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author | Yann Collet <cyan@fb.com> | 2017-10-25 08:10:53 (GMT) |
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committer | Yann Collet <cyan@fb.com> | 2017-10-25 08:10:53 (GMT) |
commit | a31b7058cb97e4393da55e78a77a1c6f0c9ae038 (patch) | |
tree | 5a5e846bf9989a3f8442b103c72ad426acdf2705 /lib | |
parent | dccf8826f1d76efcbdc655e63cc04cdbd1123619 (diff) | |
download | lz4-a31b7058cb97e4393da55e78a77a1c6f0c9ae038.zip lz4-a31b7058cb97e4393da55e78a77a1c6f0c9ae038.tar.gz lz4-a31b7058cb97e4393da55e78a77a1c6f0c9ae038.tar.bz2 |
small modification of lz4 decoder to shortcut common case (short branch).
Diffstat (limited to 'lib')
-rw-r--r-- | lib/lz4.c | 16 |
1 files changed, 16 insertions, 0 deletions
@@ -1180,6 +1180,22 @@ LZ4_FORCE_INLINE int LZ4_decompress_generic( /* get literal length */ unsigned const token = *ip++; + + if (1) + if (ip + 14 + 2 <= iend) + if ((token < 15*16) & ((token & 0xF) <= 12)) { + size_t const ll = token >> ML_BITS; + size_t const off = LZ4_readLE16(ip+ll); /* check input validity */ + if (off >= 16) { + size_t const ml = (token & 0xF) + MINMATCH; + DEBUGLOG(2, "rest:%u, ll:%2u, ml:%2u, off:%u", + (U32)(oend-op), (U32)ll, (U32)ml, (U32)off); + memcpy(op, ip, 16); op += ll; ip += ll + 2 /* offset */; + memcpy(op, op - off, 16); op += ml; + continue; + } + } + if ((length=(token>>ML_BITS)) == RUN_MASK) { unsigned s; do { |