1 files changed, 37 insertions, 51 deletions

diff --git a/Objects/longobject.c b/Objects/longobject.c
index a453241..10dde72 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -315,7 +315,6 @@ PyLong_FromUnsignedLong(unsigned long ival)
     v = _PyLong_New(ndigits);
     if (v != NULL) {
         digit *p = v->ob_digit;
-        Py_SIZE(v) = ndigits;
         while (ival) {
             *p++ = (digit)(ival & PyLong_MASK);
             ival >>= PyLong_SHIFT;
@@ -709,12 +708,33 @@ _PyLong_Sign(PyObject *vv)
     return Py_SIZE(v) == 0 ? 0 : (Py_SIZE(v) < 0 ? -1 : 1);
 }
 
+/* bits_in_digit(d) returns the unique integer k such that 2**(k-1) <= d <
+   2**k if d is nonzero, else 0. */
+
+static const unsigned char BitLengthTable[32] = {
+    0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
+};
+
+static int
+bits_in_digit(digit d)
+{
+    int d_bits = 0;
+    while (d >= 32) {
+        d_bits += 6;
+        d >>= 6;
+    }
+    d_bits += (int)BitLengthTable[d];
+    return d_bits;
+}
+
 size_t
 _PyLong_NumBits(PyObject *vv)
 {
     PyLongObject *v = (PyLongObject *)vv;
     size_t result = 0;
     Py_ssize_t ndigits;
+    int msd_bits;
 
     assert(v != NULL);
     assert(PyLong_Check(v));
@@ -725,12 +745,10 @@ _PyLong_NumBits(PyObject *vv)
         if ((size_t)(ndigits - 1) > SIZE_MAX / (size_t)PyLong_SHIFT)
             goto Overflow;
         result = (size_t)(ndigits - 1) * (size_t)PyLong_SHIFT;
-        do {
-            ++result;
-            if (result == 0)
-                goto Overflow;
-            msd >>= 1;
-        } while (msd);
+        msd_bits = bits_in_digit(msd);
+        if (SIZE_MAX - msd_bits < result)
+            goto Overflow;
+        result += msd_bits;
     }
     return result;
 
@@ -1102,7 +1120,6 @@ PyLong_FromUnsignedLongLong(unsigned long long ival)
     v = _PyLong_New(ndigits);
     if (v != NULL) {
         digit *p = v->ob_digit;
-        Py_SIZE(v) = ndigits;
         while (ival) {
             *p++ = (digit)(ival & PyLong_MASK);
             ival >>= PyLong_SHIFT;
@@ -1416,26 +1433,6 @@ PyLong_AsLongLongAndOverflow(PyObject *vv, int *overflow)
             Py_RETURN_NOTIMPLEMENTED;                   \
     } while(0)
 
-/* bits_in_digit(d) returns the unique integer k such that 2**(k-1) <= d <
-   2**k if d is nonzero, else 0. */
-
-static const unsigned char BitLengthTable[32] = {
-    0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
-};
-
-static int
-bits_in_digit(digit d)
-{
-    int d_bits = 0;
-    while (d >= 32) {
-        d_bits += 6;
-        d >>= 6;
-    }
-    d_bits += (int)BitLengthTable[d];
-    return d_bits;
-}
-
 /* x[0:m] and y[0:n] are digit vectors, LSD first, m >= n required.  x[0:n]
  * is modified in place, by adding y to it.  Carries are propagated as far as
  * x[m-1], and the remaining carry (0 or 1) is returned.
@@ -3105,9 +3102,7 @@ long_add(PyLongObject *a, PyLongObject *b)
     CHECK_BINOP(a, b);
 
     if (Py_ABS(Py_SIZE(a)) <= 1 && Py_ABS(Py_SIZE(b)) <= 1) {
-        PyObject *result = PyLong_FromLong(MEDIUM_VALUE(a) +
-                                          MEDIUM_VALUE(b));
-        return result;
+        return PyLong_FromLong(MEDIUM_VALUE(a) + MEDIUM_VALUE(b));
     }
     if (Py_SIZE(a) < 0) {
         if (Py_SIZE(b) < 0) {
@@ -3141,9 +3136,7 @@ long_sub(PyLongObject *a, PyLongObject *b)
     CHECK_BINOP(a, b);
 
     if (Py_ABS(Py_SIZE(a)) <= 1 && Py_ABS(Py_SIZE(b)) <= 1) {
-        PyObject* r;
-        r = PyLong_FromLong(MEDIUM_VALUE(a)-MEDIUM_VALUE(b));
-        return r;
+        return PyLong_FromLong(MEDIUM_VALUE(a) - MEDIUM_VALUE(b));
     }
     if (Py_SIZE(a) < 0) {
         if (Py_SIZE(b) < 0)
@@ -4296,22 +4289,22 @@ long_rshift(PyLongObject *a, PyLongObject *b)
         PyLongObject *a1, *a2;
         a1 = (PyLongObject *) long_invert(a);
         if (a1 == NULL)
-            goto rshift_error;
+            return NULL;
         a2 = (PyLongObject *) long_rshift(a1, b);
         Py_DECREF(a1);
         if (a2 == NULL)
-            goto rshift_error;
+            return NULL;
         z = (PyLongObject *) long_invert(a2);
         Py_DECREF(a2);
     }
     else {
         shiftby = PyLong_AsSsize_t((PyObject *)b);
         if (shiftby == -1L && PyErr_Occurred())
-            goto rshift_error;
+            return NULL;
         if (shiftby < 0) {
             PyErr_SetString(PyExc_ValueError,
                             "negative shift count");
-            goto rshift_error;
+            return NULL;
         }
         wordshift = shiftby / PyLong_SHIFT;
         newsize = Py_ABS(Py_SIZE(a)) - wordshift;
@@ -4323,19 +4316,15 @@ long_rshift(PyLongObject *a, PyLongObject *b)
         himask = PyLong_MASK ^ lomask;
         z = _PyLong_New(newsize);
         if (z == NULL)
-            goto rshift_error;
-        if (Py_SIZE(a) < 0)
-            Py_SIZE(z) = -(Py_SIZE(z));
+            return NULL;
         for (i = 0, j = wordshift; i < newsize; i++, j++) {
             z->ob_digit[i] = (a->ob_digit[j] >> loshift) & lomask;
             if (i+1 < newsize)
                 z->ob_digit[i] |= (a->ob_digit[j+1] << hishift) & himask;
         }
-        z = long_normalize(z);
+        z = maybe_small_long(long_normalize(z));
     }
-  rshift_error:
-    return (PyObject *) maybe_small_long(z);
-
+    return (PyObject *)z;
 }
 
 static PyObject *
@@ -5089,7 +5078,8 @@ static PyObject *
 long_bit_length(PyLongObject *v)
 {
     PyLongObject *result, *x, *y;
-    Py_ssize_t ndigits, msd_bits = 0;
+    Py_ssize_t ndigits;
+    int msd_bits;
     digit msd;
 
     assert(v != NULL);
@@ -5100,11 +5090,7 @@ long_bit_length(PyLongObject *v)
         return PyLong_FromLong(0);
 
     msd = v->ob_digit[ndigits-1];
-    while (msd >= 32) {
-        msd_bits += 6;
-        msd >>= 6;
-    }
-    msd_bits += (long)(BitLengthTable[msd]);
+    msd_bits = bits_in_digit(msd);
 
     if (ndigits <= PY_SSIZE_T_MAX/PyLong_SHIFT)
         return PyLong_FromSsize_t((ndigits-1)*PyLong_SHIFT + msd_bits);