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Add the OP_Undef and OP_IsUndef opcodes. With these, use the first register

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in the result register range as the flag to indicate EOF on an INSERT from
a SELECT, rather than allocating a separate boolean register for that task.

FossilOrigin-Name: 6fb7448550f28a3c93053e125faeaf11de1011d0
This commit is contained in:
drh
2014-02-07 13:20:31 +00:00
parent 21a919f630
commit a5750cfe01
7 changed files with 65 additions and 53 deletions
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22
manifest
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@@ -1,5 +1,5 @@
C More\scomment\supdates.\s\sNo\schanges\sto\scode. C Add\sthe\sOP_Undef\sand\sOP_IsUndef\sopcodes.\s\sWith\sthese,\suse\sthe\sfirst\sregister\nin\sthe\sresult\sregister\srange\sas\sthe\sflag\sto\sindicate\sEOF\son\san\sINSERT\sfrom\na\sSELECT,\srather\sthan\sallocating\sa\sseparate\sboolean\sregister\sfor\sthat\stask.
D 2014-02-07T03:28:02.783 D 2014-02-07T13:20:31.855
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81 F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -183,7 +183,7 @@ F src/global.c 1d7bb7ea8254ae6a68ed9bfaf65fcb3d1690b486
F src/hash.c d139319967164f139c8d1bb8a11b14db9c4ba3cd F src/hash.c d139319967164f139c8d1bb8a11b14db9c4ba3cd
F src/hash.h 8890a25af81fb85a9ad7790d32eedab4b994da22 F src/hash.h 8890a25af81fb85a9ad7790d32eedab4b994da22
F src/hwtime.h d32741c8f4df852c7d959236615444e2b1063b08 F src/hwtime.h d32741c8f4df852c7d959236615444e2b1063b08
F src/insert.c a4450f0c46a9f221622e6551ab0953b03c4f8ee8 F src/insert.c fa98632fbf46e01c7b4d2130558c74b42947f50d
F src/journal.c b4124532212b6952f42eb2c12fa3c25701d8ba8d F src/journal.c b4124532212b6952f42eb2c12fa3c25701d8ba8d
F src/legacy.c 0df0b1550b9cc1f58229644735e317ac89131f12 F src/legacy.c 0df0b1550b9cc1f58229644735e317ac89131f12
F src/lempar.c cdf0a000315332fc9b50b62f3b5e22e080a0952b F src/lempar.c cdf0a000315332fc9b50b62f3b5e22e080a0952b
@@ -280,13 +280,13 @@ F src/update.c a7df6fffce6bfedc578fda6136dd33e34a63f8ee
F src/utf.c 6fc6c88d50448c469c5c196acf21617a24f90269 F src/utf.c 6fc6c88d50448c469c5c196acf21617a24f90269
F src/util.c 15ac2627f548f5481d0d7e6c4eb67be673027695 F src/util.c 15ac2627f548f5481d0d7e6c4eb67be673027695
F src/vacuum.c 3728d74919d4fb1356f9e9a13e27773db60b7179 F src/vacuum.c 3728d74919d4fb1356f9e9a13e27773db60b7179
F src/vdbe.c 575189caf33bc3f2b9557f420e9b815afcd5ace8 F src/vdbe.c 8697f15ad86604c5a8d598b1566e1594a7956469
F src/vdbe.h e6c4c610fcabad4fa80ebb1efc6822a9367e2b26 F src/vdbe.h e6c4c610fcabad4fa80ebb1efc6822a9367e2b26
F src/vdbeInt.h 42db251e9f863401ff847b90d5fe1614c89a6a56 F src/vdbeInt.h bd6d5e70fe7c80f6aa4c56c34589762b9e933929
F src/vdbeapi.c ce4e68ea4842cc6081046f533d088dcf01d247ad F src/vdbeapi.c ce4e68ea4842cc6081046f533d088dcf01d247ad
F src/vdbeaux.c a3327afa8cfcc5bb3d38f2b2a599bac5fb63c6be F src/vdbeaux.c 3fd95b226330e1d50aedb40d750effe726ebb3fb
F src/vdbeblob.c 9542e116c1db5ed813977581d506c176e117c0ec F src/vdbeblob.c 9542e116c1db5ed813977581d506c176e117c0ec
F src/vdbemem.c 23cdc14ed43e0aafa57bd72b9bf3d5b1641afa91 F src/vdbemem.c c0bcc02d6816ab4218ac0f94b63c8ee78a0f739f
F src/vdbesort.c 9d83601f9d6243fe70dd0169a2820c5ddfd48147 F src/vdbesort.c 9d83601f9d6243fe70dd0169a2820c5ddfd48147
F src/vdbetrace.c 6f52bc0c51e144b7efdcfb2a8f771167a8816767 F src/vdbetrace.c 6f52bc0c51e144b7efdcfb2a8f771167a8816767
F src/vtab.c 21b932841e51ebd7d075e2d0ad1415dce8d2d5fd F src/vtab.c 21b932841e51ebd7d075e2d0ad1415dce8d2d5fd
@@ -1152,7 +1152,7 @@ F tool/vdbe-compress.tcl 0cf56e9263a152b84da86e75a5c0cdcdb7a47891
F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
P 1122b410de68a3c79b4c719a3a4cc4dc6a5bb39d P be24fbc22106e508975e316abe0471edd3833291
R ba81bea358565b1489c187d643f4773f R 7163c03b39a8cc1205867ee33d31d20c
