Try to move OP_Concat operations outside the inner loop. This turns out

to make things very slightly slower, at least in speedtest1.c.

FossilOrigin-Name: 8a90f69139f7014ed53303814772f9f3efbc4f79

manifest

@@ -1,5 +1,5 @@
-C Modify\sthe\sOP_RowData\sopcode\sso\sthat\swhen\sP3!=0\sit\sis\sallowed\sto\shold\san\nephemeral\scopy\sof\sthe\scontent.\s\sThis\savoids\sunnecessary\smemcpy()\soperations\nin\sthe\sxfer-optimization\sand\sVACUUM.
-D 2017-01-09T15:44:25.721
+C Try\sto\smove\sOP_Concat\soperations\soutside\sthe\sinner\sloop.\s\sThis\sturns\sout\nto\smake\sthings\svery\sslightly\sslower,\sat\sleast\sin\sspeedtest1.c.
+D 2017-01-09T18:20:45.545
 F Makefile.in 41bd4cad981487345c4a84081074bcdb876e4b2e
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
@@ -341,7 +341,7 @@ F src/ctime.c 9f2296a4e5d26ebf0e0d95a0af4628f1ea694e7a
 F src/date.c dc3f1391d9297f8c748132813aaffcb117090d6e
 F src/dbstat.c 19ee7a4e89979d4df8e44cfac7a8f905ec89b77d
 F src/delete.c a84f6229ccb9448460c287248024ceb70e10baab
-F src/expr.c f06f41e5e5daca10fb090e70a2502dcc0dbc992b
+F src/expr.c e559c6c1a0a0709aa056ea919dae0430956b890e
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 2e9aabe1aee76273aff8a84ee92c464e095400ae
 F src/func.c c67273e1ec08abbdcc14c189892a3ff6eeece86b
@@ -1543,7 +1543,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P a5fe03bc419d9c7e6068ed38810e3f183de179b5
-R 1f3e0de052f41632eb2fb92e1db69d89
+P 6e106acd74da3baa5c308a76443d2f0a7c904e5e
+R 9f6dfb3523e9de7aca6ed8bcaf1ea804
+T *branch * failed-optimization
+T *sym-failed-optimization *
+T -sym-trunk *
 U drh
-Z 8ba5841c95779521fe8c2f52b8a5492f
+Z 56c063ac5b216f23ecc2133640602b56

manifest.uuid

@@ -1 +1 @@
-6e106acd74da3baa5c308a76443d2f0a7c904e5e
+8a90f69139f7014ed53303814772f9f3efbc4f79

src/expr.c

@@ -3514,6 +3514,12 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       }
       break;
     }
+    case TK_CONCAT: {
+      if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
+        /* Try to run CONCAT operations at outside the inner loop */
+        return sqlite3ExprCodeAtInit(pParse, pExpr, -1);
+      }
+    }
     case TK_AND:
     case TK_OR:
     case TK_PLUS:
@@ -3524,8 +3530,7 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
     case TK_BITOR:
     case TK_SLASH:
     case TK_LSHIFT:
-    case TK_RSHIFT: 
-    case TK_CONCAT: {
+    case TK_RSHIFT: {
       assert( TK_AND==OP_And );            testcase( op==TK_AND );
       assert( TK_OR==OP_Or );              testcase( op==TK_OR );
       assert( TK_PLUS==OP_Add );           testcase( op==TK_PLUS );