tree-pass.h (PROP_pta): Removed.

2007-08-14  Daniel Berlin  <dberlin@dberlin.org>

	* tree-pass.h (PROP_pta): Removed.
	(TODO_rebuild_alias): New.
	(pass_may_alias): Removed.
	* tree-ssa-ccp.c (execute_fold_all_builtins): Only rebuild
	aliasing if we changed something.
	* tree-ssa-alias.c (compute_may_aliases): Make non-static.  Update
	SSA internally.
	(pass_may_alias): Removed.
	(create_structure_vars): Return TODO_rebuild_alias.
	* tree-ssa-pre.c (do_pre): Return TODO_rebuild_alias.
	* tree-sra.c (tree_sra): Only rebuild aliasing if something
	changed.
	(tree_sra_early): We never affect aliasing right now.
	* tree-flow.h (compute_may_aliases): New prototype.
	* passes.c: Remove pass_may_alias from the passes.
	(execute_function_todo): Support TODO_rebuild_alias.

From-SVN: r127491

18 files changed, 86 insertions, 92 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index bda9ad8..11d3ad8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,22 @@
+2007-08-14  Daniel Berlin  <dberlin@dberlin.org>
+
+	* tree-pass.h (PROP_pta): Removed.
+	(TODO_rebuild_alias): New.
+	(pass_may_alias): Removed.
+	* tree-ssa-ccp.c (execute_fold_all_builtins): Only rebuild
+	aliasing if we changed something.
+	* tree-ssa-alias.c (compute_may_aliases): Make non-static.  Update
+	SSA internally.
+	(pass_may_alias): Removed.
+	(create_structure_vars): Return TODO_rebuild_alias.
+	* tree-ssa-pre.c (do_pre): Return TODO_rebuild_alias.
+	* tree-sra.c (tree_sra): Only rebuild aliasing if something
+	changed.
+	(tree_sra_early): We never affect aliasing right now.
+	* tree-flow.h (compute_may_aliases): New prototype.
+	* passes.c: Remove pass_may_alias from the passes.
+	(execute_function_todo): Support TODO_rebuild_alias.	
+
 2007-08-14  Kai Tietz  <kai.tietz@onevision.com>
 
 	* i386.c: (legitimize_address): Move dllimported variable check
@@ -385,6 +404,7 @@
 	* emit-rtl.c (try_split): Relink the insns with REG_LIBCALL note
 	and with REG_RETVAL note after split.
 
+>>>>>>> .r127481
 2007-08-11  David Daney  <ddaney@avtrex.com>
 
 	* config/mips/mips.c (mips_sched_reorder):  Mark cycle parameter
diff --git a/gcc/passes.c b/gcc/passes.c
index 2d26a90..1ec6b0a 100644
--- a/gcc/passes.c
+++ b/gcc/passes.c
@@ -551,7 +551,6 @@ init_optimization_passes (void)
     {
       struct tree_opt_pass **p = &pass_all_optimizations.sub;
       NEXT_PASS (pass_create_structure_vars);
-      NEXT_PASS (pass_may_alias);
       NEXT_PASS (pass_return_slot);
       NEXT_PASS (pass_rename_ssa_copies);
 
@@ -566,26 +565,19 @@ init_optimization_passes (void)
       NEXT_PASS (pass_vrp);
       NEXT_PASS (pass_dce);
       NEXT_PASS (pass_dominator);
-
       /* The only const/copy propagation opportunities left after
 	 DOM should be due to degenerate PHI nodes.  So rather than
 	 run the full propagators, run a specialized pass which
 	 only examines PHIs to discover const/copy propagation
 	 opportunities.  */
       NEXT_PASS (pass_phi_only_cprop);
-
       NEXT_PASS (pass_tree_ifcombine);
       NEXT_PASS (pass_phiopt);
-      NEXT_PASS (pass_may_alias);
       NEXT_PASS (pass_tail_recursion);
       NEXT_PASS (pass_ch);
       NEXT_PASS (pass_stdarg);
       NEXT_PASS (pass_lower_complex);
       NEXT_PASS (pass_sra);
-      /* FIXME: SRA may generate arbitrary gimple code, exposing new
-	 aliased and call-clobbered variables.  As mentioned below,
-	 pass_may_alias should be a TODO item.  */
-      NEXT_PASS (pass_may_alias);
       NEXT_PASS (pass_rename_ssa_copies);
       NEXT_PASS (pass_dominator);
 
