From feafb3423e76d3c02a1f4fc740fb3f91a211ce1c Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sat, 3 Feb 2018 04:43:46 +0100 Subject: [PATCH] bzip2: ~1% speedup by special-casing "store 1 bit" function function old new delta bsW1 - 52 +52 BZ2_compressBlock 230 225 -5 BZ2_blockSort 125 118 -7 sendMTFValues 2070 2051 -19 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/3 up/down: 52/-31) Total: 21 bytes Signed-off-by: Denys Vlasenko --- archival/libarchive/bz/blocksort.c | 2 ++ archival/libarchive/bz/bzlib.c | 2 +- archival/libarchive/bz/compress.c | 24 ++++++++++++++++++++---- 3 files changed, 23 insertions(+), 5 deletions(-) diff --git a/archival/libarchive/bz/blocksort.c b/archival/libarchive/bz/blocksort.c index e600cb7a7..a3b099f4b 100644 --- a/archival/libarchive/bz/blocksort.c +++ b/archival/libarchive/bz/blocksort.c @@ -1056,7 +1056,9 @@ void BZ2_blockSort(EState* s) } } +#if BZ_LIGHT_DEBUG s->origPtr = -1; +#endif for (i = 0; i < s->nblock; i++) if (ptr[i] == 0) { s->origPtr = i; diff --git a/archival/libarchive/bz/bzlib.c b/archival/libarchive/bz/bzlib.c index 3572474f4..ef98bb213 100644 --- a/archival/libarchive/bz/bzlib.c +++ b/archival/libarchive/bz/bzlib.c @@ -55,7 +55,7 @@ void prepare_new_block(EState* s) { int i; s->nblock = 0; - //indexes inot s->zbits[], initialzation moved to init of s->zbits + //indexes into s->zbits[], initialzation moved to init of s->zbits //s->posZ = s->zbits; // was: s->numZ = 0; //s->state_out_pos = s->zbits; BZ_INITIALISE_CRC(s->blockCRC); diff --git a/archival/libarchive/bz/compress.c b/archival/libarchive/bz/compress.c index 271982cf2..4d0f77592 100644 --- a/archival/libarchive/bz/compress.c +++ b/archival/libarchive/bz/compress.c @@ -88,6 +88,22 @@ void bsW16(EState* s, uint32_t v) s->bsBuff |= (v << (16 - s->bsLive)); s->bsLive += 16; } +/* Same with n == 1: */ +static +#if CONFIG_BZIP2_FAST >= 5 +ALWAYS_INLINE +#endif +void bsW1(EState* s, uint32_t v) +{ + /* need space for only 1 bit, no need for loop freeing > 8 bits */ + if (s->bsLive >= 8) { + *s->posZ++ = (uint8_t)(s->bsBuff >> 24); + s->bsBuff <<= 8; + s->bsLive -= 8; + } + s->bsBuff |= (v << (31 - s->bsLive)); + s->bsLive += 1; +} /*---------------------------------------------------*/ @@ -557,8 +573,8 @@ void sendMTFValues(EState* s) for (i = 0; i < nSelectors; i++) { unsigned j; for (j = 0; j < s->selectorMtf[i]; j++) - bsW(s, 1, 1); - bsW(s, 1, 0); + bsW1(s, 1); + bsW1(s, 0); } /*--- Now the coding tables. ---*/ @@ -568,7 +584,7 @@ void sendMTFValues(EState* s) for (i = 0; i < alphaSize; i++) { while (curr < s->len[t][i]) { bsW(s, 2, 2); curr++; /* 10 */ }; while (curr > s->len[t][i]) { bsW(s, 2, 3); curr--; /* 11 */ }; - bsW(s, 1, 0); + bsW1(s, 0); } } @@ -682,7 +698,7 @@ void BZ2_compressBlock(EState* s, int is_last_block) * so as to maintain backwards compatibility with * older versions of bzip2. */ - bsW(s, 1, 0); + bsW1(s, 0); bsW(s, 24, s->origPtr); generateMTFValues(s); -- 2.25.1