diff options
Diffstat (limited to 'src/port/pg_bitutils.c')
| -rw-r--r-- | src/port/pg_bitutils.c | 155 |
1 files changed, 119 insertions, 36 deletions
diff --git a/src/port/pg_bitutils.c b/src/port/pg_bitutils.c index 640a89561a8..1197696e97c 100644 --- a/src/port/pg_bitutils.c +++ b/src/port/pg_bitutils.c @@ -103,18 +103,22 @@ const uint8 pg_number_of_ones[256] = { 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 }; -static int pg_popcount32_slow(uint32 word); -static int pg_popcount64_slow(uint64 word); +static inline int pg_popcount32_slow(uint32 word); +static inline int pg_popcount64_slow(uint64 word); +static uint64 pg_popcount_slow(const char *buf, int bytes); #ifdef TRY_POPCNT_FAST static bool pg_popcount_available(void); static int pg_popcount32_choose(uint32 word); static int pg_popcount64_choose(uint64 word); -static int pg_popcount32_fast(uint32 word); -static int pg_popcount64_fast(uint64 word); +static uint64 pg_popcount_choose(const char *buf, int bytes); +static inline int pg_popcount32_fast(uint32 word); +static inline int pg_popcount64_fast(uint64 word); +static uint64 pg_popcount_fast(const char *buf, int bytes); int (*pg_popcount32) (uint32 word) = pg_popcount32_choose; int (*pg_popcount64) (uint64 word) = pg_popcount64_choose; +uint64 (*pg_popcount) (const char *buf, int bytes) = pg_popcount_choose; #endif /* TRY_POPCNT_FAST */ #ifdef TRY_POPCNT_FAST @@ -151,11 +155,13 @@ pg_popcount32_choose(uint32 word) { pg_popcount32 = pg_popcount32_fast; pg_popcount64 = pg_popcount64_fast; + pg_popcount = pg_popcount_fast; } else { pg_popcount32 = pg_popcount32_slow; pg_popcount64 = pg_popcount64_slow; + pg_popcount = pg_popcount_slow; } return pg_popcount32(word); @@ -168,21 +174,42 @@ pg_popcount64_choose(uint64 word) { pg_popcount32 = pg_popcount32_fast; pg_popcount64 = pg_popcount64_fast; + pg_popcount = pg_popcount_fast; } else { pg_popcount32 = pg_popcount32_slow; pg_popcount64 = pg_popcount64_slow; + pg_popcount = pg_popcount_slow; } return pg_popcount64(word); } +static uint64 +pg_popcount_choose(const char *buf, int bytes) +{ + if (pg_popcount_available()) + { + pg_popcount32 = pg_popcount32_fast; + pg_popcount64 = pg_popcount64_fast; + pg_popcount = pg_popcount_fast; + } + else + { + pg_popcount32 = pg_popcount32_slow; + pg_popcount64 = pg_popcount64_slow; + pg_popcount = pg_popcount_slow; + } + + return pg_popcount(buf, bytes); +} + /* * pg_popcount32_fast * Return the number of 1 bits set in word */ -static int +static inline int pg_popcount32_fast(uint32 word) { #ifdef _MSC_VER @@ -199,7 +226,7 @@ __asm__ __volatile__(" popcntl %1,%0\n":"=q"(res):"rm"(word):"cc"); * pg_popcount64_fast * Return the number of 1 bits set in word */ -static int +static inline int pg_popcount64_fast(uint64 word) { #ifdef _MSC_VER @@ -212,6 +239,52 @@ __asm__ __volatile__(" popcntq %1,%0\n":"=q"(res):"rm"(word):"cc"); #endif } +/* + * pg_popcount_fast + * Returns the number of 1-bits in buf + */ +static uint64 +pg_popcount_fast(const char *buf, int bytes) +{ + uint64 popcnt = 0; + +#if SIZEOF_VOID_P >= 8 + /* Process in 64-bit chunks if the buffer is aligned. */ + if (buf == (const char *) TYPEALIGN(8, buf)) + { + const uint64 *words = (const uint64 *) buf; + + while (bytes >= 8) + { + popcnt += pg_popcount64_fast(*words++); + bytes -= 8; + } + + buf = (const char *) words; + } +#else + /* Process in 32-bit chunks if the buffer is aligned. */ + if (buf == (const char *) TYPEALIGN(4, buf)) + { + const uint32 *words = (const uint32 *) buf; + + while (bytes >= 4) + { + popcnt += pg_popcount32_fast(*words++); + bytes -= 4; + } + + buf = (const char *) words; + } +#endif + + /* Process any remaining bytes */ + while (bytes--) + popcnt += pg_number_of_ones[(unsigned char) *buf++]; + + return popcnt; +} + #endif /* TRY_POPCNT_FAST */ @@ -219,7 +292,7 @@ __asm__ __volatile__(" popcntq %1,%0\n":"=q"(res):"rm"(word):"cc"); * pg_popcount32_slow * Return the number of 1 bits set in word */ -static int +static inline int pg_popcount32_slow(uint32 word) { #ifdef HAVE__BUILTIN_POPCOUNT @@ -241,7 +314,7 @@ pg_popcount32_slow(uint32 word) * pg_popcount64_slow * Return the number of 1 bits set in word */ -static int +static inline int pg_popcount64_slow(uint64 word) { #ifdef HAVE__BUILTIN_POPCOUNT @@ -265,35 +338,12 @@ pg_popcount64_slow(uint64 word) #endif /* HAVE__BUILTIN_POPCOUNT */ } -#ifndef TRY_POPCNT_FAST - /* - * When the POPCNT instruction is not available, there's no point in using - * function pointers to vary the implementation between the fast and slow - * method. We instead just make these actual external functions when - * TRY_POPCNT_FAST is not defined. The compiler should be able to inline - * the slow versions here. - */ -int -pg_popcount32(uint32 word) -{ - return pg_popcount32_slow(word); -} - -int -pg_popcount64(uint64 word) -{ - return pg_popcount64_slow(word); -} - -#endif /* !TRY_POPCNT_FAST */ - -/* - * pg_popcount + * pg_popcount_slow * Returns the number of 1-bits in buf */ -uint64 -pg_popcount(const char *buf, int bytes) +static uint64 +pg_popcount_slow(const char *buf, int bytes) { uint64 popcnt = 0; @@ -305,7 +355,7 @@ pg_popcount(const char *buf, int bytes) while (bytes >= 8) { - popcnt += pg_popcount64(*words++); + popcnt += pg_popcount64_slow(*words++); bytes -= 8; } @@ -319,7 +369,7 @@ pg_popcount(const char *buf, int bytes) while (bytes >= 4) { - popcnt += pg_popcount32(*words++); + popcnt += pg_popcount32_slow(*words++); bytes -= 4; } @@ -333,3 +383,36 @@ pg_popcount(const char *buf, int bytes) return popcnt; } + +#ifndef TRY_POPCNT_FAST + +/* + * When the POPCNT instruction is not available, there's no point in using + * function pointers to vary the implementation between the fast and slow + * method. We instead just make these actual external functions when + * TRY_POPCNT_FAST is not defined. The compiler should be able to inline + * the slow versions here. + */ +int +pg_popcount32(uint32 word) +{ + return pg_popcount32_slow(word); +} + +int +pg_popcount64(uint64 word) +{ + return pg_popcount64_slow(word); +} + +/* + * pg_popcount + * Returns the number of 1-bits in buf + */ +uint64 +pg_popcount(const char *buf, int bytes) +{ + return pg_popcount_slow(buf, bytes); +} + +#endif /* !TRY_POPCNT_FAST */ |