Here is the beginnings of an effort to factor out the implementation of

scalar subqueries to be implemented as subroutines at the end of the main
body of bytecode, after the jump back to the OP_Init opcode.  This is an
incremental check-in that contains only preliminary changes.

FossilOrigin-Name: 50e5f390fbab4189c9700a2c62c951ab9acbf0a03c491e88f3e3bcf19a2311cc

diff --git a/manifest b/manifest
index 5a543b1e24967eb3d36023f8b6d9a6393a99baca..8969f652904d23296c3de9ec0d73675bae031544 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Increase\sthe\snumber\sof\sparameters\sto\ssqlite3WhereCodeOneLoopStart()\sto\nencourage\sthe\scompiler\sto\sinline\sthat\sroutine\swithin\ssqlite3WhereBegin().\nThis\sgives\sa\sperformance\simprovement.
-D 2018-12-25T00:15:37.105
+C Here\sis\sthe\sbeginnings\sof\san\seffort\sto\sfactor\sout\sthe\simplementation\sof\nscalar\ssubqueries\sto\sbe\simplemented\sas\ssubroutines\sat\sthe\send\sof\sthe\smain\nbody\sof\sbytecode,\safter\sthe\sjump\sback\sto\sthe\sOP_Init\sopcode.\s\sThis\sis\san\nincremental\scheck-in\sthat\scontains\sonly\spreliminary\schanges.
+D 2018-12-26T15:04:43.407
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in d8b254f8bb81bab43c340d70d17dc3babab40fcc8a348c8255881f780a45fee6
@@ -454,7 +454,7 @@ F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
 F src/btree.c 4429a1615440f0253d470b59f955fe84787fd6f709ae114c0a12d132ae725599
 F src/btree.h febb2e817be499570b7a2e32a9bbb4b607a9234f6b84bb9ae84916d4806e96f2
 F src/btreeInt.h 620ab4c7235f43572cf3ac2ac8723cbdf68073be4d29da24897c7b77dda5fd96
-F src/build.c cb86906fcc9150514024d74befa6905bce2323f51518cc5973e4be6a5b00fd16
+F src/build.c b620091357744710ae9940f03947b4bd69c2d5bf7cd76746e5a7cd5a8787beec
 F src/callback.c 25dda5e1c2334a367b94a64077b1d06b2553369f616261ca6783c48bcb6bda73
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 109e58d00f62e8e71ee1eb5944ac18b90171c928ab2e082e058056e1137cc20b
@@ -462,7 +462,7 @@ F src/date.c ebe1dc7c8a347117bb02570f1a931c62dd78f4a2b1b516f4837d45b7d6426957
 F src/dbpage.c 135eb3b5e74f9ef74bde5cec2571192c90c86984fa534c88bf4a055076fa19b7
 F src/dbstat.c 3c8bd4e77f0244fd2bd7cc90acf116ad2f8e82d70e536637f35ac2bc99b726f9
 F src/delete.c f7938125847e8ef485448db5fbad29acb2991381a02887dd854c1617315ab9fb
-F src/expr.c 7e6f3cd438b5023c82c52f45ef3c73d0db576092d26e5927c787a4610c3dd20a
+F src/expr.c 8f674a8295e7c0d65abf3983c2e8a671141d41274f7a3d843ae09e42c97d8a4c
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 012dd7dba1a62fda6b76e633ab303b2232ee2874a685c915065227ab20ad6ae0
 F src/func.c 7c288b4ce309b5a8b8473514b88e1f8e69a80134509a8c0db8e39c858e367e7f
@@ -505,7 +505,7 @@ F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586
 F src/pcache1.c ddc9fc7d9861cf3a1f30660264b76b1ae9e1dce5dbba085cf001d5cb6b41cf8c
 F src/pragma.c 96ce7dce4dc9cb2b7aa0e1b2ce7536870bdc00b10becc278245e775489447ea0
 F src/pragma.h fdd03d78a7497f74a3f652909f945328480089189526841ae829ce7313d98d13
-F src/prepare.c d0918fb8d00b1ebf19655e7f3d28464b3fc3c43c16d36dd06092de02244a5180
+F src/prepare.c 4fd8502d4e89ba1219ae0467222e8df4608405cb9799b78cc46c4a4990f1cc37
 F src/printf.c 0f1177cf1dd4d7827bf64d840768514ec76409abecaca9e8b577dbd065150381
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 72fe8cae7326b979e7258ab4c531956951e1a5f3fe8644c646abaec1b2eb6d95
@@ -515,7 +515,7 @@ F src/shell.c.in 207da30342db0b6fac8b2487abd60b059a5ea80cc9494bd1db76a1dd4aae7cc
 F src/sqlite.h.in b54cd42d2f3b739a00de540cafe2dcd0de3b8e1748a2db33a68def487e9e602f
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 960f1b86c3610fa23cb6a267572a97dcf286e77aa0dd3b9b23292ffaa1ea8683
-F src/sqliteInt.h 1b343307094ad33e5d38342df86e252fa997ef62f8521ca0a20f9997e2ed1081
+F src/sqliteInt.h 0e8cc89b4a589d2bb7de085ddce04ba53a2ad926c7a71ac194114c02cc9810fc
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -1792,7 +1792,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 7153552bac51295c56a1c42ca79d57195851e232509f9e9610375692f48c7e86
-R 9bbf8e3195d370c6ccbb9531f0f683fa
+P 3c2ad0e915e835b1cb2962879beff50b2745d0cefe1cfc89ef90b7879c139ce6
+R 7253304d573583193fd660d5a38c4b33
+T *branch * factor-out-scalar-subselect
+T *sym-factor-out-scalar-subselect *
+T -sym-reuse-subqueries *
 U drh
-Z f0376617780b59260b8f0b420c8797c9
+Z 7394ebc147279ea7d69a4b85835f879c

