adding tests for bitpattern_to_val

Author: mdko

pyrtl/__init__.py

@@ -28,6 +28,7 @@
 from .helperfuncs import log2
 from .helperfuncs import truncate
 from .helperfuncs import match_bitpattern
+from .helperfuncs import bitpattern_to_val
 from .helperfuncs import chop
 from .helperfuncs import val_to_signed_integer
 from .helperfuncs import val_to_formatted_str

pyrtl/helperfuncs.py

@@ -316,21 +316,21 @@ def letters_in_field_order():
             raise PyrtlError('number of fields and number of unique patterns do not match')
         try:
             intfields = [int(named_fields[n]) for n in lifo]
-        except KeyError:
-            raise PyrtlError('named field does not appear in bitpattern format string')
+        except KeyError as e:
+            raise PyrtlError('bitpattern field %s was not provided in named_field list' % e.args[0])
 
     fmap = dict(zip(lifo, intfields))
     for c in bitpattern[::-1]:
         if c == '0' or c == '1':
             bitlist.append(c)
         elif c == '?':
-            raise PyrtlError('all fields in must have names')
+            raise PyrtlError('all fields in the bitpattern must have names')
         else:
             bitlist.append(str(fmap[c] & 0x1))  # append lsb of the field
             fmap[c] = fmap[c] >> 1  # and bit shift by one position
     for f in fmap:
         if fmap[f] not in [0, -1]:
-            raise PyrtlError('too many bits given to value to fit in field')
+            raise PyrtlError('too many bits given to value to fit in field %s' % f)
     if len(bitpattern) != len(bitlist):
         raise PyrtlInternalError('resulting values have different bitwidths')
     final_str = ''.join(bitlist[::-1])

tests/test_helperfuncs.py

@@ -350,6 +350,95 @@ def test_match_bitwidth_with_pattern_matched_fields_with_bad_field_map(self):
                     out |= x.field2
 
 
+class TestBitpatternToVal(unittest.TestCase):
+    def setUp(self):
+        pyrtl.reset_working_block()
+
+    @staticmethod
+    def r5_br_immed(x):
+        # i is the 12th bit, k is the 11th bit, and j is the bottom 10 bits of the immediate field
+        return {'i': (x >> 11) & 0x1, 'k': (x >> 10) & 0x1, 'j': x & ((1 << 10) - 1)}
+
+    def test_ordered_fields(self):
+        self.assertEqual(
+            pyrtl.bitpattern_to_val('0000000rrrrrsssss000ddddd0110011', 1, 2, 3),  # RISC-V ADD
+            0b00000000000100010000000110110011
+        )
+
+        self.assertEqual(
+            pyrtl.bitpattern_to_val('iiiiiiirrrrrsssss010iiiii0100011', 1, 3, 4),  # RISC-V SW
+            0b00000000001100100010000010100011
+        )
+
+        m = TestBitpatternToVal.r5_br_immed(-5)
+        self.assertEqual(
+            pyrtl.bitpattern_to_val(
+                'ijjjjjjrrrrrsssss100jjjjk1100011', m['i'], m['j'], 2, 3, m['k']
+            ),  # RISC-V BLT
+            0b11111110001000011100101111100011
+        )
+
+    def test_named_fields(self):
+        self.assertEqual(
+            pyrtl.bitpattern_to_val(
+                '0000000rrrrrsssss000ddddd0110011', r=1, s=2, d=3
+            ),  # RISC-V ADD
+            0b00000000000100010000000110110011
+        )
+
+        self.assertEqual(
+            pyrtl.bitpattern_to_val('iiiiiiirrrrrsssss010iiiii0100011', i=1, r=3, s=4),  # RISC-V SW
+            0b00000000001100100010000010100011
+        )
+
+        self.assertEqual(
+            pyrtl.bitpattern_to_val(
+                'ijjjjjjrrrrrsssss100jjjjk1100011',
+                r=2, s=3, **TestBitpatternToVal.r5_br_immed(-5)
+            ),  # RISC-V BLT
+            0b11111110001000011100101111100011
+        )
+
+    def test_fields_all_different(self):
+        self.assertEqual(
+            pyrtl.bitpattern_to_val('abcdefg', a=1, b=0, c=1, d=0, e=0, f=1, g=0),
+            0b1010010
+        )
+
+    def test_no_fields(self):
+        self.assertEqual(
+            pyrtl.bitpattern_to_val('1010010'),
+            0b1010010
+        )
+
+    def test_error_both_ordered_and_named_fields(self):
+        with self.assertRaises(pyrtl.PyrtlError):
+            pyrtl.bitpattern_to_val('iiiiiiirrrrrsssss010iiiii0100011', 1, r=3, s=4)
+
+    def test_error_invalid_num_unique_patterns(self):
+        with self.assertRaises(pyrtl.PyrtlError):
+            pyrtl.bitpattern_to_val('iiiiiiirrrrrsssss010iiiii0100011', 1, 3)
+        with self.assertRaises(pyrtl.PyrtlError):
+            pyrtl.bitpattern_to_val('iiiiiiirrrrrsssss010iiiii0100011', i=1, r=3)
+
+    def test_error_bitpattern_field_not_provided(self):
+        with self.assertRaises(pyrtl.PyrtlError):
+            pyrtl.bitpattern_to_val('iiiiiiirrrrrsssss010iiiii0100011', i=1, r=3, t=4)
+
+    def test_error_unnamed_fields_in_bitpattern(self):
+        with self.assertRaises(pyrtl.PyrtlError):
+            pyrtl.bitpattern_to_val('iiiiiii?????sssss010iiiii0100011', 1, 3, 4)
+
+    def test_error_value_doesnt_fit_in_field(self):
+        with self.assertRaises(pyrtl.PyrtlError):
+            pyrtl.bitpattern_to_val('iiiiiiirrrrrsssss010iiiii0100011', 1, 65, 4)
+
+    @unittest.skip("This error might not be possible")
+    def test_error_bitlist_and_value_different_sizes(self):
+        with self.assertRaises(pyrtl.PyrtlError):
+            pass
+
+
 class TestChop(unittest.TestCase):
     def setUp(self):
         random.seed(8492049)