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Overview
Comment: | Simplify the range scan code generate while also avoiding an unnecessary OP_Affinity opcode. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | expr-codegen-enhancement |
Files: | files | file ages | folders |
SHA1: |
372686bfbb1da08b04bddb085e30da5d |
User & Date: | drh 2013-11-15 12:41:01.696 |
Context
2013-11-15
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15:52 | Improvements to the Expr comparison routine to make it more general. Improvements to unary-minus code generation so that it can make use of a global constant register with a zero value. (check-in: 835be656bb user: drh tags: expr-codegen-enhancement) | |
12:41 | Simplify the range scan code generate while also avoiding an unnecessary OP_Affinity opcode. (check-in: 372686bfbb user: drh tags: expr-codegen-enhancement) | |
03:30 | Merge EXPLAIN fixes from trunk. (check-in: cd579727b1 user: drh tags: expr-codegen-enhancement) | |
Changes
Changes to src/where.c.
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2997 2998 2999 3000 3001 3002 3003 | int start_constraints; /* Start of range is constrained */ int nConstraint; /* Number of constraint terms */ Index *pIdx; /* The index we will be using */ int iIdxCur; /* The VDBE cursor for the index */ int nExtraReg = 0; /* Number of extra registers needed */ int op; /* Instruction opcode */ char *zStartAff; /* Affinity for start of range constraint */ | | | 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 | int start_constraints; /* Start of range is constrained */ int nConstraint; /* Number of constraint terms */ Index *pIdx; /* The index we will be using */ int iIdxCur; /* The VDBE cursor for the index */ int nExtraReg = 0; /* Number of extra registers needed */ int op; /* Instruction opcode */ char *zStartAff; /* Affinity for start of range constraint */ char cEndAff = 0; /* Affinity for end of range constraint */ pIdx = pLoop->u.btree.pIndex; iIdxCur = pLevel->iIdxCur; assert( nEq>=pLoop->u.btree.nSkip ); /* If this loop satisfies a sort order (pOrderBy) request that ** was passed to this function to implement a "SELECT min(x) ..." |
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3038 3039 3040 3041 3042 3043 3044 | } /* Generate code to evaluate all constraint terms using == or IN ** and store the values of those terms in an array of registers ** starting at regBase. */ regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff); | > | | 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 | } /* Generate code to evaluate all constraint terms using == or IN ** and store the values of those terms in an array of registers ** starting at regBase. */ regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff); assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq ); if( zStartAff ) cEndAff = zStartAff[nEq]; addrNxt = pLevel->addrNxt; /* If we are doing a reverse order scan on an ascending index, or ** a forward order scan on a descending index, interchange the ** start and end terms (pRangeStart and pRangeEnd). */ if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC)) |
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3108 3109 3110 3111 3112 3113 3114 | if( pRangeEnd ){ Expr *pRight = pRangeEnd->pExpr->pRight; sqlite3ExprCacheRemove(pParse, regBase+nEq, 1); sqlite3ExprCode(pParse, pRight, regBase+nEq); if( (pRangeEnd->wtFlags & TERM_VNULL)==0 ){ sqlite3ExprCodeIsNullJump(v, pRight, regBase+nEq, addrNxt); } | < | < < < < < | > | | < < < | 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 | if( pRangeEnd ){ Expr *pRight = pRangeEnd->pExpr->pRight; sqlite3ExprCacheRemove(pParse, regBase+nEq, 1); sqlite3ExprCode(pParse, pRight, regBase+nEq); if( (pRangeEnd->wtFlags & TERM_VNULL)==0 ){ sqlite3ExprCodeIsNullJump(v, pRight, regBase+nEq, addrNxt); } if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_NONE && !sqlite3ExprNeedsNoAffinityChange(pRight, cEndAff) ){ codeApplyAffinity(pParse, regBase+nEq, 1, &cEndAff); } nConstraint++; testcase( pRangeEnd->wtFlags & TERM_VIRTUAL ); } sqlite3DbFree(db, zStartAff); /* Top of the loop body */ pLevel->p2 = sqlite3VdbeCurrentAddr(v); /* Check if the index cursor is past the end of the range. */ op = aEndOp[(pRangeEnd || nEq) * (1 + bRev)]; testcase( op==OP_Noop ); |
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