# Scan for "case OP_aaaa:" lines in the vdbe.c file
/^case OP_/ {
  name = $2
  sub(/:/,"",name)
  sub("\r","",name)
  op[name] = -1







  for(i=3; i<NF; i++){
    if($i=="same" && $(i+1)=="as"){
      sym = $(i+2)
      sub(/,/,"",sym)
      op[name] = tk[sym]
      used[op[name]] = 1
      sameas[op[name]] = sym
    }

    if($i=="no-push"){
      nopush[name] = 1














    }
  }
}

# Assign numbers to all opcodes and output the result.
END {
  cnt = 0
................................................................................
        printf "\n/* The following opcode values are never used */\n"
        seenUnused = 1
      }
      printf "#define %-25s %15d\n", sprintf( "OP_NotUsed_%-3d", i ), i
    }
  }

  # Generate the 10 16-bit bitmasks used by function opcodeUsesStack()
  # in vdbeaux.c. See comments in that function for details.
  # 

  nopush[0] = 0              # 0..15
  nopush[1] = 0              # 16..31
  nopush[2] = 0              # 32..47
  nopush[3] = 0              # 48..63
  nopush[4] = 0              # 64..79
  nopush[5] = 0              # 80..95
  nopush[6] = 0              # 96..111
  nopush[7] = 0              # 112..127

  nopush[8] = 0              # 128..143
  nopush[9] = 0              # 144..159
  for(name in op){
    if( nopush[name] ){
      n = op[name]


      j = n%16
      i = ((n - j)/16)
      nopush[i] = nopush[i] + (2^j)



    }
  }
  printf "\n"
  print "/* Opcodes that are guaranteed to never push a value onto the stack"
  print "** contain a 1 their corresponding position of the following mask"
  print "** set.  See the opcodeNoPush() function in vdbeaux.c  */"












  for(i=0; i<10; i++){
    printf "#define NOPUSH_MASK_%d 0x%04x\n", i, nopush[i]


  }

}

# Scan for "case OP_aaaa:" lines in the vdbe.c file
/^case OP_/ {
  name = $2
  sub(/:/,"",name)
  sub("\r","",name)
  op[name] = -1
  out1[name] = 0
  out2[name] = 0
  out3[name] = 0
  jump[name] = 0
  in1[name] = 0
  in2[name] = 0
  in3[name] = 0
  for(i=3; i<NF; i++){
    if($i=="same" && $(i+1)=="as"){
      sym = $(i+2)
      sub(/,/,"",sym)
      op[name] = tk[sym]
      used[op[name]] = 1
      sameas[op[name]] = sym
    }
    sub(",","",$i)
    if($i=="no-push"){
      nopush[name] = 1
    }else if($i=="out1"){
      out1[name] = 1
    }else if($i=="out2"){
      out2[name] = 2
    }else if($i=="out3"){
      out3[name] = 3
    }else if($i=="in1"){
      in1[name] = 1
    }else if($i=="in2"){
      in2[name] = 1
    }else if($i=="in3"){
      in3[name] = 1
    }else if($i=="jump"){
      jump[name] = 1
    }
  }
}

# Assign numbers to all opcodes and output the result.
END {
  cnt = 0
................................................................................
        printf "\n/* The following opcode values are never used */\n"
        seenUnused = 1
      }
      printf "#define %-25s %15d\n", sprintf( "OP_NotUsed_%-3d", i ), i
    }
  }

  # Generate the bitvectors:

  #
  #  bit 0:     jump
  #  bit 1:     output on P1
  #  bit 2:     output on P2
  #  bit 3:     output on P3
  #  bit 4:     input on P1
  #  bit 5:     input on P2
  #  bit 6:     input on P3
  #  bit 7:     pushes a result onto stack

  #
  for(i=0; i<=max; i++) bv[i] = 0;

  for(name in op){

    x = op[name]
    if( jump[name] ) bv[x] += 0x01;
    if( out1[name] ) bv[x] += 0x02;
    if( out2[name] ) bv[x] += 0x04;
    if( out3[name] ) bv[x] += 0x08;
    if( in1[name] ) bv[x] += 0x10;
    if( in2[name] ) bv[x] += 0x20;
    if( in3[name] ) bv[x] += 0x40;
    if( !nopush[name] ) bv[x] += 0x80;
  }

  print "\n"


  print "/* Properties such as \"out2\" or \"jump\" that are specified in"
  print "** comments following the "case" for each opcode in the vdbe.c"
  print "** are encoded into bitvectors as follows:"
  print "*/"
  print "#define OPFLG_JUMP     0x01    /* jump:  P2 holds a jump target */"
  print "#define OPFLG_OUT1     0x02    /* out1:  P1 specifies output reg */"
  print "#define OPFLG_OUT2     0x04    /* out2:  P2 specifies output reg */"
  print "#define OPFLG_OUT3     0x08    /* out3:  P3 specifies output reg */"
  print "#define OPFLG_IN1      0x10    /* in1:   P1 is an input reg */"
  print "#define OPFLG_IN2      0x20    /* in2:   P2 is an input reg */"
  print "#define OPFLG_IN3      0x40    /* in3:   P3 is an input reg */"
  print "#define OPFLG_PUSH     0x80    /* omits no-push:  Does not push */"
  print "#define OPFLG_INITIALIZER {\\"
  for(i=0; i<=max; i++){

