This makes FRE/PRE substitute values into all uses instead of leaving
copies and initializations from constants in the IL which requires
a copyprop pass to clean up things (which we usually place directly
after FRE/PRE).

This should open the possibility to remove some of the passes,
respectively the two copy-prop passes right after the two FREs
and the copyprop pass we do early in loop opts.

The patch exposes a weakness in invariant motion cost computation
and thus gfortran.dg/vect/fast-math-vect-8.f90 fails for me
on i?86 (but not on x86_64).

I want to revisit some of the ???s and uglinesses in the patch,
but this is a state that passes bootstrap and regtest otherwise
and thus ready.

Any comments?

Thanks,
Richard.

2014-05-14  Richard Biener  <rguent...@suse.de>

        * tree-ssa-pre.c (eliminate_dom_walker::before_dom_children):
        Rewrite to propagate the VN result into all uses where
        possible and to remove stmts becoming dead because of that.
        (eliminate): Generalize stmt removal handling, remove in
        reverse dominator order to support proper debug stmt
        generation.  Update stmts before removing stmts.
        * tree-ssa-propagate.c (propagate_tree_value): Remove
        bogus assert.

        * c-c++-common/pr46562-2.c: Adjust.
        * gcc.dg/tree-ssa/ssa-fre-24.c: Likewise.
        * gcc.dg/tree-ssa/ssa-fre-25.c: Likewise.
        * gcc.dg/tree-ssa/ssa-fre-32.c: Likewise.
        * gcc.dg/tree-ssa/ssa-pre-16.c: Likewise.

Index: trunk/gcc/tree-ssa-pre.c
===================================================================
*** trunk.orig/gcc/tree-ssa-pre.c       2014-05-14 14:06:26.860907895 +0200
--- trunk/gcc/tree-ssa-pre.c    2014-05-14 14:20:29.068849910 +0200
*************** eliminate_dom_walker::before_dom_childre
*** 4012,4120 ****
  
    for (gsi = gsi_start_phis (b); !gsi_end_p (gsi);)
      {
!       gimple stmt, phi = gsi_stmt (gsi);
!       tree sprime = NULL_TREE, res = PHI_RESULT (phi);
!       gimple_stmt_iterator gsi2;
! 
!       /* We want to perform redundant PHI elimination.  Do so by
!        replacing the PHI with a single copy if possible.
!        Do not touch inserted, single-argument or virtual PHIs.  */
!       if (gimple_phi_num_args (phi) == 1
!         || virtual_operand_p (res))
        {
          gsi_next (&gsi);
          continue;
        }
  
!       sprime = eliminate_avail (res);
!       if (!sprime
!         || sprime == res)
        {
!         eliminate_push_avail (res);
!         gsi_next (&gsi);
          continue;
        }
!       else if (is_gimple_min_invariant (sprime))
        {
!         if (!useless_type_conversion_p (TREE_TYPE (res),
!                                         TREE_TYPE (sprime)))
!           sprime = fold_convert (TREE_TYPE (res), sprime);
        }
  
!       if (dump_file && (dump_flags & TDF_DETAILS))
        {
!         fprintf (dump_file, "Replaced redundant PHI node defining ");
!         print_generic_expr (dump_file, res, 0);
!         fprintf (dump_file, " with ");
!         print_generic_expr (dump_file, sprime, 0);
!         fprintf (dump_file, "\n");
        }
- 
-       remove_phi_node (&gsi, false);
- 
-       if (inserted_exprs
-         && !bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res))
-         && TREE_CODE (sprime) == SSA_NAME)
-       gimple_set_plf (SSA_NAME_DEF_STMT (sprime), NECESSARY, true);
- 
-       if (!useless_type_conversion_p (TREE_TYPE (res), TREE_TYPE (sprime)))
-       sprime = fold_convert (TREE_TYPE (res), sprime);
-       stmt = gimple_build_assign (res, sprime);
-       gimple_set_plf (stmt, NECESSARY, gimple_plf (phi, NECESSARY));
- 
-       gsi2 = gsi_after_labels (b);
-       gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
-       /* Queue the copy for eventual removal.  */
-       el_to_remove.safe_push (stmt);
-       /* If we inserted this PHI node ourself, it's not an elimination.  */
-       if (inserted_exprs
-         && bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res)))
-       pre_stats.phis--;
        else
!       pre_stats.eliminations++;
      }
  
