Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Appearance settings

gh-120176: Reduce number of compares in index range checks #120181

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
lgeiger wants to merge 1 commit into from
Closed

gh-120176: Reduce number of compares in index range checks #120181

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 13 additions & 0 deletions 13 Include/internal/pycore_abstract.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,19 @@ PyObject *_PyNumber_InPlacePowerNoMod(PyObject *lhs, PyObject *rhs);

extern int _PyObject_HasLen(PyObject *o);

static inline int
_Py_ValidIndex(Py_ssize_t i, Py_ssize_t limit)
{
/* The cast to size_t lets us use just a single comparison
to check whether i is in the range: 0 <= i < limit.

See: Section 14.2 "Bounds Checking" in the Agner Fog
optimization manual found at:
https://www.agner.org/optimize/optimizing_cpp.pdf
*/
return (size_t) i < (size_t) limit;
}

/* === Sequence protocol ================================================ */

#define PY_ITERSEARCH_COUNT 1
Expand Down
5 changes: 3 additions & 2 deletions 5 Modules/_ctypes/_ctypes.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -106,6 +106,7 @@ bytes(cdata)
# include <windows.h>
#endif

#include "pycore_abstract.h" // _Py_ValidIndex()
#include "pycore_call.h" // _PyObject_CallNoArgs()
#include "pycore_ceval.h" // _Py_EnterRecursiveCall()
#ifdef MS_WIN32
Expand Down Expand Up @@ -4645,7 +4646,7 @@ Array_item(PyObject *myself, Py_ssize_t index)
CDataObject *self = (CDataObject *)myself;
Py_ssize_t offset, size;

if (index < 0 || index >= self->b_length) {
if (!_Py_ValidIndex(index, self->b_length)) {
PyErr_SetString(PyExc_IndexError,
"invalid index");
return NULL;
Expand Down Expand Up @@ -4800,7 +4801,7 @@ Array_ass_item(PyObject *myself, Py_ssize_t index, PyObject *value)
}
assert(stginfo); /* Cannot be NULL for array object instances */

if (index < 0 || index >= stginfo->length) {
if (!_Py_ValidIndex(index, stginfo->length)) {
PyErr_SetString(PyExc_IndexError,
"invalid index");
return -1;
Expand Down
5 changes: 3 additions & 2 deletions 5 Modules/_elementtree.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@
#endif

#include "Python.h"
#include "pycore_abstract.h" // _Py_ValidIndex()
#include "pycore_import.h" // _PyImport_GetModuleAttrString()
#include "pycore_pyhash.h" // _Py_HashSecret

Expand Down Expand Up @@ -1486,7 +1487,7 @@ element_getitem(PyObject* self_, Py_ssize_t index)
{
ElementObject* self = (ElementObject*) self_;

if (!self->extra || index < 0 || index >= self->extra->length) {
if (!self->extra || !_Py_ValidIndex(index, self->extra->length)) {
PyErr_SetString(
PyExc_IndexError,
"child index out of range"
Expand Down Expand Up @@ -1738,7 +1739,7 @@ element_setitem(PyObject* self_, Py_ssize_t index, PyObject* item)
Py_ssize_t i;
PyObject* old;

if (!self->extra || index < 0 || index >= self->extra->length) {
if (!self->extra || !_Py_ValidIndex(index, self->extra->length)) {
PyErr_SetString(
PyExc_IndexError,
"child assignment index out of range");
Expand Down
3 changes: 2 additions & 1 deletion 3 Modules/_sre/sre.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,7 @@ static const char copyright[] =
" SRE 2.2.2 Copyright (c) 1997-2002 by Secret Labs AB ";

#include "Python.h"
#include "pycore_abstract.h" // _Py_ValidIndex()
#include "pycore_critical_section.h" // Py_BEGIN_CRITICAL_SECTION
#include "pycore_dict.h" // _PyDict_Next()
#include "pycore_long.h" // _PyLong_GetZero()
Expand Down Expand Up @@ -2208,7 +2209,7 @@ match_getindex(MatchObject* self, PyObject* index)
}
}
}
if (i < 0 || i >= self->groups) {
if (!_Py_ValidIndex(i, self->groups)) {
/* raise IndexError if we were given a bad group number */
if (!PyErr_Occurred()) {
PyErr_SetString(PyExc_IndexError, "no such group");
Expand Down
9 changes: 5 additions & 4 deletions 9 Modules/arraymodule.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
#endif

