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simdjson
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No need for the ugly unroll loop, but requires some macro magic.

This commit is contained in:
Daniel Lemire 2018-07-28 18:31:46 -04:00
parent ecf78d7249
commit e6a8c393c4
1 changed files with 31 additions and 6 deletions
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37
main.cpp
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@ -282,11 +282,38 @@ const u32 NUM_RESERVED_NODES = 2;
const u32 DUMMY_NODE = 0;
const u32 ROOT_NODE = 1;
#ifndef NO_PDEP_WIDTH
#define NO_PDEP_WIDTH 8
#endif
#define SET_BIT(i) base_ptr[base+i] = (u32)idx + __builtin_ctzll(s);\
s = s & (s - 1);
#define SET_BIT1 SET_BIT(0)
#define SET_BIT2 SET_BIT1 SET_BIT(1)
#define SET_BIT3 SET_BIT2 SET_BIT(2)
#define SET_BIT4 SET_BIT3 SET_BIT(3)
#define SET_BIT5 SET_BIT4 SET_BIT(4)
#define SET_BIT6 SET_BIT5 SET_BIT(5)
#define SET_BIT7 SET_BIT6 SET_BIT(6)
#define SET_BIT8 SET_BIT7 SET_BIT(7)
#define SET_BIT9 SET_BIT8 SET_BIT(8)
#define SET_BIT10 SET_BIT9 SET_BIT(9)
#define SET_BIT11 SET_BIT10 SET_BIT(10)
#define SET_BIT12 SET_BIT11 SET_BIT(11)
#define SET_BIT13 SET_BIT12 SET_BIT(12)
#define SET_BIT14 SET_BIT13 SET_BIT(13)
#define SET_BIT15 SET_BIT14 SET_BIT(14)
#define SET_BIT16 SET_BIT15 SET_BIT(15)
#define CALL(macro, ...) macro(__VA_ARGS__)
#define SET_BITLOOPN(n) SET_BIT##n
// just transform the bitmask to a big list of 32-bit integers for now
// that's all; the type of character the offset points to will
// tell us exactly what we need to know. Naive but straightforward implementation
__attribute__((optimize("unroll-loops"))) // this matters for the NO_PDEP_WIDTH
never_inline bool flatten_indexes(size_t len, ParsedJson & pj) {
u32 * base_ptr = pj.structural_indexes;
base_ptr[DUMMY_NODE] = base_ptr[ROOT_NODE] = 0; // really shouldn't matter
@ -298,16 +325,14 @@ never_inline bool flatten_indexes(size_t len, ParsedJson & pj) {
base_ptr[base++] = (u32)idx + __builtin_ctzll(s); s &= s - 1ULL;
}
#elif defined(NO_PDEP_PLEASE)
#ifndef NO_PDEP_WIDTH
#define NO_PDEP_WIDTH 8
#endif
u32 cnt = __builtin_popcountll(s);
u32 next_base = base + cnt;
while (s) {
for(size_t i = 0; i < NO_PDEP_WIDTH; i++) {
CALL(SET_BITLOOPN,NO_PDEP_WIDTH)
/*for(size_t i = 0; i < NO_PDEP_WIDTH; i++) {
base_ptr[base+i] = (u32)idx + __builtin_ctzll(s);
s = s & (s - 1);
}
}*/
base += NO_PDEP_WIDTH;
}
base = next_base;