re PR tree-optimization/24300 (segfault in operand_equal_p with -ftree-vectorize)

        PR tree-opt/24300
        * Makefile.in (tree-ssa-dce.o): Depend on CFGLOOP_H.
        * tree-ssa-dce.c: Include cfgloop.h.
        (tree_ssa_dce_loop, pass_dce_loop): New.
        * tree-pass.h (pass_dce_loop): Declare it.
        * passes.c (init_optimization_passes): Use it.

From-SVN: r105250

gcc/ChangeLog

+2005-10-11  Richard Henderson  <rth@redhat.com>
+
+	PR tree-opt/24300
+	* Makefile.in (tree-ssa-dce.o): Depend on CFGLOOP_H.
+	* tree-ssa-dce.c: Include cfgloop.h.
+	(tree_ssa_dce_loop, pass_dce_loop): New.
+	* tree-pass.h (pass_dce_loop): Declare it.
+	* passes.c (init_optimization_passes): Use it.
+
 2005-10-11  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
 	PR middle-end/24263 

gcc/Makefile.in

@@ -2230,7 +2230,7 @@ mode-switching.o : mode-switching.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
 tree-ssa-dce.o : tree-ssa-dce.c $(CONFIG_H) $(SYSTEM_H) $(TREE_H) \
     $(RTL_H) $(TM_P_H) $(TREE_FLOW_H) $(DIAGNOSTIC_H) $(TIMEVAR_H) $(TM_H) \
     coretypes.h $(TREE_DUMP_H) tree-pass.h $(FLAGS_H) $(BASIC_BLOCK_H) \
-    $(GGC_H) hard-reg-set.h $(OBSTACK_H) $(TREE_GIMPLE_H)
+    $(GGC_H) hard-reg-set.h $(OBSTACK_H) $(TREE_GIMPLE_H) $(CFGLOOP_H)
 tree-ssa-ccp.o : tree-ssa-ccp.c $(TREE_FLOW_H) $(CONFIG_H) \
    $(SYSTEM_H) $(RTL_H) $(TREE_H) $(TM_P_H) $(EXPR_H) $(GGC_H) output.h \
    $(DIAGNOSTIC_H) function.h $(TIMEVAR_H) $(TM_H) coretypes.h \

gcc/passes.c

@@ -595,12 +595,7 @@ init_optimization_passes (void)
 
   p = &pass_vectorize.sub;
   NEXT_PASS (pass_lower_vector_ssa);
-  /* ??? The loop optimizers are not GC safe.  See PR 21805.
-     Turn off GC while registering this pass.  */
-  pass_dce.todo_flags_finish &= ~TODO_ggc_collect;
-  NEXT_PASS (pass_dce);
-  pass_dce.todo_flags_finish |= TODO_ggc_collect;
-  gcc_assert (p != &pass_dce.next);
+  NEXT_PASS (pass_dce_loop);
   *p = NULL;
 
   p = &pass_loop2.sub;

gcc/testsuite/gcc.dg/vect/pr24300.c

+/* { dg-do compile } */
+
+static int *** foo (int);
+
+void
+bar ()
+{
+  int ***p = foo (2);
+}
+
+extern int *nd;
+extern int ***tc;
+extern int *ap;
+extern int *as;
+extern float ss;
+
+static int ***
+foo (int Fc)
+{
+  int i, j, s, p, n, t;
+
+  n = 0;
+  for (s = 0; s < 4; s++)
+    n += nd[s];
+
+  for (i = 0; i < n; i++)
+    {
+      p = ap[i];
+      s = as[i];
+      for (j = 0; j < Fc; j++)
+	tc[p][s][j] = i * ss + j;
+    }
+
+  return (tc);
+}

gcc/tree-pass.h

@@ -243,6 +243,7 @@ extern struct tree_opt_pass pass_build_ssa;
 extern struct tree_opt_pass pass_del_ssa;
 extern struct tree_opt_pass pass_dominator;
 extern struct tree_opt_pass pass_dce;
+extern struct tree_opt_pass pass_dce_loop;
 extern struct tree_opt_pass pass_cd_dce;
 extern struct tree_opt_pass pass_merge_phi;
 extern struct tree_opt_pass pass_may_alias;

gcc/tree-ssa-dce.c

@@ -64,6 +64,7 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
 #include "tree-pass.h"
 #include "timevar.h"
 #include "flags.h"
+#include "cfgloop.h"
 
 static struct stmt_stats
 {
@@ -942,6 +943,13 @@ tree_ssa_dce (void)
 }
 
 static void
+tree_ssa_dce_loop (void)
+{
+  perform_tree_ssa_dce (/*aggressive=*/false);
+  free_numbers_of_iterations_estimates (current_loops);
+}
+
+static void
 tree_ssa_cd_dce (void)
 {
   perform_tree_ssa_dce (/*aggressive=*/optimize >= 2);
@@ -974,6 +982,26 @@ struct tree_opt_pass pass_dce =
   0					/* letter */
 };
 
+struct tree_opt_pass pass_dce_loop =
+{
+  "dceloop",				/* name */
+  gate_dce,				/* gate */
+  tree_ssa_dce_loop,			/* execute */
+  NULL,					/* sub */
+  NULL,					/* next */
+  0,					/* static_pass_number */
+  TV_TREE_DCE,				/* tv_id */
+  PROP_cfg | PROP_ssa | PROP_alias,	/* properties_required */
+  0,					/* properties_provided */
+  0,					/* properties_destroyed */
+  0,					/* todo_flags_start */
+  TODO_dump_func 
+    | TODO_update_ssa_no_phi 
+    | TODO_cleanup_cfg
+    | TODO_verify_ssa,			/* todo_flags_finish */
+  0					/* letter */
+};
+
 struct tree_opt_pass pass_cd_dce =
 {
   "cddce",				/* name */