nmigen/test/compat/test_signed.py

   1 import unittest
   2
   3 from ...compat import *
   4 from .support import SimCase
   5
   6
   7 class SignedCase(SimCase, unittest.TestCase):
   8     class TestBench(Module):
   9         def __init__(self):
  10             self.a = Signal((3, True))
  11             self.b = Signal((4, True))
  12             comps = [
  13                 lambda p, q: p > q,
  14                 lambda p, q: p >= q,
  15                 lambda p, q: p < q,
  16                 lambda p, q: p <= q,
  17                 lambda p, q: p == q,
  18                 lambda p, q: p != q,
  19             ]
  20             self.vals = []
  21             for asign in 1, -1:
  22                 for bsign in 1, -1:
  23                     for f in comps:
  24                         r = Signal()
  25                         r0 = f(asign*self.a, bsign*self.b)
  26                         self.comb += r.eq(r0)
  27                         self.vals.append((asign, bsign, f, r, r0.op))
  28
  29     def test_comparisons(self):
  30         def gen():
  31             for i in range(-4, 4):
  32                 yield self.tb.a.eq(i)
  33                 yield self.tb.b.eq(i)
  34                 yield
  35                 a = yield self.tb.a
  36                 b = yield self.tb.b
  37                 for asign, bsign, f, r, op in self.tb.vals:
  38                     r, r0 = (yield r), f(asign*a, bsign*b)
  39                     self.assertEqual(r, int(r0),
  40                             "got {}, want {}*{} {} {}*{} = {}".format(
  41                                 r, asign, a, op, bsign, b, r0))
  42         self.run_with(gen())