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Remove the subroutine return stack from the VDBE. Return addresses

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for subroutines are now stored in registers. (CVS 5191)

FossilOrigin-Name: ef1956eebcaf5aca51af8c3b406b1fd4b1f391a7
This commit is contained in:
drh
2008-06-06 15:04:36 +00:00
parent 17b90b5316
commit 2eb95377ef
8 changed files with 56 additions and 55 deletions
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27
src/select.c
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@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.429 2008/05/01 17:03:49 drh Exp $
** $Id: select.c,v 1.430 2008/06/06 15:04:37 drh Exp $
*/
#include "sqliteInt.h"
@@ -39,6 +39,7 @@ static void clearSelect(Select *p){
void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){
pDest->eDest = eDest;
pDest->iParm = iParm;
pDest->regReturn = 0;
pDest->affinity = 0;
pDest->iMem = 0;
pDest->nMem = 0;
@@ -711,7 +712,7 @@ static void selectInnerLoop(
pushOntoSorter(pParse, pOrderBy, p, r1);
sqlite3ReleaseTempReg(pParse, r1);
}else if( eDest==SRT_Subroutine ){
sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
sqlite3VdbeAddOp2(v, OP_Gosub, pDest->regReturn, iParm);
}else{
sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nColumn);
sqlite3ExprCacheAffinityChange(pParse, regResult, nColumn);
@@ -858,7 +859,7 @@ static void generateSortTail(
sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iMem, nColumn);
sqlite3ExprCacheAffinityChange(pParse, pDest->iMem, nColumn);
}else{
sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
sqlite3VdbeAddOp2(v, OP_Gosub, pDest->regReturn, iParm);
}
break;
}
@@ -3291,6 +3292,7 @@ int sqlite3Select(
/* The following variables hold addresses or labels for parts of the
** virtual machine program we are putting together */
int addrOutputRow; /* Start of subroutine that outputs a result row */
int regOutputRow; /* Return address register for outputrow subroutine */
int addrSetAbort; /* Set the abort flag and return */
int addrInitializeLoop; /* Start of code that initializes the input loop */
int addrTopOfLoop; /* Top of the input loop */
@@ -3299,6 +3301,7 @@ int sqlite3Select(
int addrEnd; /* End of all processing */
int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */
int addrReset; /* Subroutine for resetting the accumulator */
int regReset; /* Return address register for reset subroutine */
addrEnd = sqlite3VdbeMakeLabel(v);
@@ -3371,11 +3374,12 @@ int sqlite3Select(
addrSetAbort = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_Integer, 1, iAbortFlag);
VdbeComment((v, "set abort flag"));
sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
regOutputRow = ++pParse->nMem;
sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
addrOutputRow = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);
VdbeComment((v, "Groupby result generator entry point"));
sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
finalizeAggFunctions(pParse, &sAggInfo);
if( pHaving ){
sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);
@@ -3383,14 +3387,15 @@ int sqlite3Select(
selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,
distinct, pDest,
addrOutputRow+1, addrSetAbort, aff);
sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
VdbeComment((v, "end groupby result generator"));
/* Generate a subroutine that will reset the group-by accumulator
*/
addrReset = sqlite3VdbeCurrentAddr(v);
regReset = ++pParse->nMem;
resetAccumulator(pParse, &sAggInfo);
sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
sqlite3VdbeAddOp1(v, OP_Return, regReset);
/* Begin a loop that will extract all source rows in GROUP BY order.
** This might involve two separate loops with an OP_Sort in between, or
@@ -3398,7 +3403,7 @@ int sqlite3Select(
** in the right order to begin with.
*/
sqlite3VdbeResolveLabel(v, addrInitializeLoop);
sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrReset);
sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pGroupBy, 0);
if( pWInfo==0 ) goto select_end;
if( pGroupBy==0 ){
@@ -3493,11 +3498,11 @@ int sqlite3Select(
for(j=0; j<pGroupBy->nExpr; j++){
sqlite3ExprCodeMove(pParse, iBMem+j, iAMem+j);
}
sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrOutputRow);
sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
VdbeComment((v, "output one row"));
sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd);
VdbeComment((v, "check abort flag"));
sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrReset);
sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
VdbeComment((v, "reset accumulator"));
/* Update the aggregate accumulators based on the content of
@@ -3519,7 +3524,7 @@ int sqlite3Select(
/* Output the final row of result
*/
sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrOutputRow);
sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
VdbeComment((v, "output final row"));
} /* endif pGroupBy */