#include "Python.h"
#include "pycore_abstract.h" // _Py_ValidIndex()
#include "pycore_bytesobject.h" // _PyBytes_Repeat
#include "pycore_call.h" // _PyObject_CallMethod()
#include "pycore_ceval.h" // _PyEval_GetBuiltin()
Expand Down Expand Up @@ -851,7 +852,7 @@ array_length(arrayobject *a)
static PyObject *
array_item(arrayobject *a, Py_ssize_t i)
{
if (i < 0 || i >= Py_SIZE(a)) {
if (!_Py_ValidIndex(i, Py_SIZE(a))) {
PyErr_SetString(PyExc_IndexError, "array index out of range");
return NULL;
}
Expand Down Expand Up @@ -1028,7 +1029,7 @@ array_del_slice(arrayobject *a, Py_ssize_t ilow, Py_ssize_t ihigh)
static int
array_ass_item(arrayobject *a, Py_ssize_t i, PyObject *v)
{
if (i < 0 || i >= Py_SIZE(a)) {
if (!_Py_ValidIndex(i, Py_SIZE(a))) {
PyErr_SetString(PyExc_IndexError,
"array assignment index out of range");
return -1;
Expand Down Expand Up @@ -1311,7 +1312,7 @@ array_array_pop_impl(arrayobject *self, Py_ssize_t i)
}
if (i < 0)
i += Py_SIZE(self);
if (i < 0 || i >= Py_SIZE(self)) {
if (!_Py_ValidIndex(i, Py_SIZE(self))) {
PyErr_SetString(PyExc_IndexError, "pop index out of range");
return NULL;
}
Expand Down Expand Up @@ -2502,7 +2503,7 @@ array_ass_subscr(arrayobject* self, PyObject* item, PyObject* value)
return -1;
if (i < 0)
i += Py_SIZE(self);
if (i < 0 || i >= Py_SIZE(self)) {
if (!_Py_ValidIndex(i, Py_SIZE(self))) {
PyErr_SetString(PyExc_IndexError,
"array assignment index out of range");
return -1;
Expand Down
12 changes: 6 additions & 6 deletions 12 Modules/mmapmodule.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@
#endif

#include <Python.h>
#include "pycore_abstract.h" // _Py_convert_optional_to_ssize_t()
#include "pycore_abstract.h" // _Py_convert_optional_to_ssize_t(), _Py_ValidIndex()
#include "pycore_bytesobject.h" // _PyBytes_Find()
#include "pycore_fileutils.h" // _Py_stat_struct

Expand Down Expand Up @@ -1131,7 +1131,7 @@ mmap_madvise_method(mmap_object *self, PyObject *args)
return NULL;
}

if (start < 0 || start >= self->size) {
if (!_Py_ValidIndex(start, self->size)) {
PyErr_SetString(PyExc_ValueError, "madvise start out of bounds");
return NULL;
}
Expand Down Expand Up @@ -1229,7 +1229,7 @@ static PyObject *
mmap_item(mmap_object *self, Py_ssize_t i)
{
CHECK_VALID(NULL);
if (i < 0 || i >= self->size) {
if (!_Py_ValidIndex(i, self->size)) {
PyErr_SetString(PyExc_IndexError, "mmap index out of range");
return NULL;
}
Expand All @@ -1251,7 +1251,7 @@ mmap_subscript(mmap_object *self, PyObject *item)
return NULL;
if (i < 0)
i += self->size;
if (i < 0 || i >= self->size) {
if (!_Py_ValidIndex(i, self->size)) {
PyErr_SetString(PyExc_IndexError,
"mmap index out of range");
return NULL;
Expand Down Expand Up @@ -1309,7 +1309,7 @@ mmap_ass_item(mmap_object *self, Py_ssize_t i, PyObject *v)
const char *buf;