    for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
      {
!       tree lhs = NULL_TREE;
!       tree rhs = NULL_TREE;
! 
        stmt = gsi_stmt (gsi);
! 
!       if (gimple_has_lhs (stmt))
!       lhs = gimple_get_lhs (stmt);
! 
!       if (gimple_assign_single_p (stmt))
!       rhs = gimple_assign_rhs1 (stmt);
! 
!       /* Lookup the RHS of the expression, see if we have an
!        available computation for it.  If so, replace the RHS with
!        the available computation.  */
!       if (gimple_has_lhs (stmt)
!         && TREE_CODE (lhs) == SSA_NAME
!         && !gimple_has_volatile_ops  (stmt))
!       {
!         tree sprime;
!         gimple orig_stmt = stmt;
! 
!         sprime = eliminate_avail (lhs);
!         /* If there is no usable leader mark lhs as leader for its value.  */
!         if (!sprime)
!           eliminate_push_avail (lhs);
! 
          /* See PR43491.  Do not replace a global register variable when
             it is a the RHS of an assignment.  Do replace local register
             variables since gcc does not guarantee a local variable will
             be allocated in register.
!            Do not perform copy propagation or undo constant propagation.  */
!         if (gimple_assign_single_p (stmt)
!             && (TREE_CODE (rhs) == SSA_NAME
!                 || is_gimple_min_invariant (rhs)
!                 || (TREE_CODE (rhs) == VAR_DECL
!                     && is_global_var (rhs)
!                     && DECL_HARD_REGISTER (rhs))))
!           continue;
! 
          if (!sprime)
            {
              /* If there is no existing usable leader but SCCVN thinks
--- 4012,4163 ----
  
    for (gsi = gsi_start_phis (b); !gsi_end_p (gsi);)
      {
!       gimple phi = gsi_stmt (gsi);
!       tree res = PHI_RESULT (phi);
! 
!       if (virtual_operand_p (res))
        {
          gsi_next (&gsi);
          continue;
        }
  
!       tree sprime = eliminate_avail (res);
!       if (sprime
!         && sprime != res)
        {
!         if (dump_file && (dump_flags & TDF_DETAILS))
!           {
!             fprintf (dump_file, "Replaced redundant PHI node defining ");
!             print_generic_expr (dump_file, res, 0);
!             fprintf (dump_file, " with ");
!             print_generic_expr (dump_file, sprime, 0);
!             fprintf (dump_file, "\n");
!           }
! 
!         /* If we inserted this PHI node ourself, it's not an elimination.  */
!         if (inserted_exprs
!             && bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res)))
!           pre_stats.phis--;
!         else
!           pre_stats.eliminations++;
! 
!         /* If we will propagate into all uses don't bother to do
!            anything.  */
!         if (may_propagate_copy (res, sprime))
!           {
!             /* Mark the PHI for removal.  */
!             el_to_remove.safe_push (phi);
!             gsi_next (&gsi);
!             continue;
!           }
! 
!         remove_phi_node (&gsi, false);
! 
!         if (inserted_exprs
!             && !bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res))
!             && TREE_CODE (sprime) == SSA_NAME)
!           gimple_set_plf (SSA_NAME_DEF_STMT (sprime), NECESSARY, true);
! 
!         if (!useless_type_conversion_p (TREE_TYPE (res), TREE_TYPE (sprime)))
!           sprime = fold_convert (TREE_TYPE (res), sprime);
!         gimple stmt = gimple_build_assign (res, sprime);
!         /* ???  It cannot yet be necessary (DOM walk).  */
!         gimple_set_plf (stmt, NECESSARY, gimple_plf (phi, NECESSARY));
! 
!         gimple_stmt_iterator gsi2 = gsi_after_labels (b);
!         gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
          continue;
        }
! 
!       /* Inhibit the use of an inserted PHI on a loop header when
!        there is a load with that value whose address is a simple induction
!        variable.  In other cases the vectorizer won't do anything
!        anyway (either it's loop invariant or a complicated
!        expression).
!        ???  This is a somewhat awkward implementation give we don't
!        have a mapping back from load VNs to loads.   */
!       bool found = false;
!       if (flag_tree_loop_vectorize
!         && b->loop_father->header == b
!         && loop_outer (b->loop_father)
!         && inserted_exprs
!         && bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res)))
        {
!         basic_block *bbs = get_loop_body (b->loop_father);
!         for (unsigned i = 0; i < b->loop_father->num_nodes; ++i)
!           {
!             basic_block bb = bbs[i];
!             for (gimple_stmt_iterator gsi2 = gsi_start_bb (bb);
!                  !gsi_end_p (gsi2); gsi_next (&gsi2))
!               {
!                 gimple stmt = gsi_stmt (gsi2);
!                 if (!gimple_assign_load_p (stmt)
!                     || TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
!                   continue;
!                 if (VN_INFO (gimple_assign_lhs (stmt))->valnum
!                     != VN_INFO (res)->valnum)
!                   continue;
!                 ssa_op_iter iter;
!                 tree op;
!                 FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
!                   {
!                     affine_iv iv;
!                     basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (op));
!                     if (def_bb
!                         && flow_bb_inside_loop_p (b->loop_father,
!                                                   def_bb)
!                         && simple_iv (b->loop_father,
!                                       b->loop_father, op, &iv, true))
!                       {
!                         found = true;
!                         break;
!                       }
!                   }
!                 if (found)
!                   break;
!               }
!             if (found)
!               break;
!           }
!         free (bbs);
        }
  