@@ -599,7 +591,6 @@ init_optimization_passes (void)
       NEXT_PASS (pass_reassoc);
       NEXT_PASS (pass_dce);
       NEXT_PASS (pass_dse);
-      NEXT_PASS (pass_may_alias);
       NEXT_PASS (pass_forwprop);
       NEXT_PASS (pass_phiopt);
       NEXT_PASS (pass_object_sizes);
@@ -607,13 +598,8 @@ init_optimization_passes (void)
       NEXT_PASS (pass_store_copy_prop);
       NEXT_PASS (pass_fold_builtins);
       NEXT_PASS (pass_cse_sincos);
-      /* FIXME: May alias should a TODO but for 4.0.0,
-	 we add may_alias right after fold builtins
-	 which can create arbitrary GIMPLE.  */
-      NEXT_PASS (pass_may_alias);
       NEXT_PASS (pass_split_crit_edges);
       NEXT_PASS (pass_pre);
-      NEXT_PASS (pass_may_alias);
       NEXT_PASS (pass_sink_code);
       NEXT_PASS (pass_tree_loop);
 	{
@@ -637,9 +623,6 @@ init_optimization_passes (void)
 	      NEXT_PASS (pass_lower_vector_ssa);
 	      NEXT_PASS (pass_dce_loop);
 	    }
-	  /* NEXT_PASS (pass_may_alias) cannot be done again because the
-	     vectorizer creates alias relations that are not supported by
-	     pass_may_alias.  */
 	  NEXT_PASS (pass_complete_unroll);
 	  NEXT_PASS (pass_loop_prefetch);
 	  NEXT_PASS (pass_iv_optimize);
@@ -650,7 +633,7 @@ init_optimization_passes (void)
       NEXT_PASS (pass_reassoc);
       NEXT_PASS (pass_vrp);
       NEXT_PASS (pass_dominator);
-
+      
       /* The only const/copy propagation opportunities left after
 	 DOM should be due to degenerate PHI nodes.  So rather than
 	 run the full propagators, run a specialized pass which
@@ -912,7 +895,13 @@ execute_function_todo (void *data)
       update_ssa (update_flags);
       cfun->last_verified &= ~TODO_verify_ssa;
     }
-
+  
+  if (flags & TODO_rebuild_alias)
+    {
+      compute_may_aliases ();
+      cfun->curr_properties |= PROP_alias;
+    }
+  
   if (flags & TODO_remove_unused_locals)
     remove_unused_locals ();
 
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20031015-1.c b/gcc/testsuite/gcc.dg/tree-ssa/20031015-1.c
index a81edaf..46a3be7 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/20031015-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/20031015-1.c
@@ -1,7 +1,7 @@
 /* With tree-ssa, gcc.dg/20000724-1.c failed because we missed
    a VOP of x in the asm statement.  */
 /* { dg-do compile } */
-/* { dg-options "-O1 -fdump-tree-alias1-vops" } */
+/* { dg-options "-O1 -fdump-tree-salias-vops" } */
 
 struct s { int a; };
 
@@ -14,5 +14,5 @@ main(void)
 }
 
 /* The VDEF comes from the initial assignment and the asm.  */
-/* { dg-final { scan-tree-dump-times "DEF" 2 "alias1" } } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
+/* { dg-final { scan-tree-dump-times "DEF" 2 "salias" } } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20040517-1.c b/gcc/testsuite/gcc.dg/tree-ssa/20040517-1.c
index 85d5074..318ba7c 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/20040517-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/20040517-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O1 -fdump-tree-alias1-vops" } */
+/* { dg-options "-O1 -fdump-tree-salias-vops" } */
 extern void abort (void);
 int a; 
  
