text: /* Copyright (c) 2003-2004, Roger Dingledine
   * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   * Copyright (c) 2007-2021, The Tor Project, Inc. */
  /* See LICENSE for licensing information */
  
  /**
   * \file addsub.c
   *
   * \brief Helpers for addition and subtraction.
   *
   * Currently limited to non-wrapping (saturating) addition.
   **/
  
  #include "lib/intmath/addsub.h"
  #include "lib/cc/compat_compiler.h"
  
  /* Helper: safely add two uint32_t's, capping at UINT32_MAX rather
   * than overflow */
  uint32_t
  tor_add_u32_nowrap(uint32_t a, uint32_t b)
  {
    /* a+b > UINT32_MAX check, without overflow */
    if (PREDICT_UNLIKELY(a > UINT32_MAX - b)) {
      return UINT32_MAX;
    } else {
      return a+b;
    }
  }
  