!       if (found)
        {
!         if (dump_file && (dump_flags & TDF_DETAILS))
!           {
!             fprintf (dump_file, "Not replacing with ");
!             print_generic_expr (dump_file, sprime, 0);
!             fprintf (dump_file, " which would add a loop"
!                      " carried dependence to loop %d\n",
!                      b->loop_father->num);
!           }
        }
        else
!       eliminate_push_avail (res);
!       gsi_next (&gsi);
      }
  
    for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
      {
!       tree sprime = NULL_TREE;
        stmt = gsi_stmt (gsi);
!       tree lhs = gimple_get_lhs (stmt);
!       if (lhs && TREE_CODE (lhs) == SSA_NAME
!         && !gimple_has_volatile_ops (stmt)
          /* See PR43491.  Do not replace a global register variable when
             it is a the RHS of an assignment.  Do replace local register
             variables since gcc does not guarantee a local variable will
             be allocated in register.
!            ???  The fix isn't effective here.  This should instead
!            be ensured by not value-numbering them the same but treating
!            them like volatiles?  */
!         && !(gimple_assign_single_p (stmt)
!              && (TREE_CODE (gimple_assign_rhs1 (stmt)) == VAR_DECL
!                  && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt))
!                  && is_global_var (gimple_assign_rhs1 (stmt)))))
!       {
!         sprime = eliminate_avail (lhs);
          if (!sprime)
            {
              /* If there is no existing usable leader but SCCVN thinks
*************** eliminate_dom_walker::before_dom_childre
*** 4128,4229 ****
                  && (sprime = eliminate_insert (&gsi, val)) != NULL_TREE)
                eliminate_push_avail (sprime);
            }
!         else if (is_gimple_min_invariant (sprime))
            {
!             /* If there is no existing leader but SCCVN knows this
!                value is constant, use that constant.  */
!             if (!useless_type_conversion_p (TREE_TYPE (lhs),
!                                             TREE_TYPE (sprime)))
!               sprime = fold_convert (TREE_TYPE (lhs), sprime);
! 
!             if (dump_file && (dump_flags & TDF_DETAILS))
                {
!                 fprintf (dump_file, "Replaced ");
!                 print_gimple_expr (dump_file, stmt, 0, 0);
!                 fprintf (dump_file, " with ");
!                 print_generic_expr (dump_file, sprime, 0);
!                 fprintf (dump_file, " in ");
!                 print_gimple_stmt (dump_file, stmt, 0, 0);
!               }
!             pre_stats.eliminations++;
!             propagate_tree_value_into_stmt (&gsi, sprime);
!             stmt = gsi_stmt (gsi);
!             update_stmt (stmt);
  
-             /* If we removed EH side-effects from the statement, clean
-                its EH information.  */
-             if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt))
-               {
-                 bitmap_set_bit (need_eh_cleanup,
-                                 gimple_bb (stmt)->index);
                  if (dump_file && (dump_flags & TDF_DETAILS))
!                   fprintf (dump_file, "  Removed EH side-effects.\n");
                }
-             continue;
-           }
  
!         if (sprime
!             && sprime != lhs
!             && (rhs == NULL_TREE
!                 || TREE_CODE (rhs) != SSA_NAME
!                 || may_propagate_copy (rhs, sprime)))
!           {
              bool can_make_abnormal_goto
                  = is_gimple_call (stmt)
                  && stmt_can_make_abnormal_goto (stmt);
  
-             gcc_assert (sprime != rhs);
- 
-             /* Inhibit the use of an inserted PHI on a loop header when
-                the address of the memory reference is a simple induction
-                variable.  In other cases the vectorizer won't do anything
-                anyway (either it's loop invariant or a complicated
-                expression).  */
-             if (flag_tree_loop_vectorize
-                 && gimple_assign_single_p (stmt)
-                 && TREE_CODE (sprime) == SSA_NAME
-                 && loop_outer (b->loop_father))
-               {
-                 gimple def_stmt = SSA_NAME_DEF_STMT (sprime);
-                 basic_block def_bb = gimple_bb (def_stmt);
-                 if (gimple_code (def_stmt) == GIMPLE_PHI
-                     && b->loop_father->header == def_bb
-                     && has_zero_uses (sprime))
-                   {
-                     ssa_op_iter iter;
-                     tree op;
-                     bool found = false;
-                     FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
-                       {
-                         affine_iv iv;
-                         def_bb = gimple_bb (SSA_NAME_DEF_STMT (op));
-                         if (def_bb
-                             && flow_bb_inside_loop_p (b->loop_father,
-                                                       def_bb)
-                             && simple_iv (b->loop_father,
-                                           b->loop_father, op, &iv, true))
-                           {
-                             found = true;
-                             break;
-                           }
-                       }
-                     if (found)
-                       {
-                         if (dump_file && (dump_flags & TDF_DETAILS))
-                           {
-                             fprintf (dump_file, "Not replacing ");
-                             print_gimple_expr (dump_file, stmt, 0, 0);
-                             fprintf (dump_file, " with ");
-                             print_generic_expr (dump_file, sprime, 0);
-                             fprintf (dump_file, " which would add a loop"
-                                      " carried dependence to loop %d\n",
-                                      b->loop_father->num);
-                           }
-                         continue;
-                       }
-                   }
-               }
- 
              if (dump_file && (dump_flags & TDF_DETAILS))
                {
                  fprintf (dump_file, "Replaced ");
--- 4171,4243 ----
                  && (sprime = eliminate_insert (&gsi, val)) != NULL_TREE)
                eliminate_push_avail (sprime);
            }
!         if (sprime)
            {
!             /* If this now constitutes a copy duplicate points-to
!                and range info appropriately.  This is especially
!                important for inserted code.  See tree-ssa-copy.c
!                for similar code.  */
!             if (TREE_CODE (sprime) == SSA_NAME)
                {
!                 basic_block sprime_b = gimple_bb (SSA_NAME_DEF_STMT (sprime));
!                 if (POINTER_TYPE_P (TREE_TYPE (lhs))
!                     && SSA_NAME_PTR_INFO (lhs)
!                     && !SSA_NAME_PTR_INFO (sprime))
!                   {
!                     duplicate_ssa_name_ptr_info (sprime,
!                                                  SSA_NAME_PTR_INFO (lhs));
!                     if (b != sprime_b)
!                       mark_ptr_info_alignment_unknown
!                         (SSA_NAME_PTR_INFO (sprime));
!                   }
!                 else if (!POINTER_TYPE_P (TREE_TYPE (lhs))
!                          && SSA_NAME_RANGE_INFO (lhs)
!                          && !SSA_NAME_RANGE_INFO (sprime)
!                          && b == sprime_b)
!                   duplicate_ssa_name_range_info (sprime,
!                                                  SSA_NAME_RANGE_TYPE (lhs),
!                                                  SSA_NAME_RANGE_INFO (lhs));
!               }
! 
!             /* If we can propagate the value computed for LHS into
!                all uses don't bother doing anything with this stmt.  */
!             if (may_propagate_copy (lhs, sprime))
!               {
!                 /* Mark it for removal.  */
!                 el_to_remove.safe_push (stmt);
! 
!                 /* ???  Don't count copy/constant propagations.  */
!                 if (gimple_assign_single_p (stmt)
!                     && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
!                         || gimple_assign_rhs1 (stmt) == sprime))
!                   continue;
  
