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Get rid of the OP_Undef and OP_IsUndef opcodes in favor of higher-level

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OP_InitCoroutine and OP_EndCoroutine.

FossilOrigin-Name: 1ec0e9dd4b26d9f597adc8e062317d4866c5a6a6
This commit is contained in:
drh
2014-02-07 18:27:53 +00:00
parent a5750cfe01
commit 81cf13ec7b
6 changed files with 97 additions and 123 deletions
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78
src/vdbe.c
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@@ -720,20 +720,62 @@ case OP_Gosub: { /* jump */
/* Opcode: Return P1 * * * *
**
** Jump to the next instruction after the address in register P1.
** Jump to the next instruction after the address in register P1. After
** the jump, register P1 becomes undefined.
*/
case OP_Return: { /* in1 */
pIn1 = &aMem[pOp->p1];
assert( pIn1->flags & MEM_Int );
assert( pIn1->flags==MEM_Int );
pc = (int)pIn1->u.i;
pIn1->flags = MEM_Undefined;
break;
}
/* Opcode: Yield P1 * * * *
/* Opcode: InitCoroutine P1 P2 * * *
**
** Identify the co-routine at address P2 using the register P1
** as its return address. Run this opcode prior to the first
** OP_Yield to invoke the co-routine.
*/
case OP_InitCoroutine: { /* jump */
assert( pOp->p1>0 );
assert( pOp->p1<=(p->nMem-p->nCursor) );
pOut = &aMem[pOp->p1];
memAboutToChange(p, pOut);
VdbeMemRelease(pOut);
pOut->u.i = pOp->p2 - 1;
pOut->flags = MEM_Int;
break;
}
/* Opcode: EndCoroutine P1 * * * *
**
** The instruction at the address in register P1 is an OP_Yield.
** Jump to the P2 parameter of that OP_Yield.
** After the jump, register P1 becomes undefined.
*/
case OP_EndCoroutine: { /* in1 */
VdbeOp *pCaller;
pIn1 = &aMem[pOp->p1];
assert( pIn1->flags==MEM_Int );
assert( pIn1->u.i>=0 && pIn1->u.i<p->nOp );
pCaller = &aOp[pIn1->u.i];
assert( pCaller->opcode==OP_Yield );
assert( pCaller->p2>=0 && pCaller->p2<p->nOp );
pc = pCaller->p2 - 1;
pIn1->flags = MEM_Undefined;
break;
}
/* Opcode: Yield P1 P2 * * *
**
** Swap the program counter with the value in register P1.
**
** If the co-routine ends with OP_Yield or OP_Return then continue
** to the next instruction. But if the co-routine ends with
** OP_EndCoroutine, jump immediately to P2.
*/
case OP_Yield: { /* in1 */
case OP_Yield: { /* in1, jump */
int pcDest;
pIn1 = &aMem[pOp->p1];
assert( (pIn1->flags & MEM_Dyn)==0 );
@@ -985,21 +1027,6 @@ case OP_Blob: { /* out2-prerelease */
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 *
** Synopsis: r[P2]=parameter(P1,P4)
**
@@ -2154,19 +2181,6 @@ case OP_IfNot: { /* jump, in1 */
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 * * *
** Synopsis: if r[P1]==NULL goto P2
**