diff -r 39511e854e6d Modules/_bz2module.c
--- a/Modules/_bz2module.c
+++ b/Modules/_bz2module.c
@@ -427,7 +427,7 @@ decompress_buf(BZ2Decompressor *d, Py_ss
     PyObject *result;
     bz_stream *bzs = &d->bzs;
 
-    if (max_length < 0 || max_length >= INITIAL_BUFFER_SIZE)
+    if ((size_t)max_length >= (size_t)INITIAL_BUFFER_SIZE)
         result = PyBytes_FromStringAndSize(NULL, INITIAL_BUFFER_SIZE);
     else
         result = PyBytes_FromStringAndSize(NULL, max_length);
diff -r 39511e854e6d Modules/_collectionsmodule.c
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -689,7 +689,7 @@ deque_inplace_repeat(dequeobject *deque,
         /* common case, repeating a single element */
         PyObject *item = deque->leftblock->data[deque->leftindex];
 
-        if (deque->maxlen >= 0 && n > deque->maxlen)
+        if ((size_t)n > (size_t)deque->maxlen)
             n = deque->maxlen;
 
         deque->state++;
diff -r 39511e854e6d Modules/_ctypes/_ctypes.c
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -4230,7 +4230,7 @@ Array_item(PyObject *myself, Py_ssize_t 
     StgDictObject *stgdict;
 
 
-    if (index < 0 || index >= self->b_length) {
+    if ((size_t)index >= (size_t)self->b_length) {
         PyErr_SetString(PyExc_IndexError,
                         "invalid index");
         return NULL;
@@ -4373,7 +4373,7 @@ Array_ass_item(PyObject *myself, Py_ssiz
 
     stgdict = PyObject_stgdict((PyObject *)self);
     assert(stgdict); /* Cannot be NULL for array object instances */
-    if (index < 0 || index >= stgdict->length) {
+    if ((size_t)index >= (size_t)stgdict->length) {
         PyErr_SetString(PyExc_IndexError,
                         "invalid index");
         return -1;
diff -r 39511e854e6d Modules/_ctypes/cfield.c
--- a/Modules/_ctypes/cfield.c
+++ b/Modules/_ctypes/cfield.c
@@ -1140,7 +1140,7 @@ c_set(void *ptr, PyObject *value, Py_ssi
     if (PyLong_Check(value))
     {
         long longval = PyLong_AS_LONG(value);
-        if (longval < 0 || longval >= 256)
+        if ((unsigned long)longval >= 256u)
             goto error;
         *(char *)ptr = (char)longval;
         _RET(value);
diff -r 39511e854e6d Modules/_datetimemodule.c
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -466,7 +466,7 @@ normalize_pair(int *hi, int *lo, int fac
 {
     assert(factor > 0);
     assert(lo != hi);
-    if (*lo < 0 || *lo >= factor) {
+    if ((unsigned)*lo >= (unsigned)factor) {
         const int num_hi = divmod(*lo, factor, lo);
         const int new_hi = *hi + num_hi;
         assert(! SIGNED_ADD_OVERFLOWED(new_hi, *hi, num_hi));
@@ -484,14 +484,14 @@ normalize_pair(int *hi, int *lo, int fac
 static void
 normalize_d_s_us(int *d, int *s, int *us)
 {
-    if (*us < 0 || *us >= 1000000) {
+    if ((unsigned)*us >= 1000000u) {
         normalize_pair(s, us, 1000000);
         /* |s| can't be bigger than about
          * |original s| + |original us|/1000000 now.
          */
 
