*** empty log message ***

From-SVN: r999

gcc/cse.c

@@ -2948,12 +2948,12 @@ simplify_unary_operation (code, mode, op, op_mode)
       return gen_rtx (CONST_INT, VOIDmode, val);
     }
 #endif
-  else if (GET_MODE_CLASS (mode) == MODE_INT
-	   || TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT)
+  /* This was formerly used only for non-IEEE float.
+     eggert@twinsun.com says it is safe for IEEE also.  */
+  else
     {
       /* There are some simplifications we can do even if the operands
-	 aren't constant, but they don't apply to floating-point
-	 unless not IEEE.  */
+	 aren't constant.  */
       switch (code)
 	{
 	case NEG:
@@ -2979,8 +2979,6 @@ simplify_unary_operation (code, mode, op, op_mode)
 
       return 0;
     }
-  else
-    return 0;
 }
 
 /* Simplify a binary operation CODE with result mode MODE, operating on OP0

gcc/fold-const.c

@@ -3007,15 +3007,17 @@ fold (expr)
 	  /* Except with IEEE floating point, x-0 equals x.  */
 	  if (real_zerop (arg1))
 	    return non_lvalue (convert (type, arg0));
-	}
+
 	  /* Fold &x - &x.  This can happen from &x.foo - &x. 
-	 Note that can't be done for certain floats even in non-IEEE formats.
+	     This is unsafe for certain floats even in non-IEEE formats.
+	     In IEEE, it is unsafe because it does wrong for NaNs.
 	     Also note that operand_equal_p is always false is an operand
 	     is volatile.  */
 
 	  if (operand_equal_p (arg0, arg1,
 			       TREE_CODE (type) == REAL_TYPE))
 	    return convert (type, integer_zero_node);
+	}
       goto associate;
 
     case MULT_EXPR: