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Overview
Comment: | Optimization to the comparison opcodes in the byte-code engine. |
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Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
654935c7737f1a9e08fde9b220c543e8 |
User & Date: | drh 2017-08-03 00:29:23.521 |
Context
2017-08-03
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15:43 | Fix some problems in RBU test cases. Also update RBU source code to better handle the trivial case where an RBU update is applied to a database zero pages in size. (check-in: 7676b39bc1 user: dan tags: trunk) | |
00:29 | Optimization to the comparison opcodes in the byte-code engine. (check-in: 654935c773 user: drh tags: trunk) | |
2017-08-02
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22:43 | In the KeyInfo object, refactor the nField and nXField elements into nKeyField and nAllField, which are more useful and run a little faster. (check-in: aea5990eab user: drh tags: trunk) | |
Changes
Changes to src/vdbe.c.
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1951 1952 1953 1954 1955 1956 1957 | flags3 = (pIn3->flags & ~MEM_TypeMask) | (flags3 & MEM_TypeMask); } } assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 ); res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl); } compare_op: | > > > > > > > > > > | | > | > > | < < < < | 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 | flags3 = (pIn3->flags & ~MEM_TypeMask) | (flags3 & MEM_TypeMask); } } assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 ); res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl); } compare_op: /* At this point, res is negative, zero, or positive if reg[P1] is ** less than, equal to, or greater than reg[P3], respectively. Compute ** the answer to this operator in res2, depending on what the comparison ** operator actually is. The next block of code depends on the fact ** that the 6 comparison operators are consecutive integers in this ** order: NE, EQ, GT, LE, LT, GE */ assert( OP_Eq==OP_Ne+1 ); assert( OP_Gt==OP_Ne+2 ); assert( OP_Le==OP_Ne+3 ); assert( OP_Lt==OP_Ne+4 ); assert( OP_Ge==OP_Ne+5 ); if( res<0 ){ /* ne, eq, gt, le, lt, ge */ static const unsigned char aLTb[] = { 1, 0, 0, 1, 1, 0 }; res2 = aLTb[pOp->opcode - OP_Ne]; }else if( res==0 ){ static const unsigned char aEQb[] = { 0, 1, 0, 1, 0, 1 }; res2 = aEQb[pOp->opcode - OP_Ne]; }else{ static const unsigned char aGTb[] = { 1, 0, 1, 0, 0, 1 }; res2 = aGTb[pOp->opcode - OP_Ne]; } /* Undo any changes made by applyAffinity() to the input registers. */ assert( (pIn1->flags & MEM_Dyn) == (flags1 & MEM_Dyn) ); pIn1->flags = flags1; assert( (pIn3->flags & MEM_Dyn) == (flags3 & MEM_Dyn) ); pIn3->flags = flags3; if( pOp->p5 & SQLITE_STOREP2 ){ pOut = &aMem[pOp->p2]; iCompare = res; if( (pOp->p5 & SQLITE_KEEPNULL)!=0 ){ /* The KEEPNULL flag prevents OP_Eq from overwriting a NULL with 1 ** and prevents OP_Ne from overwriting NULL with 0. This flag ** is only used in contexts where either: ** (1) op==OP_Eq && (r[P2]==NULL || r[P2]==0) ** (2) op==OP_Ne && (r[P2]==NULL || r[P2]==1) ** Therefore it is not necessary to check the content of r[P2] for |
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