CHECK_VALID(-1);
if (i < 0 || i >= self->size) {
if (!_Py_ValidIndex(i, self->size)) {
PyErr_SetString(PyExc_IndexError, "mmap index out of range");
return -1;
}
Expand Down Expand Up @@ -1349,7 +1349,7 @@ mmap_ass_subscript(mmap_object *self, PyObject *item, PyObject *value)
return -1;
if (i < 0)
i += self->size;
if (i < 0 || i >= self->size) {
if (!_Py_ValidIndex(i, self->size)) {
PyErr_SetString(PyExc_IndexError,
"mmap index out of range");
return -1;
Expand Down
12 changes: 6 additions & 6 deletions 12 Objects/bytearrayobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
/* PyByteArray (bytearray) implementation */

#include "Python.h"
#include "pycore_abstract.h" // _PyIndex_Check()
#include "pycore_abstract.h" // _PyIndex_Check(), _Py_ValidIndex()
#include "pycore_bytes_methods.h"
#include "pycore_bytesobject.h"
#include "pycore_ceval.h" // _PyEval_GetBuiltin()
Expand Down Expand Up @@ -359,7 +359,7 @@ bytearray_irepeat(PyByteArrayObject *self, Py_ssize_t count)
static PyObject *
bytearray_getitem(PyByteArrayObject *self, Py_ssize_t i)
{
if (i < 0 || i >= Py_SIZE(self)) {
if (!_Py_ValidIndex(i, Py_SIZE(self))) {
PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
return NULL;
}
Expand All @@ -378,7 +378,7 @@ bytearray_subscript(PyByteArrayObject *self, PyObject *index)
if (i < 0)
i += PyByteArray_GET_SIZE(self);

if (i < 0 || i >= Py_SIZE(self)) {
if (!_Py_ValidIndex(i, Py_SIZE(self))) {
PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
return NULL;
}
Expand Down Expand Up @@ -573,7 +573,7 @@ bytearray_setitem(PyByteArrayObject *self, Py_ssize_t i, PyObject *value)
i += Py_SIZE(self);
}

if (i < 0 || i >= Py_SIZE(self)) {
if (!_Py_ValidIndex(i, Py_SIZE(self))) {
PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
return -1;
}
Expand Down Expand Up @@ -613,7 +613,7 @@ bytearray_ass_subscript(PyByteArrayObject *self, PyObject *index, PyObject *valu
i += PyByteArray_GET_SIZE(self);
}

if (i < 0 || i >= Py_SIZE(self)) {
if (!_Py_ValidIndex(i, Py_SIZE(self))) {
PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
return -1;
}
Expand Down Expand Up @@ -1911,7 +1911,7 @@ bytearray_pop_impl(PyByteArrayObject *self, Py_ssize_t index)
}
if (index < 0)
index += Py_SIZE(self);
if (index < 0 || index >= Py_SIZE(self)) {
if (!_Py_ValidIndex(index, Py_SIZE(self))) {
PyErr_SetString(PyExc_IndexError, "pop index out of range");
return NULL;
}
Expand Down
4 changes: 2 additions & 2 deletions 4 Objects/bytes_methods.c
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
#include "Python.h"
#include "pycore_abstract.h" // _PyIndex_Check()
#include "pycore_abstract.h" // _PyIndex_Check(), _Py_ValidIndex()
#include "pycore_bytes_methods.h"

PyDoc_STRVAR_shared(_Py_isspace__doc__,
Expand Down Expand Up @@ -660,7 +660,7 @@ _Py_bytes_contains(const char *str, Py_ssize_t len, PyObject *arg)
PyBuffer_Release(&varg);
return pos >= 0;
}
if (ival < 0 || ival >= 256) {
if (!_Py_ValidIndex(ival, 256)) {
PyErr_SetString(PyExc_ValueError, "byte must be in range(0, 256)");
return -1;
}
Expand Down
13 changes: 6 additions & 7 deletions 13 Objects/bytesobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
/* bytes object implementation */