    printf " 0x%02x,", bv[i]
    if( i%10==9 ) printf("\\\n");
  }
  print "}"
}

**
** 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 1.676 2008/01/04 13:57:26 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
  }
  else if( flags & MEM_Str ){
    pMem->type = SQLITE_TEXT;
  }else{
    pMem->type = SQLITE_BLOB;
  }
}


























/*
** Pop the stack N times.
*/
static void popStack(Mem **ppTos, int N){
  Mem *pTos = *ppTos;
  while( N>0 ){
................................................................................
        nProgressOps = 0;
      }
      nProgressOps++;
    }
#endif

#ifndef NDEBUG
    /* This is to check that the return value of static function
    ** opcodeNoPush() (see vdbeaux.c) returns values that match the
    ** implementation of the virtual machine in this file. If
    ** opcodeNoPush() returns non-zero, then the stack is guarenteed
    ** not to grow when the opcode is executed. If it returns zero, then
    ** the stack may grow by at most 1.
    **
    ** The global wrapper function sqlite3VdbeOpcodeUsesStack() is not 
    ** available if NDEBUG is defined at build time.
    */ 
    pStackLimit = pTos;
    if( !sqlite3VdbeOpcodeNoPush(pOp->opcode) ){

      pStackLimit++;
    }
#endif

    switch( pOp->opcode ){

/*****************************************************************************
................................................................................
/* Opcode:  Goto * P2 *
**
** An unconditional jump to address P2.
** The next instruction executed will be 
** the one at index P2 from the beginning of
** the program.
*/
case OP_Goto: {             /* no-push */
  CHECK_FOR_INTERRUPT;
  pc = pOp->p2 - 1;
  break;
}

/* Opcode:  Gosub * P2 *
**
................................................................................
** and then jump to address P2.
**
** The return address stack is of limited depth.  If too many
** OP_Gosub operations occur without intervening OP_Returns, then
** the return address stack will fill up and processing will abort
** with a fatal error.
*/
case OP_Gosub: {            /* no-push */
  assert( p->returnDepth<sizeof(p->returnStack)/sizeof(p->returnStack[0]) );
  p->returnStack[p->returnDepth++] = pc+1;
  pc = pOp->p2 - 1;
  break;
}

/* Opcode:  Return * * *
................................................................................
** the stack is not numeric (meaning that is is a NULL or a string that
** does not look like an integer or floating point number) then pop the
** stack and jump to P2.  If the top of the stack is numeric then
** convert it into the least integer that is greater than or equal to its
** current value if P1==0, or to the least integer that is strictly
** greater than its current value if P1==1.
*/
case OP_ForceInt: {            /* no-push */
  i64 v;
  assert( pTos>=p->aStack );
  applyAffinity(pTos, SQLITE_AFF_NUMERIC, encoding);
  if( (pTos->flags & (MEM_Int|MEM_Real))==0 ){
    Release(pTos);
    pTos--;
    pc = pOp->p2 - 1;
................................................................................
** without data loss, then jump immediately to P2, or if P2==0
** raise an SQLITE_MISMATCH exception.
**
** If the top of the stack is not an integer and P2 is not zero and
** P1 is 1, then the stack is popped.  In all other cases, the depth
** of the stack is unchanged.
*/
case OP_MustBeInt: {            /* no-push */
  assert( pTos>=p->aStack );
  applyAffinity(pTos, SQLITE_AFF_NUMERIC, encoding);
  if( (pTos->flags & MEM_Int)==0 ){
    if( pOp->p2==0 ){
      rc = SQLITE_MISMATCH;
      goto abort_due_to_error;
    }else{
................................................................................
*/
/* Opcode: Ge P1 P2 P4
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is greater than or equal to the
** top of the stack.  See the Eq opcode for additional information.
*/
case OP_Eq:               /* same as TK_EQ, no-push */
case OP_Ne:               /* same as TK_NE, no-push */
case OP_Lt:               /* same as TK_LT, no-push */
case OP_Le:               /* same as TK_LE, no-push */
case OP_Gt:               /* same as TK_GT, no-push */
case OP_Ge: {             /* same as TK_GE, no-push */
  Mem *pNos;
  int flags;
  int res;
  char affinity;

