Merge pull request #132 from juntyr/consts

Author: SwayamInSync

quaddtype/numpy_quaddtype/__init__.py

@@ -13,7 +13,7 @@
     'SleefQuadPrecDType', 'LongDoubleQuadPrecDType', 'is_longdouble_128', 
     # Constants
     'pi', 'e', 'log2e', 'log10e', 'ln2', 'ln10', 'max_value', 'epsilon',
-    'smallest_normal', 'smallest_subnormal',
+    'smallest_normal', 'smallest_subnormal', 'bits', 'precision', 'resolution',
     # QuadBLAS related functions
     'set_num_threads', 'get_num_threads', 'get_quadblas_version'
 ]
@@ -40,3 +40,6 @@ def LongDoubleQuadPrecDType():
 epsilon = get_sleef_constant("epsilon")
 smallest_normal = get_sleef_constant("smallest_normal")
 smallest_subnormal = get_sleef_constant("smallest_subnormal")
+bits = get_sleef_constant("bits")
+precision = get_sleef_constant("precision")
+resolution = get_sleef_constant("resolution")

quaddtype/numpy_quaddtype/src/quaddtype_main.c

@@ -73,6 +73,22 @@ get_sleef_constant(PyObject *self, PyObject *args)
     else if (strcmp(constant_name, "smallest_subnormal") == 0) {
         result->value.sleef_value = SLEEF_QUAD_DENORM_MIN;
     }
+    else if (strcmp(constant_name, "bits") == 0) {
+        Py_DECREF(result);
+        return PyLong_FromLong(sizeof(Sleef_quad) * CHAR_BIT);
+    }
+    else if (strcmp(constant_name, "precision") == 0) {
+        Py_DECREF(result);
+        // precision = int(-log10(epsilon))
+        int64_t precision = Sleef_cast_to_int64q1(Sleef_negq1(Sleef_log10q1_u10(SLEEF_QUAD_EPSILON)));
+        return PyLong_FromLong(precision);
+    }
+    else if (strcmp(constant_name, "resolution") == 0) {
+        // precision = int(-log10(epsilon))
+        int64_t precision = Sleef_cast_to_int64q1(Sleef_negq1(Sleef_log10q1_u10(SLEEF_QUAD_EPSILON)));
+        // resolution = 10 ** (-precision)
+        result->value.sleef_value = Sleef_powq1_u10(Sleef_cast_from_int64q1(10), Sleef_cast_from_int64q1(-precision));
+    }
     else {
         PyErr_SetString(PyExc_ValueError, "Unknown constant name");
         Py_DECREF(result);

quaddtype/tests/test_quaddtype.py

@@ -19,11 +19,16 @@ def test_math_constant(name, expected):
     assert np.float64(getattr(numpy_quaddtype, name)) == expected
 
 
-@pytest.mark.parametrize("name", ["max_value", "epsilon", "smallest_normal", "smallest_subnormal"])
+@pytest.mark.parametrize("name", ["max_value", "epsilon", "smallest_normal", "smallest_subnormal", "resolution"])
 def test_finfo_constant(name):
     assert isinstance(getattr(numpy_quaddtype, name), QuadPrecision)
 
 
+@pytest.mark.parametrize("name,value", [("bits", 128), ("precision", 33)])
+def test_finfo_int_constant(name, value):
+    assert getattr(numpy_quaddtype, name) == value
+
+
 def test_basic_equality():
     assert QuadPrecision("12") == QuadPrecision(
         "12.0") == QuadPrecision("12.00")