     }
-    if (*s < 0 || *s >= 24*3600) {
+    if ((unsigned)*s >= (unsigned)(24 * 3600)) {
         normalize_pair(d, s, 24*3600);
         /* |d| can't be bigger than about
          * |original d| +
diff -r 39511e854e6d Modules/_decimal/_decimal.c
--- a/Modules/_decimal/_decimal.c
+++ b/Modules/_decimal/_decimal.c
@@ -1334,12 +1334,12 @@ context_repr(PyDecContextObject *self)
 
     mem = MPD_MAX_SIGNAL_LIST;
     n = mpd_lsnprint_signals(flags, mem, ctx->status, dec_signal_string);
-    if (n < 0 || n >= mem) {
+    if ((unsigned)n >= (unsigned)mem) {
         INTERNAL_ERROR_PTR("context_repr");
     }
 
     n = mpd_lsnprint_signals(traps, mem, ctx->traps, dec_signal_string);
-    if (n < 0 || n >= mem) {
+    if ((unsigned)n >= (unsigned)mem) {
         INTERNAL_ERROR_PTR("context_repr");
     }
 
@@ -2496,7 +2496,7 @@ dectuple_as_str(PyObject *dectuple)
     }
 
     n = snprintf(cp, mem, "%s", sign_special);
-    if (n < 0 || n >= mem) {
+    if ((size_t)n >= (size_t)mem) {
         PyErr_SetString(PyExc_RuntimeError,
             "internal error in dec_sequence_as_str");
         goto error;
@@ -2536,7 +2536,7 @@ dectuple_as_str(PyObject *dectuple)
         /* not a special number */
         *cp++ = 'E';
         n = snprintf(cp, MPD_EXPDIGITS+2, "%" PRI_mpd_ssize_t, exp);
-        if (n < 0 || n >= MPD_EXPDIGITS+2) {
+        if ((unsigned)n >= (unsigned)(MPD_EXPDIGITS + 2)) {
             PyErr_SetString(PyExc_RuntimeError,
                 "internal error in dec_sequence_as_str");
             goto error;
diff -r 39511e854e6d Modules/_io/bufferedio.c
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -1109,7 +1109,7 @@ static PyObject *
        the calls to the C API are simple enough that they can't trigger
        any thread switch. */
     n = Py_SAFE_DOWNCAST(READAHEAD(self), Py_off_t, Py_ssize_t);
-    if (limit >= 0 && n > limit)
+    if ((size_t)n > (size_t)limit)
         n = limit;
     start = self->buffer + self->pos;
     s = memchr(start, '\n', n);
@@ -1161,7 +1161,7 @@ static PyObject *
             goto end;
         if (n <= 0)
             break;
-        if (limit >= 0 && n > limit)
+        if ((size_t)n > (size_t)limit)
             n = limit;
         start = self->buffer;
         end = start + n;
diff -r 39511e854e6d Modules/_lzmamodule.c
--- a/Modules/_lzmamodule.c
+++ b/Modules/_lzmamodule.c
@@ -896,7 +896,7 @@ decompress_buf(Decompressor *d, Py_ssize
     PyObject *result;
     lzma_stream *lzs = &d->lzs;
 
-    if (max_length < 0 || max_length >= INITIAL_BUFFER_SIZE)
+    if ((size_t)max_length >= (size_t)INITIAL_BUFFER_SIZE)
         result = PyBytes_FromStringAndSize(NULL, INITIAL_BUFFER_SIZE);
     else
         result = PyBytes_FromStringAndSize(NULL, max_length);
diff -r 39511e854e6d Modules/_pickle.c
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -1306,7 +1306,7 @@ static int
 static PyObject *
 _Unpickler_MemoGet(UnpicklerObject *self, Py_ssize_t idx)
 {
-    if (idx < 0 || idx >= self->memo_size)
+    if ((size_t)idx >= (size_t)self->memo_size)
         return NULL;
 
     return self->memo[idx];
diff -r 39511e854e6d Modules/_sre.c
--- a/Modules/_sre.c
+++ b/Modules/_sre.c
@@ -2006,7 +2006,7 @@ match_getslice_by_index(MatchObject* sel
     PyObject *result;
     void* ptr;
 
