From: drh <drh@noemail.net>
Date: Thu, 21 Nov 2013 16:08:52 +0000 (+0000)
Subject: When one or more arguments to a function are constants, try to factor
X-Git-Tag: version-3.8.2~63
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d1a01edac9ff763ef8d2909bf6deff4ad68345bf;p=thirdparty%2Fsqlite.git

When one or more arguments to a function are constants, try to factor
out just those arguments into initialization code.

FossilOrigin-Name: 50d350abbc9176cd6fc606bc45b8fc3020719500
---

diff --git a/manifest b/manifest
index 5d827ec820..6704560739 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Remove\sthe\sobsolete\sTK_CONST_FUNC\stoken\stype.
-D 2013-11-21T14:44:38.999
+C When\sone\sor\smore\sarguments\sto\sa\sfunction\sare\sconstants,\stry\sto\sfactor\nout\sjust\sthose\sarguments\sinto\sinitialization\scode.
+D 2013-11-21T16:08:52.350
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 8a07bebafbfda0eb67728f4bd15a36201662d1a1
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -175,7 +175,7 @@ F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c ea4b7f3623a0fcb1146e7f245d7410033e86859c
 F src/date.c 593c744b2623971e45affd0bde347631bdfa4625
 F src/delete.c 909936019ccb8d0f4a10d0d10ad607c38ee62cbe
-F src/expr.c 98800f5a545bc93ab90acf4c89e904069c8b4bcf
+F src/expr.c 3c629b4b208933c115f5652d2c6fcc877188c4fb
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c 2ab0f5384b70594468ef3ac5c7ed8ca24bfd17d5
 F src/func.c ef30d26ae4d79bbc7300c74e77fd117a0ba30235
@@ -219,12 +219,12 @@ F src/printf.c da9119eb31a187a4b99f60aa4a225141c0ebb74b
 F src/random.c 0b2dbc37fdfbfa6bd455b091dfcef5bdb32dba68
 F src/resolve.c a70e32ae6ccb7b780f2b6d3e9e21837affc25ee5
 F src/rowset.c 64655f1a627c9c212d9ab497899e7424a34222e0
-F src/select.c 253cb683e4a05b0b56b0f9c816f3c4a4e5575ebb
+F src/select.c d41381d80a22d3a83352aeca274cccf264ac277a
 F src/shell.c 849ee96c952d20e504d417e42a06acc5ca94ef17
 F src/sqlite.h.in a5dc058a909d9f14470bad9329d9e9303020ea4e
 F src/sqlite3.rc 11094cc6a157a028b301a9f06b3d03089ea37c3e
 F src/sqlite3ext.h 886f5a34de171002ad46fae8c36a7d8051c190fc
-F src/sqliteInt.h 300dbe249ea28b094bdf304d6d96d414fef0bb26
+F src/sqliteInt.h 8cd0bb5b2cd8430482460c2a302edd2619d17293
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac05a5c7017d0b9f0b4bcd701228b784f987158
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -1140,7 +1140,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P 1b0f779e19a5c0d51eddd2d88db50034d77d132c
-R 4765b9c971cb7bd4e939f413b1d14806
+P 9b4217f055e9bced186b4c56a5753bd6da7115b5
+R cd046aaa4606fb86e4dbb88d28c9046d
 U drh
-Z 408c8bf331ed8f56b61161d6e80b7e89
+Z f1aad5e966fd81185b357b5fc8c7f131
diff --git a/manifest.uuid b/manifest.uuid
index 1c14211a72..65377c8b4c 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9b4217f055e9bced186b4c56a5753bd6da7115b5
\ No newline at end of file
+50d350abbc9176cd6fc606bc45b8fc3020719500
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index 62055d246b..9d405343e9 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2681,8 +2681,21 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
         break;
       }
 
+      for(i=0; i<nFarg; i++){
+        if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
+          constMask |= (1<<i);
+        }
+        if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
+          pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
+        }
+      }
       if( pFarg ){
-        r1 = sqlite3GetTempRange(pParse, nFarg);
+        if( constMask ){
+          r1 = pParse->nMem+1;
+          pParse->nMem += nFarg;
+        }else{
+          r1 = sqlite3GetTempRange(pParse, nFarg);
+        }
 
         /* For length() and typeof() functions with a column argument,
         ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
@@ -2704,7 +2717,8 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
         }
 
         sqlite3ExprCachePush(pParse);     /* Ticket 2ea2425d34be */
-        sqlite3ExprCodeExprList(pParse, pFarg, r1, 1);
+        sqlite3ExprCodeExprList(pParse, pFarg, r1, 
+                                SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);
         sqlite3ExprCachePop(pParse, 1);   /* Ticket 2ea2425d34be */
       }else{
         r1 = 0;
@@ -2728,14 +2742,6 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
         pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
       }
 #endif
-      for(i=0; i<nFarg; i++){
-        if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
-          constMask |= (1<<i);
-        }
-        if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
-          pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
-        }
-      }
       if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
         if( !pColl ) pColl = db->pDfltColl; 
         sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
@@ -2743,7 +2749,7 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
                         (char*)pDef, P4_FUNCDEF);
       sqlite3VdbeChangeP5(v, (u8)nFarg);
-      if( nFarg ){
+      if( nFarg && constMask==0 ){
         sqlite3ReleaseTempRange(pParse, r1, nFarg);
       }
       break;
@@ -2980,6 +2986,19 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
   return inReg;
 }
 