                  if (dump_file && (dump_flags & TDF_DETAILS))
!                   {
!                     fprintf (dump_file, "Replaced ");
!                     print_gimple_expr (dump_file, stmt, 0, 0);
!                     fprintf (dump_file, " with ");
!                     print_generic_expr (dump_file, sprime, 0);
!                     fprintf (dump_file, " in all uses of ");
!                     print_gimple_stmt (dump_file, stmt, 0, 0);
!                   }
! 
!                 pre_stats.eliminations++;
!                 continue;
                }
  
!             /* If this is an assignment from our leader (which
!                happens in the case the value-number is a constant)
!                then there is nothing to do.  */
!             if (gimple_assign_single_p (stmt)
!                 && sprime == gimple_assign_rhs1 (stmt))
!               continue;
! 
!             /* Else replace its RHS.  */
              bool can_make_abnormal_goto
                  = is_gimple_call (stmt)
                  && stmt_can_make_abnormal_goto (stmt);
  
              if (dump_file && (dump_flags & TDF_DETAILS))
                {
                  fprintf (dump_file, "Replaced ");
*************** eliminate_dom_walker::before_dom_childre
*** 4237,4251 ****
              if (TREE_CODE (sprime) == SSA_NAME)
                gimple_set_plf (SSA_NAME_DEF_STMT (sprime),
                                NECESSARY, true);
-             /* We need to make sure the new and old types actually match,
-                which may require adding a simple cast, which fold_convert
-                will do for us.  */
-             if ((!rhs || TREE_CODE (rhs) != SSA_NAME)
-                 && !useless_type_conversion_p (gimple_expr_type (stmt),
-                                                TREE_TYPE (sprime)))
-               sprime = fold_convert (gimple_expr_type (stmt), sprime);
  
              pre_stats.eliminations++;
              propagate_tree_value_into_stmt (&gsi, sprime);
              stmt = gsi_stmt (gsi);
              update_stmt (stmt);
--- 4251,4262 ----
              if (TREE_CODE (sprime) == SSA_NAME)
                gimple_set_plf (SSA_NAME_DEF_STMT (sprime),
                                NECESSARY, true);
  
              pre_stats.eliminations++;
+             gimple orig_stmt = stmt;
+             if (!useless_type_conversion_p (TREE_TYPE (lhs),
+                                             TREE_TYPE (sprime)))
+               sprime = fold_convert (TREE_TYPE (lhs), sprime);
              propagate_tree_value_into_stmt (&gsi, sprime);
              stmt = gsi_stmt (gsi);
              update_stmt (stmt);
*************** eliminate_dom_walker::before_dom_childre
*** 4269,4336 ****
                  if (dump_file && (dump_flags & TDF_DETAILS))
                    fprintf (dump_file, "  Removed AB side-effects.\n");
                }
            }
        }
        /* If the statement is a scalar store, see if the expression
!        has the same value number as its rhs.  If so, the store is
!        dead.  */
!       else if (gimple_assign_single_p (stmt)
!              && !gimple_has_volatile_ops (stmt)
!              && !is_gimple_reg (gimple_assign_lhs (stmt))
!              && (TREE_CODE (rhs) == SSA_NAME
!                  || is_gimple_min_invariant (rhs)))
!       {
!         tree val;
!         val = vn_reference_lookup (gimple_assign_lhs (stmt),
!                                    gimple_vuse (stmt), VN_WALK, NULL);
!         if (TREE_CODE (rhs) == SSA_NAME)
!           rhs = VN_INFO (rhs)->valnum;
!         if (val
!             && operand_equal_p (val, rhs, 0))
!           {
!             if (dump_file && (dump_flags & TDF_DETAILS))
!               {
!                 fprintf (dump_file, "Deleted redundant store ");
!                 print_gimple_stmt (dump_file, stmt, 0, 0);
!               }
  
