diff options
| -rw-r--r-- | Makefile | 9 | ||||
| -rw-r--r-- | config.mak.uname | 3 | ||||
| -rw-r--r-- | xdiff/xutils.c | 106 |
3 files changed, 0 insertions, 118 deletions
@@ -338,11 +338,6 @@ all:: # # Define NATIVE_CRLF if your platform uses CRLF for line endings. # -# Define XDL_FAST_HASH to use an alternative line-hashing method in -# the diff algorithm. It gives a nice speedup if your processor has -# fast unaligned word loads. Does NOT work on big-endian systems! -# Enabled by default on x86_64. -# # Define GIT_USER_AGENT if you want to change how git identifies itself during # network interactions. The default is "git/$(GIT_VERSION)". # @@ -1485,10 +1480,6 @@ ifndef NO_MSGFMT_EXTENDED_OPTIONS MSGFMT += --check --statistics endif -ifneq (,$(XDL_FAST_HASH)) - BASIC_CFLAGS += -DXDL_FAST_HASH -endif - ifdef GMTIME_UNRELIABLE_ERRORS COMPAT_OBJS += compat/gmtime.o BASIC_CFLAGS += -DGMTIME_UNRELIABLE_ERRORS diff --git a/config.mak.uname b/config.mak.uname index b232908f8c..447f36ac2e 100644 --- a/config.mak.uname +++ b/config.mak.uname @@ -17,9 +17,6 @@ endif # because maintaining the nesting to match is a pain. If # we had "elif" things would have been much nicer... -ifeq ($(uname_M),x86_64) - XDL_FAST_HASH = YesPlease -endif ifeq ($(uname_S),OSF1) # Need this for u_short definitions et al BASIC_CFLAGS += -D_OSF_SOURCE diff --git a/xdiff/xutils.c b/xdiff/xutils.c index 027192a1c7..04d7b32e4e 100644 --- a/xdiff/xutils.c +++ b/xdiff/xutils.c @@ -264,110 +264,6 @@ static unsigned long xdl_hash_record_with_whitespace(char const **data, return ha; } -#ifdef XDL_FAST_HASH - -#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) - -#define ONEBYTES REPEAT_BYTE(0x01) -#define NEWLINEBYTES REPEAT_BYTE(0x0a) -#define HIGHBITS REPEAT_BYTE(0x80) - -/* Return the high bit set in the first byte that is a zero */ -static inline unsigned long has_zero(unsigned long a) -{ - return ((a - ONEBYTES) & ~a) & HIGHBITS; -} - -static inline long count_masked_bytes(unsigned long mask) -{ - if (sizeof(long) == 8) { - /* - * Jan Achrenius on G+: microoptimized version of - * the simpler "(mask & ONEBYTES) * ONEBYTES >> 56" - * that works for the bytemasks without having to - * mask them first. - */ - /* - * return mask * 0x0001020304050608 >> 56; - * - * Doing it like this avoids warnings on 32-bit machines. - */ - long a = (REPEAT_BYTE(0x01) / 0xff + 1); - return mask * a >> (sizeof(long) * 7); - } else { - /* Carl Chatfield / Jan Achrenius G+ version for 32-bit */ - /* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */ - long a = (0x0ff0001 + mask) >> 23; - /* Fix the 1 for 00 case */ - return a & mask; - } -} - -unsigned long xdl_hash_record(char const **data, char const *top, long flags) -{ - unsigned long hash = 5381; - unsigned long a = 0, mask = 0; - char const *ptr = *data; - char const *end = top - sizeof(unsigned long) + 1; - - if (flags & XDF_WHITESPACE_FLAGS) - return xdl_hash_record_with_whitespace(data, top, flags); - - ptr -= sizeof(unsigned long); - do { - hash += hash << 5; - hash ^= a; - ptr += sizeof(unsigned long); - if (ptr >= end) - break; - a = *(unsigned long *)ptr; - /* Do we have any '\n' bytes in this word? */ - mask = has_zero(a ^ NEWLINEBYTES); - } while (!mask); - - if (ptr >= end) { - /* - * There is only a partial word left at the end of the - * buffer. Because we may work with a memory mapping, - * we have to grab the rest byte by byte instead of - * blindly reading it. - * - * To avoid problems with masking in a signed value, - * we use an unsigned char here. - */ - const char *p; - for (p = top - 1; p >= ptr; p--) - a = (a << 8) + *((const unsigned char *)p); - mask = has_zero(a ^ NEWLINEBYTES); - if (!mask) - /* - * No '\n' found in the partial word. Make a - * mask that matches what we read. - */ - mask = 1UL << (8 * (top - ptr) + 7); - } - - /* The mask *below* the first high bit set */ - mask = (mask - 1) & ~mask; - mask >>= 7; - hash += hash << 5; - hash ^= a & mask; - - /* Advance past the last (possibly partial) word */ - ptr += count_masked_bytes(mask); - - if (ptr < top) { - assert(*ptr == '\n'); - ptr++; - } - - *data = ptr; - - return hash; -} - -#else /* XDL_FAST_HASH */ - unsigned long xdl_hash_record(char const **data, char const *top, long flags) { unsigned long ha = 5381; char const *ptr = *data; @@ -384,8 +280,6 @@ unsigned long xdl_hash_record(char const **data, char const *top, long flags) { return ha; } -#endif /* XDL_FAST_HASH */ - unsigned int xdl_hashbits(unsigned int size) { unsigned int val = 1, bits = 0; |