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#include <util/charset/wide.h>
#include <util/system/types.h>
#ifdef SSE41_STUB
namespace NDetail {
void UTF8ToWideImplSSE41(const unsigned char*&, const unsigned char*, wchar16*&) noexcept {
}
void UTF8ToWideImplSSE41(const unsigned char*&, const unsigned char*, wchar32*&) noexcept {
}
} // namespace NDetail
#else
#include <util/system/compiler.h>
#include <cstring>
#include <emmintrin.h>
#include <smmintrin.h>
// processes to the first error, or until less then 16 bytes left
// most code taken from https://woboq.com/blog/utf-8-processing-using-simd.html
// return dstAdvance 0 in case of problems
static Y_FORCE_INLINE ui32 Unpack16BytesIntoUtf16IfNoSurrogats(const unsigned char*& cur, __m128i& utf16Low, __m128i& utf16High) {
unsigned char curAligned[16];
memcpy(curAligned, cur, sizeof(__m128i));
__m128i chunk = _mm_load_si128(reinterpret_cast<const __m128i*>(curAligned));
// only ascii characters - simple copy
if (!_mm_movemask_epi8(chunk)) {
utf16Low = _mm_unpacklo_epi8(chunk, _mm_setzero_si128());
utf16High = _mm_unpackhi_epi8(chunk, _mm_setzero_si128());
cur += 16;
return 16;
}
__m128i chunkSigned = _mm_add_epi8(chunk, _mm_set1_epi8(0x80));
__m128i isAsciiMask = _mm_cmpgt_epi8(chunk, _mm_set1_epi8(0));
__m128i cond2 = _mm_cmplt_epi8(_mm_set1_epi8(0xc2 - 1 - 0x80), chunkSigned);
__m128i state = _mm_set1_epi8(0x0 | (char)0x80);
__m128i cond3 = _mm_cmplt_epi8(_mm_set1_epi8(0xe0 - 1 - 0x80), chunkSigned);
state = _mm_blendv_epi8(state, _mm_set1_epi8(0x2 | (char)0xc0), cond2);
int sourceAdvance;
__m128i shifts;
__m128i chunkLow, chunkHigh;
if (Y_LIKELY(!_mm_movemask_epi8(cond3))) {
// main case: no bloks of size 3 or 4
// rune len for start of multi-byte sequences (0 for b0... and b10..., 2 for b110..., etc.)
__m128i count = _mm_and_si128(state, _mm_set1_epi8(0x7));
__m128i countSub1 = _mm_subs_epu8(count, _mm_set1_epi8(0x1));
shifts = countSub1;
__m128i continuation1 = _mm_slli_si128(countSub1, 1);
shifts = _mm_add_epi8(shifts, _mm_slli_si128(shifts, 1));
shifts = _mm_add_epi8(shifts, _mm_slli_si128(shifts, 2));
__m128i counts = _mm_or_si128(count, continuation1);
__m128i isBeginMultibyteMask = _mm_cmpgt_epi8(count, _mm_set1_epi8(0));
__m128i needNoContinuationMask = _mm_cmpeq_epi8(continuation1, _mm_set1_epi8(0));
__m128i isBeginMask = _mm_add_epi8(isBeginMultibyteMask, isAsciiMask);
// each symbol should be exactly one of ascii, continuation or begin
__m128i okMask = _mm_cmpeq_epi8(isBeginMask, needNoContinuationMask);
if (_mm_movemask_epi8(okMask) != 0xFFFF) {
return 0;
}
shifts = _mm_add_epi8(shifts, _mm_slli_si128(shifts, 4));
__m128i mask = _mm_and_si128(state, _mm_set1_epi8(0xf8));
shifts = _mm_add_epi8(shifts, _mm_slli_si128(shifts, 8));
chunk = _mm_andnot_si128(mask, chunk); // from now on, we only have usefull bits
shifts = _mm_and_si128(shifts, _mm_cmplt_epi8(counts, _mm_set1_epi8(2))); // <=1
