Direct GF2-poly; minor numpy; gmpy2.prev_prime().

.travis.yml

@@ -6,14 +6,14 @@ jobs:
       - MPYC_NOPRSS=1
     install: pip install numpy==1.23.* gmpy2 uvloop
   - python: pypy3.9-7.3.9
-    install: pip install numpy==1.24.*
+    install: pip install numpy==1.25.*
   - python: 3.10
     env:
       - MPYC_NONUMPY=1
       - MPYC_NOGMPY=1
       - MPYC_NOUVLOOP=1
   - python: 3.11
-    install: pip install numpy==1.25.* gmpy2
+    install: pip install numpy==1.24.* gmpy2
   - python: 3.12
     install: pip install numpy uvloop
 before_install:

docs/install.rst

@@ -76,6 +76,10 @@ To enhance the performance of MPyC with faster integer arithmetic, install the
 `gmpy2 <https://gmpy2.readthedocs.io>`_ package, e.g.,
 using ``pip install gmpy2``.
 
+To enhance the performance of MPyC with an alternative event loop, install the
+`uvloop <https://uvloop.readthedocs.io>`_ package, e.g.,
+using ``pip install uvloop`` on Mac/Linux and currently ``pip install winloop`` on Windows.
+
 PyPy / Nuitka
 -------------
 

mpyc/finfields.py

@@ -718,8 +718,8 @@ def __init__(self, value, check=True, copy=False):
     def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
         # TODO: make more general
         cls = type(self)
-        if any(isinstance(a, np.ndarray) and a.dtype != object and a.dtype not in cls._mix_types
-               for a in inputs):
+        if any(isinstance(a, np.ndarray) and a.dtype != object
+               and not issubclass(a.dtype.type, cls._mix_types) for a in inputs):
             return NotImplemented
 
         if ufunc.__name__ == 'equal':
@@ -1358,9 +1358,7 @@ class PrimeFieldArray(FiniteFieldArray):
 
     _mix_types = int
     if np:
-        _mix_types = (int, np.int64, np.int32, np.int16, np.int8,
-                      np.uint64, np.uint32, np.uint16, np.uint8)
-        # TODO: consider use of np.integer
+        _mix_types = (int, np.integer)
 
     @classmethod
     def intarray(cls, a):
@@ -1383,10 +1381,11 @@ def __abs__(self):
     def signed_(self):
         """Return signed integer representation, symmetric around zero."""
         p = self.field.modulus
-        f = np.vectorize(lambda a: a - p if a > p>>1 else a, otypes='O')
-        return f(self.value)
-        # TODO: check following alternative, issue with np.where result containing floats
-        # return self.value - np.where(self.value > p>>1, p, 0)
+        return np.where(self.value > p>>1, self.value - p, self.value)
+        # NB: avoiding np.where(..., p, 0) which causes issues with floats, as
+        # np.result_type(1 << 63, 0) returns dtype('float64'), but
+        # np.result_type(1 << 62, 0) returns dtype('int64'), and
+        # np.result_type(1 << 64, 0) returns dtype('O').
 
     def unsigned_(self):
         """Return unsigned integer representation."""
@@ -1467,8 +1466,7 @@ class ExtensionFieldArray(FiniteFieldArray):
 
     _mix_types = (int, gfpx.Polynomial)
     if np:
-        _mix_types += (np.int64, np.int32, np.int16, np.int8,
-                       np.uint64, np.uint32, np.uint16, np.uint8)
+        _mix_types += (np.integer,)
 
     @classmethod
     def _pow(cls, a, b):  # NB: exponents assumed to be integer(s)
@@ -1534,8 +1532,7 @@ class BinaryFieldArray(ExtensionFieldArray):
 
     _mix_types = (int, gfpx.BinaryPolynomial)
     if np:
-        _mix_types += (np.int64, np.int32, np.int16, np.int8,
-                       np.uint64, np.uint32, np.uint16, np.uint8)
+        _mix_types += (np.integer,)
 
     @classmethod
     def _is_sqr(cls, a):

mpyc/gfpx.py

@@ -33,9 +33,12 @@ def GFpX(p):
     if not gmpy2.is_prime(p):
         raise ValueError('number is not prime')
 
-    BasePolynomial = BinaryPolynomial if p == 2 else Polynomial
-    GFpPolynomial = type(f'GF({p})[{X}]', (BasePolynomial,), {'__slots__': ()})
-    GFpPolynomial.p = p
+    if p == 2:
+        GFpPolynomial = BinaryPolynomial
+        GFpPolynomial.__name__ = f'GF({p})[{X}]'
+    else:
+        GFpPolynomial = type(f'GF({p})[{X}]', (Polynomial,), {'__slots__': ()})
+        GFpPolynomial.p = p
     globals()[f'GF({p})[{X}]'] = GFpPolynomial  # NB: exploit unique name dynamic Polynomial type
     return GFpPolynomial
 

mpyc/gmpy.py

@@ -79,19 +79,24 @@ def ratrec(x, y, N=None, D=None):
     raise ValueError('rational reconstruction not possible')
 
 
-def prev_prime(x):
-    """Return the greatest probable prime number < x, if any."""
-    # TODO: future releases of gmpy2 will support this function (using GMP 6.3+)
-    if x <= 2:
-        raise ValueError(f'no smaller prime')
-
-    if x == 3:
-        return 2
-
-    x -= 1 + x%2
-    while not is_prime(x):
-        x -= 2
-    return x
+try:
+    if os.getenv('MPYC_NOGMPY') == '1':
+        raise ImportError  # stub for gmpy2.prev_prime() will be loaded
+
+    from gmpy2 import prev_prime  # only available from gmpy2 2.2+ based on GMP 6.3+
+except ImportError:
+    def prev_prime(x):
+        """Return the greatest probable prime number < x, if any."""
+        if x < 3:
+            raise ValueError('x must be >= 3')
+
+        if x == 3:
+            return 2
+
+        x -= 1 + x%2
+        while not is_prime(x):
+            x -= 2
+        return x
 
 
 try:

tests/test_gfpx.py

@@ -9,11 +9,9 @@ class Arithmetic(unittest.TestCase):
 
     def setUp(self):
         gf2x = gfpx.GFpX(2)
-        gf2x_ = gfpx.BinaryPolynomial
         gf3x = gfpx.GFpX(3)
         gf101x = gfpx.GFpX(101)
-        self.mod_2 = (gf2x, gf2x_)
-        self.mod_all = self.mod_2 + (gf3x, gf101x)
+        self.mod_all = (gf2x, gf3x, gf101x)
 
     def test_modall(self):
         self.assertRaises(ValueError, gfpx.GFpX, 4)
@@ -95,10 +93,7 @@ def _test_errors(self, poly):
         self.assertRaises(ValueError, operator.pow, poly(3), -16)
 
     def test_mod2(self):
-        for poly in self.mod_2:
-            self._test_mod2(poly)
-
-    def _test_mod2(self, poly):
+        poly = gfpx.GFpX(2)
         self.assertEqual(poly([0, 1, 1]), f'{X}^2+{X}')
         self.assertEqual(poly._to_list(6), [0, 1, 1])
         self.assertEqual(poly.from_terms(f'{X}+{X}'), 0)