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| author | Denis Vlasenko <vda.linux@googlemail.com> | 2007-10-14 07:49:48 +0000 |
|---|---|---|
| committer | Denis Vlasenko <vda.linux@googlemail.com> | 2007-10-14 07:49:48 +0000 |
| commit | 6a9154b6f649341870bc06e896d2fe7235a4aef9 (patch) | |
| tree | b80d1603d370838166ada58b42cd6e0b8c7c6970 /archival/bz/compress.c | |
| parent | 3f5fdc7572d932f33f81029956b87230c9b05182 (diff) | |
| download | busybox-6a9154b6f649341870bc06e896d2fe7235a4aef9.tar.gz | |
bzip2: eliminate some divisions
Diffstat (limited to 'archival/bz/compress.c')
| -rw-r--r-- | archival/bz/compress.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/archival/bz/compress.c b/archival/bz/compress.c index 3e2fbd867..724474e2d 100644 --- a/archival/bz/compress.c +++ b/archival/bz/compress.c @@ -186,7 +186,8 @@ void generateMTFValues(EState* s) s->mtfFreq[BZ_RUNA]++; } if (zPend < 2) break; - zPend = (zPend - 2) / 2; + zPend = (uint32_t)(zPend - 2) / 2; + /* bbox: unsigned div is easier */ }; zPend = 0; } @@ -219,15 +220,18 @@ void generateMTFValues(EState* s) zPend--; while (1) { if (zPend & 1) { - mtfv[wr] = BZ_RUNB; wr++; + mtfv[wr] = BZ_RUNB; + wr++; s->mtfFreq[BZ_RUNB]++; } else { - mtfv[wr] = BZ_RUNA; wr++; + mtfv[wr] = BZ_RUNA; + wr++; s->mtfFreq[BZ_RUNA]++; } if (zPend < 2) break; - zPend = (zPend - 2) / 2; + zPend = (uint32_t)(zPend - 2) / 2; + /* bbox: unsigned div is easier */ }; zPend = 0; } @@ -288,7 +292,7 @@ void sendMTFValues(EState* s) gs = 0; while (nPart > 0) { tFreq = remF / nPart; - ge = gs-1; + ge = gs - 1; aFreq = 0; while (aFreq < tFreq && ge < alphaSize-1) { ge++; @@ -297,7 +301,7 @@ void sendMTFValues(EState* s) if (ge > gs && nPart != nGroups && nPart != 1 - && ((nGroups - nPart) % 2 == 1) + && ((nGroups - nPart) % 2 == 1) /* bbox: can this be replaced by x & 1? */ ) { aFreq -= s->mtfFreq[ge]; ge--; @@ -310,7 +314,7 @@ void sendMTFValues(EState* s) s->len[nPart-1][v] = BZ_GREATER_ICOST; nPart--; - gs = ge+1; + gs = ge + 1; remF -= aFreq; } } @@ -414,7 +418,7 @@ void sendMTFValues(EState* s) /* * Increment the symbol frequencies for the selected table. */ -/* 1% faster compress. +800 bytes */ +/* 1% faster compress. +800 bytes */ #if CONFIG_BZIP2_FEATURE_SPEED >= 4 if (nGroups == 6 && 50 == ge-gs+1) { /*--- fast track the common case ---*/ |