diff options
Diffstat (limited to 'lib/zlib_inflate/inffast.c')
| -rw-r--r-- | lib/zlib_inflate/inffast.c | 73 |
1 files changed, 62 insertions, 11 deletions
diff --git a/lib/zlib_inflate/inffast.c b/lib/zlib_inflate/inffast.c index 8550b0c..2c13ecc 100644 --- a/lib/zlib_inflate/inffast.c +++ b/lib/zlib_inflate/inffast.c @@ -21,12 +21,31 @@ - Pentium III (Anderson) - M68060 (Nikl) */ +union uu { + unsigned short us; + unsigned char b[2]; +}; + +/* Endian independed version */ +static inline unsigned short +get_unaligned16(const unsigned short *p) +{ + union uu mm; + unsigned char *b = (unsigned char *)p; + + mm.b[0] = b[0]; + mm.b[1] = b[1]; + return mm.us; +} + #ifdef POSTINC # define OFF 0 # define PUP(a) *(a)++ +# define UP_UNALIGNED(a) get_unaligned16((a)++) #else # define OFF 1 # define PUP(a) *++(a) +# define UP_UNALIGNED(a) get_unaligned16(++(a)) #endif /* @@ -239,18 +258,50 @@ void inflate_fast(z_streamp strm, unsigned start) } } else { + unsigned short *sout; + unsigned long loops; + from = out - dist; /* copy direct from output */ - do { /* minimum length is three */ - PUP(out) = PUP(from); - PUP(out) = PUP(from); - PUP(out) = PUP(from); - len -= 3; - } while (len > 2); - if (len) { - PUP(out) = PUP(from); - if (len > 1) - PUP(out) = PUP(from); - } + /* minimum length is three */ + /* Align out addr */ + if (!((long)(out - 1 + OFF) & 1)) { + PUP(out) = PUP(from); + len--; + } + sout = (unsigned short *)(out - OFF); + if (dist > 2) { + unsigned short *sfrom; + + sfrom = (unsigned short *)(from - OFF); + loops = len >> 1; + do +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + PUP(sout) = PUP(sfrom); +#else + PUP(sout) = UP_UNALIGNED(sfrom); +#endif + while (--loops); + out = (unsigned char *)sout + OFF; + from = (unsigned char *)sfrom + OFF; + } else { /* dist == 1 or dist == 2 */ + unsigned short pat16; + + pat16 = *(sout-1+OFF); + if (dist == 1) { + union uu mm; + /* copy one char pattern to both bytes */ + mm.us = pat16; + mm.b[0] = mm.b[1]; + pat16 = mm.us; + } + loops = len >> 1; + do + PUP(sout) = pat16; + while (--loops); + out = (unsigned char *)sout + OFF; + } + if (len & 1) + PUP(out) = PUP(from); } } else if ((op & 64) == 0) { /* 2nd level distance code */ |