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Merged
SwayamInSync merged 5 commits into from
Dec 4, 2025
+639 −104
Merged

FEAT: Adding Quad to and from bytes array casting support #228

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8e3eba4
to and from bytes cast
SwayamInSync Nov 20, 2025
c22e9f4
fix rounding and more tests
SwayamInSync Nov 20, 2025
5e3fce6
optimizing
SwayamInSync Nov 30, 2025
daf0611
fixes
SwayamInSync Dec 4, 2025
628a505
strlen fixes for unicode
SwayamInSync Dec 4, 2025
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299 changes: 215 additions & 84 deletions quaddtype/numpy_quaddtype/src/casts.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@ extern "C" {
#include "numpy/dtype_api.h"
}
#include <cstring>
#include <cstdlib>
#include "sleef.h"
#include "sleefquad.h"

Expand All @@ -26,7 +27,7 @@ extern "C" {
#include "dragon4.h"
#include "ops.hpp"

#define NUM_CASTS 36 // 17 to_casts + 17 from_casts + 1 quad_to_quad + 1 void_to_quad
#define NUM_CASTS 38 // 17 to_casts + 17 from_casts + 1 quad_to_quad + 1 void_to_quad
#define QUAD_STR_WIDTH 50 // 42 is enough for scientific notation float128, just keeping some buffer

static NPY_CASTING
Expand Down Expand Up @@ -249,50 +250,11 @@ unicode_to_quad_convert(const Py_UCS4 *ucs4_str, npy_intp unicode_size_chars,
return 0;
}

template <bool Aligned>
static int
unicode_to_quad_strided_loop_unaligned(PyArrayMethod_Context *context, char *const data[],
npy_intp const dimensions[], npy_intp const strides[],
void *NPY_UNUSED(auxdata))
{
npy_intp N = dimensions[0];
char *in_ptr = data[0];
char *out_ptr = data[1];
npy_intp in_stride = strides[0];
npy_intp out_stride = strides[1];

PyArray_Descr *const *descrs = context->descriptors;
QuadPrecDTypeObject *descr_out = (QuadPrecDTypeObject *)descrs[1];
QuadBackendType backend = descr_out->backend;

// Unicode strings are stored as UCS4 (4 bytes per character)
npy_intp unicode_size_chars = descrs[0]->elsize / 4;

while (N--) {
Py_UCS4 *ucs4_str = (Py_UCS4 *)in_ptr;
quad_value out_val;

if (unicode_to_quad_convert(ucs4_str, unicode_size_chars, backend, &out_val) < 0) {
return -1;
}

if (backend == BACKEND_SLEEF) {
memcpy(out_ptr, &out_val.sleef_value, sizeof(Sleef_quad));
}
else {
memcpy(out_ptr, &out_val.longdouble_value, sizeof(long double));
}

in_ptr += in_stride;
out_ptr += out_stride;
}

return 0;
}

static int
unicode_to_quad_strided_loop_aligned(PyArrayMethod_Context *context, char *const data[],
npy_intp const dimensions[], npy_intp const strides[],
void *NPY_UNUSED(auxdata))
unicode_to_quad_strided_loop(PyArrayMethod_Context *context, char *const data[],
npy_intp const dimensions[], npy_intp const strides[],
void *NPY_UNUSED(auxdata))
{
npy_intp N = dimensions[0];
char *in_ptr = data[0];
Expand All @@ -315,12 +277,7 @@ unicode_to_quad_strided_loop_aligned(PyArrayMethod_Context *context, char *const
return -1;
}

if (backend == BACKEND_SLEEF) {
*(Sleef_quad *)out_ptr = out_val.sleef_value;
}
else {
*(long double *)out_ptr = out_val.longdouble_value;
}
store_quad<Aligned>(out_ptr, out_val, backend);

in_ptr += in_stride;
out_ptr += out_stride;
Expand Down Expand Up @@ -416,10 +373,11 @@ copy_string_to_ucs4(const char *str, Py_UCS4 *out_ucs4, npy_intp unicode_size_ch
}
}

template <bool Aligned>
static int
quad_to_unicode_loop_unaligned(PyArrayMethod_Context *context, char *const data[],
npy_intp const dimensions[], npy_intp const strides[],
void *NPY_UNUSED(auxdata))
quad_to_unicode_loop(PyArrayMethod_Context *context, char *const data[],
npy_intp const dimensions[], npy_intp const strides[],
void *NPY_UNUSED(auxdata))
{
npy_intp N = dimensions[0];
char *in_ptr = data[0];
Expand All @@ -432,16 +390,9 @@ quad_to_unicode_loop_unaligned(PyArrayMethod_Context *context, char *const data[
QuadBackendType backend = descr_in->backend;

