From 9ac3dc764a78b51fe8fdcd1b4682850de098733b Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sat, 25 Apr 2009 12:19:35 +0000 Subject: unlzma: speedup, by Pascal Bellard (pascal.bellard AT ads-lu.com) LZMA_FAST off: 10% faster and: function old new delta rc_is_bit_1 - 92 +92 rc_do_normalize 45 81 +36 rc_update_bit_1 25 - -25 rc_update_bit_0 30 - -30 rc_is_bit_0_helper 38 - -38 rc_get_bit 60 17 -43 rc_read 48 - -48 unpack_lzma_stream 1768 1517 -251 ------------------------------------------------------------------------------ (add/remove: 1/4 grow/shrink: 1/2 up/down: 128/-435) Total: -307 bytes LZMA_FAST on: 14% faster and: unpack_lzma_stream 2301 2737 +436 rc_get_bit 106 - -106 --- archival/Config.in | 4 +- archival/libunarchive/decompress_unlzma.c | 154 +++++++++++------------------- 2 files changed, 60 insertions(+), 98 deletions(-) (limited to 'archival') diff --git a/archival/Config.in b/archival/Config.in index 64b44c218..e0d43c0ee 100644 --- a/archival/Config.in +++ b/archival/Config.in @@ -283,8 +283,8 @@ config FEATURE_LZMA_FAST default n depends on UNLZMA help - This option reduces decompression time by about 33% at the cost of - a 2K bigger binary. + This option reduces decompression time by about 25% at the cost of + a 1K bigger binary. config UNZIP bool "unzip" diff --git a/archival/libunarchive/decompress_unlzma.c b/archival/libunarchive/decompress_unlzma.c index 33e5cd65d..68085d68c 100644 --- a/archival/libunarchive/decompress_unlzma.c +++ b/archival/libunarchive/decompress_unlzma.c @@ -8,14 +8,15 @@ * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ - #include "libbb.h" #include "unarchive.h" #if ENABLE_FEATURE_LZMA_FAST # define speed_inline ALWAYS_INLINE +# define size_inline #else # define speed_inline +# define size_inline ALWAYS_INLINE #endif @@ -44,8 +45,8 @@ typedef struct { #define RC_MODEL_TOTAL_BITS 11 -/* Called twice: once at startup and once in rc_normalize() */ -static void rc_read(rc_t *rc) +/* Called twice: once at startup (LZMA_FAST only) and once in rc_normalize() */ +static size_inline void rc_read(rc_t *rc) { int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE); if (buffer_size <= 0) @@ -54,8 +55,17 @@ static void rc_read(rc_t *rc) rc->buffer_end = RC_BUFFER + buffer_size; } +/* Called twice, but one callsite is in speed_inline'd rc_is_bit_1() */ +static void rc_do_normalize(rc_t *rc) +{ + if (rc->ptr >= rc->buffer_end) + rc_read(rc); + rc->range <<= 8; + rc->code = (rc->code << 8) | *rc->ptr++; +} + /* Called once */ -static rc_t* rc_init(int fd) /*, int buffer_size) */ +static ALWAYS_INLINE rc_t* rc_init(int fd) /*, int buffer_size) */ { int i; rc_t *rc; @@ -63,17 +73,18 @@ static rc_t* rc_init(int fd) /*, int buffer_size) */ rc = xmalloc(sizeof(*rc) + RC_BUFFER_SIZE); rc->fd = fd; - /* rc->buffer_size = buffer_size; */ - rc->buffer_end = RC_BUFFER + RC_BUFFER_SIZE; rc->ptr = rc->buffer_end; - rc->code = 0; - rc->range = 0xFFFFFFFF; for (i = 0; i < 5; i++) { +#if ENABLE_FEATURE_LZMA_FAST if (rc->ptr >= rc->buffer_end) rc_read(rc); rc->code = (rc->code << 8) | *rc->ptr++; +#else + rc_do_normalize(rc); +#endif } + rc->range = 0xFFFFFFFF; return rc; } @@ -83,14 +94,6 @@ static ALWAYS_INLINE void rc_free(rc_t *rc) free(rc); } -/* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */ -static void rc_do_normalize(rc_t *rc) -{ - if (rc->ptr >= rc->buffer_end) - rc_read(rc); - rc->range <<= 8; - rc->code = (rc->code << 8) | *rc->ptr++; -} static ALWAYS_INLINE void rc_normalize(rc_t *rc) { if (rc->range < (1 << RC_TOP_BITS)) { @@ -98,49 +101,28 @@ static ALWAYS_INLINE void rc_normalize(rc_t *rc) } } -/* rc_is_bit_0 is called 9 times */ -/* Why rc_is_bit_0_helper exists? - * Because we want to always expose (rc->code < rc->bound) to optimizer. - * Thus rc_is_bit_0 is always inlined, and rc_is_bit_0_helper is inlined - * only if we compile for speed. - */ -static speed_inline uint32_t rc_is_bit_0_helper(rc_t *rc, uint16_t *p) +/* rc_is_bit_1 is called 9 times */ +static speed_inline int rc_is_bit_1(rc_t *rc, uint16_t *p) { rc_normalize(rc); rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS); - return rc->bound; -} -static ALWAYS_INLINE int rc_is_bit_0(rc_t *rc, uint16_t *p) -{ - uint32_t t = rc_is_bit_0_helper(rc, p); - return rc->code < t; -} - -/* Called ~10 times, but very small, thus inlined */ -static speed_inline void rc_update_bit_0(rc_t *rc, uint16_t *p) -{ - rc->range = rc->bound; - *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS; -} -static speed_inline void rc_update_bit_1(rc_t *rc, uint16_t *p) -{ + if (rc->code < rc->bound) { + rc->range = rc->bound; + *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS; + return 0; + } rc->range -= rc->bound; rc->code -= rc->bound; *p -= *p >> RC_MOVE_BITS; + return 1; } /* Called 4 times in unlzma loop */ -static int rc_get_bit(rc_t *rc, uint16_t *p, int *symbol) +static speed_inline int rc_get_bit(rc_t *rc, uint16_t *p, int *symbol) { - if (rc_is_bit_0(rc, p)) { - rc_update_bit_0(rc, p); - *symbol *= 2; - return 0; - } else { - rc_update_bit_1(rc, p); - *symbol = *symbol * 2 + 1; - return 1; - } + int ret = rc_is_bit_1(rc, p); + *symbol = *symbol * 2 + ret; + return ret; } /* Called once */ @@ -266,13 +248,13 @@ unpack_lzma_stream(int src_fd, int dst_fd) header.dst_size = SWAP_LE64(header.dst_size); if (header.dict_size == 0) - header.dict_size = 1; + header.dict_size++; buffer = xmalloc(MIN(header.dst_size, header.dict_size)); num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp)); p = xmalloc(num_probs * sizeof(*p)); - num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp)); + num_probs += LZMA_LITERAL - LZMA_BASE_SIZE; for (i = 0; i < num_probs; i++) p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1; @@ -282,9 +264,8 @@ unpack_lzma_stream(int src_fd, int dst_fd) int pos_state = (buffer_pos + global_pos) & pos_state_mask; prob = p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state; - if (rc_is_bit_0(rc, prob)) { + if (!rc_is_bit_1(rc, prob)) { mi = 1; - rc_update_bit_0(rc, prob); prob = (p + LZMA_LITERAL + (LZMA_LIT_SIZE * ((((buffer_pos + global_pos) & literal_pos_mask) << lc) + (previous_byte >> (8 - lc)) @@ -340,27 +321,21 @@ unpack_lzma_stream(int src_fd, int dst_fd) int offset; uint16_t *prob_len; - rc_update_bit_1(rc, prob); prob = p + LZMA_IS_REP + state; - if (rc_is_bit_0(rc, prob)) { - rc_update_bit_0(rc, prob); + if (!rc_is_bit_1(rc, prob)) { rep3 = rep2; rep2 = rep1; rep1 = rep0; state = state < LZMA_NUM_LIT_STATES ? 