aboutsummaryrefslogtreecommitdiff
path: root/src/expr.c
diff options
context:
space:
mode:
authordrh <drh@noemail.net>2015-08-26 14:01:41 +0000
committerdrh <drh@noemail.net>2015-08-26 14:01:41 +0000
commit5579d59fb3ccb9e9db9913a5bd50871d8e893d95 (patch)
treebd2507abb65a3e31578751108f0eef1baafefae2 /src/expr.c
parent0576bc59a730c57f14f037dc90a28d0a7ec2d51f (diff)
downloadsqlite-5579d59fb3ccb9e9db9913a5bd50871d8e893d95.tar.gz
sqlite-5579d59fb3ccb9e9db9913a5bd50871d8e893d95.zip
Evaluate expressions only once when the same expression is used in both the
result set and in the ORDER BY clause. FossilOrigin-Name: c2f3bbad778504681b39ab9399a1eb3c1a35ab3f
Diffstat (limited to 'src/expr.c')
-rw-r--r--src/expr.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/src/expr.c b/src/expr.c
index 1aebef6b1..71c552c68 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2912,7 +2912,7 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
}
sqlite3ExprCachePush(pParse); /* Ticket 2ea2425d34be */
- sqlite3ExprCodeExprList(pParse, pFarg, r1,
+ sqlite3ExprCodeExprList(pParse, pFarg, r1, 0,
SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);
sqlite3ExprCachePop(pParse); /* Ticket 2ea2425d34be */
}else{
@@ -3328,11 +3328,13 @@ int sqlite3ExprCodeExprList(
Parse *pParse, /* Parsing context */
ExprList *pList, /* The expression list to be coded */
int target, /* Where to write results */
+ int srcReg, /* Source registers if SQLITE_ECEL_REF */
u8 flags /* SQLITE_ECEL_* flags */
){
struct ExprList_item *pItem;
- int i, n;
+ int i, j, n;
u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
+ Vdbe *v = pParse->pVdbe;
assert( pList!=0 );
assert( target>0 );
assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
@@ -3340,13 +3342,14 @@ int sqlite3ExprCodeExprList(
if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
for(pItem=pList->a, i=0; i<n; i++, pItem++){
Expr *pExpr = pItem->pExpr;
- if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
+ if( (flags & SQLITE_ECEL_REF)!=0 && (j = pList->a[i].u.x.iOrderByCol)>0 ){
+ sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
+ }else if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
sqlite3ExprCodeAtInit(pParse, pExpr, target+i, 0);
}else{
int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
if( inReg!=target+i ){
VdbeOp *pOp;
- Vdbe *v = pParse->pVdbe;
if( copyOp==OP_Copy
&& (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy
&& pOp->p1+pOp->p3+1==inReg