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Overview
| Comment: | Suppress more instances of unnecessary OP_IsNull and OP_Affinity opcodes. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
bf6c0bd1c5568c6292ea0a64c8a5071e |
| User & Date: | drh 2009-11-18 01:25:27 |
Context
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2009-11-18
| ||
| 23:01 | Performance improvement by avoiding unnecessary calls to memset(). (check-in: 85940468 user: drh tags: trunk) | |
| 01:25 | Suppress more instances of unnecessary OP_IsNull and OP_Affinity opcodes. (check-in: bf6c0bd1 user: drh tags: trunk) | |
|
2009-11-17
| ||
| 23:59 | Enhancements to the VDBE opcode loop to reduce the number of machine-code instructions evaluated by about 10%. (check-in: 9744ffb3 user: drh tags: trunk) | |
Changes
Changes to src/expr.c.
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case TK_FLOAT:
case TK_BLOB:
return 0;
default:
return 1;
}
}
/*
** Return TRUE if the given expression is a constant which would be
** unchanged by OP_Affinity with the affinity given in the second
** argument.
**
** This routine is used to determine if the OP_Affinity operation
................................................................................
}
case TK_STRING: {
return aff==SQLITE_AFF_TEXT;
}
case TK_BLOB: {
return 1;
}
default: {
return 0;
}
}
}
/*
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case TK_FLOAT:
case TK_BLOB:
return 0;
default:
return 1;
}
}
/*
** Generate an OP_IsNull instruction that tests register iReg and jumps
** to location iDest if the value in iReg is NULL. The value in iReg
** was computed by pExpr. If we can look at pExpr at compile-time and
** determine that it can never generate a NULL, then the OP_IsNull operation
** can be omitted.
*/
void sqlite3ExprCodeIsNullJump(
Vdbe *v, /* The VDBE under construction */
const Expr *pExpr, /* Only generate OP_IsNull if this expr can be NULL */
int iReg, /* Test the value in this register for NULL */
int iDest /* Jump here if the value is null */
){
if( sqlite3ExprCanBeNull(pExpr) ){
sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iDest);
}
}
/*
** Return TRUE if the given expression is a constant which would be
** unchanged by OP_Affinity with the affinity given in the second
** argument.
**
** This routine is used to determine if the OP_Affinity operation
................................................................................
}
case TK_STRING: {
return aff==SQLITE_AFF_TEXT;
}
case TK_BLOB: {
return 1;
}
case TK_COLUMN: {
return p->iTable>=0 && p->iColumn<0
&& (aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC);
}
default: {
return 0;
}
}
}
/*
|
Changes to src/sqliteInt.h.
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void sqlite3Savepoint(Parse*, int, Token*);
void sqlite3CloseSavepoints(sqlite3 *);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*);
int sqlite3ExprIsInteger(Expr*, int*);
int sqlite3ExprCanBeNull(const Expr*);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
int*,int,int,int,int,int*);
|
> |
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void sqlite3Savepoint(Parse*, int, Token*);
void sqlite3CloseSavepoints(sqlite3 *);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*);
int sqlite3ExprIsInteger(Expr*, int*);
int sqlite3ExprCanBeNull(const Expr*);
void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
int*,int,int,int,int,int*);
|
Changes to src/where.c.
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sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
}
}
testcase( pTerm->eOperator & WO_ISNULL );
testcase( pTerm->eOperator & WO_IN );
if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
Expr *pRight = pTerm->pExpr->pRight;
if( sqlite3ExprCanBeNull(pRight) ){
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
}
if( zAff ){
if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_NONE ){
zAff[j] = SQLITE_AFF_NONE;
}
if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
zAff[j] = SQLITE_AFF_NONE;
}
................................................................................
start_constraints = pRangeStart || nEq>0;
/* Seek the index cursor to the start of the range. */
nConstraint = nEq;
if( pRangeStart ){
Expr *pRight = pRangeStart->pExpr->pRight;
sqlite3ExprCode(pParse, pRight, regBase+nEq);
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
if( zAff ){
if( sqlite3CompareAffinity(pRight, zAff[nConstraint])==SQLITE_AFF_NONE){
/* Since the comparison is to be performed with no conversions
** applied to the operands, set the affinity to apply to pRight to
** SQLITE_AFF_NONE. */
zAff[nConstraint] = SQLITE_AFF_NONE;
}
................................................................................
** range (if any).
*/
nConstraint = nEq;
if( pRangeEnd ){
Expr *pRight = pRangeEnd->pExpr->pRight;
sqlite3ExprCacheRemove(pParse, regBase+nEq);
sqlite3ExprCode(pParse, pRight, regBase+nEq);
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
if( zAff ){
if( sqlite3CompareAffinity(pRight, zAff[nConstraint])==SQLITE_AFF_NONE){
/* Since the comparison is to be performed with no conversions
** applied to the operands, set the affinity to apply to pRight to
** SQLITE_AFF_NONE. */
zAff[nConstraint] = SQLITE_AFF_NONE;
}
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sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
}
}
testcase( pTerm->eOperator & WO_ISNULL );
testcase( pTerm->eOperator & WO_IN );
if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
Expr *pRight = pTerm->pExpr->pRight;
sqlite3ExprCodeIsNullJump(v, pRight, regBase+j, pLevel->addrBrk);
if( zAff ){
if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_NONE ){
zAff[j] = SQLITE_AFF_NONE;
}
if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
zAff[j] = SQLITE_AFF_NONE;
}
................................................................................
start_constraints = pRangeStart || nEq>0;
/* Seek the index cursor to the start of the range. */
nConstraint = nEq;
if( pRangeStart ){
Expr *pRight = pRangeStart->pExpr->pRight;
sqlite3ExprCode(pParse, pRight, regBase+nEq);
sqlite3ExprCodeIsNullJump(v, pRight, regBase+nEq, addrNxt);
if( zAff ){
if( sqlite3CompareAffinity(pRight, zAff[nConstraint])==SQLITE_AFF_NONE){
/* Since the comparison is to be performed with no conversions
** applied to the operands, set the affinity to apply to pRight to
** SQLITE_AFF_NONE. */
zAff[nConstraint] = SQLITE_AFF_NONE;
}
................................................................................
** range (if any).
*/
nConstraint = nEq;
if( pRangeEnd ){
Expr *pRight = pRangeEnd->pExpr->pRight;
sqlite3ExprCacheRemove(pParse, regBase+nEq);
sqlite3ExprCode(pParse, pRight, regBase+nEq);
sqlite3ExprCodeIsNullJump(v, pRight, regBase+nEq, addrNxt);
if( zAff ){
if( sqlite3CompareAffinity(pRight, zAff[nConstraint])==SQLITE_AFF_NONE){
/* Since the comparison is to be performed with no conversions
** applied to the operands, set the affinity to apply to pRight to
** SQLITE_AFF_NONE. */
zAff[nConstraint] = SQLITE_AFF_NONE;
}
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