-             /* Queue stmt for removal.  */
-             el_to_remove.safe_push (stmt);
-           }
-       }
-       /* Visit COND_EXPRs and fold the comparison with the
-        available value-numbers.  */
-       else if (gimple_code (stmt) == GIMPLE_COND)
-       {
-         tree op0 = gimple_cond_lhs (stmt);
-         tree op1 = gimple_cond_rhs (stmt);
-         tree result;
- 
-         if (TREE_CODE (op0) == SSA_NAME)
-           op0 = VN_INFO (op0)->valnum;
-         if (TREE_CODE (op1) == SSA_NAME)
-           op1 = VN_INFO (op1)->valnum;
-         result = fold_binary (gimple_cond_code (stmt), boolean_type_node,
-                               op0, op1);
-         if (result && TREE_CODE (result) == INTEGER_CST)
-           {
-             if (integer_zerop (result))
-               gimple_cond_make_false (stmt);
-             else
-               gimple_cond_make_true (stmt);
-             update_stmt (stmt);
-             el_todo = TODO_cleanup_cfg;
-           }
-       }
        /* Visit indirect calls and turn them into direct calls if
         possible.  */
        if (is_gimple_call (stmt))
        {
          tree orig_fn = gimple_call_fn (stmt);
!         tree fn;
          if (!orig_fn)
!           continue;
!         if (TREE_CODE (orig_fn) == SSA_NAME)
            fn = VN_INFO (orig_fn)->valnum;
          else if (TREE_CODE (orig_fn) == OBJ_TYPE_REF
                   && TREE_CODE (OBJ_TYPE_REF_EXPR (orig_fn)) == SSA_NAME)
--- 4280,4333 ----
                  if (dump_file && (dump_flags & TDF_DETAILS))
                    fprintf (dump_file, "  Removed AB side-effects.\n");
                }
+ 
+             continue;
            }
        }
+ 
        /* If the statement is a scalar store, see if the expression
!          has the same value number as its rhs.  If so, the store is
!          dead.  */
!       if (gimple_assign_single_p (stmt)
!         && !gimple_has_volatile_ops (stmt)
!         && !is_gimple_reg (gimple_assign_lhs (stmt))
!         && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
!             || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
!         {
!           tree val;
!         tree rhs = gimple_assign_rhs1 (stmt);
!           val = vn_reference_lookup (gimple_assign_lhs (stmt),
!                                      gimple_vuse (stmt), VN_WALK, NULL);
!           if (TREE_CODE (rhs) == SSA_NAME)
!             rhs = VN_INFO (rhs)->valnum;
!           if (val
!               && operand_equal_p (val, rhs, 0))
!             {
!               if (dump_file && (dump_flags & TDF_DETAILS))
!                 {
!                   fprintf (dump_file, "Deleted redundant store ");
!                   print_gimple_stmt (dump_file, stmt, 0, 0);
!                 }
! 
!               /* Queue stmt for removal.  */
!               el_to_remove.safe_push (stmt);
!             continue;
!             }
!         }
! 
!       bool can_make_abnormal_goto = stmt_can_make_abnormal_goto (stmt);
!       bool was_noreturn = (is_gimple_call (stmt)
!                          && gimple_call_noreturn_p (stmt));
  
        /* Visit indirect calls and turn them into direct calls if
         possible.  */
        if (is_gimple_call (stmt))
        {
          tree orig_fn = gimple_call_fn (stmt);
!         tree fn = NULL_TREE;
          if (!orig_fn)
!           ;
!         else if (TREE_CODE (orig_fn) == SSA_NAME)
            fn = VN_INFO (orig_fn)->valnum;
          else if (TREE_CODE (orig_fn) == OBJ_TYPE_REF
                   && TREE_CODE (OBJ_TYPE_REF_EXPR (orig_fn)) == SSA_NAME)
*************** eliminate_dom_walker::before_dom_childre
*** 4343,4358 ****
                    fn = build_fold_addr_expr (fn);
                }
            }
!         else
!           continue;
!         if (gimple_call_addr_fndecl (fn) != NULL_TREE
!             && useless_type_conversion_p (TREE_TYPE (orig_fn),
!                                           TREE_TYPE (fn)))
            {
-             bool can_make_abnormal_goto
-                 = stmt_can_make_abnormal_goto (stmt);
-             bool was_noreturn = gimple_call_noreturn_p (stmt);
- 
              if (dump_file && (dump_flags & TDF_DETAILS))
                {
                  fprintf (dump_file, "Replacing call target with ");
--- 4340,4347 ----
                    fn = build_fold_addr_expr (fn);
                }
            }
!         if (fn && gimple_call_addr_fndecl (fn) != NULL_TREE)
            {
              if (dump_file && (dump_flags & TDF_DETAILS))
                {
                  fprintf (dump_file, "Replacing call target with ");
*************** eliminate_dom_walker::before_dom_childre
*** 4363,4398 ****
  
              gimple_call_set_fn (stmt, fn);
              el_to_update.safe_push (stmt);
  
