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Overview
| Comment: | Break up the implementation of OP_Move, OP_Copy, and OP_SCopy to reduce the number of branch instructions. (CVS 4945) |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
53e533d3a764d1973c24bffaacc505ea |
| User & Date: | drh 2008-04-01 00:36:10.000 |
Context
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2008-04-01
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| 01:42 | Initial test cases and bug fixes in the CSE logic. (CVS 4946) (check-in: e5aff09ac6 user: drh tags: trunk) | |
| 00:36 | Break up the implementation of OP_Move, OP_Copy, and OP_SCopy to reduce the number of branch instructions. (CVS 4945) (check-in: 53e533d3a7 user: drh tags: trunk) | |
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2008-03-31
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| 23:51 | Add the veryquick.test script for a very fast overview test that omits all i/o and malloc testing. (CVS 4944) (check-in: f61df8daa8 user: drh tags: trunk) | |
Changes
Changes to src/vdbe.c.
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39 40 41 42 43 44 45 | ** ** Various scripts scan this source file in order to generate HTML ** documentation, headers files, or other derived files. The formatting ** of the code in this file is, therefore, important. See other comments ** in this file for details. If in doubt, do not deviate from existing ** commenting and indentation practices when changing or adding code. ** | | | 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | ** ** Various scripts scan this source file in order to generate HTML ** documentation, headers files, or other derived files. The formatting ** of the code in this file is, therefore, important. See other comments ** in this file for details. If in doubt, do not deviate from existing ** commenting and indentation practices when changing or adding code. ** ** $Id: vdbe.c,v 1.724 2008/04/01 00:36:10 drh Exp $ */ #include "sqliteInt.h" #include <ctype.h> #include "vdbeInt.h" /* ** The following global variable is incremented every time a cursor |
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967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 | /* Opcode: Move P1 P2 * * * ** ** Move the value in register P1 over into register P2. Register P1 ** is left holding a NULL. It is an error for P1 and P2 to be the ** same register. */ /* Opcode: Copy P1 P2 * * * ** ** Make a copy of register P1 into register P2. ** ** This instruction makes a deep copy of the value. A duplicate ** is made of any string or blob constant. See also OP_SCopy. */ /* Opcode: SCopy P1 P2 * * * ** ** Make a shallow copy of register P1 into register P2. ** ** This instruction makes a shallow copy of the value. If the value ** is a string or blob, then the copy is only a pointer to the ** original and hence if the original changes so will the copy. ** Worse, if the original is deallocated, the copy becomes invalid. ** Thus the program must guarantee that the original will not change ** during the lifetime of the copy. Use OP_Copy to make a complete ** copy. */ | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > < < < < < < < < | < < < < | 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 |
/* Opcode: Move P1 P2 * * *
**
** Move the value in register P1 over into register P2. Register P1
** is left holding a NULL. It is an error for P1 and P2 to be the
** same register.
*/
case OP_Move: {
char *zMalloc;
assert( pOp->p1>0 );
assert( pOp->p1<=p->nMem );
pIn1 = &p->aMem[pOp->p1];
REGISTER_TRACE(pOp->p1, pIn1);
assert( pOp->p2>0 );
assert( pOp->p2<=p->nMem );
pOut = &p->aMem[pOp->p2];
assert( pOut!=pIn1 );
zMalloc = pOut->zMalloc;
pOut->zMalloc = 0;
sqlite3VdbeMemMove(pOut, pIn1);
pIn1->zMalloc = zMalloc;
REGISTER_TRACE(pOp->p2, pOut);
break;
}
/* Opcode: Copy P1 P2 * * *
**
** Make a copy of register P1 into register P2.
**
** This instruction makes a deep copy of the value. A duplicate
** is made of any string or blob constant. See also OP_SCopy.
*/
case OP_Copy: {
assert( pOp->p1>0 );
assert( pOp->p1<=p->nMem );
pIn1 = &p->aMem[pOp->p1];
REGISTER_TRACE(pOp->p1, pIn1);
assert( pOp->p2>0 );
assert( pOp->p2<=p->nMem );
pOut = &p->aMem[pOp->p2];
assert( pOut!=pIn1 );
sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
Deephemeralize(pOut);
REGISTER_TRACE(pOp->p2, pOut);
break;
}
/* Opcode: SCopy P1 P2 * * *
**
** Make a shallow copy of register P1 into register P2.
**
** This instruction makes a shallow copy of the value. If the value
** is a string or blob, then the copy is only a pointer to the
** original and hence if the original changes so will the copy.
** Worse, if the original is deallocated, the copy becomes invalid.
** Thus the program must guarantee that the original will not change
** during the lifetime of the copy. Use OP_Copy to make a complete
** copy.
*/
case OP_SCopy: {
assert( pOp->p1>0 );
assert( pOp->p1<=p->nMem );
pIn1 = &p->aMem[pOp->p1];
REGISTER_TRACE(pOp->p1, pIn1);
assert( pOp->p2>0 );
assert( pOp->p2<=p->nMem );
pOut = &p->aMem[pOp->p2];
assert( pOut!=pIn1 );
sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
REGISTER_TRACE(pOp->p2, pOut);
break;
}
/* Opcode: ResultRow P1 P2 * * *
**
** The registers P1 throught P1+P2-1 contain a single row of
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