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minor bt CSpeed

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Yann Collet 2015-11-06 19:03:59 +01:00
parent 628065cf98
commit a81d9ac42d
1 changed files with 10 additions and 10 deletions
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20
lib/zstdhc.c
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@ -346,25 +346,25 @@ static void ZSTD_HC_insertBt1(ZSTD_HC_CCtx* zc, const BYTE* const ip, const U32
matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend); matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */ if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* just drop , to guarantee consistency (miss a bit of compression; if someone knows better, please tell) */ break; /* just drop, to guarantee consistency (miss a little bit of compression) */
if (match[matchLength] < ip[matchLength]) if (match[matchLength] < ip[matchLength])
{ {
/* match is smaller than current */ /* match is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */ *smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */ smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */ if (matchIndex <= btLow) smallerPtr=&dummy32; /* beyond tree size, stop the search */
matchIndex = (matchIndex <= btLow) ? windowLow : nextPtr[1];
} }
else else
{ {
/* match is larger than current */ /* match is larger than current */
*largerPtr = matchIndex; *largerPtr = matchIndex;
commonLengthLarger = matchLength; commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr; largerPtr = nextPtr;
matchIndex = nextPtr[0]; if (matchIndex <= btLow) largerPtr=&dummy32; /* beyond tree size, stop the search */
matchIndex = (matchIndex <= btLow) ? windowLow : nextPtr[0];
} }
} }
@ -412,7 +412,7 @@ size_t ZSTD_HC_insertBtAndFindBestMatch (
if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit(current-matchIndex+1) - ZSTD_highbit((U32)offsetPtr[0]+1)) ) if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit(current-matchIndex+1) - ZSTD_highbit((U32)offsetPtr[0]+1)) )
bestLength = matchLength, *offsetPtr = current - matchIndex; bestLength = matchLength, *offsetPtr = current - matchIndex;
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */ if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* drop, next to null, to guarantee consistency (is there a way to do better ?) */ break; /* just drop, to guarantee consistency (miss a little bit of compression) */
} }
if (match[matchLength] < ip[matchLength]) if (match[matchLength] < ip[matchLength])
@ -420,18 +420,18 @@ size_t ZSTD_HC_insertBtAndFindBestMatch (
/* match is smaller than current */ /* match is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */ *smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */ smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */ if (matchIndex <= btLow) smallerPtr=&dummy32; /* beyond tree size, stop the search */
matchIndex = (matchIndex <= btLow) ? windowLow : nextPtr[1];
} }
else else
{ {
/* match is larger than current */ /* match is larger than current */
*largerPtr = matchIndex; *largerPtr = matchIndex;
commonLengthLarger = matchLength; commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr; largerPtr = nextPtr;
matchIndex = nextPtr[0]; if (matchIndex <= btLow) largerPtr=&dummy32; /* beyond tree size, stop the search */
matchIndex = (matchIndex <= btLow) ? windowLow : nextPtr[0];
} }
} }