#include "Python.h"
#include "pycore_abstract.h" // _PyIndex_Check()
#include "pycore_abstract.h" // _PyIndex_Check(), _Py_ValidIndex()
#include "pycore_bytes_methods.h" // _Py_bytes_startswith()
#include "pycore_bytesobject.h" // _PyBytes_Find(), _PyBytes_Repeat()
#include "pycore_call.h" // _PyObject_CallNoArgs()
Expand Down Expand Up @@ -1506,7 +1506,7 @@ bytes_contains(PyObject *self, PyObject *arg)
static PyObject *
bytes_item(PyBytesObject *a, Py_ssize_t i)
{
if (i < 0 || i >= Py_SIZE(a)) {
if (!_Py_ValidIndex(i, Py_SIZE(a))) {
PyErr_SetString(PyExc_IndexError, "index out of range");
return NULL;
}
Expand Down Expand Up @@ -1613,7 +1613,7 @@ bytes_subscript(PyBytesObject* self, PyObject* item)
return NULL;
if (i < 0)
i += PyBytes_GET_SIZE(self);
if (i < 0 || i >= PyBytes_GET_SIZE(self)) {
if (!_Py_ValidIndex(i, PyBytes_GET_SIZE(self))) {
PyErr_SetString(PyExc_IndexError,
"index out of range");
return NULL;
Expand Down Expand Up @@ -2810,7 +2810,7 @@ _PyBytes_FromList(PyObject *x)
if (value == -1 && PyErr_Occurred())
goto error;

if (value < 0 || value >= 256) {
if (!_Py_ValidIndex(value, 256)) {
PyErr_SetString(PyExc_ValueError,
"bytes must be in range(0, 256)");
goto error;
Expand Down Expand Up @@ -2851,7 +2851,7 @@ _PyBytes_FromTuple(PyObject *x)
if (value == -1 && PyErr_Occurred())
goto error;

if (value < 0 || value >= 256) {
if (!_Py_ValidIndex(value, 256)) {
PyErr_SetString(PyExc_ValueError,
"bytes must be in range(0, 256)");
goto error;
Expand Down Expand Up @@ -2904,7 +2904,7 @@ _PyBytes_FromIterator(PyObject *it, PyObject *x)
goto error;

/* Range check */
if (value < 0 || value >= 256) {
if (!_Py_ValidIndex(value, 256)) {
PyErr_SetString(PyExc_ValueError,
"bytes must be in range(0, 256)");
goto error;
Expand Down Expand Up @@ -3662,4 +3662,3 @@ _PyBytes_Repeat(char* dest, Py_ssize_t len_dest,
}
}
}

5 changes: 3 additions & 2 deletions 5 Objects/dictobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -116,6 +116,7 @@ As a consequence of this, split keys have a maximum size of 16.
#define PyDict_MINSIZE 8

#include "Python.h"
#include "pycore_abstract.h" // _Py_ValidIndex()
#include "pycore_bitutils.h" // _Py_bit_length
#include "pycore_call.h" // _PyObject_CallNoArgs()
#include "pycore_ceval.h" // _PyEval_GetBuiltin()
Expand Down Expand Up @@ -2814,7 +2815,7 @@ _PyDict_Next(PyObject *op, Py_ssize_t *ppos, PyObject **pkey,
i = *ppos;
if (_PyDict_HasSplitTable(mp)) {
assert(mp->ma_used <= SHARED_KEYS_MAX_SIZE);
if (i < 0 || i >= mp->ma_used)
if (!_Py_ValidIndex(i, mp->ma_used))
return 0;
int index = get_index_from_order(mp, i);
value = mp->ma_values->values[index];
Expand All @@ -2824,7 +2825,7 @@ _PyDict_Next(PyObject *op, Py_ssize_t *ppos, PyObject **pkey,
}
else {
Py_ssize_t n = mp->ma_keys->dk_nentries;
if (i < 0 || i >= n)
if (!_Py_ValidIndex(i, n))
return 0;
if (DK_IS_UNICODE(mp->ma_keys)) {
PyDictUnicodeEntry *entry_ptr = &DK_UNICODE_ENTRIES(mp->ma_keys)[i];
Expand Down
Loading
Morty Proxy This is a proxified and sanitized view of the page, visit original site.