npy_intp unicode_size_chars = descrs[1]->elsize / 4;
size_t elem_size = (backend == BACKEND_SLEEF) ? sizeof(Sleef_quad) : sizeof(long double);

while (N--) {
quad_value in_val;
if (backend == BACKEND_SLEEF) {
memcpy(&in_val.sleef_value, in_ptr, sizeof(Sleef_quad));
}
else {
memcpy(&in_val.longdouble_value, in_ptr, sizeof(long double));
}
quad_value in_val = load_quad<Aligned>(in_ptr, backend);

// Convert to Sleef_quad for Dragon4
Sleef_quad sleef_val = quad_to_sleef_quad(&in_val, backend);
Expand Down Expand Up @@ -471,10 +422,83 @@ quad_to_unicode_loop_unaligned(PyArrayMethod_Context *context, char *const data[
return 0;
}

// Bytes to QuadDType casting
static NPY_CASTING
bytes_to_quad_resolve_descriptors(PyObject *NPY_UNUSED(self), PyArray_DTypeMeta *dtypes[2],
PyArray_Descr *given_descrs[2], PyArray_Descr *loop_descrs[2],
npy_intp *view_offset)
{
// Bytes dtype doesn't have byte order concerns like Unicode
Py_INCREF(given_descrs[0]);
loop_descrs[0] = given_descrs[0];

if (given_descrs[1] == NULL) {
loop_descrs[1] = (PyArray_Descr *)new_quaddtype_instance(BACKEND_SLEEF);
if (loop_descrs[1] == nullptr) {
Py_DECREF(loop_descrs[0]);
return (NPY_CASTING)-1;
}
}
else {
Py_INCREF(given_descrs[1]);
loop_descrs[1] = given_descrs[1];
}

return NPY_UNSAFE_CASTING;
}

// Helper function: Convert bytes string to quad_value
static inline int
bytes_to_quad_convert(const char *bytes_str, npy_intp bytes_size,
QuadBackendType backend, quad_value *out_val)
{
// Create a null-terminated copy since bytes might not be null-terminated
char *temp_str = (char *)malloc(bytes_size + 1);
if (temp_str == NULL) {
PyErr_NoMemory();
return -1;
}

memcpy(temp_str, bytes_str, bytes_size);
temp_str[bytes_size] = '\0';
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@ngoldbaum ngoldbaum Dec 4, 2025

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you can delete this since the assignment below already handles the null-at-the-end case.


// Find the actual end (null byte or first occurrence)
npy_intp actual_len = 0;
while (actual_len < bytes_size && temp_str[actual_len] != '\0') {
actual_len++;
}
temp_str[actual_len] = '\0';

char *endptr;
int err = NumPyOS_ascii_strtoq(temp_str, backend, out_val, &endptr);

if (err < 0) {
PyErr_Format(PyExc_ValueError,
"could not convert bytes to QuadPrecision: np.bytes_(%s)", temp_str);
free(temp_str);
return -1;
}

while (ascii_isspace(*endptr)) {
endptr++;
}

if (*endptr != '\0') {
PyErr_Format(PyExc_ValueError,
"could not convert bytes to QuadPrecision: np.bytes_(%s)", temp_str);
free(temp_str);
return -1;
}

free(temp_str);
return 0;
}

template <bool Aligned>
static int
quad_to_unicode_loop_aligned(PyArrayMethod_Context *context, char *const data[],
npy_intp const dimensions[], npy_intp const strides[],
void *NPY_UNUSED(auxdata))
bytes_to_quad_strided_loop(PyArrayMethod_Context *context, char *const data[],
npy_intp const dimensions[], npy_intp const strides[],
void *NPY_UNUSED(auxdata))
{
npy_intp N = dimensions[0];
char *in_ptr = data[0];
Expand All @@ -483,38 +507,107 @@ quad_to_unicode_loop_aligned(PyArrayMethod_Context *context, char *const data[],
npy_intp out_stride = strides[1];

