re PR tree-optimization/21734 (ICE: -ftree-vectorize, segfault)

        PR tree-optimization/21734
        * tree-vectorizer.c (slpeel_update_phis_for_duplicate_loop): Use the
        phi_result when current_def is not available.
        (slpeel_update_phi_nodes_for_guard1): Don't fail if current_def is not
        available.

From-SVN: r100494

gcc/ChangeLog

+2005-06-02  Dorit Nuzman  <dorit@il.ibm.com>
+
+	PR tree-optimization/21734
+	* tree-vectorizer.c (slpeel_update_phis_for_duplicate_loop): Use the
+	phi_result when current_def is not available.
+	(slpeel_update_phi_nodes_for_guard1): Don't fail if current_def is not
+	available.	
+
 2005-06-02  David Edelsohn  <edelsohn@gnu.org>
 
 	* config/rs6000/rs6000.c (rs6000_insn_valid_within_doloop): New.

gcc/testsuite/ChangeLog

+2005-06-02  Dorit Nuzman  <dorit@il.ibm.com>
+
+	PR tree-optimization/21734
+	* g++.dg/vect/pr21734_1.cc: New.
+	* g++.dg/vect/pr21734_2.cc: New.
+
 2005-06-02  Nathan Sidwell  <nathan@codesourcery.com>
 
 	PR c++/20350

gcc/testsuite/g++.dg/vect/pr21734_1.cc

+/* { dg-do compile } */
+
+struct A
+{
+  int a[4];
+  int& operator[](int i) { return a[i]; }
+};
+
+struct B : public A
+{
+  int& operator[](int i) { return A::operator[](i); }
+};
+
+void foo(B &b)
+{
+  for (int i=0; i<4; ++i)
+    b[i] = 0;
+}
+
+/* { dg-final { cleanup-tree-dump "vect" } } */

gcc/testsuite/g++.dg/vect/pr21734_2.cc

+/* { dg-do compile } */
+
+struct A
+{
+  int a[4];
+  int* operator[](int i) { return &a[i]; }
+};
+
+void foo(A a1, A &a2)
+{
+  a1[1][1]=0;
+  for (int i=0; i<4; ++i)
+    a2.a[i]=0;
+}
+
+/* { dg-final { cleanup-tree-dump "vect" } } */

gcc/tree-vectorizer.c

@@ -320,8 +320,11 @@ slpeel_update_phis_for_duplicate_loop (struct loop *orig_loop,
 
       new_ssa_name = get_current_def (def);
       if (!new_ssa_name)
-        /* Something defined outside of the loop.  */
-        continue;
+	{
+	  /* This only happens if there are no definitions
+	     inside the loop. use the phi_result in this case.  */
+	  new_ssa_name = PHI_RESULT (phi_new);
+	}
 
       /* An ordinary ssa name defined in the loop.  */
       add_phi_arg (phi_new, new_ssa_name, loop_latch_edge (new_loop));
@@ -565,7 +568,12 @@ slpeel_update_phi_nodes_for_guard1 (edge guard_edge, struct loop *loop,
       else
         {
           current_new_name = get_current_def (loop_arg);
-          gcc_assert (current_new_name);
+	  /* current_def is not available only if the variable does not
+	     change inside the loop, in which case we also don't care
+	     about recording a current_def for it because we won't be
+	     trying to create loop-exit-phis for it.  */
+	  if (!current_new_name)
+	    continue;
         }
 #ifdef ENABLE_CHECKING
       gcc_assert (get_current_def (current_new_name) == NULL_TREE);