+/*
+** Factor out the code of the given expression to initialization time.
+*/
+void sqlite3ExprCodeAtInit(Parse *pParse, Expr *pExpr, int regDest){
+  ExprList *p;
+  assert( pParse->cookieGoto>0 ); /* Only possible if cookie will be coded */
+  p = pParse->pConstExpr;
+  pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
+  p = sqlite3ExprListAppend(pParse, p, pExpr);
+  if( p ) p->a[p->nExpr-1].u.iConstExprReg = regDest;
+  pParse->pConstExpr = p;
+}
+
 /*
 ** Generate code to evaluate an expression and store the results
 ** into a register.  Return the register number where the results
@@ -3010,10 +3029,8 @@ int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
         }
       }
     }
-    p = sqlite3ExprListAppend(pParse, p, sqlite3ExprDup(pParse->db, pExpr, 0));
-    pParse->pConstExpr = p;
     r2 = ++pParse->nMem;
-    if( p ) p->a[p->nExpr-1].u.iConstExprReg = r2;
+    sqlite3ExprCodeAtInit(pParse, pExpr, r2);
   }else{
     int r1 = sqlite3GetTempReg(pParse);
     r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
@@ -3358,25 +3375,36 @@ void sqlite3ExplainExprList(Vdbe *pOut, ExprList *pList){
 ** expression list into a sequence of registers beginning at target.
 **
 ** Return the number of elements evaluated.
+**
+** The SQLITE_ECEL_DUP flag prevents the arguments from being
+** filled using OP_SCopy.  OP_Copy must be used instead.
+**
+** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
+** factored out into initialization code.
 */
 int sqlite3ExprCodeExprList(
   Parse *pParse,     /* Parsing context */
   ExprList *pList,   /* The expression list to be coded */
   int target,        /* Where to write results */
-  int doHardCopy     /* Make a hard copy of every element */
+  u8 flags           /* SQLITE_ECEL_* flags */
 ){
   struct ExprList_item *pItem;
   int i, n;
+  u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
   assert( pList!=0 );
   assert( target>0 );
   assert( pParse->pVdbe!=0 );  /* Never gets this far otherwise */
   n = pList->nExpr;
+  if( pParse->cookieGoto<=0 ) flags &= ~SQLITE_ECEL_FACTOR;
   for(pItem=pList->a, i=0; i<n; i++, pItem++){
     Expr *pExpr = pItem->pExpr;
-    int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
-    if( inReg!=target+i ){
-      sqlite3VdbeAddOp2(pParse->pVdbe, doHardCopy ? OP_Copy : OP_SCopy,
-                        inReg, target+i);
+    if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
+      sqlite3ExprCodeAtInit(pParse, pExpr, target+i);
+    }else{
+      int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
+      if( inReg!=target+i ){
+        sqlite3VdbeAddOp2(pParse->pVdbe, copyOp, inReg, target+i);
+      }
     }
   }
   return n;
diff --git a/src/select.c b/src/select.c
index 04a523434b..aa8e54b02f 100644
--- a/src/select.c
+++ b/src/select.c
@@ -599,7 +599,8 @@ static void selectInnerLoop(
     ** values returned by the SELECT are not required.
     */
     sqlite3ExprCacheClear(pParse);
-    sqlite3ExprCodeExprList(pParse, pEList, regResult, eDest==SRT_Output);
+    sqlite3ExprCodeExprList(pParse, pEList, regResult,
+                            (eDest==SRT_Output)?SQLITE_ECEL_DUP:0);
   }
   nColumn = nResultCol;
 
@@ -3885,7 +3886,7 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
     if( pList ){
       nArg = pList->nExpr;
       regAgg = sqlite3GetTempRange(pParse, nArg);
-      sqlite3ExprCodeExprList(pParse, pList, regAgg, 1);
+      sqlite3ExprCodeExprList(pParse, pList, regAgg, SQLITE_ECEL_DUP);
     }else{
       nArg = 0;
       regAgg = 0;
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 84c69972a1..7c4c04337b 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2903,10 +2903,13 @@ void sqlite3ExprCacheRemove(Parse*, int, int);
 void sqlite3ExprCacheClear(Parse*);
 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
 int sqlite3ExprCode(Parse*, Expr*, int);
+void sqlite3ExprCodeAtInit(Parse*, Expr*, int);
 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
-int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
+int sqlite3ExprCodeExprList(Parse*, ExprList*, int, u8);
+#define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */
+#define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */
 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
 Table *sqlite3FindTable(sqlite3*,const char*, const char*);