/* Number of bits currently held in @bitbuf */
unsigned bitcount;
- /* Pointer to one past the next position in the output buffer at which
- * to output a 16-bit coding unit */
- le16 *next;
-
/* Pointer to the beginning of the output buffer (this is the "end" when
* writing backwards!) */
- le16 *begin;
+ u8 *begin;
+
+ /* Pointer to just past the next position in the output buffer at which
+ * to output a 16-bit coding unit */
+ u8 *next;
};
/* This structure tracks the state of range encoding and its output, which
u32 cache_size;
/* Pointer to the beginning of the output buffer */
- le16 *begin;
+ u8 *begin;
/* Pointer to the position in the output buffer at which the next coding
* unit must be written */
- le16 *next;
+ u8 *next;
/* Pointer to just past the end of the output buffer */
- le16 *end;
+ u8 *end;
};
/* Bookkeeping information for an adaptive Huffman code */
static inline void
check_that_powers_fit_in_bitfield(void)
{
- BUILD_BUG_ON(LZMS_NUM_DELTA_POWER_SYMS > (1 << (31 - DELTA_SOURCE_POWER_SHIFT)));
+ STATIC_ASSERT(LZMS_NUM_DELTA_POWER_SYMS <= (1 << (31 - DELTA_SOURCE_POWER_SHIFT)));
}
/* A stripped-down version of the adaptive state in LZMS which excludes the
*
* Note: this adaptive state structure also does not include the
* probability entries or current Huffman codewords. Those aren't
- * maintained per-position and are only updated occassionally.
+ * maintained per-position and are only updated occasionally.
*/
struct lzms_adaptive_state state;
} _aligned_attribute(64);
unsigned lz_rep_states[LZMS_NUM_LZ_REP_DECISIONS];
unsigned delta_state;
unsigned delta_rep_states[LZMS_NUM_DELTA_REP_DECISIONS];
- struct lzms_probability_entry main_probs[LZMS_NUM_MAIN_PROBS];
- struct lzms_probability_entry match_probs[LZMS_NUM_MATCH_PROBS];
- struct lzms_probability_entry lz_probs[LZMS_NUM_LZ_PROBS];
- struct lzms_probability_entry lz_rep_probs[LZMS_NUM_LZ_REP_DECISIONS]
- [LZMS_NUM_LZ_REP_PROBS];
- struct lzms_probability_entry delta_probs[LZMS_NUM_DELTA_PROBS];
- struct lzms_probability_entry delta_rep_probs[LZMS_NUM_DELTA_REP_DECISIONS]
- [LZMS_NUM_DELTA_REP_PROBS];
+ struct lzms_probabilites probs;
/* Huffman codes */
/*
* Initialize the range encoder @rc to write forwards to the specified buffer
- * @out that is @count 16-bit integers long.
+ * @out that is @size bytes long.
*/
static void
-lzms_range_encoder_init(struct lzms_range_encoder *rc, le16 *out, size_t count)
+lzms_range_encoder_init(struct lzms_range_encoder *rc, u8 *out, size_t size)
{
rc->lower_bound = 0;
rc->range_size = 0xffffffff;
rc->cache = 0;
rc->cache_size = 1;
rc->begin = out;
- rc->next = out - 1;
- rc->end = out + count;
+ rc->next = out - sizeof(le16);
+ rc->end = out + (size & ~1);
}
/*
do {
if (likely(rc->next >= rc->begin)) {
if (rc->next != rc->end) {
- put_unaligned_u16_le(rc->cache +
- (u16)(rc->lower_bound >> 32),
- rc->next++);
+ put_unaligned_le16(rc->cache +
+ (u16)(rc->lower_bound >> 32),
+ rc->next);
+ rc->next += sizeof(le16);
}
} else {
- rc->next++;
+ rc->next += sizeof(le16);
}
rc->cache = 0xffff;
} while (--rc->cache_size != 0);
lzms_encode_main_bit(struct lzms_compressor *c, int bit)
{
lzms_encode_bit(bit, &c->main_state, LZMS_NUM_MAIN_PROBS,
- c->main_probs, &c->rc);
+ c->probs.main, &c->rc);
}