-    if (index < 0 || index >= self->groups) {
+    if ((size_t)index >= (size_t)self->groups) {
         /* raise IndexError if we were given a bad group number */
         PyErr_SetString(
             PyExc_IndexError,
@@ -2226,7 +2226,7 @@ static Py_ssize_t
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
+    if ((size_t)index >= (size_t)self->groups) {
         PyErr_SetString(
             PyExc_IndexError,
             "no such group"
@@ -2253,7 +2253,7 @@ static Py_ssize_t
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
+    if ((size_t)index >= (size_t)self->groups) {
         PyErr_SetString(
             PyExc_IndexError,
             "no such group"
@@ -2307,7 +2307,7 @@ static PyObject *
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
+    if ((size_t)index >= (size_t)self->groups) {
         PyErr_SetString(
             PyExc_IndexError,
             "no such group"
diff -r 39511e854e6d Modules/_testbuffer.c
--- a/Modules/_testbuffer.c
+++ b/Modules/_testbuffer.c
@@ -1568,7 +1568,7 @@ ptr_from_index(Py_buffer *base, Py_ssize
     if (index < 0) {
         index += nitems;
     }
-    if (index < 0 || index >= nitems) {
+    if ((size_t)index >= (size_t)nitems) {
         PyErr_SetString(PyExc_IndexError, "index out of bounds");
         return NULL;
     }
@@ -2335,7 +2335,7 @@ get_pointer(PyObject *self, PyObject *ar
         indices[i] = PyLong_AsSsize_t(x);
         if (PyErr_Occurred())
             goto out;
-        if (indices[i] < 0 || indices[i] >= view.shape[i]) {
+        if ((size_t)indices[i] >= (size_t)view.shape[i]) {
             PyErr_Format(PyExc_ValueError,
                 "get_pointer(): invalid index %zd at position %zd",
                 indices[i], i);
diff -r 39511e854e6d Modules/_winapi.c
--- a/Modules/_winapi.c
+++ b/Modules/_winapi.c
@@ -1330,12 +1330,12 @@ static PyObject *
         return NULL;
     }
     nhandles = PySequence_Length(handle_seq);
-    if (nhandles == -1)
-        return NULL;
-    if (nhandles < 0 || nhandles >= MAXIMUM_WAIT_OBJECTS - 1) {
-        PyErr_Format(PyExc_ValueError,
-                     "need at most %zd handles, got a sequence of length %zd",
-                     MAXIMUM_WAIT_OBJECTS - 1, nhandles);
+    if ((size_t)nhandles >= (size_t)(MAXIMUM_WAIT_OBJECTS - 1)) {
+        if (nhandles != -1 && !PyErr_Occurred()) {
+            PyErr_Format(PyExc_ValueError,
+                         "need at most %zd handles, got a sequence of length %zd",
+                         (Py_ssize_t)(MAXIMUM_WAIT_OBJECTS - 1), nhandles);
+        }
         return NULL;
     }
     for (i = 0; i < nhandles; i++) {
diff -r 39511e854e6d Modules/arraymodule.c
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -716,7 +716,7 @@ array_length(arrayobject *a)
 static PyObject *
 array_item(arrayobject *a, Py_ssize_t i)
 {
-    if (i < 0 || i >= Py_SIZE(a)) {
+    if ((size_t)i >= (size_t)Py_SIZE(a)) {
         PyErr_SetString(PyExc_IndexError, "array index out of range");
         return NULL;
     }
@@ -884,7 +884,7 @@ array_del_slice(arrayobject *a, Py_ssize
 static int
 array_ass_item(arrayobject *a, Py_ssize_t i, PyObject *v)
 {
-    if (i < 0 || i >= Py_SIZE(a)) {
+    if ((size_t)i >= (size_t)Py_SIZE(a)) {
         PyErr_SetString(PyExc_IndexError,
                          "array assignment index out of range");
         return -1;
@@ -1156,7 +1156,7 @@ array_array_pop_impl(arrayobject *self, 
     }
     if (i < 0)
         i += Py_SIZE(self);
-    if (i < 0 || i >= Py_SIZE(self)) {
+    if ((size_t)i >= (size_t)Py_SIZE(self)) {
         PyErr_SetString(PyExc_IndexError, "pop index out of range");
         return NULL;
     }
@@ -2336,7 +2336,7 @@ array_ass_subscr(arrayobject* self, PyOb
             return -1;
         if (i < 0)
             i += Py_SIZE(self);
-        if (i < 0 || i >= Py_SIZE(self)) {
+        if ((size_t)i >= (size_t)Py_SIZE(self)) {
             PyErr_SetString(PyExc_IndexError,
                 "array assignment index out of range");
             return -1;
diff -r 39511e854e6d Modules/audioop.c
--- a/Modules/audioop.c
+++ b/Modules/audioop.c
@@ -415,7 +415,7 @@ audioop_getsample_impl(PyObject *module,
 