diff --git a/manifest.uuid b/manifest.uuid
index 66f30e11aefac5bcefaf657aa56cd3d09467f47a..734f7bfe1f21bae971123a46a15defed56bc0ecb 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3c2ad0e915e835b1cb2962879beff50b2745d0cefe1cfc89ef90b7879c139ce6
\ No newline at end of file
+50e5f390fbab4189c9700a2c62c951ab9acbf0a03c491e88f3e3bcf19a2311cc
\ No newline at end of file

diff --git a/src/build.c b/src/build.c
index e60c1e0b1137937268bb2469fd762ca744f886b5..0f6670af832638347743fdef2bc43bce4b477d7a 100644 (file)
--- a/src/build.c
+++ b/src/build.c
@@ -168,7 +168,7 @@ void sqlite3FinishCoding(Parse *pParse){
     ** on each used database.
     */
     if( db->mallocFailed==0 
-     && (DbMaskNonZero(pParse->cookieMask) || pParse->pConstExpr)
+     && (DbMaskNonZero(pParse->cookieMask) || pParse->pAuxExpr)
     ){
       int iDb, i;
       assert( sqlite3VdbeGetOp(v, 0)->opcode==OP_Init );
@@ -207,17 +207,25 @@ void sqlite3FinishCoding(Parse *pParse){
       */
       sqlite3AutoincrementBegin(pParse);
 
-      /* Code constant expressions that where factored out of inner loops */
-      if( pParse->pConstExpr ){
-        ExprList *pEL = pParse->pConstExpr;
+      if( pParse->pAuxExpr ){
+        ExprList *pEL = pParse->pAuxExpr;
+        struct ExprList_item *pX;
         pParse->okConstFactor = 0;
-        for(i=0; i<pEL->nExpr; i++){
-          sqlite3ExprCode(pParse, pEL->a[i].pExpr, pEL->a[i].u.iConstExprReg);
+        /* Code constant expressions that where factored out of inner loops */
+        for(pX=pEL->a, i=pEL->nExpr; i>0; i--, pX++){
+          if( pX->bAuxSubrtn ) continue;
+          sqlite3ExprCode(pParse, pX->pExpr, pX->u.iConstExprReg);
         }
+        sqlite3VdbeGoto(v, 1);  /* Jump back to the main code */
+        /* Code subroutines factored out from main */
+        for(pX=pEL->a, i=pEL->nExpr; i>0; i--, pX++){
+          if( !pX->bAuxSubrtn ) continue;
+          /* sqlite3ExprCode(pParse, pX->pExpr, pX->u.iConstExprReg); */
+        }
+      }else{
+        /* Jump back to the beginning of main */
+        sqlite3VdbeGoto(v, 1);
       }
-
-      /* Finally, jump back to the beginning of the executable code. */
-      sqlite3VdbeGoto(v, 1);
     }
   }
 