U mistachkin U drh
Z fafd555fb9fada47058f4a33fbcaaf41 Z 84c60c97897782670b677e52594a24b3

2
manifest.uuid
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@@ -1 +1 @@
be24fbc22106e508975e316abe0471edd3833291 6fb7448550f28a3c93053e125faeaf11de1011d0

43
src/insert.c
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@@ -349,17 +349,13 @@ void sqlite3AutoincrementEnd(Parse *pParse){
** co-routine. Run the co-routine to its next breakpoint ** co-routine. Run the co-routine to its next breakpoint
** by calling "OP_Yield $X" where $X is pDest->iSDParm. ** by calling "OP_Yield $X" where $X is pDest->iSDParm.
** **
** pDest->iSDParm+1 The register holding the "completed" flag for the
** co-routine. This register is 0 if the previous Yield
** generated a new result row, or 1 if the subquery
** has completed. If the Yield is called again
** after this register becomes 1, then the VDBE will
** halt with an SQLITE_INTERNAL error.
**
** pDest->iSdst First result register. ** pDest->iSdst First result register.
** **
** pDest->nSdst Number of result registers. ** pDest->nSdst Number of result registers.
** **
** At EOF the first result register will be marked as "undefined" so that
** the caller can know when to stop reading results.
**
** This routine handles all of the register allocation and fills in the ** This routine handles all of the register allocation and fills in the
** pDest structure appropriately. ** pDest structure appropriately.
** **
@@ -370,7 +366,6 @@ void sqlite3AutoincrementEnd(Parse *pParse){
** reg[pDest->iSdst+pDest->nSdst-1]: ** reg[pDest->iSdst+pDest->nSdst-1]:
** **
** X <- A ** X <- A
** EOF <- 0
** goto B ** goto B
** A: setup for the SELECT ** A: setup for the SELECT
** loop rows in the SELECT ** loop rows in the SELECT
@@ -378,7 +373,7 @@ void sqlite3AutoincrementEnd(Parse *pParse){
** yield X ** yield X
** end loop ** end loop
** cleanup after the SELECT ** cleanup after the SELECT
** EOF <- 1 ** R <- undefined (signals EOF)
** yield X ** yield X
** halt-error ** halt-error
** B: ** B:
@@ -387,7 +382,7 @@ void sqlite3AutoincrementEnd(Parse *pParse){
** **
** [ Co-routine generated by this subroutine, shown above ] ** [ Co-routine generated by this subroutine, shown above ]
** S: yield X ** S: yield X
** if EOF goto E ** if R==undefined goto E
** if skip this row, goto C ** if skip this row, goto C
** if terminate loop, goto E ** if terminate loop, goto E
** deal with this row ** deal with this row
@@ -396,27 +391,23 @@ void sqlite3AutoincrementEnd(Parse *pParse){
*/ */
int sqlite3CodeCoroutine(Parse *pParse, Select *pSelect, SelectDest *pDest){ int sqlite3CodeCoroutine(Parse *pParse, Select *pSelect, SelectDest *pDest){
int regYield; /* Register holding co-routine entry-point */ int regYield; /* Register holding co-routine entry-point */
int regEof; /* Register holding co-routine completion flag */
int addrTop; /* Top of the co-routine */ int addrTop; /* Top of the co-routine */
int j1; /* Jump instruction */ int j1; /* Jump instruction */
int rc; /* Result code */ int rc; /* Result code */
Vdbe *v; /* VDBE under construction */ Vdbe *v; /* VDBE under construction */
regYield = ++pParse->nMem; regYield = ++pParse->nMem;
regEof = ++pParse->nMem;
v = sqlite3GetVdbe(pParse); v = sqlite3GetVdbe(pParse);
addrTop = sqlite3VdbeCurrentAddr(v); addrTop = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_Integer, addrTop+2, regYield); /* X <- A */ sqlite3VdbeAddOp2(v, OP_Integer, addrTop+1, regYield); /* X <- A */
VdbeComment((v, "Co-routine entry point")); VdbeComment((v, "Co-routine entry point"));
sqlite3VdbeAddOp2(v, OP_Integer, 0, regEof); /* EOF <- 0 */
VdbeComment((v, "Co-routine completion flag"));
sqlite3SelectDestInit(pDest, SRT_Coroutine, regYield); sqlite3SelectDestInit(pDest, SRT_Coroutine, regYield);