__m128i chunk_right = _mm_slli_si128(chunk, 1);
shifts = _mm_blendv_epi8(shifts, _mm_srli_si128(shifts, 1),
_mm_srli_si128(_mm_slli_epi16(shifts, 7), 1));
chunkLow = _mm_blendv_epi8(chunk,
_mm_or_si128(chunk, _mm_and_si128(_mm_slli_epi16(chunk_right, 6), _mm_set1_epi8(0xc0))),
_mm_cmpeq_epi8(counts, _mm_set1_epi8(1)));
chunkHigh = _mm_and_si128(chunk, _mm_cmpeq_epi8(counts, _mm_set1_epi8(2)));
shifts = _mm_blendv_epi8(shifts, _mm_srli_si128(shifts, 2),
_mm_srli_si128(_mm_slli_epi16(shifts, 6), 2));
chunkHigh = _mm_srli_epi32(chunkHigh, 2);
shifts = _mm_blendv_epi8(shifts, _mm_srli_si128(shifts, 4),
_mm_srli_si128(_mm_slli_epi16(shifts, 5), 4));
int c = _mm_extract_epi16(counts, 7);
sourceAdvance = !(c & 0x0200) ? 16 : 15;
} else {
__m128i mask3 = _mm_slli_si128(cond3, 1);
__m128i cond4 = _mm_cmplt_epi8(_mm_set1_epi8(0xf0 - 1 - 0x80), chunkSigned);
state = _mm_blendv_epi8(state, _mm_set1_epi8(0x3 | (char)0xe0), cond3);
// 4 bytes sequences are not vectorize. Fall back to the scalar processing
if (Y_UNLIKELY(_mm_movemask_epi8(cond4))) {
return 0;
}
// rune len for start of multi-byte sequences (0 for b0... and b10..., 2 for b110..., etc.)
__m128i count = _mm_and_si128(state, _mm_set1_epi8(0x7));
__m128i countSub1 = _mm_subs_epu8(count, _mm_set1_epi8(0x1));
__m128i continuation2 = _mm_slli_si128(_mm_subs_epu8(count, _mm_set1_epi8(0x2)), 2);
shifts = countSub1;
__m128i continuation1 = _mm_slli_si128(countSub1, 1);
shifts = _mm_add_epi8(shifts, _mm_slli_si128(shifts, 1));
__m128i continuationsRunelen = _mm_or_si128(continuation1, continuation2);
shifts = _mm_add_epi8(shifts, _mm_slli_si128(shifts, 2));
__m128i counts = _mm_or_si128(count, continuationsRunelen);
__m128i isBeginMultibyteMask = _mm_cmpgt_epi8(count, _mm_set1_epi8(0));
__m128i needNoContinuationMask = _mm_cmpeq_epi8(continuationsRunelen, _mm_set1_epi8(0));
__m128i isBeginMask = _mm_add_epi8(isBeginMultibyteMask, isAsciiMask);
// each symbol should be exactly one of ascii, continuation or begin
__m128i okMask = _mm_cmpeq_epi8(isBeginMask, needNoContinuationMask);
if (_mm_movemask_epi8(okMask) != 0xFFFF) {
return 0;
}
shifts = _mm_add_epi8(shifts, _mm_slli_si128(shifts, 4));
__m128i mask = _mm_and_si128(state, _mm_set1_epi8(0xf8));
shifts = _mm_add_epi8(shifts, _mm_slli_si128(shifts, 8));
chunk = _mm_andnot_si128(mask, chunk); // from now on, we only have usefull bits
shifts = _mm_and_si128(shifts, _mm_cmplt_epi8(counts, _mm_set1_epi8(2))); // <=1
__m128i chunk_right = _mm_slli_si128(chunk, 1);
shifts = _mm_blendv_epi8(shifts, _mm_srli_si128(shifts, 1),
_mm_srli_si128(_mm_slli_epi16(shifts, 7), 1));
chunkLow = _mm_blendv_epi8(chunk,
_mm_or_si128(chunk, _mm_and_si128(_mm_slli_epi16(chunk_right, 6), _mm_set1_epi8(0xc0))),
_mm_cmpeq_epi8(counts, _mm_set1_epi8(1)));
chunkHigh = _mm_and_si128(chunk, _mm_cmpeq_epi8(counts, _mm_set1_epi8(2)));
shifts = _mm_blendv_epi8(shifts, _mm_srli_si128(shifts, 2),
_mm_srli_si128(_mm_slli_epi16(shifts, 6), 2));
chunkHigh = _mm_srli_epi32(chunkHigh, 2);
