database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-08 03:22:21 +03:00
Code Activity

Factor out the code generator for BETWEEN into a subroutine.

Browse Source 
FossilOrigin-Name: 5735f60b23460e7677b9c982a26bc13b0f4ed02b
This commit is contained in:
drh
2009-11-12 13:32:22 +00:00
parent 779b8f126e
commit 36c563a293
3 changed files with 76 additions and 68 deletions
Download Patch File Download Diff File Expand all files Collapse all files

118
src/expr.c
View File

@@ -2991,6 +2991,62 @@ int sqlite3ExprCodeExprList(
return n;
}
/*
** Generate code for a BETWEEN operator.
**
** x BETWEEN y AND z
**
** The above is equivalent to
**
** x>=y AND x<=z
**
** Code it as such, taking care to do the common subexpression
** elementation of x.
*/
static void exprCodeBetween(
Parse *pParse, /* Parsing and code generating context */
Expr *pExpr, /* The BETWEEN expression */
int dest, /* Jump here if the jump is taken */
int jumpIfTrue, /* Take the jump if the BETWEEN is true */
int jumpIfNull /* Take the jump if the BETWEEN is NULL */
){
Expr exprAnd; /* The AND operator in x>=y AND x<=z */
Expr compLeft; /* The x>=y term */
Expr compRight; /* The x<=z term */
Expr exprX; /* The x subexpression */
int regFree1 = 0; /* Temporary use register */
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
exprX = *pExpr->pLeft;
exprAnd.op = TK_AND;
exprAnd.pLeft = &compLeft;
exprAnd.pRight = &compRight;
compLeft.op = TK_GE;
compLeft.pLeft = &exprX;
compLeft.pRight = pExpr->x.pList->a[0].pExpr;
compRight.op = TK_LE;
compRight.pLeft = &exprX;
compRight.pRight = pExpr->x.pList->a[1].pExpr;
exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, &regFree1);
exprX.op = TK_REGISTER;
if( jumpIfTrue ){
sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
}else{
sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
}
sqlite3ReleaseTempReg(pParse, regFree1);
/* Ensure adequate test coverage */
testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1==0 );
testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1!=0 );
testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1==0 );
testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1!=0 );
testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1==0 );
testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1!=0 );
testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1==0 );
testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1!=0 );
}
/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is true but execution
@@ -3090,36 +3146,7 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
break;
}
case TK_BETWEEN: {
/* x BETWEEN y AND z
**
** Is equivalent to
**
** x>=y AND x<=z
**
** Code it as such, taking care to do the common subexpression
** elementation of x.
*/
Expr exprAnd;
Expr compLeft;
Expr compRight;
Expr exprX;
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
exprX = *pExpr->pLeft;
exprAnd.op = TK_AND;
exprAnd.pLeft = &compLeft;
exprAnd.pRight = &compRight;
compLeft.op = TK_GE;
compLeft.pLeft = &exprX;
compLeft.pRight = pExpr->x.pList->a[0].pExpr;
compRight.op = TK_LE;
compRight.pLeft = &exprX;
compRight.pRight = pExpr->x.pList->a[1].pExpr;
exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, &regFree1);
testcase( regFree1==0 );
exprX.op = TK_REGISTER;
testcase( jumpIfNull==0 );
sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
exprCodeBetween(pParse, pExpr, dest, 1, jumpIfNull);
break;
}
default: {
@@ -3250,36 +3277,7 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
break;
}
case TK_BETWEEN: {
/* x BETWEEN y AND z
**
** Is equivalent to
**
** x>=y AND x<=z
**
** Code it as such, taking care to do the common subexpression
** elementation of x.
*/
Expr exprAnd;
Expr compLeft;
Expr compRight;
Expr exprX;
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
exprX = *pExpr->pLeft;
exprAnd.op = TK_AND;
exprAnd.pLeft = &compLeft;
exprAnd.pRight = &compRight;
compLeft.op = TK_GE;
compLeft.pLeft = &exprX;
compLeft.pRight = pExpr->x.pList->a[0].pExpr;
compRight.op = TK_LE;
compRight.pLeft = &exprX;
compRight.pRight = pExpr->x.pList->a[1].pExpr;
exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, &regFree1);
testcase( regFree1==0 );
exprX.op = TK_REGISTER;
testcase( jumpIfNull==0 );
sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
exprCodeBetween(pParse, pExpr, dest, 0, jumpIfNull);
break;
}
default: {