@@ -17,5 +17,5 @@ void bar (void)
    malloc functions may clobber global memory.  Only the function result
    does not alias any other pointer.
    Hence, we must have a VDEF for a before and after the call to foo().  */
-/* { dg-final { scan-tree-dump-times "VDEF" 2 "alias1"} } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
+/* { dg-final { scan-tree-dump-times "VDEF" 2 "salias"} } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20040911-1.c b/gcc/testsuite/gcc.dg/tree-ssa/20040911-1.c
index 3ddef71..ac2b961 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/20040911-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/20040911-1.c
@@ -1,7 +1,7 @@
 /* Verify that points-to information is handled properly for PTR + OFFSET
    pointer arithmetics.  */
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-alias1-vops" } */
+/* { dg-options "-O2 -fdump-tree-salias-vops" } */
 
 char buf[4], *q;
 int foo (int i)
@@ -18,5 +18,5 @@ int foo (int i)
   return *p;
 }
 
-/* { dg-final { scan-tree-dump-not "VUSE <c" "alias1" } } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
+/* { dg-final { scan-tree-dump-not "VUSE <c" "salias" } } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/alias-12.c b/gcc/testsuite/gcc.dg/tree-ssa/alias-12.c
index 4094526..970ddc7 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/alias-12.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/alias-12.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-alias1-vops" } */
+/* { dg-options "-O2 -fdump-tree-salias-vops" } */
 
 struct {
 	int i;
@@ -13,6 +13,6 @@ int foo(int i)
 	return a.x[i];
 }
 
-/* { dg-final { scan-tree-dump "VDEF" "alias1" } } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
+/* { dg-final { scan-tree-dump "VDEF" "salias" } } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
 
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/inline_asm-1.c b/gcc/testsuite/gcc.dg/tree-ssa/inline_asm-1.c
index e14c45e..97c25b1 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/inline_asm-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/inline_asm-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O1 -fdump-tree-optimized -fdump-tree-alias1-vops" } */
+/* { dg-options "-O1 -fdump-tree-optimized -fdump-tree-salias-vops" } */
 /* Test to make sure that inline-asm causes a V_MAY_DEF and that we call test_function twice. */
 
 char test_function(void ) __attribute__((__pure__));
@@ -16,5 +16,5 @@ char f(char *a)
 /* { dg-final { cleanup-tree-dump "optimized" } } */
 
 /* There should a VDEF for the inline-asm.  */
-/* { dg-final { scan-tree-dump-times "VDEF" 1 "alias1"} } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
+/* { dg-final { scan-tree-dump-times "VDEF" 1 "salias"} } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/inline_asm-2.c b/gcc/testsuite/gcc.dg/tree-ssa/inline_asm-2.c
index f3dd1fd..33443e0 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/inline_asm-2.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/inline_asm-2.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O1 -fdump-tree-alias1-vops" } */
+/* { dg-options "-O1 -fdump-tree-salias-vops" } */
 /* Test to make sure that inline-asm causes a V_MAY_DEF. */
 
 
@@ -14,5 +14,5 @@ void f(char *a)
 }
 
 /* There should a VDEF for the inline-asm and one for the link_error.  */
-/* { dg-final { scan-tree-dump-times "VDEF" 2 "alias1"} } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
+/* { dg-final { scan-tree-dump-times "VDEF" 2 "salias"} } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr23382.c b/gcc/testsuite/gcc.dg/tree-ssa/pr23382.c
index 62b4051e..d0b2088 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr23382.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr23382.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */ 
-/* { dg-options "-O2 -fdump-tree-alias-vops" } */
+/* { dg-options "-O2 -fdump-tree-salias-vops" } */
 struct a
 {
   int length;
@@ -13,14 +13,5 @@ int f(void)
    struct a *a = malloc(sizeof(struct a));
    return a->length;
 }
-/* { dg-final { scan-tree-dump-times "VDEF <HEAP" 1 "alias1"} } */
-/* { dg-final { scan-tree-dump-times "VDEF <HEAP" 1 "alias2"} } */
-/* { dg-final { scan-tree-dump-times "VDEF <HEAP" 1 "alias3"} } */
-/* { dg-final { scan-tree-dump-times "VDEF <HEAP" 1 "alias4"} } */
-/* { dg-final { scan-tree-dump-times "VDEF <HEAP" 1 "alias5"} } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
-/* { dg-final { cleanup-tree-dump "alias2" } } */
-/* { dg-final { cleanup-tree-dump "alias3" } } */
-/* { dg-final { cleanup-tree-dump "alias4" } } */
-/* { dg-final { cleanup-tree-dump "alias5" } } */
-/* { dg-final { cleanup-tree-dump "alias6" } } */
+/* { dg-final { scan-tree-dump-times "VDEF <HEAP" 1 "salias"} } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr26421.c b/gcc/testsuite/gcc.dg/tree-ssa/pr26421.c
index 4a6560a..d2d99ba 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr26421.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr26421.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-alias1-vops" } */
+/* { dg-options "-O2 -fdump-tree-salias-vops" } */
 