static void
lzms_encode_match_bit(struct lzms_compressor *c, int bit)
{
lzms_encode_bit(bit, &c->match_state, LZMS_NUM_MATCH_PROBS,
- c->match_probs, &c->rc);
+ c->probs.match, &c->rc);
}
static void
lzms_encode_lz_bit(struct lzms_compressor *c, int bit)
{
lzms_encode_bit(bit, &c->lz_state, LZMS_NUM_LZ_PROBS,
- c->lz_probs, &c->rc);
+ c->probs.lz, &c->rc);
}
static void
lzms_encode_lz_rep_bit(struct lzms_compressor *c, int bit, int idx)
{
lzms_encode_bit(bit, &c->lz_rep_states[idx], LZMS_NUM_LZ_REP_PROBS,
- c->lz_rep_probs[idx], &c->rc);
+ c->probs.lz_rep[idx], &c->rc);
}
static void
lzms_encode_delta_bit(struct lzms_compressor *c, int bit)
{
lzms_encode_bit(bit, &c->delta_state, LZMS_NUM_DELTA_PROBS,
- c->delta_probs, &c->rc);
+ c->probs.delta, &c->rc);
}
static void
lzms_encode_delta_rep_bit(struct lzms_compressor *c, int bit, int idx)
{
lzms_encode_bit(bit, &c->delta_rep_states[idx], LZMS_NUM_DELTA_REP_PROBS,
- c->delta_rep_probs[idx], &c->rc);
+ c->probs.delta_rep[idx], &c->rc);
}
/******************************************************************************
/*
* Initialize the output bitstream @os to write backwards to the specified
- * buffer @out that is @count 16-bit integers long.
+ * buffer @out that is @size bytes long.
*/
static void
lzms_output_bitstream_init(struct lzms_output_bitstream *os,
- le16 *out, size_t count)
+ u8 *out, size_t size)
{
os->bitbuf = 0;
os->bitcount = 0;
- os->next = out + count;
os->begin = out;
+ os->next = out + (size & ~1);
}
/*
os->bitcount -= 16;
/* Write a coding unit, unless it would underflow the buffer. */
- if (os->next != os->begin)
- put_unaligned_u16_le(os->bitbuf >> os->bitcount, --os->next);
+ if (os->next != os->begin) {
+ os->next -= sizeof(le16);
+ put_unaligned_le16(os->bitbuf >> os->bitcount, os->next);
+ }
/* Optimization for call sites that never write more than 16
* bits at once. */
if (os->next == os->begin)
return false;
- if (os->bitcount != 0)
- put_unaligned_u16_le(os->bitbuf << (16 - os->bitcount), --os->next);
+ if (os->bitcount != 0) {
+ os->next -= sizeof(le16);
+ put_unaligned_le16(os->bitbuf << (16 - os->bitcount), os->next);
+ }
return true;
}
check_cost_shift(void)
{
/* lzms_bit_costs is hard-coded to the current COST_SHIFT. */
- BUILD_BUG_ON(COST_SHIFT != 6);
+ STATIC_ASSERT(COST_SHIFT == 6);
}
#if 0
static inline u32
lzms_literal_cost(struct lzms_compressor *c, unsigned main_state, unsigned literal)
{
- return lzms_bit_0_cost(main_state, c->main_probs) +
+ return lzms_bit_0_cost(main_state, c->probs.main) +
((u32)c->literal_lens[literal] << COST_SHIFT);
}
static inline void
lzms_update_state(u8 *state_p, int bit, unsigned num_states)
{
- *state_p = ((*state_p << 1) | bit) % num_states;
+ *state_p = ((*state_p << 1) | bit) & (num_states - 1);
}
static inline void
lzms_init_delta_matchfinder(struct lzms_compressor *c)
{
/* Set all entries to use an invalid power, which will never match. */
- BUILD_BUG_ON(NUM_POWERS_TO_CONSIDER >= (1 << (32 - DELTA_SOURCE_POWER_SHIFT)));
+ STATIC_ASSERT(NUM_POWERS_TO_CONSIDER < (1 << (32 - DELTA_SOURCE_POWER_SHIFT)));
memset(c->delta_hash_table, 0xFF, sizeof(c->delta_hash_table));
/* Initialize the next hash code for each power. We can just use zeroes
* delta context with the specified @span.
