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mirror of https://github.com/sqlite/sqlite.git synced 2025-11-14 00:22:38 +03:00

Simplify the accumulator reset for aggregate query processing so that it

uses a single multi-register OP_Null rather than a separate OP_Null for each
register.

FossilOrigin-Name: 2c7fd9b043f5f3d9d8e22dbefa84a9770ca951d0
This commit is contained in:
drh
2013-12-20 13:11:45 +00:00
parent 1001ee8819
commit 7e61d18eb4
4 changed files with 26 additions and 14 deletions

View File

@@ -3822,14 +3822,23 @@ static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
Vdbe *v = pParse->pVdbe;
int i;
struct AggInfo_func *pFunc;
if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
return;
}
int nReg = pAggInfo->nFunc + pAggInfo->nColumn;
if( nReg==0 ) return;
#ifdef SQLITE_DEBUG
/* Verify that all AggInfo registers are within the range specified by
** AggInfo.mnReg..AggInfo.mxReg */
assert( nReg==pAggInfo->mxReg-pAggInfo->mnReg+1 );
for(i=0; i<pAggInfo->nColumn; i++){
sqlite3VdbeAddOp2(v, OP_Null, 0, pAggInfo->aCol[i].iMem);
assert( pAggInfo->aCol[i].iMem>=pAggInfo->mnReg
&& pAggInfo->aCol[i].iMem<=pAggInfo->mxReg );
}
for(i=0; i<pAggInfo->nFunc; i++){
assert( pAggInfo->aFunc[i].iMem>=pAggInfo->mnReg
&& pAggInfo->aFunc[i].iMem<=pAggInfo->mxReg );
}
#endif
sqlite3VdbeAddOp3(v, OP_Null, 0, pAggInfo->mnReg, pAggInfo->mxReg);
for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
sqlite3VdbeAddOp2(v, OP_Null, 0, pFunc->iMem);
if( pFunc->iDistinct>=0 ){
Expr *pE = pFunc->pExpr;
assert( !ExprHasProperty(pE, EP_xIsSelect) );
@@ -4407,6 +4416,7 @@ int sqlite3Select(
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
sNC.pAggInfo = &sAggInfo;
sAggInfo.mnReg = pParse->nMem+1;
sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr+1 : 0;
sAggInfo.pGroupBy = pGroupBy;
sqlite3ExprAnalyzeAggList(&sNC, pEList);
@@ -4421,6 +4431,7 @@ int sqlite3Select(
sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->x.pList);
sNC.ncFlags &= ~NC_InAggFunc;
}
sAggInfo.mxReg = pParse->nMem;
if( db->mallocFailed ) goto select_end;
/* Processing for aggregates with GROUP BY is very different and