diff options
| -rw-r--r-- | Changes | 2 | ||||
| -rw-r--r-- | lzfP.h | 37 | ||||
| -rw-r--r-- | lzf_c.c | 15 |
3 files changed, 39 insertions, 15 deletions
@@ -6,6 +6,8 @@ and only a small win on amd cpus. - improve c++ compatibility of the code. - slightly improve compressor speed. + - halved memory requirements for compressor on 64 bit architectures, + which can improve the speed quite a bit on older cpus. 3.5 Fri May 1 02:28:42 CEST 2009 - lzf_compress did sometimes write one octet past the given output @@ -121,27 +121,52 @@ # define CHECK_INPUT 1 #endif +/* + * Whether to store pointers or offsets inside the hash table. On + * 64 bit architetcures, pointers take up twice as much space, + * and might also be slower. Default is to autodetect. + */ +/*#define LZF_USER_OFFSETS autodetect */ + /*****************************************************************************/ /* nothing should be changed below */ #ifdef __cplusplus # include <cstring> +# include <climits> using namespace std; #else # include <string.h> +# include <limits.h> +#endif + +#ifndef LZF_USE_OFFSETS +# if defined (WIN32) +# define LZF_USE_OFFSETS defined(_M_X64) +# else +# ifdef __cplusplus +# include <cstdint> +# else +# include <stdint.h> +# endif +# define LZF_USE_OFFSETS (UINTPTR_MAX > 0xffffffffU) +# endif #endif typedef unsigned char u8; -typedef const u8 *LZF_STATE[1 << (HLOG)]; +#if LZF_USE_OFFSETS +# define LZF_HSLOT_BIAS ((const u8 *)in_data) + typedef unsigned int LZF_HSLOT; +#else +# define LZF_HSLOT_BIAS 0 + typedef const u8 *LZF_HSLOT; +#endif + +typedef LZF_HSLOT LZF_STATE[1 << (HLOG)]; #if !STRICT_ALIGN /* for unaligned accesses we need a 16 bit datatype. */ -# ifdef __cplusplus -# include <climits> -# else -# include <limits.h> -# endif # if USHRT_MAX == 65535 typedef unsigned short u16; # elif UINT_MAX == 65535 @@ -106,7 +106,6 @@ lzf_compress (const void *const in_data, unsigned int in_len, #if !LZF_STATE_ARG LZF_STATE htab; #endif - const u8 **hslot; const u8 *ip = (const u8 *)in_data; u8 *op = (u8 *)out_data; const u8 *in_end = ip + in_len; @@ -133,10 +132,6 @@ lzf_compress (const void *const in_data, unsigned int in_len, #if INIT_HTAB memset (htab, 0, sizeof (htab)); -# if 0 - for (hslot = htab; hslot < htab + HSIZE; hslot++) - *hslot++ = ip; -# endif #endif lit = 0; op++; /* start run */ @@ -144,9 +139,11 @@ lzf_compress (const void *const in_data, unsigned int in_len, hval = FRST (ip); while (ip < in_end - 2) { + LZF_HSLOT *hslot; + hval = NEXT (hval, ip); hslot = htab + IDX (hval); - ref = *hslot; *hslot = ip; + ref = *hslot + LZF_HSLOT_BIAS; *hslot = ip - LZF_HSLOT_BIAS; if (1 #if INIT_HTAB @@ -236,12 +233,12 @@ lzf_compress (const void *const in_data, unsigned int in_len, hval = FRST (ip); hval = NEXT (hval, ip); - htab[IDX (hval)] = ip; + htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; ip++; # if VERY_FAST && !ULTRA_FAST hval = NEXT (hval, ip); - htab[IDX (hval)] = ip; + htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; ip++; # endif #else @@ -250,7 +247,7 @@ lzf_compress (const void *const in_data, unsigned int in_len, do { hval = NEXT (hval, ip); - htab[IDX (hval)] = ip; + htab[IDX (hval)] = ip - LZF_HSLOT_BIAS; ip++; } while (len--); |