[PATCH] Paper over(?) PR48271

[Richard Guenther]

This maybe papers over PR48271, we're modifying the CFG and yet
marking some BBs for cleanup.  Well, at least the jump-threading
case is supposed to work this way.  DOM doesn't deserve too much
love, so ...

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2011-03-24  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/48271
	* tree-ssa-dom.c (tree_ssa_dominator_optimize): Only cleanup
	blocks that still exist.

	* g++.dg/torture/pr48271.C: New testcase.

Index: gcc/tree-ssa-dom.c
===================================================================
*** gcc/tree-ssa-dom.c	(revision 171387)
--- gcc/tree-ssa-dom.c	(working copy)
*************** tree_ssa_dominator_optimize (void)
*** 701,707 ****
      gimple_stmt_iterator gsi;
      basic_block bb;
      FOR_EACH_BB (bb)
!       {for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
  	  update_stmt_if_modified (gsi_stmt (gsi));
        }
    }
--- 701,708 ----
      gimple_stmt_iterator gsi;
      basic_block bb;
      FOR_EACH_BB (bb)
!       {
! 	for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
  	  update_stmt_if_modified (gsi_stmt (gsi));
        }
    }
*************** tree_ssa_dominator_optimize (void)
*** 734,740 ****
        EXECUTE_IF_SET_IN_BITMAP (need_eh_cleanup, 0, i, bi)
  	{
  	  basic_block bb = BASIC_BLOCK (i);
! 	  if (single_succ_p (bb) == 1
  	      && (single_succ_edge (bb)->flags & EDGE_EH) == 0)
  	    {
  	      bitmap_clear_bit (need_eh_cleanup, i);
--- 735,742 ----
        EXECUTE_IF_SET_IN_BITMAP (need_eh_cleanup, 0, i, bi)
  	{
  	  basic_block bb = BASIC_BLOCK (i);
! 	  if (bb
! 	      && single_succ_p (bb)
  	      && (single_succ_edge (bb)->flags & EDGE_EH) == 0)
  	    {
  	      bitmap_clear_bit (need_eh_cleanup, i);
Index: gcc/testsuite/g++.dg/torture/pr48271.C
===================================================================
*** gcc/testsuite/g++.dg/torture/pr48271.C	(revision 0)
--- gcc/testsuite/g++.dg/torture/pr48271.C	(revision 0)
***************
*** 0 ****
--- 1,119 ----
+ // { dg-do compile }
+ // { dg-options "-ftree-vrp -fno-guess-branch-probability -fnon-call-exceptions" }
+ 
+ void *xalloc ();
+ void xfree (void *);
+ void error ();
+ 
+ static inline void *
+ MallocT ()
+ {
+   void *p = xalloc ();
+   if (!p)
+     error ();
+   return p;
+ }
+ 
+ 
+ struct ByteBlob
+ {
+   int *header;
+ 
+   ByteBlob();
+ 
+   ~ByteBlob ()
+   {
+     Free ();
+   }
+ 
+   int RawFree (int * p)
+   {
+     if (!p)
+       error ();
+     xfree (p);
+   }
+ 
+   int *LengthRef ();
+ 
+   void Free ()
+   {
+     if (*header)
+       RawFree (header);
+   }
+ 
+   int Append (int num_ints)
+   {
+     if (*header)
+       MallocT ();
+     *LengthRef () += num_ints;
+   }
+ };
+ 
+ struct CBlobT:ByteBlob
+ {
+   ~CBlobT ()
+   {
+     Free ();
+   }
+ };
+ 
+ template < class T > struct FixedSizeArray
+ {
+   int HeaderSize;
+   T *data;
+   FixedSizeArray ();
+   int RefCnt ()
+   {
+     return *(int *) MallocT ();
+   }
+    ~FixedSizeArray ()
+   {
+     if (RefCnt ())
+       for (T * pItem = data + Length (); pItem != data; pItem--)
+ 	T ();
+   }
+   int Length ();
+ };
+ 
+ class SmallArray
+ {
+   typedef FixedSizeArray < int > SubArray;
+   typedef FixedSizeArray < SubArray > SuperArray;
+   SuperArray data;
+ };
+ 
+ struct CHashTableT
+ {
+   int *m_slots;
+   ~CHashTableT ()
+   {
+     delete m_slots;
+   }
+ };
+ 
+ struct CYapfBaseT
+ {
+   int *PfGetSettings ();
+   SmallArray m_arr;
+   CHashTableT m_closed;
+   CYapfBaseT ()
+   {
+     MallocT ();
+   }
+ };
+ 
+ struct CYapfCostRailT:CYapfBaseT
+ {
+   CBlobT m_sig_look_ahead_costs;
+   CYapfCostRailT ()
+   {
+     m_sig_look_ahead_costs.Append (*Yapf ()->PfGetSettings ());
+     Yapf ()->PfGetSettings ();
+   }
+   CYapfBaseT *Yapf ();
+ };
+ 
+ void stCheckReverseTrain ()
+ {
+   CYapfCostRailT pf1;
+ }