Minor optimization in sqlite3WindowCodeStep().

FossilOrigin-Name: b1322ffb6e63a110998068bf4f0a903028bd4fc0464ae1e517d745fb46423f39

manifest

@@ -1,5 +1,5 @@
-C Allow\sreal\svalues\sto\sbe\sused\sin\sPRECEDING\sand\sFOLLOWING\sexpressions\sfor\sRANGE\swindow\sframes.
-D 2019-03-12T18:28:51.117
+C Minor\soptimization\sin\ssqlite3WindowCodeStep().
+D 2019-03-13T08:28:51.566
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 236d2739dc3e823c3c909bca2d6cef93009bafbefd7018a8f3281074ecb92954
@@ -604,7 +604,7 @@ F src/where.c 8a207cb2ca6b99e1edb1e4bbff9b0504385a759cbf66180d1deb34d80ca4b799
 F src/whereInt.h 5f14db426ca46a83eabab1ae9aa6d4b8f27504ad35b64c290916289b1ddb2e88
 F src/wherecode.c ce7b21e1be2b981d62683fc59c4ca73a04a7ff2f1ebec23d41baf2da2349afd6
 F src/whereexpr.c 36b47f7261d6b6f1a72d774c113b74beddf6745aba1018e64b196e29db233442
-F src/window.c 536bc80552d11f95a3524f8a7239727f94115ada67d1dd900e4988196346c225
+F src/window.c ac687a055121a757d951584285d1ae4554245f98cd17f6092118b29c17340d8f
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/affinity2.test a6d901b436328bd67a79b41bb0ac2663918fe3bd
 F test/affinity3.test 6a101af2fc945ce2912f6fe54dd646018551710d
@@ -1812,7 +1812,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 5129bcc996b3c9f78ab6b674a4364787e7b353b90f15f027cad4431012022c30
-R f73d694ac4c1f1f064a3ca7465b32f6d
+P 25ff7091cb12c63b1864ce68a9151f8432af5804b5ae905a2175761ab4b9fdd8
+R 8c316b11f34d1b1237d8105ff52ba315
 U dan
-Z ea7ae61d59972a80f1c852bccb429b9d
+Z b674509c0d99256be9c341d8d5499a74

manifest.uuid

@@ -1 +1 @@
-25ff7091cb12c63b1864ce68a9151f8432af5804b5ae905a2175761ab4b9fdd8
+b1322ffb6e63a110998068bf4f0a903028bd4fc0464ae1e517d745fb46423f39

src/window.c

@@ -2114,7 +2114,6 @@ void sqlite3WindowCodeStep(
   Window *pMWin = p->pWin;
   ExprList *pOrderBy = pMWin->pOrderBy;
   Vdbe *v = sqlite3GetVdbe(pParse);
-  int regFlushPart;               /* Register for "Gosub flush_partition" */
   int csrWrite;                   /* Cursor used to write to eph. table */
   int csrInput = p->pSrc->a[0].iCursor;     /* Cursor of sub-select */
   int nInput = p->pSrc->a[0].pTab->nCol;    /* Number of cols returned by sub */
@@ -2122,7 +2121,7 @@ void sqlite3WindowCodeStep(
   int addrIfNot;                  /* Address of OP_IfNot */
   int addrGosubFlush;             /* Address of OP_Gosub to flush: */
   int addrInteger;                /* Address of OP_Integer */
-  int addrEmpty = 0;              /* Address of OP_Rewind in flush: */
+  int addrEmpty;                  /* Address of OP_Rewind in flush: */
   int regStart = 0;               /* Value of <expr> PRECEDING */
   int regEnd = 0;                 /* Value of <expr> FOLLOWING */
   int regNew;                     /* Array of registers holding new input row */
@@ -2130,6 +2129,7 @@ void sqlite3WindowCodeStep(
   int regRowid;                   /* Rowid for regRecord in eph table */
   int regNewPeer = 0;             /* Peer values for new row (part of regNew) */
   int regPeer = 0;                /* Peer values for current row */
+  int regFlushPart = 0;           /* Register for "Gosub flush_partition" */
   WindowCodeArg s;                /* Context object for sub-routines */
   int lblWhereEnd;                /* Label just before sqlite3WhereEnd() code */
 
@@ -2154,11 +2154,13 @@ void sqlite3WindowCodeStep(
   s.start.csr = s.current.csr+2;
   s.end.csr = s.current.csr+3;
 
+  /* Allocate registers for the array of values from the sub-query, the
+  ** samve values in record form, and the rowid used to insert said record
+  ** into the ephemeral table.  */
   regNew = pParse->nMem+1;
   pParse->nMem += nInput;
   regRecord = ++pParse->nMem;
   regRowid = ++pParse->nMem;
-  regFlushPart = ++pParse->nMem;
 
   /* If the window frame contains an "<expr> PRECEDING" or "<expr> FOLLOWING"
   ** clause, allocate registers to store the results of evaluating each
@@ -2203,6 +2205,7 @@ void sqlite3WindowCodeStep(
     int regNewPart = regNew + pMWin->nBufferCol;
     KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pPart, 0, 0);
 
+    regFlushPart = ++pParse->nMem;
     addr = sqlite3VdbeAddOp3(v, OP_Compare, regNewPart, pMWin->regPart, nPart);
     sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);
     sqlite3VdbeAddOp3(v, OP_Jump, addr+2, addr+4, addr+2);