Add the new OP_Once opcode. Use it to clean up and simplify various

one-time initialization sections in the code, including the fix for
ticket [002caede898ae].

FossilOrigin-Name: 7f00552b739fad79517b042a6ed61abe743a917b

1 files changed, 6 insertions, 8 deletions

diff --git a/src/expr.c b/src/expr.c
index 7bfcf5733..6fd08b27f 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1462,8 +1462,7 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
       int iMem = ++pParse->nMem;
       int iAddr;
 
-      iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
-      sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
+      iAddr = sqlite3VdbeAddOp1(v, OP_Once, iMem);
 
       sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
       eType = IN_INDEX_ROWID;
@@ -1494,8 +1493,7 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
           char *pKey;
   
           pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
-          iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
-          sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
+          iAddr = sqlite3VdbeAddOp1(v, OP_Once, iMem);
   
           sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
                                pKey,P4_KEYINFO_HANDOFF);
@@ -1580,6 +1578,7 @@ int sqlite3CodeSubselect(
   int rReg = 0;                           /* Register storing resulting */
   Vdbe *v = sqlite3GetVdbe(pParse);
   if( NEVER(v==0) ) return 0;
+  assert( sqlite3VdbeCurrentAddr(v)>0 );
   sqlite3ExprCachePush(pParse);
 
   /* This code must be run in its entirety every time it is encountered
@@ -1594,8 +1593,7 @@ int sqlite3CodeSubselect(
   */
   if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->pTriggerTab ){
     int mem = ++pParse->nMem;
-    sqlite3VdbeAddOp1(v, OP_If, mem);
-    testAddr = sqlite3VdbeAddOp2(v, OP_Integer, 1, mem);
+    testAddr = sqlite3VdbeAddOp1(v, OP_Once, mem);
     assert( testAddr>0 || pParse->db->mallocFailed );
   }
 
@@ -1695,7 +1693,7 @@ int sqlite3CodeSubselect(
           ** expression we need to rerun this code each time.
           */
           if( testAddr && !sqlite3ExprIsConstant(pE2) ){
-            sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
+            sqlite3VdbeChangeToNoop(v, testAddr);
             testAddr = 0;
           }
 
@@ -1766,7 +1764,7 @@ int sqlite3CodeSubselect(
   }
 
   if( testAddr ){
-    sqlite3VdbeJumpHere(v, testAddr-1);
+    sqlite3VdbeJumpHere(v, testAddr);
   }
   sqlite3ExprCachePop(pParse, 1);