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#include "bid_trans.h"

BID_F80_CONST_DEF( c_8000,     400bf40000000000, 0000000000000000); // 8000
BID_F80_CONST_DEF( c_neg_8000, c00bf40000000000, 0000000000000000); //-8000
BID_F80_CONST_DEF( c_1e2000,   59f2cf6c9c9bc5f8, 84a294e53edc955f); // 1e2000
BID_F80_CONST_DEF( c_1em2000,  260b1ad56d712a5d, 7f02384e5ded39be); // 1e-2000

// TODO need to set up as hex
#if __ENABLE_BINARY80__
#define EXPL_OVERFL 1.0e2000l
#else
#define EXPL_OVERFL 1.0e200
#endif

BID_TYPE0_FUNCTION_ARGTYPE1(BID_UINT64, bid64_exp, BID_UINT64, x)

  BID_UINT64 res;
  BID_F80_TYPE xd, rd;
  int z;

    // test if x is NaN
    if ((x & NAN_MASK64) == NAN_MASK64) {
#ifdef BID_SET_STATUS_FLAGS
      if (((x & SNAN_MASK64) == SNAN_MASK64)    // sNaN
          )
        __set_status_flags (pfpsf, BID_INVALID_EXCEPTION);
#endif
                res = x & 0xfc03ffffffffffffull; //quiet and make combination 0 (canonize)
                if ((res & 0x0003ffffffffffffull) > 999999999999999ull) {       // payload
                        res &= ~0x0003ffffffffffffull;
                }
      BID_RETURN (res);
    }

        BIDECIMAL_CALL1_NORND_NOSTAT (bid64_isZero, z, x);
        if (z) {
                // 1 according C99
                res = 0x31c0000000000001ull;
           BID_RETURN (res);
        }
        BIDECIMAL_CALL1_NORND_NOSTAT (bid64_isInf, z, x);
        if (z) {
                // 0 or Inf according C99
                if (x & MASK_SIGN) {
                        res = 0x31c0000000000000ull;
                } else {
                        res = 0x7800000000000000ull;
                }
#ifdef BID_SET_STATUS_FLAGS
                *pfpsf = 0;
#endif
           BID_RETURN (res);
        }

// Otherwise just do the operation "naively".
// We inherit the special cases from the binary function
// except for ensuring correct overflow behaviour in
// directed rounding modes.

  BIDECIMAL_CALL1(bid64_to_binary80,xd,x);
  if (__bid_f80_gt( xd, c_8000.v ) ) { BID_F80_ASSIGN(rd, c_1e2000 ); }
  else if (__bid_f80_lt( xd, c_neg_8000.v ) ) { BID_F80_ASSIGN(rd, c_1em2000); }
  else __bid_f80_exp( rd, xd );

  BIDECIMAL_CALL1(binary80_to_bid64,res,rd);
  BID_RETURN (res);
}
