Index: tree-ssa-dom.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-ssa-dom.c,v
retrieving revision 2.56
diff -c -p -r2.56 tree-ssa-dom.c
*** tree-ssa-dom.c	29 Sep 2004 02:50:46 -0000	2.56
--- tree-ssa-dom.c	5 Oct 2004 19:51:39 -0000
*************** static void restore_currdefs_to_original
*** 266,271 ****
--- 266,272 ----
  static void register_definitions_for_stmt (tree);
  static edge single_incoming_edge_ignoring_loop_edges (basic_block);
  static void restore_nonzero_vars_to_original_value (void);
+ static inline bool unsafe_associative_fp_binop (tree);
  
  /* Local version of fold that doesn't introduce cruft.  */
  
*************** record_equality (tree x, tree y)
*** 1547,1552 ****
--- 1548,1563 ----
    record_const_or_copy_1 (x, y, prev_x);
  }
  
+ /* return true, if it is ok to do folding of an associative expression */ 
+ static inline bool
+ unsafe_associative_fp_binop (tree exp)
+ {
+   enum tree_code code = TREE_CODE (exp);
+   return !(!flag_unsafe_math_optimizations
+            && (code == MULT_EXPR || code == PLUS_EXPR)
+            && FLOAT_TYPE_P (TREE_TYPE (exp)));
+ }
+ 
  /* STMT is a MODIFY_EXPR for which we were unable to find RHS in the
     hash tables.  Try to simplify the RHS using whatever equivalences
     we may have recorded.
*************** simplify_rhs_and_lookup_avail_expr (stru
*** 1606,1612 ****
  	  tree rhs_def_rhs = TREE_OPERAND (rhs_def_stmt, 1);
  	  enum tree_code rhs_def_code = TREE_CODE (rhs_def_rhs);
  
! 	  if (rhs_code == rhs_def_code
  	      || (rhs_code == PLUS_EXPR && rhs_def_code == MINUS_EXPR)
  	      || (rhs_code == MINUS_EXPR && rhs_def_code == PLUS_EXPR))
  	    {
--- 1617,1623 ----
  	  tree rhs_def_rhs = TREE_OPERAND (rhs_def_stmt, 1);
  	  enum tree_code rhs_def_code = TREE_CODE (rhs_def_rhs);
  
! 	  if ((rhs_code == rhs_def_code && unsafe_associative_fp_binop (rhs))
  	      || (rhs_code == PLUS_EXPR && rhs_def_code == MINUS_EXPR)
  	      || (rhs_code == MINUS_EXPR && rhs_def_code == PLUS_EXPR))
  	    {