regression/ieee-real.sml

   1 structure R = Real
   2 structure I = IEEEReal
   3 structure V = Word8Vector
   4 structure P = PackRealBig
   5
   6 fun setRM mode =
   7    (I.setRoundingMode mode;
   8     if I.getRoundingMode () <> mode
   9        then raise Fail "setRM"
  10     else ())
  11
  12 fun up() = setRM I.TO_POSINF
  13 fun down() = setRM I.TO_NEGINF
  14 fun near() = setRM I.TO_NEAREST
  15 fun zero() = setRM I.TO_ZERO
  16
  17   (*
  18
  19   61 digits of 1 / 10 in Mathematica
  20
  21   In[7]:= RealDigits[1 / 10,2,61]
  22
  23   Out[7]= {{1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0,
  24                0, 1, 1, 0, 0, 1, 1, 0, 0, 1,
  25                1, 0, 0, 1, 1, 0, 0, 1, 1, 0,
  26                0, 1, 1, 0, 0, 1, 1, 0, 0, 1,
  27                1, 0, 0, 1, 1, 0, 0, 1, 1, 0,
  28                0, 1, 1, 0, 0, 1, 1, 0, 0, 1},-3}
  29
  30   *)
  31
  32
  33 val mtenth_lo = (down();1.0 / 10.0)
  34 val mtenth_hi = (up();1.0 / 10.0)
  35 val mtenth_near = (near();1.0 / 10.0)
  36 val mtenth_zero = (zero();1.0 / 10.0)
  37
  38 fun word8vectorToString v = V.foldr (fn(w,s) => Word8.toString w ^ s) "" v
  39
  40 val _ = print(word8vectorToString (P.toBytes mtenth_lo) ^ "\n")
  41 val _ = print(word8vectorToString (P.toBytes mtenth_hi) ^ "\n")
  42 val _ = print(word8vectorToString (P.toBytes mtenth_near) ^ "\n")
  43 val _ = print(word8vectorToString (P.toBytes mtenth_zero) ^ "\n")