Merge recent trunk enhancements into the sessions branch.

FossilOrigin-Name: 68c8937e83b770d5ec6b1855c1bde81057c11b5f

1 files changed, 8 insertions, 11 deletions

diff --git a/src/select.c b/src/select.c
index 91b3d4345..a9cecaa39 100644
--- a/src/select.c
+++ b/src/select.c
@@ -563,20 +563,17 @@ static void pushOntoSorter(
   }
   sqlite3VdbeAddOp2(v, op, pSort->iECursor, regRecord);
   if( pSelect->iLimit ){
-    int addr1, addr2;
+    int addr;
     int iLimit;
     if( pSelect->iOffset ){
       iLimit = pSelect->iOffset+1;
     }else{
       iLimit = pSelect->iLimit;
     }
-    addr1 = sqlite3VdbeAddOp1(v, OP_IfZero, iLimit); VdbeCoverage(v);
-    sqlite3VdbeAddOp2(v, OP_AddImm, iLimit, -1);
-    addr2 = sqlite3VdbeAddOp0(v, OP_Goto);
-    sqlite3VdbeJumpHere(v, addr1);
+    addr = sqlite3VdbeAddOp3(v, OP_IfNotZero, iLimit, 0, -1); VdbeCoverage(v);
     sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor);
     sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor);
-    sqlite3VdbeJumpHere(v, addr2);
+    sqlite3VdbeJumpHere(v, addr);
   }
 }
 
@@ -973,7 +970,7 @@ static void selectInnerLoop(
   ** the output for us.
   */
   if( pSort==0 && p->iLimit ){
-    sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1); VdbeCoverage(v);
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
   }
 }
 
@@ -1826,7 +1823,7 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
       sqlite3ExprCode(pParse, p->pLimit, iLimit);
       sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);
       VdbeComment((v, "LIMIT counter"));
-      sqlite3VdbeAddOp2(v, OP_IfZero, iLimit, iBreak); VdbeCoverage(v);
+      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);
     }
     if( p->pOffset ){
       p->iOffset = iOffset = ++pParse->nMem;
@@ -2045,7 +2042,7 @@ static void generateWithRecursiveQuery(
   selectInnerLoop(pParse, p, p->pEList, iCurrent,
       0, 0, pDest, addrCont, addrBreak);
   if( regLimit ){
-    sqlite3VdbeAddOp3(v, OP_IfZero, regLimit, addrBreak, -1);
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, regLimit, addrBreak);
     VdbeCoverage(v);
   }
   sqlite3VdbeResolveLabel(v, addrCont);
@@ -2270,7 +2267,7 @@ static int multiSelect(
       p->iLimit = pPrior->iLimit;
       p->iOffset = pPrior->iOffset;
       if( p->iLimit ){
-        addr = sqlite3VdbeAddOp1(v, OP_IfZero, p->iLimit); VdbeCoverage(v);
+        addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
         VdbeComment((v, "Jump ahead if LIMIT reached"));
       }
       explainSetInteger(iSub2, pParse->iNextSelectId);
@@ -2671,7 +2668,7 @@ static int generateOutputSubroutine(
   /* Jump to the end of the loop if the LIMIT is reached.
   */
   if( p->iLimit ){
-    sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1); VdbeCoverage(v);
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
   }
 
   /* Generate the subroutine return