     if (!audioop_check_parameters(fragment->len, width))
         return NULL;
-    if (index < 0 || index >= fragment->len/width) {
+    if ((size_t)index >= (size_t)(fragment->len / width)) {
         PyErr_SetString(AudioopError, "Index out of range");
         return NULL;
     }
diff -r 39511e854e6d Modules/gcmodule.c
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -1210,7 +1210,7 @@ gc_collect(PyObject *self, PyObject *arg
     if (!PyArg_ParseTupleAndKeywords(args, kws, "|i", keywords, &genarg))
         return NULL;
 
-    else if (genarg < 0 || genarg >= NUM_GENERATIONS) {
+    else if ((unsigned)genarg >= (unsigned)NUM_GENERATIONS) {
         PyErr_SetString(PyExc_ValueError, "invalid generation");
         return NULL;
     }
diff -r 39511e854e6d Modules/mmapmodule.c
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -779,7 +779,7 @@ static PyObject *
 mmap_item(mmap_object *self, Py_ssize_t i)
 {
     CHECK_VALID(NULL);
-    if (i < 0 || i >= self->size) {
+    if ((size_t)i >= (size_t)self->size) {
         PyErr_SetString(PyExc_IndexError, "mmap index out of range");
         return NULL;
     }
@@ -796,7 +796,7 @@ mmap_subscript(mmap_object *self, PyObje
             return NULL;
         if (i < 0)
             i += self->size;
-        if (i < 0 || i >= self->size) {
+        if ((size_t)i >= (size_t)self->size) {
             PyErr_SetString(PyExc_IndexError,
                 "mmap index out of range");
             return NULL;
@@ -864,7 +864,7 @@ mmap_ass_item(mmap_object *self, Py_ssiz
     const char *buf;
 
     CHECK_VALID(-1);
-    if (i < 0 || i >= self->size) {
+    if ((size_t)i >= (size_t)self->size) {
         PyErr_SetString(PyExc_IndexError, "mmap index out of range");
         return -1;
     }
@@ -901,7 +901,7 @@ mmap_ass_subscript(mmap_object *self, Py
             return -1;
         if (i < 0)
             i += self->size;
-        if (i < 0 || i >= self->size) {
+        if ((size_t)i >= (size_t)self->size) {
             PyErr_SetString(PyExc_IndexError,
                             "mmap index out of range");
             return -1;
diff -r 39511e854e6d Modules/unicodedata.c
--- a/Modules/unicodedata.c
+++ b/Modules/unicodedata.c
@@ -412,7 +412,7 @@ unicodedata_UCD_decomposition_impl(PyObj
             return PyUnicode_FromString(""); /* unassigned */
     }
 
-    if (code < 0 || code >= 0x110000)
+    if ((unsigned)code >= 0x110000u)
         index = 0;
     else {
         index = decomp_index1[(code>>DECOMP_SHIFT)];
diff -r 39511e854e6d Objects/bytearrayobject.c
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -47,7 +47,7 @@ static int
         Py_DECREF(index);
     }
 
-    if (face_value < 0 || face_value >= 256) {
+    if ((unsigned long)face_value >= 256u) {
         /* this includes the OverflowError in case the long is too large */
         PyErr_SetString(PyExc_ValueError, "byte must be in range(0, 256)");
         *value = -1;
@@ -373,7 +373,7 @@ bytearray_getitem(PyByteArrayObject *sel
 {
     if (i < 0)
         i += Py_SIZE(self);
-    if (i < 0 || i >= Py_SIZE(self)) {
+    if ((size_t)i >= (size_t)Py_SIZE(self)) {
         PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
         return NULL;
     }
@@ -392,7 +392,7 @@ bytearray_subscript(PyByteArrayObject *s
         if (i < 0)
             i += PyByteArray_GET_SIZE(self);
 
