+	* tree-scalar-evolution.c (scev_const_prop): Do not prolong life
+	range of ssa names that appear on abnormal edges.
+	* tree-ssa-loop-ivopts.c (contains_abnormal_ssa_name_p): Export.
+	* tree-flow.h (contains_abnormal_ssa_name_p): Declare.
+
 2005-05-17  Bernd Schmidt  <bernd.schmidt@analog.com>
 
 	PR middle-end/27620

gcc/tree-flow.h

@@ -842,6 +842,7 @@ bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 			struct tree_niter_desc *niter);
 void tree_unroll_loop (struct loops *, struct loop *, unsigned,
 		       edge, struct tree_niter_desc *);
+bool contains_abnormal_ssa_name_p (tree);
 
 /* In tree-ssa-threadedge.c */
 extern bool potentially_threadable_block (basic_block);

gcc/tree-scalar-evolution.c

@@ -2802,7 +2802,11 @@ scev_const_prop (void)
 	  def = analyze_scalar_evolution_in_loop (ex_loop, loop, def, NULL);
 	  def = compute_overall_effect_of_inner_loop (ex_loop, def);
 	  if (!tree_does_not_contain_chrecs (def)
-	      || chrec_contains_symbols_defined_in_loop (def, ex_loop->num))
+	      || chrec_contains_symbols_defined_in_loop (def, ex_loop->num)
+	      /* Moving the computation from the loop may prolong life range
+		 of some ssa names, which may cause problems if they appear
+		 on abnormal edges.  */
+	      || contains_abnormal_ssa_name_p (def))
 	    continue;
 
 	  /* Eliminate the phi node and replace it by a computation outside

gcc/tree-ssa-loop-ivopts.c

@@ -678,7 +678,7 @@ idx_contains_abnormal_ssa_name_p (tree base, tree *index,
 /* Returns true if EXPR contains a ssa name that occurs in an
    abnormal phi node.  */
 
-static bool
+bool
 contains_abnormal_ssa_name_p (tree expr)
 {
   enum tree_code code;