j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0); j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
rc = sqlite3Select(pParse, pSelect, pDest); rc = sqlite3Select(pParse, pSelect, pDest);
assert( pParse->nErr==0 || rc ); assert( pParse->nErr==0 || rc );
if( pParse->db->mallocFailed && rc==SQLITE_OK ) rc = SQLITE_NOMEM; if( pParse->db->mallocFailed && rc==SQLITE_OK ) rc = SQLITE_NOMEM;
if( rc ) return rc; if( rc ) return rc;
sqlite3VdbeAddOp2(v, OP_Integer, 1, regEof); /* EOF <- 1 */ sqlite3VdbeAddOp1(v, OP_Undef, pDest->iSdst); /* Signal EOF */
sqlite3VdbeAddOp1(v, OP_Yield, regYield); /* yield X */ sqlite3VdbeAddOp1(v, OP_Yield, regYield); /* yield X */
sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort); sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort);
VdbeComment((v, "End of coroutine")); VdbeComment((v, "End of coroutine"));
@@ -488,7 +479,6 @@ static int xferOptimization(
** and the SELECT clause does not read from <table> at any time. ** and the SELECT clause does not read from <table> at any time.
** The generated code follows this template: ** The generated code follows this template:
** **
** EOF <- 0
** X <- A ** X <- A
** goto B ** goto B
** A: setup for the SELECT ** A: setup for the SELECT
@@ -497,12 +487,12 @@ static int xferOptimization(
** yield X ** yield X
** end loop ** end loop
** cleanup after the SELECT ** cleanup after the SELECT
** EOF <- 1 ** R <- undefined (signals EOF)
** yield X ** yield X
** goto A ** goto A
** B: open write cursor to <table> and its indices ** B: open write cursor to <table> and its indices
** C: yield X ** C: yield X
** if EOF goto D ** if R=undefined goto D
** insert the select result into <table> from R..R+n ** insert the select result into <table> from R..R+n
** goto C ** goto C
** D: cleanup ** D: cleanup
@@ -513,7 +503,6 @@ static int xferOptimization(
** we have to use a intermediate table to store the results of ** we have to use a intermediate table to store the results of
** the select. The template is like this: ** the select. The template is like this:
** **
** EOF <- 0
** X <- A ** X <- A
** goto B ** goto B
** A: setup for the SELECT ** A: setup for the SELECT
@@ -522,12 +511,12 @@ static int xferOptimization(
** yield X ** yield X
** end loop ** end loop
** cleanup after the SELECT ** cleanup after the SELECT
** EOF <- 1 ** R <- undefined (signals EOF)
** yield X ** yield X
** halt-error ** halt-error
** B: open temp table ** B: open temp table
** L: yield X ** L: yield X
** if EOF goto M ** if R=undefined goto M
** insert row from R..R+n into temp table ** insert row from R..R+n into temp table
** goto L ** goto L
** M: open write cursor to <table> and its indices ** M: open write cursor to <table> and its indices
@@ -576,7 +565,6 @@ void sqlite3Insert(
int regIns; /* Block of regs holding rowid+data being inserted */ int regIns; /* Block of regs holding rowid+data being inserted */
int regRowid; /* registers holding insert rowid */ int regRowid; /* registers holding insert rowid */
int regData; /* register holding first column to insert */ int regData; /* register holding first column to insert */
int regEof = 0; /* Register recording end of SELECT data */
int *aRegIdx = 0; /* One register allocated to each index */ int *aRegIdx = 0; /* One register allocated to each index */
#ifndef SQLITE_OMIT_TRIGGER #ifndef SQLITE_OMIT_TRIGGER
@@ -689,7 +677,6 @@ void sqlite3Insert(
int rc = sqlite3CodeCoroutine(pParse, pSelect, &dest); int rc = sqlite3CodeCoroutine(pParse, pSelect, &dest);
if( rc ) goto insert_cleanup; if( rc ) goto insert_cleanup;
regEof = dest.iSDParm + 1;
regFromSelect = dest.iSdst; regFromSelect = dest.iSdst;
assert( pSelect->pEList ); assert( pSelect->pEList );
nColumn = pSelect->pEList->nExpr; nColumn = pSelect->pEList->nExpr;