-        if (i < 0 || i >= Py_SIZE(self)) {
+        if ((size_t)i >= (size_t)Py_SIZE(self)) {
             PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
             return NULL;
         }
@@ -578,7 +578,7 @@ bytearray_setitem(PyByteArrayObject *sel
     if (i < 0)
         i += Py_SIZE(self);
 
-    if (i < 0 || i >= Py_SIZE(self)) {
+    if ((size_t)i >= (size_t)Py_SIZE(self)) {
         PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
         return -1;
     }
@@ -609,7 +609,7 @@ bytearray_ass_subscript(PyByteArrayObjec
         if (i < 0)
             i += PyByteArray_GET_SIZE(self);
 
-        if (i < 0 || i >= Py_SIZE(self)) {
+        if ((size_t)i >= (size_t)Py_SIZE(self)) {
             PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
             return -1;
         }
@@ -1703,7 +1703,7 @@ bytearray_pop_impl(PyByteArrayObject *se
     }
     if (index < 0)
         index += Py_SIZE(self);
-    if (index < 0 || index >= Py_SIZE(self)) {
+    if ((size_t)index >= (size_t)Py_SIZE(self)) {
         PyErr_SetString(PyExc_IndexError, "pop index out of range");
         return NULL;
     }
diff -r 39511e854e6d Objects/bytes_methods.c
--- a/Objects/bytes_methods.c
+++ b/Objects/bytes_methods.c
@@ -657,7 +657,7 @@ int
         PyBuffer_Release(&varg);
         return pos >= 0;
     }
-    if (ival < 0 || ival >= 256) {
+    if ((size_t)ival >= 256u) {
         PyErr_SetString(PyExc_ValueError, "byte must be in range(0, 256)");
         return -1;
     }
diff -r 39511e854e6d Objects/bytesobject.c
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -821,7 +821,7 @@ PyObject *
                 assert(PyUnicode_IS_ASCII(temp));
                 pbuf = (const char *)PyUnicode_1BYTE_DATA(temp);
                 len = PyUnicode_GET_LENGTH(temp);
-                if (prec >= 0 && len > prec)
+                if ((size_t)len > (size_t)prec)
                     len = prec;
                 break;
 
@@ -831,7 +831,7 @@ PyObject *
                 temp = format_obj(v, &pbuf, &len);
                 if (temp == NULL)
                     goto error;
-                if (prec >= 0 && len > prec)
+                if ((size_t)len > (size_t)prec)
                     len = prec;
                 break;
 
@@ -1493,7 +1493,7 @@ bytes_contains(PyObject *self, PyObject 
 static PyObject *
 bytes_item(PyBytesObject *a, Py_ssize_t i)
 {
-    if (i < 0 || i >= Py_SIZE(a)) {
+    if ((size_t)i >= (size_t)Py_SIZE(a)) {
         PyErr_SetString(PyExc_IndexError, "index out of range");
         return NULL;
     }
@@ -1629,7 +1629,7 @@ bytes_subscript(PyBytesObject* self, PyO
             return NULL;
         if (i < 0)
             i += PyBytes_GET_SIZE(self);
-        if (i < 0 || i >= PyBytes_GET_SIZE(self)) {
+        if ((size_t)i >= (size_t)PyBytes_GET_SIZE(self)) {
             PyErr_SetString(PyExc_IndexError,
                             "index out of range");
             return NULL;
@@ -2688,7 +2688,7 @@ static PyObject *
             goto error;
 
