mdw@git.distorted.org.uk Git - mLib/blob - utils/t/bits-testgen.py

   1 #! /usr/bin/python
   2 ### -*-python-*-
   3 ###
   4 ### Generate input script and expected output for bit manipulation,
   5 ### particularly 64-bit arithmetic.
   6
   7 import sys as SYS
   8 import random as R
   9
  10 NVEC = 64
  11 WD = 64
  12 LIMIT = 1 << WD
  13 MASK = LIMIT - 1
  14
  15 ARGS = SYS.argv[1:]; ARGS.reverse()
  16 def arg(default = None):
  17   if len(ARGS): return ARGS.pop()
  18   else: return default
  19
  20 R.seed(None)
  21 SEED = int(arg(R.randrange(0, 1 << 32)))
  22 R.seed(SEED)
  23
  24 print '### Test vectors for 64-bit arithmetic macros'
  25 print '###   [generated; seed = 0x%08x]' % SEED
  26
  27 def rol(x, n): return ((x << n) | (x >> (WD - n))) & MASK
  28 def ror(x, n): return ((x >> n) | (x << (WD - n))) & MASK
  29 def put(x): return '%0*x' % (WD/4, x)
  30
  31 for name, func in [('lsl', lambda x, n: x << n),
  32                    ('lsr', lambda x, n: x >> n),
  33                    ('rol', rol),
  34                    ('ror', ror)]:
  35   print '\n%s64 {' % name
  36   for i in xrange(NVEC):
  37     x = R.randrange(LIMIT)
  38     sh = R.randrange(0, 70) & 63
  39     print '  %s %2d %s;' % (put(x), sh, put(func(x, sh) & MASK))
  40   for i in xrange(4):
  41     x = R.randrange(LIMIT)
  42     sh = 32
  43     print '  %s %2d %s;' % (put(x), sh, put(func(x, sh) & MASK))
  44   print '}'
  45
  46 for name, func in [('add', lambda x, y: x + y),
  47                    ('sub', lambda x, y: x - y)]:
  48   print '\n%s64 {' % name
  49   for i in xrange(NVEC):
  50     x = R.randrange(LIMIT)
  51     y = R.randrange(LIMIT)
  52     print '  %s %s %s;' % (put(x), put(y), put(func(x, y) & MASK))
  53   print '}'