src/nmutil/test/test_clz.py

   1 from nmigen.sim import Delay
   2 from nmutil.clz import CLZ, clz
   3 from nmutil.sim_util import do_sim
   4 import unittest
   5
   6
   7 def reference_clz(v, width):
   8     assert isinstance(width, int) and 0 <= width
   9     assert isinstance(v, int) and 0 <= v < 1 << width
  10     msb = 1 << (width - 1)
  11     retval = 0
  12     while retval < width:
  13         if v & msb:
  14             break
  15         v <<= 1
  16         retval += 1
  17     return retval
  18
  19
  20 class TestCLZ(unittest.TestCase):
  21     def tst(self, width):
  22         assert isinstance(width, int) and 0 <= width
  23         dut = CLZ(width)
  24
  25         def process():
  26             for inp in range(1 << width):
  27                 expected = reference_clz(inp, width)
  28                 with self.subTest(inp=hex(inp), expected=expected):
  29                     yield dut.sig_in.eq(inp)
  30                     yield Delay(1e-6)
  31                     sim_lz = yield dut.lz
  32                     py_lz = clz(inp, width)
  33                     with self.subTest(sim_lz=sim_lz, py_lz=py_lz):
  34                         self.assertEqual(sim_lz, expected)
  35                         self.assertEqual(py_lz, expected)
  36         with do_sim(self, dut, [dut.sig_in, dut.lz]) as sim:
  37             sim.add_process(process)
  38             sim.run()
  39
  40     def test_1(self):
  41         self.tst(1)
  42
  43     def test_2(self):
  44         self.tst(2)
  45
  46     def test_3(self):
  47         self.tst(3)
  48
  49     def test_4(self):
  50         self.tst(4)
  51
  52     def test_5(self):
  53         self.tst(5)
  54
  55     def test_6(self):
  56         self.tst(6)
  57
  58     def test_7(self):
  59         self.tst(7)
  60
  61     def test_8(self):
  62         self.tst(8)
  63
  64     def test_9(self):
  65         self.tst(9)
  66
  67     def test_10(self):
  68         self.tst(10)
  69
  70     def test_11(self):
  71         self.tst(11)
  72
  73     def test_12(self):
  74         self.tst(12)
  75
  76
  77 if __name__ == "__main__":
  78     unittest.main()