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Adding compile-time option to test the speed of the fast flatten (research-oriented). (#181)

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Daniel Lemire 2019-06-03 13:37:09 -04:00 committed by GitHub
parent f0bee2ac8b
commit 9239f75123
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1 changed files with 20 additions and 0 deletions
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20
src/stage1_find_marks.cpp
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@ -439,6 +439,25 @@ really_inline void find_whitespace_and_structurals(simd_input in,
#endif
}
#ifdef SIMDJSON_NAIVE_FLATTEN // useful for benchmarking
//
// This is just a naive implementation. It should be normally
// disable, but can be used for research purposes to compare
// again our optimized version.
really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
uint32_t idx, uint64_t bits) {
uint32_t * out_ptr = base_ptr + base;
while(bits != 0) {
out_ptr[0] = idx + trailingzeroes(bits);
bits = bits & (bits - 1);
out_ptr++;
}
}
base = (out_ptr - base_ptr);
}
#else
// flatten out values in 'bits' assuming that they are are to have values of idx
// plus their position in the bitvector, and store these indexes at
// base_ptr[base] incrementing base as we go
@ -504,6 +523,7 @@ really_inline void flatten_bits(uint32_t *base_ptr, uint32_t &base,
}
base = next_base;
}
#endif
// return a updated structural bit vector with quoted contents cleared out and
// pseudo-structural characters added to the mask