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[mypyc] Fix int operations on Python 3.12 (#15470)
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The representation of `int` objects was changed in Python 3.12.

Define some helper macros to make it possible to support all Python
versions we care about without too much code duplication.

Work on mypyc/mypyc#995.

Co-authored-by: Shantanu <[email protected]>
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@JukkaL @hauntsaninja
JukkaL and hauntsaninja committed Jun 24, 2023
1 parent 1fab96b commit 9bd8563
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Showing 3 changed files with 126 additions and 14 deletions.
33 changes: 22 additions & 11 deletions mypyc/lib-rt/int_ops.c
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Original file line number Diff line number Diff line change
Expand Up @@ -308,10 +308,10 @@ PyObject *CPyBool_Str(bool b) {
}

static void CPyLong_NormalizeUnsigned(PyLongObject *v) {
Py_ssize_t i = v->ob_base.ob_size;
while (i > 0 && v->ob_digit[i - 1] == 0)
Py_ssize_t i = CPY_LONG_SIZE_UNSIGNED(v);
while (i > 0 && CPY_LONG_DIGIT(v, i - 1) == 0)
i--;
v->ob_base.ob_size = i;
CPyLong_SetUnsignedSize(v, i);
}

// Bitwise op '&', '|' or '^' using the generic (slow) API
Expand Down Expand Up @@ -361,8 +361,8 @@ static digit *GetIntDigits(CPyTagged n, Py_ssize_t *size, digit *buf) {
return buf;
} else {
PyLongObject *obj = (PyLongObject *)CPyTagged_LongAsObject(n);
*size = obj->ob_base.ob_size;
return obj->ob_digit;
*size = CPY_LONG_SIZE_SIGNED(obj);
return &CPY_LONG_DIGIT(obj, 0);
}
}

Expand Down Expand Up @@ -399,20 +399,20 @@ static CPyTagged BitwiseLongOp(CPyTagged a, CPyTagged b, char op) {
Py_ssize_t i;
if (op == '&') {
for (i = 0; i < asize; i++) {
r->ob_digit[i] = adigits[i] & bdigits[i];
CPY_LONG_DIGIT(r, i) = adigits[i] & bdigits[i];
}
} else {
if (op == '|') {
for (i = 0; i < asize; i++) {
r->ob_digit[i] = adigits[i] | bdigits[i];
CPY_LONG_DIGIT(r, i) = adigits[i] | bdigits[i];
}
} else {
for (i = 0; i < asize; i++) {
r->ob_digit[i] = adigits[i] ^ bdigits[i];
CPY_LONG_DIGIT(r, i) = adigits[i] ^ bdigits[i];
}
}
for (; i < bsize; i++) {
r->ob_digit[i] = bdigits[i];
CPY_LONG_DIGIT(r, i) = bdigits[i];
}
}
CPyLong_NormalizeUnsigned(r);
Expand Down Expand Up @@ -521,7 +521,7 @@ int64_t CPyLong_AsInt64(PyObject *o) {
Py_ssize_t size = Py_SIZE(lobj);
if (likely(size == 1)) {
// Fast path
return lobj->ob_digit[0];
return CPY_LONG_DIGIT(lobj, 0);
} else if (likely(size == 0)) {
return 0;
}
Expand Down Expand Up @@ -576,14 +576,25 @@ int64_t CPyInt64_Remainder(int64_t x, int64_t y) {

int32_t CPyLong_AsInt32(PyObject *o) {
if (likely(PyLong_Check(o))) {
#if CPY_3_12_FEATURES
PyLongObject *lobj = (PyLongObject *)o;
size_t tag = CPY_LONG_TAG(lobj);
if (likely(tag == (1 << CPY_NON_SIZE_BITS))) {
// Fast path
return CPY_LONG_DIGIT(lobj, 0);
} else if (likely(tag == CPY_SIGN_ZERO)) {
return 0;
}
#else
PyLongObject *lobj = (PyLongObject *)o;
Py_ssize_t size = lobj->ob_base.ob_size;
if (likely(size == 1)) {
// Fast path
return lobj->ob_digit[0];
return CPY_LONG_DIGIT(lobj, 0);
} else if (likely(size == 0)) {
return 0;
}
#endif
}
// Slow path
int overflow;
Expand Down
40 changes: 40 additions & 0 deletions mypyc/lib-rt/mypyc_util.h
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Original file line number Diff line number Diff line change
Expand Up @@ -72,4 +72,44 @@ static inline CPyTagged CPyTagged_ShortFromSsize_t(Py_ssize_t x) {
// Are we targeting Python 3.12 or newer?
#define CPY_3_12_FEATURES (PY_VERSION_HEX >= 0x030c0000)

#if CPY_3_12_FEATURES

// Same as macros in CPython internal/pycore_long.h, but with a CPY_ prefix
#define CPY_NON_SIZE_BITS 3
#define CPY_SIGN_ZERO 1
#define CPY_SIGN_NEGATIVE 2
#define CPY_SIGN_MASK 3

#define CPY_LONG_DIGIT(o, n) ((o)->long_value.ob_digit[n])

