Files
simdjson-simdjson/include/simdjson/icelake/bitmask.h
Daniel Lemire e8f370b085 Basic AVX-512 implementation (icelake or better) (#1813)
* Add cascadelake implementation, which use AVX512 Intrinsics to optimize performance(#1811)

Co-authored-by: mellonyou <fangzheng.zhang@intel.com>
Co-authored-by: wanweiqiangintel <weiqiang.wan@intel.com>
2022-05-25 11:14:02 -04:00

26 lines
731 B
C++

#ifndef SIMDJSON_ICELAKE_BITMASK_H
#define SIMDJSON_ICELAKE_BITMASK_H
namespace simdjson {
namespace SIMDJSON_IMPLEMENTATION {
namespace {
//
// Perform a "cumulative bitwise xor," flipping bits each time a 1 is encountered.
//
// For example, prefix_xor(00100100) == 00011100
//
simdjson_really_inline uint64_t prefix_xor(const uint64_t bitmask) {
// There should be no such thing with a processor supporting avx2
// but not clmul.
__m128i all_ones = _mm_set1_epi8('\xFF');
__m128i result = _mm_clmulepi64_si128(_mm_set_epi64x(0ULL, bitmask), all_ones, 0);
return _mm_cvtsi128_si64(result);
}
} // unnamed namespace
} // namespace SIMDJSON_IMPLEMENTATION
} // namespace simdjson
#endif // SIMDJSON_ICELAKE_BITMASK_H