  pNos = &pTos[-1];
  flags = pTos->flags|pNos->flags;
................................................................................
** false, then jump to p2.  Otherwise continue to the next instruction.
** An integer is false if zero and true otherwise.  A string is
** false if it has zero length and true otherwise.
**
** If the value popped of the stack is NULL, then take the jump if P1
** is true and fall through if P1 is false.
*/
case OP_If:                 /* no-push */
case OP_IfNot: {            /* no-push */
  int c;
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Null ){
    c = pOp->p1;
  }else{
#ifdef SQLITE_OMIT_FLOATING_POINT
    c = sqlite3VdbeIntValue(pTos);
................................................................................
**
** Check the top of the stack and jump to P2 if the top of the stack
** is NULL.  If P1 is positive, then pop P1 elements from the stack
** regardless of whether or not the jump is taken.  If P1 is negative,
** pop -P1 elements from the stack only if the jump is taken and leave
** the stack unchanged if the jump is not taken.
*/
case OP_IsNull: {            /* same as TK_ISNULL, no-push */
  if( pTos->flags & MEM_Null ){
    pc = pOp->p2-1;
    if( pOp->p1<0 ){
      popStack(&pTos, -pOp->p1);
    }
  }
  if( pOp->p1>0 ){
................................................................................
/* Opcode: NotNull P1 P2 *
**
** Jump to P2 if the top abs(P1) values on the stack are all not NULL.  
** Regardless of whether or not the jump is taken, pop the stack
** P1 times if P1 is greater than zero.  But if P1 is negative,
** leave the stack unchanged.
*/
case OP_NotNull: {            /* same as TK_NOTNULL, no-push */
  int i, cnt;
  cnt = pOp->p1;
  if( cnt<0 ) cnt = -cnt;
  assert( &pTos[1-cnt] >= p->aStack );
  for(i=0; i<cnt && (pTos[1+i-cnt].flags & MEM_Null)==0; i++){}
  if( i>=cnt ) pc = pOp->p2-1;
  if( pOp->p1>0 ) popStack(&pTos, cnt);
................................................................................
** Works like OP_MakeIdxRec except data is taken from registers
** rather than from the stack.  The P1 register is an integer which
** is the number of register to use in building the new record.
** Data is taken from P1+1, P1+2, ..., P1+mem[P1].
*/
case OP_RegMakeRec:
case OP_RegMakeIRec:
case OP_MakeIdxRec:
case OP_MakeRecord: {
  /* Assuming the record contains N fields, the record format looks
  ** like this:
  **
  ** ------------------------------------------------------------------------
  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** ------------------------------------------------------------------------
  **
................................................................................
** cursor P1 so that it points to the largest entry that is less than
** or equal to the key that was popped from the stack.
** If there are no records less than or eqal to the key and P2 is not zero,
** then jump to P2.
**
** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLt
*/
case OP_MoveLt:         /* no-push */
case OP_MoveLe:         /* no-push */
case OP_MoveGe:         /* no-push */
case OP_MoveGt: {       /* no-push */
  int i = pOp->p1;
  Cursor *pC;

  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  assert( pC!=0 );
................................................................................
** pointing to the entry that matches.  The blob is popped from the stack.
**
** The difference between this operation and Distinct is that
** Distinct does not pop the key from the stack.
**
** See also: Distinct, Found, MoveTo, NotExists, IsUnique
*/
case OP_Distinct:       /* no-push */
case OP_NotFound:       /* no-push */
case OP_Found: {        /* no-push */
  int i = pOp->p1;
  int alreadyExists = 0;
  Cursor *pC;
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
................................................................................
** jump to P2.  If any entry does exist where the index string
** matches K but the record number is not R, then the record
** number for that entry is pushed onto the stack and control
** falls through to the next instruction.
**
** See also: Distinct, NotFound, NotExists, Found
*/
case OP_IsUnique: {        /* no-push */
  int i = pOp->p1;
  Mem *pNos = &pTos[-1];
  Cursor *pCx;
  BtCursor *pCrsr;
  i64 R;

  /* Pop the value R off the top of the stack
................................................................................
** The difference between this operation and NotFound is that this
** operation assumes the key is an integer and that P1 is a table whereas
** NotFound assumes key is a blob constructed from MakeRecord and
** P1 is an index.
**
** See also: Distinct, Found, MoveTo, NotFound, IsUnique
*/
case OP_NotExists: {        /* no-push */
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  Mem *pKey;
  if( pOp->p3 ){
    assert( pOp->p3<=p->nMem );
    pKey = &p->aMem[pOp->p3];
................................................................................
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the last entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Last: {        /* no-push */
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  assert( pC!=0 );
................................................................................
** Sorting is accomplished by writing records into a sorting index,
** then rewinding that index and playing it back from beginning to
** end.  We use the OP_Sort opcode instead of OP_Rewind to do the
** rewinding so that the global variable will be incremented and
** regression tests can determine whether or not the optimizer is
** correctly optimizing out sorts.
*/
case OP_Sort: {        /* no-push */
#ifdef SQLITE_TEST
  sqlite3_sort_count++;
  sqlite3_search_count--;
#endif
  /* Fall through into OP_Rewind */
}
/* Opcode: Rewind P1 P2 *
................................................................................
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the first entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Rewind: {        /* no-push */
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  int res;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
................................................................................
/* Opcode: Prev P1 P2 *
**
** Back up cursor P1 so that it points to the previous key/data pair in its
** table or index.  If there is no previous key/value pairs then fall through
** to the following instruction.  But if the cursor backup was successful,
** jump immediately to P2.
*/
case OP_Prev:          /* no-push */
case OP_Next: {        /* no-push */
  Cursor *pC;
  BtCursor *pCrsr;