              /* When changing a call into a noreturn call, cfg cleanup
                 is needed to fix up the noreturn call.  */
              if (!was_noreturn && gimple_call_noreturn_p (stmt))
                el_todo |= TODO_cleanup_cfg;
  
!             /* If we removed EH side-effects from the statement, clean
!                its EH information.  */
!             if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
!               {
!                 bitmap_set_bit (need_eh_cleanup,
!                                 gimple_bb (stmt)->index);
!                 if (dump_file && (dump_flags & TDF_DETAILS))
!                   fprintf (dump_file, "  Removed EH side-effects.\n");
!               }
! 
!             /* Likewise for AB side-effects.  */
!             if (can_make_abnormal_goto
!                 && !stmt_can_make_abnormal_goto (stmt))
!               {
!                 bitmap_set_bit (need_ab_cleanup,
!                                 gimple_bb (stmt)->index);
!                 if (dump_file && (dump_flags & TDF_DETAILS))
!                   fprintf (dump_file, "  Removed AB side-effects.\n");
!               }
  
!             /* Changing an indirect call to a direct call may
!                have exposed different semantics.  This may
!                require an SSA update.  */
!             el_todo |= TODO_update_ssa_only_virtuals;
            }
        }
      }
--- 4352,4477 ----
  
              gimple_call_set_fn (stmt, fn);
              el_to_update.safe_push (stmt);
+             gimple_set_modified (stmt, true);
+ 
+             /* Changing an indirect call to a direct call may
+                have exposed different semantics.  This may
+                require an SSA update.  */
+             el_todo |= TODO_update_ssa_only_virtuals;
+           }
+       }
+ 
+       /* If we didn't replace the whole stmt (or propagate the result
+          into all uses), replace all uses on this stmt with their
+        leaders.  */
+       use_operand_p use_p;
+       ssa_op_iter iter;
+       FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
+       {
+         tree use = USE_FROM_PTR (use_p);
+         /* ???  The call code above leaves stmt operands un-updated.  */
+         if (TREE_CODE (use) != SSA_NAME)
+           continue;
+         tree sprime = eliminate_avail (use);
+         if (sprime && sprime != use
+             && may_propagate_copy (use, sprime)
+             /* We substitute into debug stmts to avoid excessive
+                debug temporaries created by removed stmts, but we need
+                to avoid doing so for inserted sprimes as we never want
+                to create debug temporaries for them.  */
+             && (!inserted_exprs
+                 || TREE_CODE (sprime) != SSA_NAME
+                 || !is_gimple_debug (stmt)
+                 || !bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))))
+           {
+             propagate_value (use_p, sprime);
+             gimple_set_modified (stmt, true);
+             if (TREE_CODE (sprime) == SSA_NAME
+                 && !is_gimple_debug (stmt))
+               gimple_set_plf (SSA_NAME_DEF_STMT (sprime),
+                               NECESSARY, true);
+           }
+       }
  
+       if (gimple_modified_p (stmt))
+       {
+         /* If a formerly non-invariant ADDR_EXPR is turned into an
+            invariant one it was on a separate stmt.  */
+         if (gimple_assign_single_p (stmt)
+             && TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR)
+           recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt));
+         gimple old_stmt = stmt;
+         if (is_gimple_call (stmt))
+           {
+             /* ???  Only fold calls inplace for now, this may create new
+                SSA names which in turn will confuse free_scc_vn SSA name
+                release code.  */
+             fold_stmt_inplace (&gsi);
              /* When changing a call into a noreturn call, cfg cleanup
                 is needed to fix up the noreturn call.  */
              if (!was_noreturn && gimple_call_noreturn_p (stmt))
                el_todo |= TODO_cleanup_cfg;
+           }
+         else
+           {
+             fold_stmt (&gsi);
+             stmt = gsi_stmt (gsi);
+             if ((gimple_code (stmt) == GIMPLE_COND
+                  && (gimple_cond_true_p (stmt)
+                      || gimple_cond_false_p (stmt)))
+                 || (gimple_code (stmt) == GIMPLE_SWITCH
+                     && TREE_CODE (gimple_switch_index (stmt)) == INTEGER_CST))
+               el_todo |= TODO_cleanup_cfg;
+           }
+         /* If we removed EH side-effects from the statement, clean
+            its EH information.  */
+         if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
+           {
+             bitmap_set_bit (need_eh_cleanup,
+                             gimple_bb (stmt)->index);
+             if (dump_file && (dump_flags & TDF_DETAILS))
+               fprintf (dump_file, "  Removed EH side-effects.\n");
+           }
+         /* Likewise for AB side-effects.  */
+         if (can_make_abnormal_goto
+             && !stmt_can_make_abnormal_goto (stmt))
+           {
+             bitmap_set_bit (need_ab_cleanup,
+                             gimple_bb (stmt)->index);
+             if (dump_file && (dump_flags & TDF_DETAILS))
+               fprintf (dump_file, "  Removed AB side-effects.\n");
+           }
+         /* Update the stmt if that was not defered.  */
+         if (el_to_update.is_empty ()
+             || el_to_update.last () != stmt)
+           update_stmt (stmt);
+       }
  
