pickles/ieee754.pk


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// Note that all the methods and functions are duplicated across the formats,
// with different constants substituted to compute the "all ones"
// of the exponents and the bitmask for the significand MSB.
// ieee754.pk and ieee754-test.pk are intended for upstream poke/pickles/
// but left here until they can be properly upstreamed.

type IEEE754_binary16 = struct int<16> {
  uint<1> sign;
  uint<5> exp;
  uint<10> frac; // aka significand aka mantissa

  fun exp_all_ones = uint<1>: {
    return 0x1f == exp;
  }
  method is_nan = uint<1>: {
    // if msb of frac is 1: signaling
    // if msb of frac is 0: quiet NaN
    return 0 != frac && exp_all_ones();
  }
  method is_snan = uint<1>: {
    return exp_all_ones() && (0x200 & frac);
  }
  method is_qnan = uint<1>: {
    return is_nan()      && !(0x200 & frac);
  }
  method is_inf = uint<1>: {
    return 0 == frac && exp_all_ones();
  }
};

type IEEE754_binary32 = struct int<32> {
  uint<1> sign;
  uint<8> exp;
  uint<23> frac; // aka significand aka mantissa

  fun exp_all_ones = uint<1>: {
    return 0xff == exp;
  }
  method is_nan = uint<1>: {
    // if msb of frac is 1: signaling
    // if msb of frac is 0: quiet NaN
    return 0 != frac && exp_all_ones();
  }
  method is_snan = uint<1>: {
    return exp_all_ones() && (0x400000 & frac);
  }
  method is_qnan = uint<1>: {
    return is_nan()      && !(0x400000 & frac);
  }
  method is_inf = uint<1>: {
    return 0 == frac && exp_all_ones();
  }
};

type IEEE754_binary64 = struct int<64> {
  uint<1> sign;
  uint<11> exp;
  uint<52> frac; // aka significand aka mantissa

  fun exp_all_ones = uint<1>: {
    return 0x7ff == exp;
  }
  method is_nan = uint<1>: {
    // if msb of frac is 1: signaling
    // if msb of frac is 0: quiet NaN
    return 0 != frac && exp_all_ones();
  }
  method is_snan = uint<1>: {
    return exp_all_ones() && (0x4000000000000 & frac);
  }
  method is_qnan = uint<1>: {
    return is_nan()      && !(0x4000000000000 & frac);
  }
  method is_inf = uint<1>: {
    return 0 == frac && exp_all_ones();
  }
};

type Float_16 = IEEE754_binary16;
type Float_32 = IEEE754_binary32;
type Float_64 = IEEE754_binary64;