shifts = _mm_blendv_epi8(shifts, _mm_srli_si128(shifts, 4),
_mm_srli_si128(_mm_slli_epi16(shifts, 5), 4));
chunkHigh = _mm_or_si128(chunkHigh,
_mm_and_si128(_mm_and_si128(_mm_slli_epi32(chunk_right, 4), _mm_set1_epi8(0xf0)),
mask3));
int c = _mm_extract_epi16(counts, 7);
sourceAdvance = !(c & 0x0200) ? 16 : !(c & 0x02) ? 15
: 14;
}
shifts = _mm_blendv_epi8(shifts, _mm_srli_si128(shifts, 8),
_mm_srli_si128(_mm_slli_epi16(shifts, 4), 8));
chunkHigh = _mm_slli_si128(chunkHigh, 1);
__m128i shuf = _mm_add_epi8(shifts, _mm_set_epi8(15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0));
chunkLow = _mm_shuffle_epi8(chunkLow, shuf);
chunkHigh = _mm_shuffle_epi8(chunkHigh, shuf);
utf16Low = _mm_unpacklo_epi8(chunkLow, chunkHigh);
utf16High = _mm_unpackhi_epi8(chunkLow, chunkHigh);
ui32 s = _mm_extract_epi32(shifts, 3);
ui32 destAdvance = sourceAdvance - (0xff & (s >> (8 * (3 - 16 + sourceAdvance))));
cur += sourceAdvance;
return destAdvance;
}
namespace NDetail {
void UTF8ToWideImplSSE41(const unsigned char*& cur, const unsigned char* last, wchar16*& dest) noexcept {
alignas(16) wchar16 destAligned[16];
while (cur + 16 <= last) {
__m128i utf16Low;
__m128i utf16High;
ui32 dstAdvance = Unpack16BytesIntoUtf16IfNoSurrogats(cur, utf16Low, utf16High);
if (dstAdvance == 0) {
break;
}
_mm_store_si128(reinterpret_cast<__m128i*>(destAligned), utf16Low);
_mm_store_si128(reinterpret_cast<__m128i*>(destAligned) + 1, utf16High);
memcpy(dest, destAligned, sizeof(__m128i) * 2);
dest += dstAdvance;
}
// The rest will be handled sequencially.
// Possible improvement: go back to the vectorized processing after the error or the 4 byte sequence
}
void UTF8ToWideImplSSE41(const unsigned char*& cur, const unsigned char* last, wchar32*& dest) noexcept {
alignas(16) wchar32 destAligned[16];
while (cur + 16 <= last) {
__m128i utf16Low;
__m128i utf16High;
ui32 dstAdvance = Unpack16BytesIntoUtf16IfNoSurrogats(cur, utf16Low, utf16High);
if (dstAdvance == 0) {
break;
}
// NOTE: we only work in case without surrogat pairs, so we can make simple copying with zeroes in 2 high bytes
__m128i utf32_lowlow = _mm_unpacklo_epi16(utf16Low, _mm_set1_epi8(0));
__m128i utf32_lowhigh = _mm_unpackhi_epi16(utf16Low, _mm_set1_epi8(0));
__m128i utf32_highlow = _mm_unpacklo_epi16(utf16High, _mm_set1_epi8(0));
__m128i utf32_highhigh = _mm_unpackhi_epi16(utf16High, _mm_set1_epi8(0));
_mm_store_si128(reinterpret_cast<__m128i*>(destAligned), utf32_lowlow);
_mm_store_si128(reinterpret_cast<__m128i*>(destAligned) + 1, utf32_lowhigh);
_mm_store_si128(reinterpret_cast<__m128i*>(destAligned) + 2, utf32_highlow);
_mm_store_si128(reinterpret_cast<__m128i*>(destAligned) + 3, utf32_highhigh);
memcpy(dest, destAligned, sizeof(__m128i) * 4);
dest += dstAdvance;
}
// The rest will be handled sequencially.
// Possible improvement: go back to the vectorized processing after the error or the 4 byte sequence
}
} // namespace NDetail
#endif
|
