diff options
Diffstat (limited to 'lib/lzo/lzo1x_compress.c')
| -rw-r--r-- | lib/lzo/lzo1x_compress.c | 100 |
1 files changed, 89 insertions, 11 deletions
diff --git a/lib/lzo/lzo1x_compress.c b/lib/lzo/lzo1x_compress.c index 236eb21167b5..89cd561201ff 100644 --- a/lib/lzo/lzo1x_compress.c +++ b/lib/lzo/lzo1x_compress.c @@ -20,7 +20,7 @@ static noinline size_t lzo1x_1_do_compress(const unsigned char *in, size_t in_len, unsigned char *out, size_t *out_len, - size_t ti, void *wrkmem) + size_t ti, void *wrkmem, signed char *state_offset) { const unsigned char *ip; unsigned char *op; @@ -35,27 +35,85 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len, ip += ti < 4 ? 4 - ti : 0; for (;;) { - const unsigned char *m_pos; + const unsigned char *m_pos = NULL; size_t t, m_len, m_off; u32 dv; + u32 run_length = 0; literal: ip += 1 + ((ip - ii) >> 5); next: if (unlikely(ip >= ip_end)) break; dv = get_unaligned_le32(ip); - t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK; - m_pos = in + dict[t]; - dict[t] = (lzo_dict_t) (ip - in); - if (unlikely(dv != get_unaligned_le32(m_pos))) - goto literal; + + if (dv == 0) { + const unsigned char *ir = ip + 4; + const unsigned char *limit = ip_end + < (ip + MAX_ZERO_RUN_LENGTH + 1) + ? ip_end : ip + MAX_ZERO_RUN_LENGTH + 1; +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \ + defined(LZO_FAST_64BIT_MEMORY_ACCESS) + u64 dv64; + + for (; (ir + 32) <= limit; ir += 32) { + dv64 = get_unaligned((u64 *)ir); + dv64 |= get_unaligned((u64 *)ir + 1); + dv64 |= get_unaligned((u64 *)ir + 2); + dv64 |= get_unaligned((u64 *)ir + 3); + if (dv64) + break; + } + for (; (ir + 8) <= limit; ir += 8) { + dv64 = get_unaligned((u64 *)ir); + if (dv64) { +# if defined(__LITTLE_ENDIAN) + ir += __builtin_ctzll(dv64) >> 3; +# elif defined(__BIG_ENDIAN) + ir += __builtin_clzll(dv64) >> 3; +# else +# error "missing endian definition" +# endif + break; + } + } +#else + while ((ir < (const unsigned char *) + ALIGN((uintptr_t)ir, 4)) && + (ir < limit) && (*ir == 0)) + ir++; + for (; (ir + 4) <= limit; ir += 4) { + dv = *((u32 *)ir); + if (dv) { +# if defined(__LITTLE_ENDIAN) + ir += __builtin_ctz(dv) >> 3; +# elif defined(__BIG_ENDIAN) + ir += __builtin_clz(dv) >> 3; +# else +# error "missing endian definition" +# endif + break; + } + } +#endif + while (likely(ir < limit) && unlikely(*ir == 0)) + ir++; + run_length = ir - ip; + if (run_length > MAX_ZERO_RUN_LENGTH) + run_length = MAX_ZERO_RUN_LENGTH; + } else { + t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK; + m_pos = in + dict[t]; + dict[t] = (lzo_dict_t) (ip - in); + if (unlikely(dv != get_unaligned_le32(m_pos))) + goto literal; + } ii -= ti; ti = 0; t = ip - ii; if (t != 0) { if (t <= 3) { - op[-2] |= t; + op[*state_offset] |= t; COPY4(op, ii); op += t; } else if (t <= 16) { @@ -88,6 +146,17 @@ next: } } + if (unlikely(run_length)) { + ip += run_length; + run_length -= MIN_ZERO_RUN_LENGTH; + put_unaligned_le32((run_length << 21) | 0xfffc18 + | (run_length & 0x7), op); + op += 4; + run_length = 0; + *state_offset = -3; + goto finished_writing_instruction; + } + m_len = 4; { #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64) @@ -170,7 +239,6 @@ m_len_done: m_off = ip - m_pos; ip += m_len; - ii = ip; if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) { m_off -= 1; *op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2)); @@ -207,6 +275,9 @@ m_len_done: *op++ = (m_off << 2); *op++ = (m_off >> 6); } + *state_offset = -2; +finished_writing_instruction: + ii = ip; goto next; } *out_len = op - out; @@ -221,6 +292,12 @@ int lzo1x_1_compress(const unsigned char *in, size_t in_len, unsigned char *op = out; size_t l = in_len; size_t t = 0; + signed char state_offset = -2; + + // LZO v0 will never write 17 as first byte, + // so this is used to version the bitstream + *op++ = 17; + *op++ = LZO_VERSION; while (l > 20) { size_t ll = l <= (M4_MAX_OFFSET + 1) ? l : (M4_MAX_OFFSET + 1); @@ -229,7 +306,8 @@ int lzo1x_1_compress(const unsigned char *in, size_t in_len, break; BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS); memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t)); - t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem); + t = lzo1x_1_do_compress(ip, ll, op, out_len, + t, wrkmem, &state_offset); ip += ll; op += *out_len; l -= ll; @@ -242,7 +320,7 @@ int lzo1x_1_compress(const unsigned char *in, size_t in_len, if (op == out && t <= 238) { *op++ = (17 + t); } else if (t <= 3) { - op[-2] |= t; + op[state_offset] |= t; } else if (t <= 18) { *op++ = (t - 3); } else { |