*/
static inline u32
-lzms_delta_hash(const u8 *p, u32 span)
+lzms_delta_hash(const u8 *p, const u32 pos, u32 span)
{
/* A delta match has a certain span and an offset that is a multiple of
* that span. To reduce wasted space we use a single combined hash
* include in the hash code computation the span and the low-order bits
* of the current position. */
- BUILD_BUG_ON(NBYTES_HASHED_FOR_DELTA != 3);
+ STATIC_ASSERT(NBYTES_HASHED_FOR_DELTA == 3);
u8 d0 = *(p + 0) - *(p + 0 - span);
u8 d1 = *(p + 1) - *(p + 1 - span);
u8 d2 = *(p + 2) - *(p + 2 - span);
- u32 v = ((span + ((u32)(uintptr_t)p & (span - 1))) << 24) |
+ u32 v = ((span + (pos & (span - 1))) << 24) |
((u32)d2 << 16) | ((u32)d1 << 8) | d0;
return lz_hash(v, DELTA_HASH_ORDER);
}
const u32 span = (u32)1 << power;
if (unlikely(pos < span))
continue;
- const u32 next_hash = lzms_delta_hash(in_next + 1, span);
+ const u32 next_hash = lzms_delta_hash(in_next + 1, pos + 1, span);
const u32 hash = c->next_delta_hashes[power];
c->delta_hash_table[hash] =
(power << DELTA_SOURCE_POWER_SHIFT) | pos;
c->next_delta_hashes[power] = next_hash;
- prefetch(&c->delta_hash_table[next_hash]);
+ prefetchw(&c->delta_hash_table[next_hash]);
}
} while (in_next++, pos++, --count);
}
* can be reached using a match or literal from the current position. This is
* essentially Dijkstra's algorithm in disguise: the graph nodes are positions,
* the graph edges are possible matches/literals to code, and the cost of each
- * edge is the estimated number of bits that will be required to output the
- * corresponding match or literal. But one difference is that we actually
- * compute the lowest-cost path in pieces, where each piece is terminated when
- * there are no choices to be made.
+ * edge is the estimated number of bits (scaled up by COST_SHIFT) that will be
+ * required to output the corresponding match or literal. But one difference is
+ * that we actually compute the lowest-cost path in pieces, where each piece is
+ * terminated when there are no choices to be made.
*
* The costs of literals and matches are estimated using the range encoder
* states and the semi-adaptive Huffman codes. Except for range encoding
u32 base_cost = cur_node->cost +
lzms_bit_1_cost(cur_node->state.main_state,
- c->main_probs) +
+ c->probs.main) +
lzms_bit_0_cost(cur_node->state.match_state,
- c->match_probs) +
+ c->probs.match) +
lzms_bit_1_cost(cur_node->state.lz_state,
- c->lz_probs);
+ c->probs.lz);
for (int i = 0; i < rep_idx; i++)
base_cost += lzms_bit_1_cost(cur_node->state.lz_rep_states[i],
- c->lz_rep_probs[i]);
+ c->probs.lz_rep[i]);
if (rep_idx < LZMS_NUM_LZ_REP_DECISIONS)
base_cost += lzms_bit_0_cost(cur_node->state.lz_rep_states[rep_idx],
- c->lz_rep_probs[rep_idx]);
+ c->probs.lz_rep[rep_idx]);
u32 len = 2;
do {
main_state = ((main_state << 1) | 0) % LZMS_NUM_MAIN_PROBS;
/* add LZ-rep0 cost */
- cost += lzms_bit_1_cost(main_state, c->main_probs) +
- lzms_bit_0_cost(match_state, c->match_probs) +
- lzms_bit_1_cost(lz_state, c->lz_probs) +
- lzms_bit_0_cost(lz_rep0_state, c->lz_rep_probs[0]) +
+ cost += lzms_bit_1_cost(main_state, c->probs.main) +
+ lzms_bit_0_cost(match_state, c->probs.match) +
+ lzms_bit_1_cost(lz_state, c->probs.lz) +
+ lzms_bit_0_cost(lz_rep0_state, c->probs.lz_rep[0]) +
lzms_fast_length_cost(c, rep0_len);
const u32 total_len = rep_len + 1 + rep0_len;
u32 base_cost = cur_node->cost +
lzms_bit_1_cost(cur_node->state.main_state,
