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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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44
src/insert.c
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@@ -373,16 +373,13 @@ void sqlite3AutoincrementEnd(Parse *pParse){
** yield X
** end loop
** cleanup after the SELECT
** R <- undefined (signals EOF)
** yield X
** halt-error
** end co-routine R
** B:
**
** To use this subroutine, the caller generates code as follows:
**
** [ Co-routine generated by this subroutine, shown above ]
** S: yield X
** if R==undefined goto E
** S: yield X, at EOF goto E
** if skip this row, goto C
** if terminate loop, goto E
** deal with this row
@@ -399,18 +396,14 @@ int sqlite3CodeCoroutine(Parse *pParse, Select *pSelect, SelectDest *pDest){
regYield = ++pParse->nMem;
v = sqlite3GetVdbe(pParse);
addrTop = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_Integer, addrTop+1, regYield); /* X <- A */
VdbeComment((v, "Co-routine entry point"));
sqlite3VdbeAddOp2(v, OP_InitCoroutine, regYield, addrTop+2);
sqlite3SelectDestInit(pDest, SRT_Coroutine, regYield);
j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
rc = sqlite3Select(pParse, pSelect, pDest);
assert( pParse->nErr==0 || rc );
if( pParse->db->mallocFailed && rc==SQLITE_OK ) rc = SQLITE_NOMEM;
if( rc ) return rc;
sqlite3VdbeAddOp1(v, OP_Undef, pDest->iSdst); /* Signal EOF */
sqlite3VdbeAddOp1(v, OP_Yield, regYield); /* yield X */
sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort);
VdbeComment((v, "End of coroutine"));
sqlite3VdbeAddOp1(v, OP_EndCoroutine, regYield);
sqlite3VdbeJumpHere(v, j1); /* label B: */
return rc;
}
@@ -487,12 +480,9 @@ static int xferOptimization(
** yield X
** end loop
** cleanup after the SELECT
** R <- undefined (signals EOF)
** yield X
** goto A
** end-coroutine X
** B: open write cursor to <table> and its indices
** C: yield X
** if R=undefined goto D
** C: yield X, at EOF goto D
** insert the select result into <table> from R..R+n
** goto C
** D: cleanup
@@ -511,12 +501,9 @@ static int xferOptimization(
** yield X
** end loop
** cleanup after the SELECT
** R <- undefined (signals EOF)
** yield X
** halt-error
** end co-routine R
** B: open temp table
** L: yield X
** if R=undefined goto M
** L: yield X, at EOF goto M
** insert row from R..R+n into temp table
** goto L
** M: open write cursor to <table> and its indices
@@ -701,8 +688,7 @@ void sqlite3Insert(
** here is from the 4th template:
**
** B: open temp table
** L: yield X
** if R=undefined goto M
** L: yield X, goto M at EOF
** insert row from R..R+n into temp table
** goto L
** M: ...
@@ -710,19 +696,17 @@ void sqlite3Insert(
int regRec; /* Register to hold packed record */
int regTempRowid; /* Register to hold temp table ROWID */
int addrTop; /* Label "L" */
int addrIf; /* Address of jump to M */
srcTab = pParse->nTab++;
regRec = sqlite3GetTempReg(pParse);
regTempRowid = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
addrTop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
addrIf = sqlite3VdbeAddOp1(v, OP_IsUndef, regFromSelect);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
sqlite3VdbeJumpHere(v, addrIf);
sqlite3VdbeJumpHere(v, addrTop);
sqlite3ReleaseTempReg(pParse, regRec);
sqlite3ReleaseTempReg(pParse, regTempRowid);
}
@@ -834,7 +818,7 @@ void sqlite3Insert(
/* This block codes the top of loop only. The complete loop is the
** following pseudocode (template 4):
**
** rewind temp table
** rewind temp table, if empty goto D
** C: loop over rows of intermediate table
** transfer values form intermediate table into <table>
** end loop
@@ -846,14 +830,12 @@ void sqlite3Insert(
/* This block codes the top of loop only. The complete loop is the
** following pseudocode (template 3):
**
** C: yield X
** if R=undefined goto D
** C: yield X, at EOF goto D
** insert the select result into <table> from R..R+n
** goto C
** D: ...
*/
addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
addrInsTop = sqlite3VdbeAddOp1(v, OP_IsUndef, dest.iSdst);
addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
}
/* Allocate registers for holding the rowid of the new row,