         /* Range check */
-        if (value < 0 || value >= 256) {
+        if ((size_t)value >= 256u) {
             PyErr_SetString(PyExc_ValueError,
                             "bytes must be in range(0, 256)");
             goto error;
diff -r 39511e854e6d Objects/exceptions.c
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -2921,7 +2921,7 @@ static int
         if (colon_index < -1) {
             return -1;
         }
-        if (colon_index >= 0 && colon_index < text_len) {
+        if ((size_t)colon_index < (size_t)text_len) {
             /* Check again, starting from just after the colon */
             if (_check_for_legacy_statements(self, colon_index+1) < 0) {
                 return -1;
diff -r 39511e854e6d Objects/listobject.c
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -202,7 +202,7 @@ PyList_GetItem(PyObject *op, Py_ssize_t 
         PyErr_BadInternalCall();
         return NULL;
     }
-    if (i < 0 || i >= Py_SIZE(op)) {
+    if ((size_t)i >= (size_t)Py_SIZE(op)) {
         if (indexerr == NULL) {
             indexerr = PyUnicode_FromString(
                 "list index out of range");
@@ -225,7 +225,7 @@ PyList_SetItem(PyObject *op, Py_ssize_t 
         PyErr_BadInternalCall();
         return -1;
     }
-    if (i < 0 || i >= Py_SIZE(op)) {
+    if ((size_t)i >= (size_t)Py_SIZE(op)) {
         Py_XDECREF(newitem);
         PyErr_SetString(PyExc_IndexError,
                         "list assignment index out of range");
@@ -414,7 +414,7 @@ list_contains(PyListObject *a, PyObject 
 static PyObject *
 list_item(PyListObject *a, Py_ssize_t i)
 {
-    if (i < 0 || i >= Py_SIZE(a)) {
+    if ((size_t)i >= (size_t)Py_SIZE(a)) {
         if (indexerr == NULL) {
             indexerr = PyUnicode_FromString(
                 "list index out of range");
@@ -733,7 +733,7 @@ list_inplace_repeat(PyListObject *self, 
 static int
 list_ass_item(PyListObject *a, Py_ssize_t i, PyObject *v)
 {
-    if (i < 0 || i >= Py_SIZE(a)) {
+    if ((size_t)i >= (size_t)Py_SIZE(a)) {
         PyErr_SetString(PyExc_IndexError,
                         "list assignment index out of range");
         return -1;
@@ -927,7 +927,7 @@ listpop(PyListObject *self, PyObject *ar
     }
     if (i < 0)
         i += Py_SIZE(self);
-    if (i < 0 || i >= Py_SIZE(self)) {
+    if ((size_t)i >= (size_t)Py_SIZE(self)) {
         PyErr_SetString(PyExc_IndexError, "pop index out of range");
         return NULL;
     }
@@ -2922,7 +2922,7 @@ listreviter_next(listreviterobject *it)
     assert(PyList_Check(seq));
 