!       /* Make the new value available - for fully redundant LHS we
!          continue with the next stmt above.  */
!       if (lhs && TREE_CODE (lhs) == SSA_NAME)
!       eliminate_push_avail (lhs);
!     }
  
!   /* Replace destination PHI arguments.  */
!   edge_iterator ei;
!   edge e;
!   FOR_EACH_EDGE (e, ei, b->succs)
!     {
!       for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
!       {
!         gimple phi = gsi_stmt (gsi);
!         use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e);
!         tree arg = USE_FROM_PTR (use_p);
!         if (TREE_CODE (arg) != SSA_NAME
!             || virtual_operand_p (arg))
!           continue;
!         tree sprime = eliminate_avail (arg);
!         if (sprime && may_propagate_copy (arg, sprime))
!           {
!             propagate_value (use_p, sprime);
!             if (TREE_CODE (sprime) == SSA_NAME)
!               gimple_set_plf (SSA_NAME_DEF_STMT (sprime), NECESSARY, true);
            }
        }
      }
*************** eliminate (void)
*** 4431,4485 ****
    el_avail.release ();
    el_avail_stack.release ();
  
    /* We cannot remove stmts during BB walk, especially not release SSA
       names there as this confuses the VN machinery.  The stmts ending
!      up in el_to_remove are either stores or simple copies.  */
!   FOR_EACH_VEC_ELT (el_to_remove, i, stmt)
      {
!       tree lhs = gimple_assign_lhs (stmt);
!       tree rhs = gimple_assign_rhs1 (stmt);
!       use_operand_p use_p;
!       gimple use_stmt;
  
!       /* If there is a single use only, propagate the equivalency
!        instead of keeping the copy.  */
!       if (TREE_CODE (lhs) == SSA_NAME
!         && TREE_CODE (rhs) == SSA_NAME
!         && single_imm_use (lhs, &use_p, &use_stmt)
!         && may_propagate_copy (USE_FROM_PTR (use_p), rhs))
        {
!         SET_USE (use_p, rhs);
!         update_stmt (use_stmt);
!         if (inserted_exprs
!             && bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (lhs))
!             && TREE_CODE (rhs) == SSA_NAME)
!           gimple_set_plf (SSA_NAME_DEF_STMT (rhs), NECESSARY, true);
        }
  
!       /* If this is a store or a now unused copy, remove it.  */
!       if (TREE_CODE (lhs) != SSA_NAME
!         || has_zero_uses (lhs))
        {
          basic_block bb = gimple_bb (stmt);
-         gsi = gsi_for_stmt (stmt);
          unlink_stmt_vdef (stmt);
          if (gsi_remove (&gsi, true))
            bitmap_set_bit (need_eh_cleanup, bb->index);
-         if (inserted_exprs
-             && TREE_CODE (lhs) == SSA_NAME)
-           bitmap_clear_bit (inserted_exprs, SSA_NAME_VERSION (lhs));
          release_defs (stmt);
        }
      }
    el_to_remove.release ();
  
-   /* We cannot update call statements with virtual operands during
-      SSA walk.  This might remove them which in turn makes our
-      VN lattice invalid.  */
-   FOR_EACH_VEC_ELT (el_to_update, i, stmt)
-     update_stmt (stmt);
-   el_to_update.release ();
- 
    return el_todo;
  }
  
--- 4510,4560 ----
    el_avail.release ();
    el_avail_stack.release ();
  
+   /* We cannot update call statements with virtual operands during
+      SSA walk.  This might remove them which in turn makes our
+      VN lattice invalid.  */
+   FOR_EACH_VEC_ELT (el_to_update, i, stmt)
+     update_stmt (stmt);
+   el_to_update.release ();
+ 
    /* We cannot remove stmts during BB walk, especially not release SSA
       names there as this confuses the VN machinery.  The stmts ending
!      up in el_to_remove are either stores or simple copies.
!      Remove stmts in reverse order to make debug stmt creation possible.  */
!   while (!el_to_remove.is_empty ())
      {
!       stmt = el_to_remove.pop ();
  
!       if (dump_file && (dump_flags & TDF_DETAILS))
        {
!         fprintf (dump_file, "Removing dead stmt ");
!         print_gimple_stmt (dump_file, stmt, 0, 0);
        }
  