  CHECK_FOR_INTERRUPT;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  if( pC==0 ){
................................................................................
** In either case, the stack is popped once.
**
** If P4 is the "+" string (or any other non-NULL string) then the
** index taken from the top of the stack is temporarily increased by
** an epsilon prior to the comparison.  This makes the opcode work
** like IdxLE.
*/
case OP_IdxLT:          /* no-push */
case OP_IdxGT:          /* no-push */
case OP_IdxGE: {        /* no-push */
  int i= pOp->p1;
  Cursor *pC;

  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );
  assert( pTos>=p->aStack );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
................................................................................
** Attempt to read a single integer from the Fifo. If P1 is zero,
** push the result onto the stack. Otherwise, store the read integer 
** in register P1.
** 
** If the Fifo is empty do not push an entry onto the stack or set
** a memory register but instead jump to P2.
*/
case OP_FifoRead: {
  i64 v;
  CHECK_FOR_INTERRUPT;
  if( sqlite3VdbeFifoPop(&p->sFifo, &v)==SQLITE_DONE ){
    pc = pOp->p2 - 1;
  }else{
    Mem *pOut = &p->aMem[pOp->p1];
    assert( pOp->p1>0 && pOp->p1<=p->nMem );
................................................................................
/* Opcode: IfMemPos P1 P2 *
**
** If the value of memory cell P1 is 1 or greater, jump to P2.
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemPos: {        /* no-push */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i>0 ){
     pc = pOp->p2 - 1;
................................................................................
/* Opcode: IfMemNeg P1 P2 *
**
** If the value of memory cell P1 is less than zero, jump to P2. 
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemNeg: {        /* no-push */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i<0 ){
     pc = pOp->p2 - 1;
................................................................................
/* Opcode: IfMemZero P1 P2 *
**
** If the value of memory cell P1 is exactly 0, jump to P2. 
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemZero: {        /* no-push */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i==0 ){
     pc = pOp->p2 - 1;
................................................................................
  break;
}

/* Opcode: IfMemNull P1 P2 *
**
** If the value of memory cell P1 is NULL, jump to P2. 
*/
case OP_IfMemNull: {        /* no-push */
  int i = pOp->p1;
  assert( i>0 && i<=p->nMem );
  if( p->aMem[i].flags & MEM_Null ){
     pc = pOp->p2 - 1;
  }
  break;
}
................................................................................
#if !defined(SQLITE_OMIT_AUTOVACUUM)
/* Opcode: IncrVacuum P1 P2 *
**
** Perform a single step of the incremental vacuum procedure on
** the P1 database. If the vacuum has finished, jump to instruction
** P2. Otherwise, fall through to the next instruction.
*/
case OP_IncrVacuum: {        /* no-push */
  Btree *pBt;

  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( (p->btreeMask & (1<<pOp->p1))!=0 );
  pBt = db->aDb[pOp->p1].pBt;
  rc = sqlite3BtreeIncrVacuum(pBt);
  if( rc==SQLITE_DONE ){
................................................................................
** P3. Register P3+1 stores the argc parameter to be passed to the
** xFilter method. Registers P3+2..P3+1+argc are the argc additional
** parametersneath additional parameters which are passed to
** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.
**
** A jump is made to P2 if the result set after filtering would be empty.
*/
case OP_VFilter: {   /* no-push */
  int nArg;
  int iQuery;
  const sqlite3_module *pModule;
  Mem *pQuery = &p->aMem[pOp->p3];
  Mem *pArgc = &pQuery[1];

  Cursor *pCur = p->apCsr[pOp->p1];
................................................................................
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VNext P1 P2 *
**
** Advance virtual table P1 to the next row in its result set and
** jump to instruction P2.  Or, if the virtual table has reached
** the end of its result set, then fall through to the next instruction.
*/
case OP_VNext: {   /* no-push */
  const sqlite3_module *pModule;
  int res = 0;

  Cursor *pCur = p->apCsr[pOp->p1];
  assert( pCur->pVtabCursor );
  pModule = pCur->pVtabCursor->pVtab->pModule;
  if( pModule->xNext==0 ){

**
** 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 1.677 2008/01/04 16:50:09 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
  }
  else if( flags & MEM_Str ){
    pMem->type = SQLITE_TEXT;
  }else{
    pMem->type = SQLITE_BLOB;
  }
}