     index = it->it_index;
-    if (index>=0 && index < PyList_GET_SIZE(seq)) {
+    if ((size_t)index < (size_t)PyList_GET_SIZE(seq)) {
         item = PyList_GET_ITEM(seq, index);
         it->it_index--;
         Py_INCREF(item);
diff -r 39511e854e6d Objects/memoryobject.c
--- a/Objects/memoryobject.c
+++ b/Objects/memoryobject.c
@@ -2175,7 +2175,7 @@ lookup_dimension(Py_buffer *view, char *
     if (index < 0) {
         index += nitems;
     }
-    if (index < 0 || index >= nitems) {
+    if ((size_t)index >= (size_t)nitems) {
         PyErr_Format(PyExc_IndexError,
                      "index out of bounds on dimension %d", dim + 1);
         return NULL;
diff -r 39511e854e6d Objects/tupleobject.c
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -149,7 +149,7 @@ PyTuple_GetItem(PyObject *op, Py_ssize_t
         PyErr_BadInternalCall();
         return NULL;
     }
-    if (i < 0 || i >= Py_SIZE(op)) {
+    if ((size_t)i >= (size_t)Py_SIZE(op)) {
         PyErr_SetString(PyExc_IndexError, "tuple index out of range");
         return NULL;
     }
@@ -165,7 +165,7 @@ PyTuple_SetItem(PyObject *op, Py_ssize_t
         PyErr_BadInternalCall();
         return -1;
     }
-    if (i < 0 || i >= Py_SIZE(op)) {
+    if ((size_t)i >= (size_t)Py_SIZE(op)) {
         Py_XDECREF(newitem);
         PyErr_SetString(PyExc_IndexError,
                         "tuple assignment index out of range");
@@ -389,7 +389,7 @@ tuplecontains(PyTupleObject *a, PyObject
 static PyObject *
 tupleitem(PyTupleObject *a, Py_ssize_t i)
 {
-    if (i < 0 || i >= Py_SIZE(a)) {
+    if ((size_t)i >= (size_t)Py_SIZE(a)) {
         PyErr_SetString(PyExc_IndexError, "tuple index out of range");
         return NULL;
     }
diff -r 39511e854e6d Objects/unicodeobject.c
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -4168,7 +4168,7 @@ PyUnicode_ReadChar(PyObject *unicode, Py
         PyErr_BadArgument();
         return (Py_UCS4)-1;
     }
-    if (index < 0 || index >= PyUnicode_GET_LENGTH(unicode)) {
+    if ((size_t)index >= (size_t)PyUnicode_GET_LENGTH(unicode)) {
         PyErr_SetString(PyExc_IndexError, "string index out of range");
         return (Py_UCS4)-1;
     }
@@ -4185,7 +4185,7 @@ PyUnicode_WriteChar(PyObject *unicode, P
         return -1;
     }
     assert(PyUnicode_IS_READY(unicode));
-    if (index < 0 || index >= PyUnicode_GET_LENGTH(unicode)) {
+    if ((size_t)index >= (size_t)PyUnicode_GET_LENGTH(unicode)) {
         PyErr_SetString(PyExc_IndexError, "string index out of range");
         return -1;
     }
@@ -11547,7 +11547,7 @@ unicode_getitem(PyObject *self, Py_ssize
         PyErr_BadArgument();
         return NULL;
     }
-    if (index < 0 || index >= PyUnicode_GET_LENGTH(self)) {
+    if ((size_t)index >= (size_t)PyUnicode_GET_LENGTH(self)) {
         PyErr_SetString(PyExc_IndexError, "string index out of range");
         return NULL;
     }
@@ -14585,7 +14585,7 @@ unicode_format_arg_output(struct unicode
     /* Truncate the string for "s", "r" and "a" formats
        if the precision is set */
     if (arg->ch == 's' || arg->ch == 'r' || arg->ch == 'a') {
-        if (arg->prec >= 0 && len > arg->prec)
+        if ((size_t)len > (size_t)arg->prec)
             len = arg->prec;
     }
 
diff -r 39511e854e6d Parser/acceler.c
--- a/Parser/acceler.c
+++ b/Parser/acceler.c
@@ -102,7 +102,7 @@ fixstate(grammar *g, state *s)
         }
         else if (lbl == EMPTY)
             s->s_accept = 1;
-        else if (lbl >= 0 && lbl < nl)
+        else if ((unsigned)lbl < (unsigned)nl)
             accel[lbl] = a->a_arrow;
     }
     while (nl > 0 && accel[nl-1] == -1)
diff -r 39511e854e6d Python/marshal.c
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -1426,7 +1426,7 @@ r_object(RFILE *p)
 
     case TYPE_REF:
         n = r_long(p);
-        if (n < 0 || n >= PyList_GET_SIZE(p->refs)) {
+        if ((size_t)n >= (size_t)PyList_GET_SIZE(p->refs)) {
             if (n == -1 && PyErr_Occurred())
                 break;
             PyErr_SetString(PyExc_ValueError, "bad marshal data (invalid reference)");
diff -r 39511e854e6d Python/pystrtod.c
--- a/Python/pystrtod.c
+++ b/Python/pystrtod.c
@@ -674,8 +674,7 @@ ensure_decimal_point(char* buffer, size_
            arrive here as a result of using the empty format code or
            repr/str builtins and those never want an upper case 'E' */
         written = PyOS_snprintf(p, buf_avail, "e%+.02d", digit_count-1);
-        if (!(0 <= written &&
-              written < Py_SAFE_DOWNCAST(buf_avail, size_t, int)))
+        if ((size_t)written >= buf_avail)
             /* output truncated, or something else bad happened */
             return NULL;
         remove_trailing_zeros(buffer);