 typedef struct {
   int i;
@@ -16,5 +16,5 @@ int foo(void)
   return a.i;
 }
 
-/* { dg-final { scan-tree-dump-times "VDEF" 2 "alias1" } } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
+/* { dg-final { scan-tree-dump-times "VDEF" 2 "salias" } } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pta-fp.c b/gcc/testsuite/gcc.dg/tree-ssa/pta-fp.c
index 4a64d24..b9d84df 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pta-fp.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pta-fp.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */ 
-/* { dg-options "-O2 -fdump-tree-alias1" } */
+/* { dg-options "-O2 -fdump-tree-salias" } */
 extern double cos (double);
 extern double sin (double);
 double f(double a)
@@ -22,5 +22,5 @@ double f(double a)
 }
 /* The points-to set of the final function pointer should be "sin cos" */
 
-/* { dg-final { scan-tree-dump-times "{ sin cos }" 1 "alias1"} } */
-/* { dg-final { cleanup-tree-dump "alias1" } } */
+/* { dg-final { scan-tree-dump-times "{ sin cos }" 1 "salias"} } */
+/* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/salias-1.c b/gcc/testsuite/gcc.dg/tree-ssa/salias-1.c
index 9933cc8..5e47db4 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/salias-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/salias-1.c
@@ -15,5 +15,5 @@ int foo(void)
   return a.b.c.j;
 }
 
-/* { dg-final { scan-tree-dump-times "SFT" 2 "salias" } } */
+/* { dg-final { scan-tree-dump-times "structure field tag SFT" 2 "salias" } } */
 /* { dg-final { cleanup-tree-dump "salias" } } */
diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h
index 7e60dae..f55922b 100644
--- a/gcc/tree-flow.h
+++ b/gcc/tree-flow.h
@@ -831,6 +831,7 @@ extern void record_vars (tree);
 extern bool block_may_fallthru (const_tree);
 
 /* In tree-ssa-alias.c  */
+extern unsigned int compute_may_aliases (void);
 extern void dump_may_aliases_for (FILE *, tree);
 extern void debug_may_aliases_for (tree);
 extern void dump_alias_info (FILE *);
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index fc12a6c..5a20772 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -149,12 +149,11 @@ struct dump_file_info
 #define PROP_gimple_leh		(1 << 2)	/* lowered eh */
 #define PROP_cfg		(1 << 3)
 #define PROP_referenced_vars	(1 << 4)
-#define PROP_pta		(1 << 5)
-#define PROP_ssa		(1 << 6)
-#define PROP_no_crit_edges      (1 << 7)
-#define PROP_rtl		(1 << 8)
-#define PROP_alias		(1 << 9)
-#define PROP_gimple_lomp	(1 << 10)	/* lowered OpenMP directives */
+#define PROP_ssa		(1 << 5)
+#define PROP_no_crit_edges      (1 << 6)
+#define PROP_rtl		(1 << 7)
+#define PROP_alias		(1 << 8)
+#define PROP_gimple_lomp	(1 << 9)	/* lowered OpenMP directives */
 
 #define PROP_trees \
   (PROP_gimple_any | PROP_gimple_lcf | PROP_gimple_leh | PROP_gimple_lomp)
@@ -228,6 +227,9 @@ struct dump_file_info
 /* Internally used for the first instance of a pass.  */
 #define TODO_mark_first_instance	(1 << 18)
 
