/* Pointer to the next little-endian 16-bit integer in the compressed
* input data (reading forwards). */
- const le16 *next;
+ const u8 *next;
/* Pointer to the end of the compressed input data. */
- const le16 *end;
+ const u8 *end;
};
typedef u64 bitbuf_t;
/* Pointer to the one past the next little-endian 16-bit integer in the
* compressed input data (reading backwards). */
- const le16 *next;
+ const u8 *next;
/* Pointer to the beginning of the compressed input data. */
- const le16 *begin;
+ const u8 *begin;
};
#define BITBUF_NBITS (8 * sizeof(bitbuf_t))
};
/* Initialize the input bitstream @is to read backwards from the compressed data
- * buffer @in that is @count 16-bit integers long. */
+ * buffer @in that is @count bytes long. */
static void
lzms_input_bitstream_init(struct lzms_input_bitstream *is,
- const le16 *in, size_t count)
+ const u8 *in, size_t count)
{
is->bitbuf = 0;
is->bitsleft = 0;
avail = BITBUF_NBITS - is->bitsleft;
if (UNALIGNED_ACCESS_IS_FAST && CPU_IS_LITTLE_ENDIAN &&
- WORDSIZE == 8 && likely((u8 *)is->next - (u8 *)is->begin >= 8))
+ WORDSIZE == 8 && likely(is->next - is->begin >= 8))
{
- is->next -= avail >> 4;
+ is->next -= (avail & ~15) >> 3;
is->bitbuf |= load_u64_unaligned(is->next) << (avail & 15);
is->bitsleft += avail & ~15;
} else {
- if (likely(is->next != is->begin))
- is->bitbuf |= (bitbuf_t)le16_to_cpu(*--is->next)
+ if (likely(is->next != is->begin)) {
+ is->next -= sizeof(le16);
+ is->bitbuf |= (bitbuf_t)get_unaligned_le16(is->next)
<< (avail - 16);
- if (likely(is->next != is->begin))
- is->bitbuf |=(bitbuf_t)le16_to_cpu(*--is->next)
+ }
+ if (likely(is->next != is->begin)) {
+ is->next -= sizeof(le16);
+ is->bitbuf |= (bitbuf_t)get_unaligned_le16(is->next)
<< (avail - 32);
+ }
is->bitsleft += 32;
}
}
}
/* Initialize the range decoder @rd to read forwards from the compressed data
- * buffer @in that is @count 16-bit integers long. */
+ * buffer @in that is @count bytes long. */
static void
lzms_range_decoder_init(struct lzms_range_decoder *rd,
- const le16 *in, size_t count)
+ const u8 *in, size_t count)
{
rd->range = 0xffffffff;
- rd->code = ((u32)le16_to_cpu(in[0]) << 16) | le16_to_cpu(in[1]);
- rd->next = in + 2;
+ rd->code = ((u32)get_unaligned_le16(in) << 16) |
+ get_unaligned_le16(in + 2);
+ rd->next = in + 4;
rd->end = in + count;
}
if (!(rd->range & 0xFFFF0000)) {
rd->range <<= 16;
rd->code <<= 16;
- if (likely(rd->next != rd->end))
- rd->code |= le16_to_cpu(*rd->next++);
+ if (likely(rd->next != rd->end)) {
+ rd->code |= get_unaligned_le16(rd->next);
+ rd->next += sizeof(le16);
+ }
}
/* Based on the probability, calculate the bound between the 0-bit
*
* 1. LZMS-compressed data is a series of 16-bit integers, so the
* compressed data buffer cannot take up an odd number of bytes.
- * 2. To prevent poor performance on some architectures, we require that
- * the compressed data buffer is 2-byte aligned.
- * 3. There must be at least 4 bytes of compressed data, since otherwise
+ * 2. There must be at least 4 bytes of compressed data, since otherwise
* we cannot even initialize the range decoder.
*/
- if ((in_nbytes & 1) || ((uintptr_t)in & 1) || (in_nbytes < 4))
+ if ((in_nbytes & 1) || (in_nbytes < 4))
return -1;
- lzms_range_decoder_init(&rd, in, in_nbytes / sizeof(le16));
+ lzms_range_decoder_init(&rd, in, in_nbytes);
- lzms_input_bitstream_init(&is, in, in_nbytes / sizeof(le16));
+ lzms_input_bitstream_init(&is, in, in_nbytes);
lzms_init_probabilities(&d->probs);