/*
** Properties of opcodes.  The OPFLG_INITIALIZER macro is
** created by mkopcodeh.awk during compilation.  Data is obtained
** from the comments following the "case OP_xxxx:" statements in
** this file.  
**
**      jump:      OPFLG_JUMP
**      out1:      OPFLG_OUT1
**      out2:      OPFLG_OUT2
**      out3:      OPFLG_OUT3
**      in1:       OPFLG_IN1
**      in2:       OPFLG_IN2
**      in3:       OPFLG_IN3
*/
static unsigned char opcodeProperty[] = OPFLG_INITIALIZER;

/*
** Return true if an opcode has any of the OPFLG_xxx properties
** specified by mask.
*/
int sqlite3VdbeOpcodeHasProperty(int opcode, int mask){
  assert( opcode>0 && opcode<sizeof(opcodeProperty) );
  return (opcodeProperty[opcode]&mask)!=0;
}

/*
** Pop the stack N times.
*/
static void popStack(Mem **ppTos, int N){
  Mem *pTos = *ppTos;
  while( N>0 ){
................................................................................
        nProgressOps = 0;
      }
      nProgressOps++;
    }
#endif

#ifndef NDEBUG
    /* This is to check to make sure that the OPFLG_PUSH property
    ** is set correctly on all opcodes.







    */ 
    pStackLimit = pTos;

    if( sqlite3VdbeOpcodeHasProperty(pOp->opcode, OPFLG_PUSH) ){
      pStackLimit++;
    }
#endif

    switch( pOp->opcode ){

/*****************************************************************************
................................................................................
/* Opcode:  Goto * P2 *
**
** An unconditional jump to address P2.
** The next instruction executed will be 
** the one at index P2 from the beginning of
** the program.
*/
case OP_Goto: {             /* no-push, jump */
  CHECK_FOR_INTERRUPT;
  pc = pOp->p2 - 1;
  break;
}

/* Opcode:  Gosub * P2 *
**
................................................................................
** and then jump to address P2.
**
** The return address stack is of limited depth.  If too many
** OP_Gosub operations occur without intervening OP_Returns, then
** the return address stack will fill up and processing will abort
** with a fatal error.
*/
case OP_Gosub: {            /* no-push, jump */
  assert( p->returnDepth<sizeof(p->returnStack)/sizeof(p->returnStack[0]) );
  p->returnStack[p->returnDepth++] = pc+1;
  pc = pOp->p2 - 1;
  break;
}

/* Opcode:  Return * * *
................................................................................
** the stack is not numeric (meaning that is is a NULL or a string that
** does not look like an integer or floating point number) then pop the
** stack and jump to P2.  If the top of the stack is numeric then
** convert it into the least integer that is greater than or equal to its
** current value if P1==0, or to the least integer that is strictly
** greater than its current value if P1==1.
*/
case OP_ForceInt: {            /* no-push, jump */
  i64 v;
  assert( pTos>=p->aStack );
  applyAffinity(pTos, SQLITE_AFF_NUMERIC, encoding);
  if( (pTos->flags & (MEM_Int|MEM_Real))==0 ){
    Release(pTos);
    pTos--;
    pc = pOp->p2 - 1;
................................................................................
** without data loss, then jump immediately to P2, or if P2==0
** raise an SQLITE_MISMATCH exception.
**
** If the top of the stack is not an integer and P2 is not zero and
** P1 is 1, then the stack is popped.  In all other cases, the depth
** of the stack is unchanged.
*/
case OP_MustBeInt: {            /* no-push, jump */
  assert( pTos>=p->aStack );
  applyAffinity(pTos, SQLITE_AFF_NUMERIC, encoding);
  if( (pTos->flags & MEM_Int)==0 ){
    if( pOp->p2==0 ){
      rc = SQLITE_MISMATCH;
      goto abort_due_to_error;
    }else{
................................................................................
*/
/* Opcode: Ge P1 P2 P4
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is greater than or equal to the
** top of the stack.  See the Eq opcode for additional information.
*/
case OP_Eq:               /* same as TK_EQ, no-push, jump */
case OP_Ne:               /* same as TK_NE, no-push, jump */
case OP_Lt:               /* same as TK_LT, no-push, jump */
case OP_Le:               /* same as TK_LE, no-push, jump */
case OP_Gt:               /* same as TK_GT, no-push, jump */
case OP_Ge: {             /* same as TK_GE, no-push, jump */
  Mem *pNos;
  int flags;
  int res;
  char affinity;