diff --git a/src/expr.c b/src/expr.c
index f0a3a070a6578fc85238558b00bfd24a876f1900..ebb6b200d35d82fad2d5521ee3d8a76bb0161e67 100644 (file)
--- a/src/expr.c
+++ b/src/expr.c
@@ -1950,7 +1950,7 @@ int sqlite3ExprIsConstant(Expr *p){
 **       operands created by the constant propagation optimization.
 **
 ** When this routine returns true, it indicates that the expression
-** can be added to the pParse->pConstExpr list and evaluated once when
+** can be added to the pParse->pAuxExpr list and evaluated once when
 ** the prepared statement starts up.  See sqlite3ExprCodeAtInit().
 */
 int sqlite3ExprIsConstantNotJoin(Expr *p){
@@ -4138,7 +4138,7 @@ int sqlite3ExprCodeAtInit(
 ){
   ExprList *p;
   assert( ConstFactorOk(pParse) );
-  p = pParse->pConstExpr;
+  p = pParse->pAuxExpr;
   if( regDest<0 && p ){
     struct ExprList_item *pItem;
     int i;
@@ -4156,7 +4156,7 @@ int sqlite3ExprCodeAtInit(
      if( regDest<0 ) regDest = ++pParse->nMem;
      pItem->u.iConstExprReg = regDest;
   }
-  pParse->pConstExpr = p;
+  pParse->pAuxExpr = p;
   return regDest;
 }
 
@@ -4394,7 +4394,7 @@ static void exprCodeBetween(
   }else{
     /* Mark the expression is being from the ON or USING clause of a join
     ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
-    ** it into the Parse.pConstExpr list.  We should use a new bit for this,
+    ** it into the Parse.pAuxExpr list.  We should use a new bit for this,
     ** for clarity, but we are out of bits in the Expr.flags field so we
     ** have to reuse the EP_FromJoin bit.  Bummer. */
     exprX.flags |= EP_FromJoin;

diff --git a/src/prepare.c b/src/prepare.c
index b43a37f1fd3e07093d163ea4e80d000c98885a8f..4f0f10a5d8432a41876f426f33c77c9be9298f66 100644 (file)
--- a/src/prepare.c
+++ b/src/prepare.c
@@ -506,7 +506,7 @@ int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){
 void sqlite3ParserReset(Parse *pParse){
   sqlite3 *db = pParse->db;
   sqlite3DbFree(db, pParse->aLabel);
-  sqlite3ExprListDelete(db, pParse->pConstExpr);
+  sqlite3ExprListDelete(db, pParse->pAuxExpr);
   if( db ){
     assert( db->lookaside.bDisable >= pParse->disableLookaside );
     db->lookaside.bDisable -= pParse->disableLookaside;

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 57938fa9b315ff1dc4ddf567c59ace66da816d70..2ca1de619ef957ea18fa13014caa6312c5eb1ea6 100644 (file)
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2587,8 +2587,9 @@ struct ExprList {
     u8 sortOrder;           /* 1 for DESC or 0 for ASC */
     unsigned done :1;       /* A flag to indicate when processing is finished */
     unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
-    unsigned reusable :1;   /* Constant expression is reusable */
+    unsigned reusable   :1; /* Constant expression is reusable */
     unsigned bSorterRef :1; /* Defer evaluation until after sorting */
+    unsigned bAuxSubrtn :1; /* Member of pAuxExpr to be coded as a subroutine */
     union {
       struct {
         u16 iOrderByCol;      /* For ORDER BY, column number in result set */
@@ -3076,7 +3077,7 @@ struct Parse {
                        ** of the base register during check-constraint eval */
   int nLabel;          /* Number of labels used */
   int *aLabel;         /* Space to hold the labels */
-  ExprList *pConstExpr;/* Constant expressions */
+  ExprList *pAuxExpr;  /* Exprs coded at initialization or as subroutines */
   Token constraintName;/* Name of the constraint currently being parsed */
   yDbMask writeMask;   /* Start a write transaction on these databases */
   yDbMask cookieMask;  /* Bitmask of schema verified databases */