[mypyc] feat: new primitive for int.bit_length

mypyc/lib-rt/CPy.h

@@ -139,6 +139,7 @@ CPyTagged CPyTagged_Remainder_(CPyTagged left, CPyTagged right);
 CPyTagged CPyTagged_BitwiseLongOp_(CPyTagged a, CPyTagged b, char op);
 CPyTagged CPyTagged_Rshift_(CPyTagged left, CPyTagged right);
 CPyTagged CPyTagged_Lshift_(CPyTagged left, CPyTagged right);
+CPyTagged CPyTagged_BitLength(CPyTagged self);
 
 PyObject *CPyTagged_Str(CPyTagged n);
 CPyTagged CPyTagged_FromFloat(double f);

mypyc/lib-rt/int_ops.c

@@ -581,3 +581,24 @@ double CPyTagged_TrueDivide(CPyTagged x, CPyTagged y) {
     }
     return 1.0;
 }
+
+// int.bit_length()
+CPyTagged CPyTagged_BitLength(CPyTagged self) {
+    PyObject *pyint = CPyTagged_StealAsObject(self);
+    if (!PyLong_Check(pyint)) {
+        Py_DECREF(pyint);
+        PyErr_SetString(PyExc_TypeError, "self must be int");
+        return CPY_INT_TAG;
+    }
+    PyObject *res = PyObject_CallMethod(pyint, "bit_length", NULL);
+    Py_DECREF(pyint);
+    if (!res) {
+        return CPY_INT_TAG;
+    }
+    long value = PyLong_AsLong(res);
+    Py_DECREF(res);
+    if (value == -1 && PyErr_Occurred()) {
+        return CPY_INT_TAG;
+    }
+    return value << 1;
+}

mypyc/primitives/int_ops.py

@@ -31,7 +31,14 @@
     str_rprimitive,
     void_rtype,
 )
-from mypyc.primitives.registry import binary_op, custom_op, function_op, load_address_op, unary_op
+from mypyc.primitives.registry import (
+    binary_op,
+    custom_op,
+    function_op,
+    load_address_op,
+    method_op,
+    unary_op,
+)
 
 # Constructors for builtins.int and native int types have the same behavior. In
 # interpreted mode, native int types are just aliases to 'int'.
@@ -305,3 +312,12 @@ def int_unary_op(name: str, c_function_name: str) -> PrimitiveDescription:
     c_function_name="PyLong_Check",
     error_kind=ERR_NEVER,
 )
+
+# int.bit_length()
+method_op(
+    name="bit_length",
+    arg_types=[int_rprimitive],
+    return_type=int_rprimitive,
+    c_function_name="CPyTagged_BitLength",
+    error_kind=ERR_MAGIC,
+)

mypyc/test-data/fixtures/ir.py

@@ -81,6 +81,7 @@ def __lt__(self, n: int) -> bool: pass
     def __gt__(self, n: int) -> bool: pass
     def __le__(self, n: int) -> bool: pass
     def __ge__(self, n: int) -> bool: pass
+    def bit_length(self) -> int: pass
 
 class str:
     @overload

mypyc/test-data/irbuild-int.test

@@ -210,3 +210,13 @@ L0:
     r0 = CPyTagged_Invert(n)
     x = r0
     return x
+
+[case testIntBitLength]
+def f(x: int) -> int:
+    return x.bit_length()
+[out]
+def f(x):
+    x, r0 :: int
+L0:
+    r0 = CPyTagged_BitLength(x)
+    return r0

mypyc/test-data/run-integers.test

@@ -572,3 +572,13 @@ class subc(int):
 [file userdefinedint.py]
 class int:
     pass
+
+[case testBitLength]
+def bit_length(n: int) -> int:
+    return n.bit_length()
+def test_bit_length() -> None:
+    assert bit_length(0) == 0
+    assert bit_length(1) == 1
+    assert bit_length(255) == 8
+    assert bit_length(256) == 9
+    assert bit_length(-256) == 9