@@ -715,7 +702,7 @@ void sqlite3Insert(
** **
** B: open temp table ** B: open temp table
** L: yield X ** L: yield X
** if EOF goto M ** if R=undefined goto M
** insert row from R..R+n into temp table ** insert row from R..R+n into temp table
** goto L ** goto L
** M: ... ** M: ...
@@ -730,7 +717,7 @@ void sqlite3Insert(
regTempRowid = sqlite3GetTempReg(pParse); regTempRowid = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn); sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
addrTop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm); addrTop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
addrIf = sqlite3VdbeAddOp1(v, OP_If, regEof); addrIf = sqlite3VdbeAddOp1(v, OP_IsUndef, regFromSelect);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec); sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid); sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid); sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
@@ -860,13 +847,13 @@ void sqlite3Insert(
** following pseudocode (template 3): ** following pseudocode (template 3):
** **
** C: yield X ** C: yield X
** if EOF goto D ** if R=undefined goto D
** insert the select result into <table> from R..R+n ** insert the select result into <table> from R..R+n
** goto C ** goto C
** D: ... ** D: ...
*/ */
addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm); addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
addrInsTop = sqlite3VdbeAddOp1(v, OP_If, regEof); addrInsTop = sqlite3VdbeAddOp1(v, OP_IsUndef, dest.iSdst);
} }
/* Allocate registers for holding the rowid of the new row, /* Allocate registers for holding the rowid of the new row,

37
src/vdbe.c
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@@ -393,7 +393,7 @@ void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
** Print the value of a register for tracing purposes: ** Print the value of a register for tracing purposes:
*/ */
static void memTracePrint(Mem *p){ static void memTracePrint(Mem *p){
if( p->flags & MEM_Invalid ){ if( p->flags & MEM_Undefined ){
printf(" undefined"); printf(" undefined");
}else if( p->flags & MEM_Null ){ }else if( p->flags & MEM_Null ){
printf(" NULL"); printf(" NULL");
@@ -702,7 +702,6 @@ check_for_interrupt:
} }
/* Opcode: Gosub P1 P2 * * * /* Opcode: Gosub P1 P2 * * *
** Synopsis: r[P1]=pc; pc=P2
** **
** Write the current address onto register P1 ** Write the current address onto register P1
** and then jump to address P2. ** and then jump to address P2.
@@ -720,7 +719,6 @@ case OP_Gosub: { /* jump */
} }
/* Opcode: Return P1 * * * * /* Opcode: Return P1 * * * *
** Synopsis: pc=r[P1]+1
** **
** Jump to the next instruction after the address in register P1. ** Jump to the next instruction after the address in register P1.
*/ */
@@ -732,7 +730,6 @@ case OP_Return: { /* in1 */
} }
/* Opcode: Yield P1 * * * * /* Opcode: Yield P1 * * * *
** Synopsis: swap(pc,r[P1])
** **
** Swap the program counter with the value in register P1. ** Swap the program counter with the value in register P1.
*/ */
@@ -974,7 +971,7 @@ case OP_Null: { /* out2-prerelease */
} }
/* Opcode: Blob P1 P2 * P4 /* Opcode: Blob P1 P2 * P4 *
** Synopsis: r[P2]=P4 (len=P1) ** Synopsis: r[P2]=P4 (len=P1)
** **
** P4 points to a blob of data P1 bytes long. Store this ** P4 points to a blob of data P1 bytes long. Store this
@@ -988,6 +985,21 @@ case OP_Blob: { /* out2-prerelease */
break; break;