PyArray_Descr *const *descrs = context->descriptors;
QuadPrecDTypeObject *descr_in = (QuadPrecDTypeObject *)descrs[0];
QuadBackendType backend = descr_in->backend;
QuadPrecDTypeObject *descr_out = (QuadPrecDTypeObject *)descrs[1];
QuadBackendType backend = descr_out->backend;

npy_intp unicode_size_chars = descrs[1]->elsize / 4;
npy_intp bytes_size = descrs[0]->elsize;

while (N--) {
quad_value in_val;
if (backend == BACKEND_SLEEF) {
in_val.sleef_value = *(Sleef_quad *)in_ptr;
quad_value out_val;

if (bytes_to_quad_convert(in_ptr, bytes_size, backend, &out_val) < 0) {
return -1;
}
else {
in_val.longdouble_value = *(long double *)in_ptr;

store_quad<Aligned>(out_ptr, out_val, backend);

in_ptr += in_stride;
out_ptr += out_stride;
}

return 0;
}

// QuadDType to bytes
static NPY_CASTING
quad_to_bytes_resolve_descriptors(PyObject *NPY_UNUSED(self), PyArray_DTypeMeta *dtypes[2],
PyArray_Descr *given_descrs[2], PyArray_Descr *loop_descrs[2],
npy_intp *view_offset)
{
npy_intp required_size_bytes = QUAD_STR_WIDTH;

if (given_descrs[1] == NULL) {
PyArray_Descr *new_descr = PyArray_DescrNewFromType(NPY_STRING);
if (new_descr == NULL) {
return (NPY_CASTING)-1;
}
new_descr->elsize = required_size_bytes;
loop_descrs[1] = new_descr;
}
else {
Py_INCREF(given_descrs[1]);
loop_descrs[1] = given_descrs[1];
}

// Convert to Sleef_quad for Dragon4
Sleef_quad sleef_val = quad_to_sleef_quad(&in_val, backend);
Py_INCREF(given_descrs[0]);
loop_descrs[0] = given_descrs[0];

// Get string representation with adaptive notation
PyObject *py_str = quad_to_string_adaptive(&sleef_val, unicode_size_chars);
*view_offset = 0;

// If target descriptor is wide enough, it's a safe cast
if (loop_descrs[1]->elsize >= required_size_bytes) {
return NPY_SAFE_CASTING;
}
return NPY_SAME_KIND_CASTING;
}

// Helper function: Copy string to bytes output buffer
static inline void
copy_string_to_bytes(const char *str, char *out_bytes, npy_intp bytes_size)
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@ngoldbaum ngoldbaum Dec 4, 2025

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I'd call this copy_cstring_to_bytes to make it clearer that str has to be null-terminated.

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@ngoldbaum ngoldbaum Dec 4, 2025

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or just inline it because the function only has one caller

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@SwayamInSync SwayamInSync Dec 4, 2025

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I thought it might be later needed for adding variable-len string support, but it seems that'll also be simple as a strncpy call

{
npy_intp str_len = strlen(str);
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strlen is a timebomb in any C codebase. Use strnlen or strncpy instead.


npy_intp copy_len = (str_len < bytes_size) ? str_len : bytes_size;
memcpy(out_bytes, str, copy_len);

// Pad remaining space with null bytes
for (npy_intp i = copy_len; i < bytes_size; i++) {
out_bytes[i] = '\0';
}
}

template <bool Aligned>
static int
quad_to_bytes_loop(PyArrayMethod_Context *context, char *const data[],
npy_intp const dimensions[], npy_intp const strides[],
void *NPY_UNUSED(auxdata))
{
npy_intp N = dimensions[0];
char *in_ptr = data[0];
char *out_ptr = data[1];
npy_intp in_stride = strides[0];
npy_intp out_stride = strides[1];

PyArray_Descr *const *descrs = context->descriptors;
QuadPrecDTypeObject *descr_in = (QuadPrecDTypeObject *)descrs[0];
QuadBackendType backend = descr_in->backend;

npy_intp bytes_size = descrs[1]->elsize;

while (N--) {
quad_value in_val = load_quad<Aligned>(in_ptr, backend);
Sleef_quad sleef_val = quad_to_sleef_quad(&in_val, backend);
PyObject *py_str = quad_to_string_adaptive(&sleef_val, bytes_size);
if (py_str == NULL) {
return -1;
}

const char *temp_str = PyUnicode_AsUTF8(py_str);
if (temp_str == NULL) {
Py_DECREF(py_str);
return -1;
}

// Convert char string to UCS4 and store in output
Py_UCS4 *out_ucs4 = (Py_UCS4 *)out_ptr;
copy_string_to_ucs4(temp_str, out_ucs4, unicode_size_chars);
copy_string_to_bytes(temp_str, out_ptr, bytes_size);