  pNos = &pTos[-1];
  flags = pTos->flags|pNos->flags;
................................................................................
** false, then jump to p2.  Otherwise continue to the next instruction.
** An integer is false if zero and true otherwise.  A string is
** false if it has zero length and true otherwise.
**
** If the value popped of the stack is NULL, then take the jump if P1
** is true and fall through if P1 is false.
*/
case OP_If:                 /* no-push, jump */
case OP_IfNot: {            /* no-push, jump */
  int c;
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Null ){
    c = pOp->p1;
  }else{
#ifdef SQLITE_OMIT_FLOATING_POINT
    c = sqlite3VdbeIntValue(pTos);
................................................................................
**
** Check the top of the stack and jump to P2 if the top of the stack
** is NULL.  If P1 is positive, then pop P1 elements from the stack
** regardless of whether or not the jump is taken.  If P1 is negative,
** pop -P1 elements from the stack only if the jump is taken and leave
** the stack unchanged if the jump is not taken.
*/
case OP_IsNull: {            /* same as TK_ISNULL, no-push, jump */
  if( pTos->flags & MEM_Null ){
    pc = pOp->p2-1;
    if( pOp->p1<0 ){
      popStack(&pTos, -pOp->p1);
    }
  }
  if( pOp->p1>0 ){
................................................................................
/* Opcode: NotNull P1 P2 *
**
** Jump to P2 if the top abs(P1) values on the stack are all not NULL.  
** Regardless of whether or not the jump is taken, pop the stack
** P1 times if P1 is greater than zero.  But if P1 is negative,
** leave the stack unchanged.
*/
case OP_NotNull: {            /* same as TK_NOTNULL, no-push, jump */
  int i, cnt;
  cnt = pOp->p1;
  if( cnt<0 ) cnt = -cnt;
  assert( &pTos[1-cnt] >= p->aStack );
  for(i=0; i<cnt && (pTos[1+i-cnt].flags & MEM_Null)==0; i++){}
  if( i>=cnt ) pc = pOp->p2-1;
  if( pOp->p1>0 ) popStack(&pTos, cnt);
................................................................................
** Works like OP_MakeIdxRec except data is taken from registers
** rather than from the stack.  The P1 register is an integer which
** is the number of register to use in building the new record.
** Data is taken from P1+1, P1+2, ..., P1+mem[P1].
*/
case OP_RegMakeRec:
case OP_RegMakeIRec:
case OP_MakeIdxRec:          /* jump */
case OP_MakeRecord: {        /* jump */
  /* Assuming the record contains N fields, the record format looks
  ** like this:
  **
  ** ------------------------------------------------------------------------
  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** ------------------------------------------------------------------------
  **
................................................................................
** cursor P1 so that it points to the largest entry that is less than
** or equal to the key that was popped from the stack.
** If there are no records less than or eqal to the key and P2 is not zero,
** then jump to P2.
**
** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLt
*/
case OP_MoveLt:         /* no-push, jump */
case OP_MoveLe:         /* no-push, jump */
case OP_MoveGe:         /* no-push, jump */
case OP_MoveGt: {       /* no-push, jump */
  int i = pOp->p1;
  Cursor *pC;

  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  assert( pC!=0 );
................................................................................
** pointing to the entry that matches.  The blob is popped from the stack.
**
** The difference between this operation and Distinct is that
** Distinct does not pop the key from the stack.
**
** See also: Distinct, Found, MoveTo, NotExists, IsUnique
*/
case OP_Distinct:       /* no-push, jump */
case OP_NotFound:       /* no-push, jump */
case OP_Found: {        /* no-push, jump */
  int i = pOp->p1;
  int alreadyExists = 0;
  Cursor *pC;
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
................................................................................
** jump to P2.  If any entry does exist where the index string
** matches K but the record number is not R, then the record
** number for that entry is pushed onto the stack and control
** falls through to the next instruction.
**
** See also: Distinct, NotFound, NotExists, Found
*/
case OP_IsUnique: {        /* no-push, jump */
  int i = pOp->p1;
  Mem *pNos = &pTos[-1];
  Cursor *pCx;
  BtCursor *pCrsr;
  i64 R;

  /* Pop the value R off the top of the stack
................................................................................
** The difference between this operation and NotFound is that this
** operation assumes the key is an integer and that P1 is a table whereas
** NotFound assumes key is a blob constructed from MakeRecord and
** P1 is an index.
**
** See also: Distinct, Found, MoveTo, NotFound, IsUnique
*/
case OP_NotExists: {        /* no-push, jump */
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  Mem *pKey;
  if( pOp->p3 ){
    assert( pOp->p3<=p->nMem );
    pKey = &p->aMem[pOp->p3];
................................................................................
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the last entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Last: {        /* no-push, jump */
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  assert( pC!=0 );
................................................................................
** Sorting is accomplished by writing records into a sorting index,
** then rewinding that index and playing it back from beginning to
** end.  We use the OP_Sort opcode instead of OP_Rewind to do the
** rewinding so that the global variable will be incremented and
** regression tests can determine whether or not the optimizer is
** correctly optimizing out sorts.
*/
case OP_Sort: {        /* no-push, jump */
#ifdef SQLITE_TEST
  sqlite3_sort_count++;
  sqlite3_search_count--;
#endif
  /* Fall through into OP_Rewind */
}
/* Opcode: Rewind P1 P2 *
................................................................................
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the first entry in the database table or index.
** If the table or index is empty and P2>0, then jump immediately to P2.
** If P2 is 0 or if the table or index is not empty, fall through
** to the following instruction.
*/
case OP_Rewind: {        /* no-push, jump */
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  int res;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
................................................................................
/* Opcode: Prev P1 P2 *
**
** Back up cursor P1 so that it points to the previous key/data pair in its
** table or index.  If there is no previous key/value pairs then fall through
** to the following instruction.  But if the cursor backup was successful,
** jump immediately to P2.
*/
case OP_Prev:          /* no-push, jump */
case OP_Next: {        /* no-push, jump */
  Cursor *pC;
  BtCursor *pCrsr;