} }
/* Opcode: Undef P1 * * * *
** Synopsis: r[P1]=undef
**
** Mark register P1 as undefined.
*/
case OP_Undef: {
assert( pOp->p1>0 );
assert( pOp->p1<=(p->nMem-p->nCursor) );
pOut = &aMem[pOp->p1];
memAboutToChange(p, pOut);
VdbeMemRelease(pOut);
pOut->flags = MEM_Undefined;
break;
}
/* Opcode: Variable P1 P2 * P4 * /* Opcode: Variable P1 P2 * P4 *
** Synopsis: r[P2]=parameter(P1,P4) ** Synopsis: r[P2]=parameter(P1,P4)
** **
@@ -2142,6 +2154,19 @@ case OP_IfNot: { /* jump, in1 */
break; break;
} }
/* Opcode: IsUndef P1 P2 * * *
** Synopsis: if r[P1]==undefined goto P2
**
** Jump to P2 if the value in register P1 is undefined
*/
case OP_IsUndef: { /* jump */
pIn1 = &aMem[pOp->p1];
if( (pIn1->flags & MEM_Undefined)!=0 ){
pc = pOp->p2 - 1;
}
break;
}
/* Opcode: IsNull P1 P2 * * * /* Opcode: IsNull P1 P2 * * *
** Synopsis: if r[P1]==NULL goto P2 ** Synopsis: if r[P1]==NULL goto P2
** **
@@ -5191,7 +5216,7 @@ case OP_Program: { /* jump */
pEnd = &VdbeFrameMem(pFrame)[pFrame->nChildMem]; pEnd = &VdbeFrameMem(pFrame)[pFrame->nChildMem];
for(pMem=VdbeFrameMem(pFrame); pMem!=pEnd; pMem++){ for(pMem=VdbeFrameMem(pFrame); pMem!=pEnd; pMem++){
pMem->flags = MEM_Invalid; pMem->flags = MEM_Undefined;
pMem->db = db; pMem->db = db;
} }
}else{ }else{

4
src/vdbeInt.h
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@@ -198,7 +198,7 @@ struct Mem {
#define MEM_Blob 0x0010 /* Value is a BLOB */ #define MEM_Blob 0x0010 /* Value is a BLOB */
#define MEM_RowSet 0x0020 /* Value is a RowSet object */ #define MEM_RowSet 0x0020 /* Value is a RowSet object */
#define MEM_Frame 0x0040 /* Value is a VdbeFrame object */ #define MEM_Frame 0x0040 /* Value is a VdbeFrame object */
#define MEM_Invalid 0x0080 /* Value is undefined */ #define MEM_Undefined 0x0080 /* Value is undefined */
#define MEM_Cleared 0x0100 /* NULL set by OP_Null, not from data */ #define MEM_Cleared 0x0100 /* NULL set by OP_Null, not from data */
#define MEM_TypeMask 0x01ff /* Mask of type bits */ #define MEM_TypeMask 0x01ff /* Mask of type bits */
@@ -230,7 +230,7 @@ struct Mem {
** is for use inside assert() statements only. ** is for use inside assert() statements only.
*/ */
#ifdef SQLITE_DEBUG #ifdef SQLITE_DEBUG
#define memIsValid(M) ((M)->flags & MEM_Invalid)==0 #define memIsValid(M) ((M)->flags & MEM_Undefined)==0
#endif #endif
/* /*

6
src/vdbeaux.c
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@@ -1234,7 +1234,7 @@ static void releaseMemArray(Mem *p, int N){
p->zMalloc = 0; p->zMalloc = 0;
} }
p->flags = MEM_Invalid; p->flags = MEM_Undefined;
} }
db->mallocFailed = malloc_failed; db->mallocFailed = malloc_failed;
} }
@@ -1702,7 +1702,7 @@ void sqlite3VdbeMakeReady(
p->aMem--; /* aMem[] goes from 1..nMem */ p->aMem--; /* aMem[] goes from 1..nMem */
p->nMem = nMem; /* not from 0..nMem-1 */ p->nMem = nMem; /* not from 0..nMem-1 */
for(n=1; n<=nMem; n++){ for(n=1; n<=nMem; n++){
p->aMem[n].flags = MEM_Invalid; p->aMem[n].flags = MEM_Undefined;
p->aMem[n].db = db; p->aMem[n].db = db;
} }
} }
@@ -1814,7 +1814,7 @@ static void Cleanup(Vdbe *p){
int i; int i;
if( p->apCsr ) for(i=0; i<p->nCursor; i++) assert( p->apCsr[i]==0 ); if( p->apCsr ) for(i=0; i<p->nCursor; i++) assert( p->apCsr[i]==0 );
if( p->aMem ){ if( p->aMem ){
for(i=1; i<=p->nMem; i++) assert( p->aMem[i].flags==MEM_Invalid ); for(i=1; i<=p->nMem; i++) assert( p->aMem[i].flags==MEM_Undefined );
} }
#endif #endif

2
src/vdbemem.c
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@@ -587,7 +587,7 @@ void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
Mem *pX; Mem *pX;
for(i=1, pX=&pVdbe->aMem[1]; i<=pVdbe->nMem; i++, pX++){ for(i=1, pX=&pVdbe->aMem[1]; i<=pVdbe->nMem; i++, pX++){
if( pX->pScopyFrom==pMem ){ if( pX->pScopyFrom==pMem ){
pX->flags |= MEM_Invalid; pX->flags |= MEM_Undefined;
pX->pScopyFrom = 0; pX->pScopyFrom = 0;
} }
} }