!       tree lhs;
!       if (gimple_code (stmt) == GIMPLE_PHI)
!       lhs = gimple_phi_result (stmt);
!       else
!       lhs = gimple_get_lhs (stmt);
! 
!       if (inserted_exprs
!         && TREE_CODE (lhs) == SSA_NAME)
!       bitmap_clear_bit (inserted_exprs, SSA_NAME_VERSION (lhs));
! 
!       gsi = gsi_for_stmt (stmt);
!       if (gimple_code (stmt) == GIMPLE_PHI)
!       remove_phi_node (&gsi, true);
!       else
        {
          basic_block bb = gimple_bb (stmt);
          unlink_stmt_vdef (stmt);
          if (gsi_remove (&gsi, true))
            bitmap_set_bit (need_eh_cleanup, bb->index);
          release_defs (stmt);
        }
      }
    el_to_remove.release ();
  
    return el_todo;
  }
  
Index: trunk/gcc/testsuite/c-c++-common/pr46562-2.c
===================================================================
*** trunk.orig/gcc/testsuite/c-c++-common/pr46562-2.c   2014-05-14 
14:06:26.860907895 +0200
--- trunk/gcc/testsuite/c-c++-common/pr46562-2.c        2014-05-14 
14:15:15.536871496 +0200
*************** int foo(void)
*** 9,13 ****
    return *p;
  }
  
! /* { dg-final { scan-tree-dump "= 0;" "fre1" } } */
  /* { dg-final { cleanup-tree-dump "fre1" } } */
--- 9,13 ----
    return *p;
  }
  
! /* { dg-final { scan-tree-dump "return 0;" "fre1" } } */
  /* { dg-final { cleanup-tree-dump "fre1" } } */
Index: trunk/gcc/tree-ssa-propagate.c
===================================================================
*** trunk.orig/gcc/tree-ssa-propagate.c 2014-05-14 14:06:26.860907895 +0200
--- trunk/gcc/tree-ssa-propagate.c      2014-05-14 14:15:15.537871496 +0200
*************** replace_exp (use_operand_p op_p, tree va
*** 1410,1420 ****
  void
  propagate_tree_value (tree *op_p, tree val)
  {
-   gcc_checking_assert (!(TREE_CODE (val) == SSA_NAME
-                        && *op_p
-                        && TREE_CODE (*op_p) == SSA_NAME
-                        && !may_propagate_copy (*op_p, val)));
- 
    if (TREE_CODE (val) == SSA_NAME)
      *op_p = val;
    else
--- 1410,1415 ----
Index: trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-24.c
===================================================================
*** trunk.orig/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-24.c       2014-05-14 
14:06:26.860907895 +0200
--- trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-24.c    2014-05-14 
14:15:15.537871496 +0200
*************** int bazzoo (void)
*** 30,34 ****
    return b.i;
  }
  
! /* { dg-final { scan-tree-dump-times "= 0;" 5 "fre1" } } */
  /* { dg-final { cleanup-tree-dump "fre1" } } */
--- 30,34 ----
    return b.i;
  }
  
! /* { dg-final { scan-tree-dump-times "return 0;" 4 "fre1" } } */
  /* { dg-final { cleanup-tree-dump "fre1" } } */
Index: trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-25.c
===================================================================
*** trunk.orig/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-25.c       2014-05-14 
14:06:26.860907895 +0200
--- trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-25.c    2014-05-14 
14:15:15.537871496 +0200
*************** int foo (struct X *p)
*** 14,18 ****
  
  /* We should optimize this to return 0.  */
  
! /* { dg-final { scan-tree-dump "= 0;" "fre1" } } */
  /* { dg-final { cleanup-tree-dump "fre1" } } */
--- 14,18 ----
  
  /* We should optimize this to return 0.  */
  
! /* { dg-final { scan-tree-dump "return 0;" "fre1" } } */
  /* { dg-final { cleanup-tree-dump "fre1" } } */
Index: trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-32.c
===================================================================
*** trunk.orig/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-32.c       2014-05-14 
14:06:26.860907895 +0200
--- trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-32.c    2014-05-14 
14:15:15.538871496 +0200
*************** bar (_Complex float x)
*** 23,28 ****
    return z;
  } 
  
! /* We should CSE all the way to replace the final assignment to z with x.  */
! /* { dg-final { scan-tree-dump-times "with x_1\\\(D\\\) in z" 3 "fre1" } } */
  /* { dg-final { cleanup-tree-dump "fre1" } } */
--- 23,28 ----
    return z;
  } 
  
! /* We should CSE all the way to replace the return value with x.  */
! /* { dg-final { scan-tree-dump-times "return x_\\d\+\\(D\\);" 2 "fre1" } } */
  /* { dg-final { cleanup-tree-dump "fre1" } } */
Index: trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-16.c
===================================================================
*** trunk.orig/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-16.c       2014-05-14 
14:06:26.860907895 +0200
--- trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-16.c    2014-05-14 
14:15:15.538871496 +0200
*************** int foo(int k, int *x)
*** 11,15 ****
    }  while (++j<k);
    return res;
  }
! /* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre"} } */
  /* { dg-final { cleanup-tree-dump "pre" } } */
--- 11,15 ----
    }  while (++j<k);
    return res;
  }
! /* { dg-final { scan-tree-dump-times "Eliminated: 2" 1 "pre"} } */
  /* { dg-final { cleanup-tree-dump "pre" } } */

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