- c->main_probs) +
+ c->probs.main) +
lzms_bit_1_cost(cur_node->state.match_state,
- c->match_probs) +
+ c->probs.match) +
lzms_bit_1_cost(cur_node->state.delta_state,
- c->delta_probs);
+ c->probs.delta);
for (int i = 0; i < rep_idx; i++)
base_cost += lzms_bit_1_cost(cur_node->state.delta_rep_states[i],
- c->delta_rep_probs[i]);
+ c->probs.delta_rep[i]);
if (rep_idx < LZMS_NUM_DELTA_REP_DECISIONS)
base_cost += lzms_bit_0_cost(cur_node->state.delta_rep_states[rep_idx],
- c->delta_rep_probs[rep_idx]);
+ c->probs.delta_rep[rep_idx]);
u32 len = 2;
do {
u32 base_cost = cur_node->cost +
lzms_bit_1_cost(cur_node->state.main_state,
- c->main_probs) +
+ c->probs.main) +
lzms_bit_0_cost(cur_node->state.match_state,
- c->match_probs) +
+ c->probs.match) +
lzms_bit_0_cost(cur_node->state.lz_state,
- c->lz_probs);
+ c->probs.lz);
if (c->try_lzmatch_lit_lzrep0 &&
likely(in_end - (in_next + c->matches[0].length) >= 3))
main_state = ((main_state << 1) | 0) % LZMS_NUM_MAIN_PROBS;
/* add LZ-rep0 cost */
- cost += lzms_bit_1_cost(main_state, c->main_probs) +
- lzms_bit_0_cost(match_state, c->match_probs) +
- lzms_bit_1_cost(lz_state, c->lz_probs) +
+ cost += lzms_bit_1_cost(main_state, c->probs.main) +
+ lzms_bit_0_cost(match_state, c->probs.match) +
+ lzms_bit_1_cost(lz_state, c->probs.lz) +
lzms_bit_0_cost(cur_node->state.lz_rep_states[0],
- c->lz_rep_probs[0]) +
+ c->probs.lz_rep[0]) +
lzms_fast_length_cost(c, rep0_len);
const u32 total_len = len + 1 + rep0_len;
const u32 pos = in_next - c->in_buffer;
/* Consider each possible power (log2 of span) */
- BUILD_BUG_ON(NUM_POWERS_TO_CONSIDER > LZMS_NUM_DELTA_POWER_SYMS);
+ STATIC_ASSERT(NUM_POWERS_TO_CONSIDER <= LZMS_NUM_DELTA_POWER_SYMS);
for (u32 power = 0; power < NUM_POWERS_TO_CONSIDER; power++) {
const u32 span = (u32)1 << power;
if (unlikely(pos < span))
continue;
- const u32 next_hash = lzms_delta_hash(in_next + 1, span);
+ const u32 next_hash = lzms_delta_hash(in_next + 1, pos + 1, span);
const u32 hash = c->next_delta_hashes[power];
const u32 cur_match = c->delta_hash_table[hash];
c->delta_hash_table[hash] = (power << DELTA_SOURCE_POWER_SHIFT) | pos;
c->next_delta_hashes[power] = next_hash;
- prefetch(&c->delta_hash_table[next_hash]);
+ prefetchw(&c->delta_hash_table[next_hash]);
if (power != cur_match >> DELTA_SOURCE_POWER_SHIFT)
continue;
/* Check the first 3 bytes before entering the
* extension loop. */
- BUILD_BUG_ON(NBYTES_HASHED_FOR_DELTA != 3);
+ STATIC_ASSERT(NBYTES_HASHED_FOR_DELTA == 3);
if (((u8)(*(in_next + 0) - *(in_next + 0 - span)) !=
(u8)(*(matchptr + 0) - *(matchptr + 0 - span))) ||
((u8)(*(in_next + 1) - *(in_next + 1 - span)) !=
/* Extend the delta match to its full length. */
const u32 len = lzms_extend_delta_match(in_next,
matchptr,
- 3,
+ NBYTES_HASHED_FOR_DELTA,
in_end - in_next,
span);
u32 base_cost = cur_node->cost +
lzms_bit_1_cost(cur_node->state.main_state,
- c->main_probs) +
+ c->probs.main) +
lzms_bit_1_cost(cur_node->state.match_state,
- c->match_probs) +
+ c->probs.match) +
lzms_bit_0_cost(cur_node->state.delta_state,
- c->delta_probs) +
+ c->probs.delta) +
lzms_delta_source_cost(c, power, raw_offset);
u32 l = NBYTES_HASHED_FOR_DELTA;
/* Add cost of LZ-rep0 */
const u32 cost = cur_and_lit_cost +
- lzms_bit_1_cost(main_state, c->main_probs) +
+ lzms_bit_1_cost(main_state, c->probs.main) +
lzms_bit_0_cost(cur_node->state.match_state,
- c->match_probs) +
+ c->probs.match) +
