re PR tree-optimization/46177 (ICE: in prop_phis, at…

re PR tree-optimization/46177 (ICE: in prop_phis, at tree-loop-distribution.c:327 with -fno-tree-copy-prop -ftree-loop-distribution)

2010-11-02  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/46177
	* tree-loop-distribution.c (prop_phis): Use
	mark_virtual_phi_result_for_renaming.

	* gcc.dg/pr46177.c: New testcase.

From-SVN: r166193

gcc/ChangeLog

+2010-11-02  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/46177
+	* tree-loop-distribution.c (prop_phis): Use
+	mark_virtual_phi_result_for_renaming.
+
 2010-11-02  Martin Jambor  <mjambor@suse.cz>
 
 	PR middle-end/46120

gcc/testsuite/ChangeLog

+2010-11-02  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/46177
+	* gcc.dg/pr46177.c: New testcase.
+
 2010-11-02  Martin Jambor  <mjambor@suse.cz>
 
 	PR middle-end/46120

gcc/testsuite/gcc.dg/pr46177.c

+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-copy-prop -ftree-loop-distribution" } */
+
+extern int A[];
+extern int B[];
+
+void
+foo (int j, int c)
+{
+  int i;
+
+  if (c)
+    for (i = 0; i < j; i++)
+      A[i] = B[i] = 0;
+
+  for (i = 0; i < j; i++)
+    A[i] = B[i];
+}

gcc/tree-loop-distribution.c

@@ -317,27 +317,20 @@ static void
 prop_phis (basic_block b)
 {
   gimple_stmt_iterator psi;
-  gimple_seq phis = phi_nodes (b);
 
-  for (psi = gsi_start (phis); !gsi_end_p (psi); )
+  for (psi = gsi_start_phis (b); !gsi_end_p (psi); )
     {
       gimple phi = gsi_stmt (psi);
-      tree def = gimple_phi_result (phi), use = gimple_phi_arg_def (phi, 0);
-
-      gcc_assert (gimple_phi_num_args (phi) == 1);
+      tree def = gimple_phi_result (phi);
 
       if (!is_gimple_reg (def))
-	{
-	  imm_use_iterator iter;
-	  use_operand_p use_p;
-	  gimple stmt;
-
-	  FOR_EACH_IMM_USE_STMT (stmt, iter, def)
-	    FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
-	      SET_USE (use_p, use);
-	}
+	mark_virtual_phi_result_for_renaming (phi);
       else
+	{
+	  tree use = gimple_phi_arg_def (phi, 0);
+	  gcc_assert (gimple_phi_num_args (phi) == 1);
 	  replace_uses_by (def, use);
+	}
 
       remove_phi_node (&psi, true);
     }