  CHECK_FOR_INTERRUPT;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  if( pC==0 ){
................................................................................
** In either case, the stack is popped once.
**
** If P4 is the "+" string (or any other non-NULL string) then the
** index taken from the top of the stack is temporarily increased by
** an epsilon prior to the comparison.  This makes the opcode work
** like IdxLE.
*/
case OP_IdxLT:          /* no-push, jump */
case OP_IdxGT:          /* no-push, jump */
case OP_IdxGE: {        /* no-push, jump */
  int i= pOp->p1;
  Cursor *pC;

  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );
  assert( pTos>=p->aStack );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
................................................................................
** Attempt to read a single integer from the Fifo. If P1 is zero,
** push the result onto the stack. Otherwise, store the read integer 
** in register P1.
** 
** If the Fifo is empty do not push an entry onto the stack or set
** a memory register but instead jump to P2.
*/
case OP_FifoRead: {         /* jump */
  i64 v;
  CHECK_FOR_INTERRUPT;
  if( sqlite3VdbeFifoPop(&p->sFifo, &v)==SQLITE_DONE ){
    pc = pOp->p2 - 1;
  }else{
    Mem *pOut = &p->aMem[pOp->p1];
    assert( pOp->p1>0 && pOp->p1<=p->nMem );
................................................................................
/* Opcode: IfMemPos P1 P2 *
**
** If the value of memory cell P1 is 1 or greater, jump to P2.
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemPos: {        /* no-push, jump */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i>0 ){
     pc = pOp->p2 - 1;
................................................................................
/* Opcode: IfMemNeg P1 P2 *
**
** If the value of memory cell P1 is less than zero, jump to P2. 
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemNeg: {        /* no-push, jump */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i<0 ){
     pc = pOp->p2 - 1;
................................................................................
/* Opcode: IfMemZero P1 P2 *
**
** If the value of memory cell P1 is exactly 0, jump to P2. 
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemZero: {        /* no-push, jump */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i==0 ){
     pc = pOp->p2 - 1;
................................................................................
  break;
}

/* Opcode: IfMemNull P1 P2 *
**
** If the value of memory cell P1 is NULL, jump to P2. 
*/
case OP_IfMemNull: {        /* no-push, jump */
  int i = pOp->p1;
  assert( i>0 && i<=p->nMem );
  if( p->aMem[i].flags & MEM_Null ){
     pc = pOp->p2 - 1;
  }
  break;
}
................................................................................
#if !defined(SQLITE_OMIT_AUTOVACUUM)
/* Opcode: IncrVacuum P1 P2 *
**
** Perform a single step of the incremental vacuum procedure on
** the P1 database. If the vacuum has finished, jump to instruction
** P2. Otherwise, fall through to the next instruction.
*/
case OP_IncrVacuum: {        /* no-push, jump */
  Btree *pBt;

  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( (p->btreeMask & (1<<pOp->p1))!=0 );
  pBt = db->aDb[pOp->p1].pBt;
  rc = sqlite3BtreeIncrVacuum(pBt);
  if( rc==SQLITE_DONE ){
................................................................................
** P3. Register P3+1 stores the argc parameter to be passed to the
** xFilter method. Registers P3+2..P3+1+argc are the argc additional
** parametersneath additional parameters which are passed to
** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.
**
** A jump is made to P2 if the result set after filtering would be empty.
*/
case OP_VFilter: {   /* no-push, jump */
  int nArg;
  int iQuery;
  const sqlite3_module *pModule;
  Mem *pQuery = &p->aMem[pOp->p3];
  Mem *pArgc = &pQuery[1];

  Cursor *pCur = p->apCsr[pOp->p1];
................................................................................
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VNext P1 P2 *
**
** Advance virtual table P1 to the next row in its result set and
** jump to instruction P2.  Or, if the virtual table has reached
** the end of its result set, then fall through to the next instruction.
*/
case OP_VNext: {   /* no-push, jump */
  const sqlite3_module *pModule;
  int res = 0;

  Cursor *pCur = p->apCsr[pOp->p1];
  assert( pCur->pVtabCursor );
  pModule = pCur->pVtabCursor->pVtab->pModule;
  if( pModule->xNext==0 ){

void sqlite3VdbeIntegerAffinity(Mem*);
int sqlite3VdbeMemRealify(Mem*);
int sqlite3VdbeMemNumerify(Mem*);
int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
void sqlite3VdbeMemRelease(Mem *p);
int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
const char *sqlite3OpcodeName(int);


