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#include "bid_internal.h"

/*****************************************************************************
 *  BID128 fdim
 ****************************************************************************/

/*
 fdim returns x - y if x > y, and +0 is x <= y
 Exceptions: P, O, I (U could only be unmasked, which is not supported)
 */

BID128_FUNCTION_ARG2 (bid128_fdim, x, y)
  BID_UINT128 res;
  int cmpres;
  BID_FPSC tmp_fpsf = 0; // dummy fpsf for calls to comparison functions

  tmp_fpsf = *pfpsf;    // save fpsf
#if DECIMAL_CALL_BY_REFERENCE
  bid128_quiet_greater (&cmpres, &x, &y 
      _EXC_FLAGS_ARG _EXC_MASKS_ARG _EXC_INFO_ARG);
#else    
  cmpres = bid128_quiet_greater (x, y 
      _EXC_FLAGS_ARG _EXC_MASKS_ARG _EXC_INFO_ARG);
#endif 
  *pfpsf = tmp_fpsf;    // restore fpsf
  if (((x.w[BID_HIGH_128W] & MASK_NAN) != MASK_NAN) && ((y.w[BID_HIGH_128W] & MASK_NAN) != MASK_NAN) &&
      !cmpres) { // if x != NaN and y != NaN and x <= y return +0
    res.w[BID_HIGH_128W] = 0x3040000000000000ull;
    res.w[BID_LOW_128W] = 0x0000000000000000ull;
    BID_RETURN (res);
  }

  // else if x = NaN or y = NaN or x > y return x - y

#if DECIMAL_CALL_BY_REFERENCE
  bid128_sub (&res, &x, &y 
      _RND_MODE_ARG _EXC_FLAGS_ARG _EXC_MASKS_ARG _EXC_INFO_ARG);
#else
  res = bid128_sub (x, y 
      _RND_MODE_ARG _EXC_FLAGS_ARG _EXC_MASKS_ARG _EXC_INFO_ARG);
#endif
  BID_RETURN (res);
}
