re PR debug/48159 (ICE: SIGSEGV in build2_stat (tree.c:3802) with -ftree-loop-distribution -g)

	PR debug/48159
	* tree-ssa.c (reset_debug_uses): New function.
	* tree-flow.h (reset_debug_uses): New prototype.
	* tree-data-ref.c (stmts_from_loop): Ignore debug stmts.
	* tree-loop-distribution.c (generate_loops_for_partition): Call
	reset_debug_uses on the stmts that will be removed.  Keep around
	all debug stmts, don't count them as bits in partition bitmap.
	(generate_builtin): Don't count debug stmts or labels as bits in
	partition bitmap.

	* gcc.dg/pr48159-1.c: New test.
	* gcc.dg/pr48159-2.c: New test.

From-SVN: r173656

1 files changed, 31 insertions, 0 deletions

diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index fe8a74c..f596fcd 100644
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -507,6 +507,37 @@ insert_debug_temps_for_defs (gimple_stmt_iterator *gsi)
     }
 }
 
+/* Reset all debug stmts that use SSA_NAME(s) defined in STMT.  */
+
+void
+reset_debug_uses (gimple stmt)
+{
+  ssa_op_iter op_iter;
+  def_operand_p def_p;
+  imm_use_iterator imm_iter;
+  gimple use_stmt;
+
+  if (!MAY_HAVE_DEBUG_STMTS)
+    return;
+
+  FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF)
+    {
+      tree var = DEF_FROM_PTR (def_p);
+
+      if (TREE_CODE (var) != SSA_NAME)
+	continue;
+
+      FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, var)
+	{
+	  if (!gimple_debug_bind_p (use_stmt))
+	    continue;
+
+	  gimple_debug_bind_reset_value (use_stmt);
+	  update_stmt (use_stmt);
+	}
+    }
+}
+
 /* Delete SSA DEFs for SSA versions in the TOREMOVE bitmap, removing
    dominated stmts before their dominators, so that release_ssa_defs
    stands a chance of propagating DEFs into debug bind stmts.  */