Move constant computation to C++

Author: juntyr

quaddtype/numpy_quaddtype/__init__.py

@@ -18,8 +18,6 @@
     'set_num_threads', 'get_num_threads', 'get_quadblas_version'
 ]
 
-import numpy as np
-
 def SleefQuadPrecision(value):
     return QuadPrecision(value, backend='sleef')
 
@@ -42,6 +40,6 @@ def LongDoubleQuadPrecDType():
 epsilon = get_sleef_constant("epsilon")
 smallest_normal = get_sleef_constant("smallest_normal")
 smallest_subnormal = get_sleef_constant("smallest_subnormal")
-bits = SleefQuadPrecDType().itemsize * 8
-precision = int(-np.log10(epsilon))
-resolution = SleefQuadPrecision(10) ** (-precision)
+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))
+        auto 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))
+        auto 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);