+/* Rebuild aliasing info.  */
+#define TODO_rebuild_alias                (1 << 19)
+
 #define TODO_update_ssa_any		\
     (TODO_update_ssa			\
      | TODO_update_ssa_no_phi		\
@@ -278,7 +280,6 @@ 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;
 extern struct tree_opt_pass pass_split_crit_edges;
 extern struct tree_opt_pass pass_pre;
 extern struct tree_opt_pass pass_profile;
diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index f2e64c7..5d69a49 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -2400,6 +2400,8 @@ tree_sra (void)
       scan_function ();
       decide_instantiations ();
       scalarize_function ();
+      if (!bitmap_empty_p (sra_candidates))
+	todoflags |= TODO_rebuild_alias;
     }
 
   /* Free allocated memory.  */
@@ -2422,7 +2424,7 @@ tree_sra_early (void)
   ret = tree_sra ();
   early_sra = false;
 
-  return ret;
+  return ret & ~TODO_rebuild_alias;
 }
 
 static bool
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index b1dcf44..3889ea5 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -1634,10 +1634,12 @@ done:
    grouped to avoid severe compile-time slow downs and memory
    consumption. See compute_memory_partitions.  */
 
-static unsigned int
+unsigned int
 compute_may_aliases (void)
 {
   struct alias_info *ai;
+
+  timevar_push (TV_TREE_MAY_ALIAS);
   
   memset (&alias_stats, 0, sizeof (alias_stats));
 
@@ -1731,33 +1733,15 @@ compute_may_aliases (void)
 
   /* Deallocate memory used by aliasing data structures.  */
   delete_alias_info (ai);
+
+  if (need_ssa_update_p ())
+    update_ssa (TODO_update_ssa);
+
+  timevar_pop (TV_TREE_MAY_ALIAS);
   
   return 0;
 }
 
-
-struct tree_opt_pass pass_may_alias = 
-{
-  "alias",				/* name */
-  NULL,					/* gate */
-  compute_may_aliases,			/* execute */
-  NULL,					/* sub */
-  NULL,					/* next */
-  0,					/* static_pass_number */
-  TV_TREE_MAY_ALIAS,			/* tv_id */
-  PROP_cfg | PROP_ssa,			/* properties_required */
-  PROP_alias,				/* properties_provided */
-  0,					/* properties_destroyed */
-  0,					/* todo_flags_start */
-  TODO_dump_func
-    | TODO_update_ssa
-    | TODO_ggc_collect
-    | TODO_verify_ssa
-    | TODO_verify_stmts, 		/* todo_flags_finish */
-  0					/* letter */
-};
-
-
 /* Data structure used to count the number of dereferences to PTR
    inside an expression.  */
 struct count_ptr_d
@@ -4028,7 +4012,7 @@ create_structure_vars (void)
 	  }
       }
 
-  return 0;
+  return TODO_rebuild_alias;
 }
 
 static bool
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 5d4d3d8..e6dfcd8 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -2640,6 +2640,8 @@ execute_fold_all_builtins (void)
 {
   bool cfg_changed = false;
   basic_block bb;
+  unsigned int todoflags = 0;
+  
   FOR_EACH_BB (bb)
     {
       block_stmt_iterator i;
@@ -2697,6 +2699,7 @@ execute_fold_all_builtins (void)
 		{
 		  bool ok = set_rhs (stmtp, result);
 		  gcc_assert (ok);
+		  todoflags |= TODO_rebuild_alias;
 		}
 	    }
 
@@ -2728,9 +2731,12 @@ execute_fold_all_builtins (void)
 	    bsi_next (&i);
 	}
     }
-
+  
   /* Delete unreachable blocks.  */
-  return cfg_changed ? TODO_cleanup_cfg : 0;
+  if (cfg_changed)
+    todoflags |= TODO_cleanup_cfg;
+  
+  return todoflags;
 }
 
 
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 059af12..bfbf20e 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -3981,7 +3981,7 @@ static unsigned int
 do_pre (void)
 {
   execute_pre (false);
-  return 0;
+  return TODO_rebuild_alias;
 }
 
 static bool