// Only available on Python 3.12 and later
#define CPY_LONG_TAG(o) ((o)->long_value.lv_tag)
#define CPY_LONG_IS_NEGATIVE(o) (((o)->long_value.lv_tag & CPY_SIGN_MASK) == CPY_SIGN_NEGATIVE)
// Only available on Python 3.12 and later
#define CPY_LONG_SIZE(o) ((o)->long_value.lv_tag >> CPY_NON_SIZE_BITS)
// Number of digits; negative for negative ints
#define CPY_LONG_SIZE_SIGNED(o) (CPY_LONG_IS_NEGATIVE(o) ? -CPY_LONG_SIZE(o) : CPY_LONG_SIZE(o))
// Number of digits, assuming int is non-negative
#define CPY_LONG_SIZE_UNSIGNED(o) CPY_LONG_SIZE(o)

static inline void CPyLong_SetUnsignedSize(PyLongObject *o, Py_ssize_t n) {
if (n == 0)
o->long_value.lv_tag = CPY_SIGN_ZERO;
else
o->long_value.lv_tag = n << CPY_NON_SIZE_BITS;
}

#else

#define CPY_LONG_DIGIT(o, n) ((o)->ob_digit[n])
#define CPY_LONG_IS_NEGATIVE(o) (((o)->ob_base.ob_size < 0)
#define CPY_LONG_SIZE_SIGNED(o) ((o)->ob_base.ob_size)
#define CPY_LONG_SIZE_UNSIGNED(o) ((o)->ob_base.ob_size)

static inline void CPyLong_SetUnsignedSize(PyLongObject *o, Py_ssize_t n) {
o->ob_base.ob_size = n;
}

#endif

#endif
67 changes: 64 additions & 3 deletions mypyc/lib-rt/pythonsupport.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -129,6 +129,65 @@ init_subclass(PyTypeObject *type, PyObject *kwds)
return 0;
}

#if CPY_3_12_FEATURES

static inline Py_ssize_t
CPyLong_AsSsize_tAndOverflow(PyObject *vv, int *overflow)
{
/* This version by Tim Peters */
PyLongObject *v = (PyLongObject *)vv;
size_t x, prev;
Py_ssize_t res;
Py_ssize_t i;
int sign;

*overflow = 0;

res = -1;
i = CPY_LONG_TAG(v);

// TODO: Combine zero and non-zero cases helow?
if (likely(i == (1 << CPY_NON_SIZE_BITS))) {
res = CPY_LONG_DIGIT(v, 0);
} else if (likely(i == CPY_SIGN_ZERO)) {
res = 0;
} else if (i == ((1 << CPY_NON_SIZE_BITS) | CPY_SIGN_NEGATIVE)) {
res = -(sdigit)CPY_LONG_DIGIT(v, 0);
} else {
sign = 1;
x = 0;
if (i & CPY_SIGN_NEGATIVE) {
sign = -1;
}
i >>= CPY_NON_SIZE_BITS;
while (--i >= 0) {
prev = x;
x = (x << PyLong_SHIFT) + CPY_LONG_DIGIT(v, i);
if ((x >> PyLong_SHIFT) != prev) {
*overflow = sign;
goto exit;
}
}
/* Haven't lost any bits, but casting to long requires extra
* care (see comment above).
*/
if (x <= (size_t)CPY_TAGGED_MAX) {
res = (Py_ssize_t)x * sign;
}
else if (sign < 0 && x == CPY_TAGGED_ABS_MIN) {
res = CPY_TAGGED_MIN;
}
else {
*overflow = sign;
/* res is already set to -1 */
}
}
exit:
return res;
}

#else

// Adapted from longobject.c in Python 3.7.0

/* This function adapted from PyLong_AsLongLongAndOverflow, but with
Expand Down Expand Up @@ -156,11 +215,11 @@ CPyLong_AsSsize_tAndOverflow(PyObject *vv, int *overflow)
i = Py_SIZE(v);

if (likely(i == 1)) {
res = v->ob_digit[0];
res = CPY_LONG_DIGIT(v, 0);
} else if (likely(i == 0)) {
res = 0;
} else if (i == -1) {
res = -(sdigit)v->ob_digit[0];
res = -(sdigit)CPY_LONG_DIGIT(v, 0);
} else {
sign = 1;
x = 0;
Expand All @@ -170,7 +229,7 @@ CPyLong_AsSsize_tAndOverflow(PyObject *vv, int *overflow)
}
while (--i >= 0) {
prev = x;
x = (x << PyLong_SHIFT) + v->ob_digit[i];
x = (x << PyLong_SHIFT) + CPY_LONG_DIGIT(v, i);
if ((x >> PyLong_SHIFT) != prev) {
*overflow = sign;
goto exit;
Expand All @@ -194,6 +253,8 @@ CPyLong_AsSsize_tAndOverflow(PyObject *vv, int *overflow)
return res;
}

#endif

// Adapted from listobject.c in Python 3.7.0
static int
list_resize(PyListObject *self, Py_ssize_t newsize)
Expand Down

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