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UnrealEngine/Engine/Source/ThirdParty/Blosc/c-blosc-1.21.0/blosc/bitshuffle-generic.c
Brandyn / Techy fcc1b09210 init
2026-04-04 15:40:51 -05:00

221 lines
6.7 KiB
C

/*********************************************************************
Blosc - Blocked Shuffling and Compression Library
Author: Francesc Alted <francesc@blosc.org>
See LICENSES/BLOSC.txt for details about copyright and rights to use.
**********************************************************************/
#include "bitshuffle-generic.h"
/* Transpose bytes within elements, starting partway through input. */
int64_t blosc_internal_bshuf_trans_byte_elem_remainder(const void* in, void* out, const size_t size,
const size_t elem_size, const size_t start) {
char* in_b = (char*) in;
char* out_b = (char*) out;
size_t ii, jj, kk;
CHECK_MULT_EIGHT(start);
if (size > start) {
/* ii loop separated into 2 loops so the compiler can unroll */
/* the inner one. */
for (ii = start; ii + 7 < size; ii += 8) {
for (jj = 0; jj < elem_size; jj++) {
for (kk = 0; kk < 8; kk++) {
out_b[jj * size + ii + kk]
= in_b[ii * elem_size + kk * elem_size + jj];
}
}
}
for (ii = size - size % 8; ii < size; ii ++) {
for (jj = 0; jj < elem_size; jj++) {
out_b[jj * size + ii] = in_b[ii * elem_size + jj];
}
}
}
return size * elem_size;
}
/* Transpose bytes within elements. */
int64_t blosc_internal_bshuf_trans_byte_elem_scal(const void* in, void* out, const size_t size,
const size_t elem_size) {
return blosc_internal_bshuf_trans_byte_elem_remainder(in, out, size, elem_size, 0);
}
/* Transpose bits within bytes. */
int64_t blosc_internal_bshuf_trans_bit_byte_remainder(const void* in, void* out, const size_t size,
const size_t elem_size, const size_t start_byte) {
const uint64_t* in_b = (const uint64_t*) in;
uint8_t* out_b = (uint8_t*) out;
uint64_t x, t;
size_t ii, kk;
size_t nbyte = elem_size * size;
size_t nbyte_bitrow = nbyte / 8;
uint64_t e=1;
const int little_endian = *(uint8_t *) &e == 1;
const size_t bit_row_skip = little_endian ? nbyte_bitrow : -nbyte_bitrow;
const int64_t bit_row_offset = little_endian ? 0 : 7 * nbyte_bitrow;
CHECK_MULT_EIGHT(nbyte);
CHECK_MULT_EIGHT(start_byte);
for (ii = start_byte / 8; ii < nbyte_bitrow; ii ++) {
x = in_b[ii];
if (little_endian) {
TRANS_BIT_8X8(x, t);
} else {
TRANS_BIT_8X8_BE(x, t);
}
for (kk = 0; kk < 8; kk ++) {
out_b[bit_row_offset + kk * bit_row_skip + ii] = x;
x = x >> 8;
}
}
return size * elem_size;
}
/* Transpose bits within bytes. */
static int64_t bshuf_trans_bit_byte_scal(const void* in, void* out, const size_t size,
const size_t elem_size) {
return blosc_internal_bshuf_trans_bit_byte_remainder(in, out, size, elem_size, 0);
}
/* General transpose of an array, optimized for large element sizes. */
int64_t blosc_internal_bshuf_trans_elem(const void* in, void* out, const size_t lda,
const size_t ldb, const size_t elem_size) {
char* in_b = (char*) in;
char* out_b = (char*) out;
size_t ii, jj;
for (ii = 0; ii < lda; ii++) {
for (jj = 0; jj < ldb; jj++) {
memcpy(&out_b[(jj*lda + ii) * elem_size],
&in_b[(ii*ldb + jj) * elem_size], elem_size);
}
}
return lda * ldb * elem_size;
}
/* Transpose rows of shuffled bits (size / 8 bytes) within groups of 8. */
int64_t blosc_internal_bshuf_trans_bitrow_eight(const void* in, void* out, const size_t size,
const size_t elem_size) {
size_t nbyte_bitrow = size / 8;
CHECK_MULT_EIGHT(size);
return blosc_internal_bshuf_trans_elem(in, out, 8, elem_size, nbyte_bitrow);
}
/* Transpose bits within elements. */
int64_t blosc_internal_bshuf_trans_bit_elem_scal(const void* in, void* out, const size_t size,
const size_t elem_size, void* tmp_buf) {
int64_t count;
CHECK_MULT_EIGHT(size);
count = blosc_internal_bshuf_trans_byte_elem_scal(in, out, size, elem_size);
CHECK_ERR(count);
count = bshuf_trans_bit_byte_scal(out, tmp_buf, size, elem_size);
CHECK_ERR(count);
count = blosc_internal_bshuf_trans_bitrow_eight(tmp_buf, out, size, elem_size);
return count;
}
/* For data organized into a row for each bit (8 * elem_size rows), transpose
* the bytes. */
static int64_t bshuf_trans_byte_bitrow_scal(const void* in, void* out, const size_t size,
const size_t elem_size) {
char* in_b = (char*) in;
char* out_b = (char*) out;
size_t nbyte_row = size / 8;
size_t ii, jj, kk;
CHECK_MULT_EIGHT(size);
for (jj = 0; jj < elem_size; jj++) {
for (ii = 0; ii < nbyte_row; ii++) {
for (kk = 0; kk < 8; kk++) {
out_b[ii * 8 * elem_size + jj * 8 + kk] = \
in_b[(jj * 8 + kk) * nbyte_row + ii];
}
}
}
return size * elem_size;
}
/* Shuffle bits within the bytes of eight element blocks. */
int64_t blosc_internal_bshuf_shuffle_bit_eightelem_scal(const void* in, void* out,
const size_t size, const size_t elem_size) {
const char *in_b;
char *out_b;
uint64_t x, t;
size_t ii, jj, kk;
size_t nbyte, out_index;
uint64_t e=1;
const int little_endian = *(uint8_t *) &e == 1;
const size_t elem_skip = little_endian ? elem_size : -elem_size;
const uint64_t elem_offset = little_endian ? 0 : 7 * elem_size;
CHECK_MULT_EIGHT(size);
in_b = (const char*) in;
out_b = (char*) out;
nbyte = elem_size * size;
for (jj = 0; jj < 8 * elem_size; jj += 8) {
for (ii = 0; ii + 8 * elem_size - 1 < nbyte; ii += 8 * elem_size) {
x = *((uint64_t*) &in_b[ii + jj]);
if (little_endian) {
TRANS_BIT_8X8(x, t);
} else {
TRANS_BIT_8X8_BE(x, t);
}
for (kk = 0; kk < 8; kk++) {
out_index = ii + jj / 8 + elem_offset + kk * elem_skip;
*((uint8_t*) &out_b[out_index]) = x;
x = x >> 8;
}
}
}
return size * elem_size;
}
/* Untranspose bits within elements. */
int64_t blosc_internal_bshuf_untrans_bit_elem_scal(const void* in, void* out, const size_t size,
const size_t elem_size, void* tmp_buf) {
int64_t count;
CHECK_MULT_EIGHT(size);
count = bshuf_trans_byte_bitrow_scal(in, tmp_buf, size, elem_size);
CHECK_ERR(count);
count = blosc_internal_bshuf_shuffle_bit_eightelem_scal(tmp_buf, out, size, elem_size);
return count;
}