--- liblzf/lzf_c.c 2007/11/13 08:38:56 1.21 +++ liblzf/lzf_c.c 2007/11/13 10:41:52 1.22 @@ -47,7 +47,13 @@ #ifndef FRST # define FRST(p) (((p[0]) << 8) | p[1]) # define NEXT(v,p) (((v) << 8) | p[2]) -# define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) +# if ULTRA_FAST +# define IDX(h) (((h >> (3*8 - HLOG)) - h ) & (HSIZE - 1)) +# elif VERY_FAST +# define IDX(h) (((h >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) +# else +# define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) +# endif /*# define IDX(h) ((ip[0] * 121 ^ ip[1] * 33 ^ ip[2] * 1) & (HSIZE-1))*/ #endif /* @@ -70,13 +76,6 @@ #define MAX_OFF (1 << 13) #define MAX_REF ((1 << 8) + (1 << 3)) -#if (__i386 || __amd64) && __GNUC__ >= 3 -# define lzf_movsb(dst, src, len) \ - asm ("rep movsb" \ - : "=D" (dst), "=S" (src), "=c" (len) \ - : "0" (dst), "1" (src), "2" (len)); -#endif - #if __GNUC__ >= 3 # define expect(expr,value) __builtin_expect ((expr),(value)) # define inline inline @@ -115,9 +114,12 @@ u8 *out_end = op + out_len; const u8 *ref; - unsigned int hval = FRST (ip); + unsigned int hval; unsigned long off; - int lit = 0; + int lit; + + if (!in_len || !out_len) + return 0; #if INIT_HTAB memset (htab, 0, sizeof (htab)); @@ -127,163 +129,145 @@ # endif #endif - for (;;) + lit = 0; op++; /* start run */ + + hval = FRST (ip); + while (ip < in_end - 2) { - if (expect_true (ip < in_end - 2)) - { - hval = NEXT (hval, ip); - hslot = htab + IDX (hval); - ref = *hslot; *hslot = ip; + hval = NEXT (hval, ip); + hslot = htab + IDX (hval); + ref = *hslot; *hslot = ip; - if (1 + if (1 #if INIT_HTAB && !USE_MEMCPY - && ref < ip /* the next test will actually take care of this, but this is faster */ + && ref < ip /* the next test will actually take care of this, but this is faster */ #endif - && (off = ip - ref - 1) < MAX_OFF - && ip + 4 < in_end - && ref > (u8 *)in_data + && (off = ip - ref - 1) < MAX_OFF + && ip + 4 < in_end + && ref > (u8 *)in_data #if STRICT_ALIGN - && ref[0] == ip[0] - && ref[1] == ip[1] - && ref[2] == ip[2] + && ref[0] == ip[0] + && ref[1] == ip[1] + && ref[2] == ip[2] #else - && *(u16 *)ref == *(u16 *)ip - && ref[2] == ip[2] + && *(u16 *)ref == *(u16 *)ip + && ref[2] == ip[2] #endif - ) - { - /* match found at *ref++ */ - unsigned int len = 2; - unsigned int maxlen = in_end - ip - len; - maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; + ) + { + /* match found at *ref++ */ + unsigned int len = 2; + unsigned int maxlen = in_end - ip - len; + maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; + + if (expect_false (op + 1 + 3 >= out_end)) + return 0; - if (expect_false (op + lit + 1 + 3 >= out_end)) - return 0; + op [- lit - 1] = lit - 1; /* stop run */ + op -= !lit; /* undo run if length is zero */ - if (expect_false (lit)) + for (;;) + { + if (expect_true (maxlen > 16)) { - *op++ = lit - 1; - lit = -lit; - do - *op++ = ip[lit]; - while (expect_false (++lit)); + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; + len++; if (ref [len] != ip [len]) break; } - for (;;) - { - if (expect_true (maxlen > 16)) - { - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - len++; if (ref [len] != ip [len]) break; - } - - do - len++; - while (len < maxlen && ref[len] == ip[len]); + do + len++; + while (len < maxlen && ref[len] == ip[len]); - break; - } + break; + } - len -= 2; - ip++; + len -= 2; + ip++; - if (len < 7) - { - *op++ = (off >> 8) + (len << 5); - } - else - { - *op++ = (off >> 8) + ( 7 << 5); - *op++ = len - 7; - } + if (len < 7) + { + *op++ = (off >> 8) + (len << 5); + } + else + { + *op++ = (off >> 8) + ( 7 << 5); + *op++ = len - 7; + } - *op++ = off; + *op++ = off; #if ULTRA_FAST || VERY_FAST - ip += len; + ip += len; #if VERY_FAST && !ULTRA_FAST - --ip; + --ip; #endif - hval = FRST (ip); + hval = FRST (ip); - hval = NEXT (hval, ip); - htab[IDX (hval)] = ip; - ip++; + hval = NEXT (hval, ip); + htab[IDX (hval)] = ip; + ip++; #if VERY_FAST && !ULTRA_FAST + hval = NEXT (hval, ip); + htab[IDX (hval)] = ip; + ip++; +#endif +#else + do + { hval = NEXT (hval, ip); htab[IDX (hval)] = ip; ip++; -#endif -#else - do - { - hval = NEXT (hval, ip); - htab[IDX (hval)] = ip; - ip++; - } - while (len--); -#endif - continue; } + while (len--); +#endif + lit = 0; op++; /* start run */ + continue; } - else if (expect_false (ip == in_end)) - break; /* one more literal byte we must copy */ + + if (expect_false (op >= out_end)) + return 0; + lit++; - ip++; + *op++ = *ip++; if (expect_false (lit == MAX_LIT)) { - if (op + 1 + MAX_LIT >= out_end) - return 0; - - *op++ = MAX_LIT - 1; - -#ifdef lzf_movsb - ip -= MAX_LIT; - lzf_movsb (op, ip, lit); -#else - lit = -lit; - do - *op++ = ip[lit]; - while (++lit); -#endif + op [- lit - 1] = lit - 1; /* stop run */ + lit = 0; op++; /* start run */ } } - if (lit) - { - if (op + lit + 1 >= out_end) - return 0; + if (op + lit + 2 >= out_end) + return 0; - *op++ = lit - 1; -#ifdef lzf_movsb - ip -= lit; - lzf_movsb (op, ip, lit); -#else - lit = -lit; - do - *op++ = ip[lit]; - while (++lit); -#endif + while (ip < in_end) + { + lit++; + *op++ = *ip++; } - return op - (u8 *) out_data; + op [- lit - 1] = lit - 1; + + return op - (u8 *)out_data; }