Py_DECREF(py_str);

Expand Down Expand Up @@ -1243,8 +1336,8 @@ init_casts_internal(void)
PyArray_DTypeMeta **unicode_to_quad_dtypes = new PyArray_DTypeMeta *[2]{&PyArray_UnicodeDType, &QuadPrecDType};
PyType_Slot *unicode_to_quad_slots = new PyType_Slot[4]{
{NPY_METH_resolve_descriptors, (void *)&unicode_to_quad_resolve_descriptors},
{NPY_METH_strided_loop, (void *)&unicode_to_quad_strided_loop_aligned},
{NPY_METH_unaligned_strided_loop, (void *)&unicode_to_quad_strided_loop_unaligned},
{NPY_METH_strided_loop, (void *)&unicode_to_quad_strided_loop<true>},
{NPY_METH_unaligned_strided_loop, (void *)&unicode_to_quad_strided_loop<false>},
{0, nullptr}};

PyArrayMethod_Spec *unicode_to_quad_spec = new PyArrayMethod_Spec{
Expand All @@ -1262,8 +1355,8 @@ init_casts_internal(void)
PyArray_DTypeMeta **quad_to_unicode_dtypes = new PyArray_DTypeMeta *[2]{&QuadPrecDType, &PyArray_UnicodeDType};
PyType_Slot *quad_to_unicode_slots = new PyType_Slot[4]{
{NPY_METH_resolve_descriptors, (void *)&quad_to_unicode_resolve_descriptors},
{NPY_METH_strided_loop, (void *)&quad_to_unicode_loop_aligned},
{NPY_METH_unaligned_strided_loop, (void *)&quad_to_unicode_loop_unaligned},
{NPY_METH_strided_loop, (void *)&quad_to_unicode_loop<true>},
{NPY_METH_unaligned_strided_loop, (void *)&quad_to_unicode_loop<false>},
{0, nullptr}};

PyArrayMethod_Spec *quad_to_unicode_spec = new PyArrayMethod_Spec{
Expand All @@ -1277,6 +1370,44 @@ init_casts_internal(void)
};
add_spec(quad_to_unicode_spec);

// Bytes to QuadPrecision cast
PyArray_DTypeMeta **bytes_to_quad_dtypes = new PyArray_DTypeMeta *[2]{&PyArray_BytesDType, &QuadPrecDType};
PyType_Slot *bytes_to_quad_slots = new PyType_Slot[4]{
{NPY_METH_resolve_descriptors, (void *)&bytes_to_quad_resolve_descriptors},
{NPY_METH_strided_loop, (void *)&bytes_to_quad_strided_loop<true>},
{NPY_METH_unaligned_strided_loop, (void *)&bytes_to_quad_strided_loop<false>},
{0, nullptr}};

PyArrayMethod_Spec *bytes_to_quad_spec = new PyArrayMethod_Spec{
.name = "cast_Bytes_to_QuadPrec",
.nin = 1,
.nout = 1,
.casting = NPY_UNSAFE_CASTING,
.flags = NPY_METH_SUPPORTS_UNALIGNED,
.dtypes = bytes_to_quad_dtypes,
.slots = bytes_to_quad_slots,
};
add_spec(bytes_to_quad_spec);

// QuadPrecision to Bytes
PyArray_DTypeMeta **quad_to_bytes_dtypes = new PyArray_DTypeMeta *[2]{&QuadPrecDType, &PyArray_BytesDType};
PyType_Slot *quad_to_bytes_slots = new PyType_Slot[4]{
{NPY_METH_resolve_descriptors, (void *)&quad_to_bytes_resolve_descriptors},
{NPY_METH_strided_loop, (void *)&quad_to_bytes_loop<true>},
{NPY_METH_unaligned_strided_loop, (void *)&quad_to_bytes_loop<false>},
{0, nullptr}};

PyArrayMethod_Spec *quad_to_bytes_spec = new PyArrayMethod_Spec{
.name = "cast_QuadPrec_to_Bytes",
.nin = 1,
.nout = 1,
.casting = NPY_UNSAFE_CASTING,
.flags = NPY_METH_SUPPORTS_UNALIGNED,
.dtypes = quad_to_bytes_dtypes,
.slots = quad_to_bytes_slots,
};
add_spec(quad_to_bytes_spec);

specs[spec_count] = nullptr;
return specs;
}
Expand Down
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