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Improvements to the Expr comparison routine to make it more general.

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Improvements to unary-minus code generation so that it can make use of
a global constant register with a zero value.

FossilOrigin-Name: 835be656bb0e83c8108104869166aa9dd850d265
This commit is contained in:
drh
2013-11-15 15:52:39 +00:00
parent 33cad2fb46
commit 10d1edf0b6
4 changed files with 41 additions and 34 deletions
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57
src/expr.c
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@@ -2356,6 +2356,7 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
int regFree2 = 0; /* If non-zero free this temporary register */
int r1, r2, r3, r4; /* Various register numbers */
sqlite3 *db = pParse->db; /* The database connection */
Expr tempX; /* Temporary expression node */
assert( target>0 && target<=pParse->nMem );
if( v==0 ){
@@ -2575,8 +2576,10 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
codeReal(v, pLeft->u.zToken, 1, target);
#endif
}else{
regFree1 = r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
tempX.op = TK_INTEGER;
tempX.flags = EP_IntValue|EP_TokenOnly;
tempX.u.iValue = 0;
r1 = sqlite3ExprCodeTemp(pParse, &tempX, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);
sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
testcase( regFree2==0 );
@@ -2892,7 +2895,6 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
ExprList *pEList; /* List of WHEN terms */
struct ExprList_item *aListelem; /* Array of WHEN terms */
Expr opCompare; /* The X==Ei expression */
Expr cacheX; /* Cached expression X */
Expr *pX; /* The X expression */
Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; )
@@ -2904,13 +2906,13 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
nExpr = pEList->nExpr;
endLabel = sqlite3VdbeMakeLabel(v);
if( (pX = pExpr->pLeft)!=0 ){
cacheX = *pX;
tempX = *pX;
testcase( pX->op==TK_COLUMN );
testcase( pX->op==TK_REGISTER );
exprToRegister(&cacheX, sqlite3ExprCodeTemp(pParse, pX, &regFree1));
exprToRegister(&tempX, sqlite3ExprCodeTemp(pParse, pX, &regFree1));
testcase( regFree1==0 );
opCompare.op = TK_EQ;
opCompare.pLeft = &cacheX;
opCompare.pLeft = &tempX;
pTest = &opCompare;
/* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
** The value in regFree1 might get SCopy-ed into the file result.
@@ -3732,16 +3734,18 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
** an incorrect 0 or 1 could lead to a malfunction.
*/
int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){
if( pA==0||pB==0 ){
u32 combinedFlags;
if( pA==0 || pB==0 ){
return pB==pA ? 0 : 2;
}
assert( !ExprHasProperty(pA, EP_TokenOnly|EP_Reduced) );
assert( !ExprHasProperty(pB, EP_TokenOnly|EP_Reduced) );
if( ExprHasProperty(pA, EP_xIsSelect) || ExprHasProperty(pB, EP_xIsSelect) ){
combinedFlags = pA->flags | pB->flags;
if( combinedFlags & EP_IntValue ){
if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
return 0;
}
return 2;
}
if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
if( pA->op!=pB->op && (pA->op!=TK_REGISTER || pA->op2!=pB->op) ){
if( pA->op!=pB->op /*&& (pA->op!=TK_REGISTER || pA->op2!=pB->op)*/ ){
if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB, iTab)<2 ){
return 1;
}
@@ -3750,23 +3754,26 @@ int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){
}
return 2;
}
if( sqlite3ExprCompare(pA->pLeft, pB->pLeft, iTab) ) return 2;
if( sqlite3ExprCompare(pA->pRight, pB->pRight, iTab) ) return 2;
if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
if( pA->iColumn!=pB->iColumn ) return 2;
if( pA->iTable!=pB->iTable
&& pA->op!=TK_REGISTER
&& (pA->iTable!=iTab || pB->iTable>=0) ) return 2;
if( ExprHasProperty(pA, EP_IntValue) ){
if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
return 2;
}
}else if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken){
if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken ){
if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
return pA->op==TK_COLLATE ? 1 : 2;
}
}
if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
testcase( combinedFlags & EP_TokenOnly );
testcase( combinedFlags & EP_Reduced );
if( (combinedFlags & EP_TokenOnly)==0 ){
if( combinedFlags & EP_xIsSelect ) return 2;
if( sqlite3ExprCompare(pA->pLeft, pB->pLeft, iTab) ) return 2;
if( sqlite3ExprCompare(pA->pRight, pB->pRight, iTab) ) return 2;
if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
if( (combinedFlags & EP_Reduced)==0 ){
if( pA->iColumn!=pB->iColumn ) return 2;
if( pA->iTable!=pB->iTable
&& pA->op!=TK_REGISTER
&& (pA->iTable!=iTab || pB->iTable>=0) ) return 2;
}
}
return 0;
}