lzms_bit_1_cost(cur_node->state.lz_state,
- c->lz_probs) +
+ c->probs.lz) +
lzms_bit_0_cost(cur_node->state.lz_rep_states[0],
- c->lz_rep_probs[0]) +
+ c->probs.lz_rep[0]) +
lzms_fast_length_cost(c, rep0_len);
const u32 total_len = 1 + rep0_len;
* Finalize the adaptive state that results from taking this
* lowest-cost path. */
struct lzms_item item_to_take = cur_node->item;
- struct lzms_optimum_node *source_node = cur_node - (item_to_take.length);
+ struct lzms_optimum_node *source_node = cur_node - item_to_take.length;
int next_item_idx = -1;
for (unsigned i = 0; i < cur_node->num_extra_items; i++) {
item_to_take = cur_node->extra_items[i];
if (source >= LZMS_NUM_DELTA_REPS) {
/* Explicit offset delta match */
- u32 pair = source - (LZMS_NUM_DELTA_REPS - 1);
lzms_update_delta_state(&cur_node->state, 0);
- cur_node->state.upcoming_delta_pair = pair;
+ cur_node->state.upcoming_delta_pair =
+ source - (LZMS_NUM_DELTA_REPS - 1);
} else {
/* Repeat offset delta match */
int rep_idx = source;
for (int i = 0; i < LZMS_NUM_DELTA_REP_DECISIONS; i++)
c->delta_rep_states[i] = 0;
- lzms_init_probability_entries(c->main_probs, LZMS_NUM_MAIN_PROBS);
- lzms_init_probability_entries(c->match_probs, LZMS_NUM_MATCH_PROBS);
- lzms_init_probability_entries(c->lz_probs, LZMS_NUM_LZ_PROBS);
- for (int i = 0; i < LZMS_NUM_LZ_REP_DECISIONS; i++)
- lzms_init_probability_entries(c->lz_rep_probs[i], LZMS_NUM_LZ_REP_PROBS);
- lzms_init_probability_entries(c->delta_probs, LZMS_NUM_DELTA_PROBS);
- for (int i = 0; i < LZMS_NUM_DELTA_REP_DECISIONS; i++)
- lzms_init_probability_entries(c->delta_rep_probs[i], LZMS_NUM_DELTA_REP_PROBS);
+ lzms_init_probabilities(&c->probs);
}
static void
static size_t
lzms_finalize(struct lzms_compressor *c)
{
- size_t num_forwards_units;
- size_t num_backwards_units;
+ size_t num_forwards_bytes;
+ size_t num_backwards_bytes;
/* Flush both the forwards and backwards streams, and make sure they
* didn't cross each other and start overwriting each other's data. */
* bitstream. Move the data output by the backwards bitstream to be
* adjacent to the data output by the forward bitstream, and calculate
* the compressed size that this results in. */
- num_forwards_units = c->rc.next - c->rc.begin;
- num_backwards_units = c->rc.end - c->os.next;
+ num_forwards_bytes = c->rc.next - c->rc.begin;
+ num_backwards_bytes = c->rc.end - c->os.next;
- memmove(c->rc.next, c->os.next, num_backwards_units * sizeof(le16));
+ memmove(c->rc.next, c->os.next, num_backwards_bytes);
- return (num_forwards_units + num_backwards_units) * sizeof(le16);
+ return num_forwards_bytes + num_backwards_bytes;
}
static u64
}
static size_t
-lzms_compress(const void *in, size_t in_nbytes,
- void *out, size_t out_nbytes_avail, void *_c)
+lzms_compress(const void *restrict in, size_t in_nbytes,
+ void *restrict out, size_t out_nbytes_avail, void *restrict _c)
{
struct lzms_compressor *c = _c;
size_t result;
lzms_init_delta_matchfinder(c);
/* Initialize the encoder structures. */
- lzms_range_encoder_init(&c->rc, out, out_nbytes_avail / sizeof(le16));
- lzms_output_bitstream_init(&c->os, out, out_nbytes_avail / sizeof(le16));
+ lzms_range_encoder_init(&c->rc, out, out_nbytes_avail);
+ lzms_output_bitstream_init(&c->os, out, out_nbytes_avail);
lzms_init_states_and_probabilities(c);
lzms_init_huffman_codes(c, lzms_get_num_offset_slots(c->in_nbytes));
git://wimlib.net / wimlib / blobdiff