#ifndef NDEBUG
  void sqlite3VdbeMemSanity(Mem*);
  int sqlite3VdbeOpcodeNoPush(u8);
#endif
int sqlite3VdbeMemTranslate(Mem*, u8);
#ifdef SQLITE_DEBUG
  void sqlite3VdbePrintSql(Vdbe*);
  void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
#endif
int sqlite3VdbeMemHandleBom(Mem *pMem);

void sqlite3VdbeIntegerAffinity(Mem*);
int sqlite3VdbeMemRealify(Mem*);
int sqlite3VdbeMemNumerify(Mem*);
int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
void sqlite3VdbeMemRelease(Mem *p);
int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
const char *sqlite3OpcodeName(int);
int sqlite3VdbeOpcodeHasProperty(int, int);

#ifndef NDEBUG
  void sqlite3VdbeMemSanity(Mem*);

#endif
int sqlite3VdbeMemTranslate(Mem*, u8);
#ifdef SQLITE_DEBUG
  void sqlite3VdbePrintSql(Vdbe*);
  void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
#endif
int sqlite3VdbeMemHandleBom(Mem *pMem);

  assert( p->magic==VDBE_MAGIC_INIT );
  assert( j>=0 && j<p->nLabel );
  if( p->aLabel ){
    p->aLabel[j] = p->nOp;
  }
}

/*
** Return non-zero if opcode 'op' is guarenteed not to push more values
** onto the VDBE stack than it pops off.
*/
static int opcodeNoPush(u8 op){
  /* The 10 NOPUSH_MASK_n constants are defined in the automatically
  ** generated header file opcodes.h. Each is a 16-bit bitmask, one
  ** bit corresponding to each opcode implemented by the virtual
  ** machine in vdbe.c. The bit is true if the word "no-push" appears
  ** in a comment on the same line as the "case OP_XXX:" in 
  ** sqlite3VdbeExec() in vdbe.c.
  **
  ** If the bit is true, then the corresponding opcode is guarenteed not
  ** to grow the stack when it is executed. Otherwise, it may grow the
  ** stack by at most one entry.
  **
  ** NOPUSH_MASK_0 corresponds to opcodes 0 to 15. NOPUSH_MASK_1 contains
  ** one bit for opcodes 16 to 31, and so on.
  **
  ** 16-bit bitmasks (rather than 32-bit) are specified in opcodes.h 
  ** because the file is generated by an awk program. Awk manipulates
  ** all numbers as floating-point and we don't want to risk a rounding
  ** error if someone builds with an awk that uses (for example) 32-bit 
  ** IEEE floats.
  */ 
  static const u32 masks[5] = {
    NOPUSH_MASK_0 + (((unsigned)NOPUSH_MASK_1)<<16),
    NOPUSH_MASK_2 + (((unsigned)NOPUSH_MASK_3)<<16),
    NOPUSH_MASK_4 + (((unsigned)NOPUSH_MASK_5)<<16),
    NOPUSH_MASK_6 + (((unsigned)NOPUSH_MASK_7)<<16),
    NOPUSH_MASK_8 + (((unsigned)NOPUSH_MASK_9)<<16)
  };
  assert( op<32*5 );
  return (masks[op>>5] & (1<<(op&0x1F)));
}

#ifndef NDEBUG
int sqlite3VdbeOpcodeNoPush(u8 op){
  return opcodeNoPush(op);
}
#endif

/*
** Loop through the program looking for P2 values that are negative.
** Each such value is a label.  Resolve the label by setting the P2
** value to its correct non-zero value.
**
** This routine is called once after all opcodes have been inserted.
**
................................................................................
      int n;
      assert( p->nOp - i >= 3 );
      assert( pOp[-1].opcode==OP_MemInt );
      n = pOp[-1].p1;
      if( n>nMaxArgs ) nMaxArgs = n;
#endif
    }
    if( opcodeNoPush(opcode) ){
      nMaxStack--;
    }

    if( pOp->p2>=0 ) continue;
    assert( -1-pOp->p2<p->nLabel );
    pOp->p2 = aLabel[-1-pOp->p2];
  }

  assert( p->magic==VDBE_MAGIC_INIT );
  assert( j>=0 && j<p->nLabel );
  if( p->aLabel ){
    p->aLabel[j] = p->nOp;
  }
}











































/*
** Loop through the program looking for P2 values that are negative.
** Each such value is a label.  Resolve the label by setting the P2
** value to its correct non-zero value.
**
** This routine is called once after all opcodes have been inserted.
**
................................................................................
      int n;
      assert( p->nOp - i >= 3 );
      assert( pOp[-1].opcode==OP_MemInt );
      n = pOp[-1].p1;
      if( n>nMaxArgs ) nMaxArgs = n;
#endif
    }
    if( !sqlite3VdbeOpcodeHasProperty(opcode, OPFLG_PUSH) ){
      nMaxStack--;
    }

    if( pOp->p2>=0 ) continue;
    assert( -1-pOp->p2<p->nLabel );
    pOp->p2 = aLabel[-1-pOp->p2];
  }