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author | drh <drh@noemail.net> | 2009-11-12 13:32:22 +0000 |
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committer | drh <drh@noemail.net> | 2009-11-12 13:32:22 +0000 |
commit | 36c563a29349cab10621db06dd3992bc281ce58e (patch) | |
tree | 3ff4bb9dd3a837b88054ca77c5066352653883c0 /src/expr.c | |
parent | 779b8f126e7f6b25af34bd14499c50387512607f (diff) | |
download | sqlite-36c563a29349cab10621db06dd3992bc281ce58e.tar.gz sqlite-36c563a29349cab10621db06dd3992bc281ce58e.zip |
Factor out the code generator for BETWEEN into a subroutine.
FossilOrigin-Name: 5735f60b23460e7677b9c982a26bc13b0f4ed02b
Diffstat (limited to 'src/expr.c')
-rw-r--r-- | src/expr.c | 118 |
1 files changed, 58 insertions, 60 deletions
diff --git a/src/expr.c b/src/expr.c index 249ab9037..b16657c61 100644 --- a/src/expr.c +++ b/src/expr.c @@ -2992,6 +2992,62 @@ int sqlite3ExprCodeExprList( } /* +** 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, ®Free1); + 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 ** continues straight thru if the expression is false. @@ -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, ®Free1); - 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, ®Free1); - testcase( regFree1==0 ); - exprX.op = TK_REGISTER; - testcase( jumpIfNull==0 ); - sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull); + exprCodeBetween(pParse, pExpr, dest, 0, jumpIfNull); break; } default: { |