0 : 3; prob = p + LZMA_LEN_CODER; } else { - rc_update_bit_1(rc, prob); - prob = p + LZMA_IS_REP_G0 + state; - if (rc_is_bit_0(rc, prob)) { - rc_update_bit_0(rc, prob); + prob += LZMA_IS_REP_G0 - LZMA_IS_REP; + if (!rc_is_bit_1(rc, prob)) { prob = (p + LZMA_IS_REP_0_LONG + (state << LZMA_NUM_POS_BITS_MAX) + pos_state ); - if (rc_is_bit_0(rc, prob)) { - rc_update_bit_0(rc, prob); - + if (!rc_is_bit_1(rc, prob)) { state = state < LZMA_NUM_LIT_STATES ? 9 : 11; #if ENABLE_FEATURE_LZMA_FAST pos = buffer_pos - rep0; @@ -372,25 +347,16 @@ unpack_lzma_stream(int src_fd, int dst_fd) len = 1; goto string; #endif - } else { - rc_update_bit_1(rc, prob); } } else { uint32_t distance; - rc_update_bit_1(rc, prob); - prob = p + LZMA_IS_REP_G1 + state; - if (rc_is_bit_0(rc, prob)) { - rc_update_bit_0(rc, prob); - distance = rep1; - } else { - rc_update_bit_1(rc, prob); - prob = p + LZMA_IS_REP_G2 + state; - if (rc_is_bit_0(rc, prob)) { - rc_update_bit_0(rc, prob); - distance = rep2; - } else { - rc_update_bit_1(rc, prob); + prob += LZMA_IS_REP_G1 - LZMA_IS_REP_G0; + distance = rep1; + if (rc_is_bit_1(rc, prob)) { + prob += LZMA_IS_REP_G2 - LZMA_IS_REP_G1; + distance = rep2; + if (rc_is_bit_1(rc, prob)) { distance = rep3; rep3 = rep2; } @@ -404,24 +370,20 @@ unpack_lzma_stream(int src_fd, int dst_fd) } prob_len = prob + LZMA_LEN_CHOICE; - if (rc_is_bit_0(rc, prob_len)) { - rc_update_bit_0(rc, prob_len); - prob_len = (prob + LZMA_LEN_LOW - + (pos_state << LZMA_LEN_NUM_LOW_BITS)); + if (!rc_is_bit_1(rc, prob_len)) { + prob_len += LZMA_LEN_LOW - LZMA_LEN_CHOICE + + (pos_state << LZMA_LEN_NUM_LOW_BITS); offset = 0; num_bits = LZMA_LEN_NUM_LOW_BITS; } else { - rc_update_bit_1(rc, prob_len); - prob_len = prob + LZMA_LEN_CHOICE_2; - if (rc_is_bit_0(rc, prob_len)) { - rc_update_bit_0(rc, prob_len); - prob_len = (prob + LZMA_LEN_MID - + (pos_state << LZMA_LEN_NUM_MID_BITS)); + prob_len += LZMA_LEN_CHOICE_2 - LZMA_LEN_CHOICE; + if (!rc_is_bit_1(rc, prob_len)) { + prob_len += LZMA_LEN_MID - LZMA_LEN_CHOICE_2 + + (pos_state << LZMA_LEN_NUM_MID_BITS); offset = 1 << LZMA_LEN_NUM_LOW_BITS; num_bits = LZMA_LEN_NUM_MID_BITS; } else { - rc_update_bit_1(rc, prob_len); - prob_len = prob + LZMA_LEN_HIGH; + prob_len += LZMA_LEN_HIGH - LZMA_LEN_CHOICE_2; offset = ((1 << LZMA_LEN_NUM_LOW_BITS) + (1 << LZMA_LEN_NUM_MID_BITS)); num_bits = LZMA_LEN_NUM_HIGH_BITS; @@ -438,19 +400,20 @@ unpack_lzma_stream(int src_fd, int dst_fd) ((len < LZMA_NUM_LEN_TO_POS_STATES ? len : LZMA_NUM_LEN_TO_POS_STATES - 1) << LZMA_NUM_POS_SLOT_BITS); - rc_bit_tree_decode(rc, prob, LZMA_NUM_POS_SLOT_BITS, - &pos_slot); + rc_bit_tree_decode(rc, prob, + LZMA_NUM_POS_SLOT_BITS, &pos_slot); + rep0 = pos_slot; if (pos_slot >= LZMA_START_POS_MODEL_INDEX) { num_bits = (pos_slot >> 1) - 1; rep0 = 2 | (pos_slot & 1); + prob = p + LZMA_ALIGN; if (pos_slot < LZMA_END_POS_MODEL_INDEX) { rep0 <<= num_bits; - prob = p + LZMA_SPEC_POS + rep0 - pos_slot - 1; + prob += LZMA_SPEC_POS - LZMA_ALIGN - 1 + rep0 - pos_slot; } else { num_bits -= LZMA_NUM_ALIGN_BITS; while (num_bits--) rep0 = (rep0 << 1) | rc_direct_bit(rc); - prob = p + LZMA_ALIGN; rep0 <<= LZMA_NUM_ALIGN_BITS; num_bits = LZMA_NUM_ALIGN_BITS; } @@ -461,8 +424,7 @@ unpack_lzma_stream(int src_fd, int dst_fd) rep0 |= i; i <<= 1; } - } else - rep0 = pos_slot; + } if (++rep0 == 0) break; } -- cgit v1.2.3