/* Codewords for the LZX main, length, and aligned offset Huffman codes */
struct lzx_codewords {
- u16 main[LZX_MAINCODE_MAX_NUM_SYMBOLS];
- u16 len[LZX_LENCODE_NUM_SYMBOLS];
- u16 aligned[LZX_ALIGNEDCODE_NUM_SYMBOLS];
+ u32 main[LZX_MAINCODE_MAX_NUM_SYMBOLS];
+ u32 len[LZX_LENCODE_NUM_SYMBOLS];
+ u32 aligned[LZX_ALIGNEDCODE_NUM_SYMBOLS];
};
/* Codeword lengths (in bits) for the LZX main, length, and aligned offset
* MIN_MATCH_LEN. */
if (match_len_minus_2 < LZX_NUM_PRIMARY_LENS) {
len_header = match_len_minus_2;
- /* No length footer-- mark it with a special
- * value. */
- len_footer = (unsigned)(-1);
} else {
len_header = LZX_NUM_PRIMARY_LENS;
len_footer = match_len_minus_2 - LZX_NUM_PRIMARY_LENS;
/* If there is a length footer, output it using the
* length Huffman code. */
- if (len_footer != (unsigned)(-1)) {
+ if (len_header == LZX_NUM_PRIMARY_LENS)
bitstream_put_bits(out, codes->codewords.len[len_footer],
codes->lens.len[len_footer]);
- }
num_extra_bits = lzx_get_num_extra_bits(position_slot);
input_idx_t precode_freqs[restrict LZX_PRECODE_NUM_SYMBOLS],
u8 output_syms[restrict num_syms],
u8 precode_lens[restrict LZX_PRECODE_NUM_SYMBOLS],
- u16 precode_codewords[restrict LZX_PRECODE_NUM_SYMBOLS],
+ u32 precode_codewords[restrict LZX_PRECODE_NUM_SYMBOLS],
unsigned *num_additional_bits_ret)
{
memset(precode_freqs, 0,
input_idx_t precode_freqs[LZX_PRECODE_NUM_SYMBOLS];
u8 output_syms[num_syms];
u8 precode_lens[LZX_PRECODE_NUM_SYMBOLS];
- u16 precode_codewords[LZX_PRECODE_NUM_SYMBOLS];
+ u32 precode_codewords[LZX_PRECODE_NUM_SYMBOLS];
unsigned i;
unsigned num_output_syms;
u8 precode_sym;
/* The match offset shall be encoded as a position slot (itself encoded
* as part of the main symbol) and a position footer. */
position_slot = lzx_get_position_slot(match_offset, queue);
- position_footer = (match_offset + LZX_OFFSET_OFFSET) -
- lzx_position_base[position_slot];
+ position_footer = (match_offset + LZX_OFFSET_OFFSET) &
+ ((1U << lzx_get_num_extra_bits(position_slot)) - 1);
/* The match length shall be encoded as a length header (itself encoded
* as part of the main symbol) and an optional length footer. */
spec->num_chosen_matches = 0;
memset(&freqs, 0, sizeof(freqs));
- for (unsigned i = spec->window_pos; i < spec->window_pos + spec->block_size; ) {
+ const u8 *window_ptr = &ctx->window[spec->window_pos];
+ const u8 *window_end = &window_ptr[spec->block_size];
+ struct lzx_match *next_chosen_match =
+ &ctx->chosen_matches[spec->chosen_matches_start_pos];
+
+ while (window_ptr != window_end) {
struct raw_match raw_match;
struct lzx_match lzx_match;
* null value and therefore cannot
* generate such matches. */
BUILD_BUG_ON(LZX_MIN_MATCH_LEN != 2);
- lzx_match.data = lzx_tally_literal(ctx->window[i],
+ lzx_match.data = lzx_tally_literal(*window_ptr++,
&freqs);
- i += 1;
- ctx->chosen_matches[spec->chosen_matches_start_pos +
- spec->num_chosen_matches++]
- = lzx_match;
- lzx_match.data = lzx_tally_literal(ctx->window[i],
+ *next_chosen_match++ = lzx_match;
+ lzx_match.data = lzx_tally_literal(*window_ptr++,
&freqs);
- i += 1;
} else {
lzx_match.data = lzx_tally_match(raw_match.len,
raw_match.offset,
&freqs,
&ctx->queue);
- i += raw_match.len;
+ window_ptr += raw_match.len;
}
} else {
- lzx_match.data = lzx_tally_literal(ctx->window[i], &freqs);
- i += 1;
+ lzx_match.data = lzx_tally_literal(*window_ptr++, &freqs);
}
- ctx->chosen_matches[spec->chosen_matches_start_pos +
- spec->num_chosen_matches++] = lzx_match;
+ *next_chosen_match++ = lzx_match;
}
+ spec->num_chosen_matches = next_chosen_match -
+ &ctx->chosen_matches[spec->chosen_matches_start_pos];
lzx_make_huffman_codes(&freqs, &spec->codes,
ctx->num_main_syms);