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
diff --git a/src/select.c b/src/select.c
index 132d546..d075116 100644
--- a/src/select.c
+++ b/src/select.c
@@ -3822,14 +3822,23 @@
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 @@
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 @@
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
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index af018ed..a33ff4d 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1688,6 +1688,7 @@
int sortingIdx; /* Cursor number of the sorting index */
int sortingIdxPTab; /* Cursor number of pseudo-table */
int nSortingColumn; /* Number of columns in the sorting index */
+ int mnReg, mxReg; /* Range of registers allocated for aCol and aFunc */
ExprList *pGroupBy; /* The group by clause */
struct AggInfo_col { /* For each column used in source tables */
Table *pTab; /* Source table */