tests/libpspp/float-format.at

   1 AT_BANNER([floating point formats])
   2
   3 AT_SETUP([floating point format conversions])
   4 AT_DATA([float-format.txt], [dnl
   5 # Each of the tests below checks that conversion between
   6 # floating-point formats works correctly.  Comparisons that use ==
   7 # require that conversion from any format on the line to any other
   8 # format on the line work losslessly.  Comparisons that use => only
   9 # check that conversions work losslessly in the given direction.
  10
  11 # Key to format names:
  12 # isl: IEEE single-precision, little endian
  13 # isb: IEEE single-precision, big endian
  14 # idl: IEEE double-precision, little endian
  15 # idb: IEEE double-precision, big endian
  16 # vf: VAX F
  17 # vd: VAX D
  18 # vg: VAX G
  19 # zs: Z architecture short
  20 # zl: Z architecture long
  21 # x: hexadecimal digits
  22
  23 # IEEE special values.
  24  0 == isb(x'00000000')
  25 x('Infinity') == isb(x'7f800000')
  26 x('-Infinity') == isb(x'ff800000')
  27 x('NaN:') => isb(x'7f800001')           # NaN requires nonzero fraction.
  28 x('NaN:e000000000000000') == isb(x'7ff00000') == idb(x'7ffe000000000000')
  29 x('NaN:5a5a5e0000000000') == isb(x'7fad2d2f') == idb(x'7ff5a5a5e0000000')
  30 x('NaN:975612abcdef4000') == idb(x'7ff975612abcdef4')
  31 x('-NaN:e000000000000000') == isb(x'fff00000') == idb(x'fffe000000000000')
  32 x('-NaN:5a5a5e0000000000') == isb(x'ffad2d2f') == idb(x'fff5a5a5e0000000')
  33 x('-NaN:975612abcdef4000') == idb(x'fff975612abcdef4')
  34
  35 # PSPP special values.
  36 x('Missing') == isb(x'ff7fffff') == idb(x'ffefffffffffffff') == isl(x'ffff7fff') == idl(x'ffffffffffffefff') == vf(x'ffffffff') == vd(x'ffffffffffffffff') == vg(x'ffffffffffffffff') == zs(x'ffffffff') == zl(x'ffffffffffffffff')
  37 x('Lowest') == isb(x'ff7ffffe') == idb(x'ffeffffffffffffe') == isl(x'feff7fff') == idl(x'feffffffffffefff') == vf(x'fffffeff') == vd(x'fffffeffffffffff') == vg(x'fffffeffffffffff') == zs(x'fffffffe') == zl(x'fffffffffffffffe')
  38 x('Highest') == isb(x'7f7fffff') == idb(x'7fefffffffffffff') == isl(x'ffff7f7f') == idl(x'ffffffffffffef7f') == vf(x'ff7fffff') == vd(x'ffffffffff7fffff') == vg(x'ffffffffff7fffff') == zs(x'7fffffff') == zl(x'7fffffffffffffff')
  39
  40 # From Wikipedia.
  41 0.15625 == isb(b'00111110001000000000000000000000')
  42 -118.625 == isb(b'11000010111011010100000000000000')
  43
  44 # http://www.psc.edu/general/software/packages/ieee/ieee.html
  45 x('NaN:0400000000000000') == isb(b'01111111100000100000000000000000')
  46 x('-NaN:2225540000000000') == isb(b'11111111100100010001001010101010')
  47 2 == isb(b'01000000000000000000000000000000')
  48 6.5 == isb(b'01000000110100000000000000000000')
  49 -6.5 == isb(b'11000000110100000000000000000000')
  50 x('.4p-124') == isb(b'00000000100000000000000000000000')
  51 x('.2p-124') == isb(b'00000000010000000000000000000000')
  52
  53 # Using converter at http://babbage.cs.qc.edu/IEEE-754/Decimal.html
  54 # plus Emacs 'calc' to convert decimal to hexadecimal
  55 x('.7b74bc6a7ef9db23p8') => isb(x'42f6e979')            # 123.456
  56 x('.7b74bc6a7ef9db23p8') => idb(x'405edd2f1a9fbe77')
  57 x('.817427d2d4642004p-12') => isb(x'39017428')          # .0001234567
  58 x('.817427d2d4642004p-12') => idb(x'3f202e84fa5a8c84')
  59 x('.446c3b15f9926688p168') => isb(x'7f800000')          # 1e50; overflow
  60 x('.446c3b15f9926688p168') => idb(x'4a511b0ec57e649a')
  61
  62 # From multiple editions of the z/Architecture Principles of Operation
  63 # manual.
  64               1.0 == zs(x'41100000') == isb(x'3f800000')
  65               0.5 == zs(x'40800000') == isb(x'3f000000')
  66        x('.4p-4') == zs(x'3f400000') == isb(x'3c800000')
  67                 0 == zs(x'00000000') == isb(x'00000000')
  68                      zs(x'80000000') == isb(x'80000000')
  69               -15 == zs(x'c1f00000') == isb(x'c1700000')
  70 # x('.ffffffp252') == zs(x'7fffffff')
  71       x('.3b4p8') == zs(x'423b4000')
  72      x('.1p-256') == zs(x'00100000')
  73      x('.4p-124') == zs(x'21400000') == isb(x'00800000')
  74      x('.8p-148') == zs(x'1b800000') == isb(x'00000001')
  75 # x('.ffffffp128') == zs(x'60ffffff') == isb(x'7f7fffff')
  76      x('.1p-256') == zs(x'00100000')
  77      x('.1p-256') => isb(x'00000000')              # Underflow to zero.
  78  x('.ffffffp248') == zs(x'7effffff')
  79  x('.ffffffp248') => isb(x'7f800000')              # Overflow to +Infinity.
  80
  81             x('.4p-1020') => zl(x'0000000000000000')     # Underflow to zero.
  82             x('.4p-1020') == idb(x'0010000000000000')
  83             x('.4p-1072') => zl(x'0000000000000000')     # Underflow to zero.
  84             x('.4p-1072') => idb(x'0000000000000001')
  85 x('.fffffffffffff8p1024') => zl(x'7fffffffffffffff')     # Overflow to maxval.
  86 x('.fffffffffffff8p1024') => idb(x'7fefffffffffffff')
  87             x('.1p-256') == zl(x'0010000000000000') == idb(x'2fb0000000000000')
  88  x('.ffffffffffffffp248') == zl(x'7effffffffffffff')
  89  x('.ffffffffffffffp248') => idb(x'4f70000000000000')   # Loses precision.
  90 ])
  91 AT_CHECK(
  92   [sed 's/#.*//
  93 s/^[    ]*//
  94 s/[     ]*$//
  95 s/^\(..*\)$/DEBUG FLOAT FORMAT \1./' < float-format.txt > float-format.sps])
  96 AT_CHECK([pspp --testing-mode -O format=csv float-format.sps])
  97 AT_CLEANUP