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Merge pull request #2217 from terrelln/cover-redundant

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[cover] Remove unnecessary mask and dedup hash functions
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Nick Terrell 2020-06-22 17:41:13 -07:00 committed by GitHub
commit 081691a3aa
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1 changed files with 6 additions and 14 deletions
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20
lib/dictBuilder/fastcover.c
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@ -21,6 +21,7 @@
#include "../common/threading.h" #include "../common/threading.h"
#include "cover.h" #include "cover.h"
#include "../common/zstd_internal.h" /* includes zstd.h */ #include "../common/zstd_internal.h" /* includes zstd.h */
#include "../compress/zstd_compress_internal.h" /* ZSTD_hash*() */
#ifndef ZDICT_STATIC_LINKING_ONLY #ifndef ZDICT_STATIC_LINKING_ONLY
#define ZDICT_STATIC_LINKING_ONLY #define ZDICT_STATIC_LINKING_ONLY
#endif #endif
@ -75,25 +76,16 @@ static clock_t g_time = 0;
/*-************************************* /*-*************************************
* Hash Functions (matching zstd_compress_internal.h) * Hash Functions
***************************************/ ***************************************/
static const U64 FASTCOVER_prime6bytes = 227718039650203ULL;
static size_t FASTCOVER_hash6(U64 u, U32 h) { return (size_t)(((u << (64-48)) * FASTCOVER_prime6bytes) >> (64-h)) ; }
static size_t FASTCOVER_hash6Ptr(const void* p, U32 h) { return FASTCOVER_hash6(MEM_readLE64(p), h); }
static const U64 FASTCOVER_prime8bytes = 0xCF1BBCDCB7A56463ULL;
static size_t FASTCOVER_hash8(U64 u, U32 h) { return (size_t)(((u) * FASTCOVER_prime8bytes) >> (64-h)) ; }
static size_t FASTCOVER_hash8Ptr(const void* p, U32 h) { return FASTCOVER_hash8(MEM_readLE64(p), h); }
/** /**
* Hash the d-byte value pointed to by p and mod 2^f * Hash the d-byte value pointed to by p and mod 2^f into the frequency vector
*/ */
static size_t FASTCOVER_hashPtrToIndex(const void* p, U32 h, unsigned d) { static size_t FASTCOVER_hashPtrToIndex(const void* p, U32 f, unsigned d) {
if (d == 6) { if (d == 6) {
return FASTCOVER_hash6Ptr(p, h) & ((1 << h) - 1); return ZSTD_hash6Ptr(p, f);
} }
return FASTCOVER_hash8Ptr(p, h) & ((1 << h) - 1); return ZSTD_hash8Ptr(p, f);
} }