From: drh <drh@noemail.net>
Date: Mon, 11 Apr 2016 18:15:37 +0000 (+0000)
Subject: Performance optimizations in the column cache of the code generator, and
X-Git-Tag: version-3.13.0~105
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bea119cdebd9fa581302c0e3f5d8c31ca0628965;p=thirdparty%2Fsqlite.git

Performance optimizations in the column cache of the code generator, and
especially the sqlite3ExprCacheRemove() routine.

FossilOrigin-Name: e35b345cf858018ae0c07f79725f8d58062168db
---

diff --git a/manifest b/manifest
index c6cd43627e..278efe9dfc 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Simplification\sand\sperformance\simprovements\sin\ssqlite3ExprDup()\sand\sits\nsubroutines.\s\sMore\swork\sis\spossible\sin\sthis\sarea.
-D 2016-04-11T16:43:43.285
+C Performance\soptimizations\sin\sthe\scolumn\scache\sof\sthe\scode\sgenerator,\sand\nespecially\sthe\ssqlite3ExprCacheRemove()\sroutine.
+D 2016-04-11T18:15:37.821
 F Makefile.in eba680121821b8a60940a81454316f47a341487a
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 1f123a0757f6f04f0341accb46457e116817159a
@@ -329,7 +329,7 @@ F src/ctime.c 60e135af364d777a9ab41c97e5e89cd224da6198
 F src/date.c 0b73e681c11fca867fec554750c07fe0d4e417c1
 F src/dbstat.c c845548d4346e606e2f2b7d2e714ace2b8a7dd1b
 F src/delete.c 78eb999114ec04fcf1b7d123ccedb4b5b734930e
-F src/expr.c 16829fcf84b41d16b3d2e74e4e30ea8315cbba88
+F src/expr.c 22d553f3e6425586513219a9dfbbf6c57581c736
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c 4c0bd09e602b8ae8d36d81e31e4872d0b53c87bb
 F src/func.c 552d300265aed09eea21f68ac742a440550c0062
@@ -380,7 +380,7 @@ F src/shell.c b7922fa264f8c8d72a5ec6dd0b091e15a93c4de5
 F src/sqlite.h.in c8f41612dc1a9b5212a891e1b65a5f589b8b884a
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 98f72cbfe00169c39089115427d06ea05fe4b4a2
-F src/sqliteInt.h 8a3ca5847b3cbd0ee3333f5615e3db049f550727
+F src/sqliteInt.h e4a3229829dd20db9a0348d2119711272c33c757
 F src/sqliteLimit.h c0373387c287c8d0932510b5547ecde31b5da247
 F src/status.c 70912d7be68e9e2dbc4010c93d344af61d4c59ba
 F src/table.c 5226df15ab9179b9ed558d89575ea0ce37b03fc9
@@ -1482,7 +1482,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P e554a4c38bda9c73bf129bb7c665c53ccc4d96a8
-R ddaad63736e0e0e6322e4bbbe74f8062
+P 476cc2838824e0667e80ce527b9caa551dee4a77
+R add6544c70f21201cd7c87d168cad7da
 U drh
-Z db16ea712247dfbc518b4dea8f54265a
+Z 1ce8fe8f94193e403ead86e0c919fda1
diff --git a/manifest.uuid b/manifest.uuid
index c7adec1100..ce5bbdda1c 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-476cc2838824e0667e80ce527b9caa551dee4a77
\ No newline at end of file
+e35b345cf858018ae0c07f79725f8d58062168db
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index 53ba58101c..37a7624db1 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2335,6 +2335,19 @@ static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
   }
 }
 
+#if defined(SQLITE_DEBUG)
+/*
+** Verify the consistency of the column cache
+*/
+static int cacheIsValid(Parse *pParse){
+  int i, n;
+  for(i=n=0; i<SQLITE_N_COLCACHE; i++){
+    if( pParse->aColCache[i].iReg>0 ) n++;
+  }
+  return n==pParse->nColCache;
+}
+#endif
+
 /*
 ** Clear a cache entry.
 */
@@ -2345,6 +2358,9 @@ static void cacheEntryClear(Parse *pParse, struct yColCache *p){
     }
     p->tempReg = 0;
   }
+  p->iReg = 0;
+  pParse->nColCache--;
+  assert( cacheIsValid(pParse) );
 }
 
 
@@ -2388,6 +2404,8 @@ void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
       p->iReg = iReg;
       p->tempReg = 0;
       p->lru = pParse->iCacheCnt++;
+      pParse->nColCache++;
+      assert( cacheIsValid(pParse) );
       return;
     }
   }
@@ -2409,6 +2427,7 @@ void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
     p->iReg = iReg;
     p->tempReg = 0;
     p->lru = pParse->iCacheCnt++;
+    assert( cacheIsValid(pParse) );
     return;
   }
 }
@@ -2418,15 +2437,13 @@ void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
 ** Purge the range of registers from the column cache.
 */
 void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){
-  int i;
-  int iLast = iReg + nReg - 1;
   struct yColCache *p;
-  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
-    int r = p->iReg;
-    if( r>=iReg && r<=iLast ){
-      cacheEntryClear(pParse, p);
-      p->iReg = 0;
-    }
+  if( iReg<=0 || pParse->nColCache==0 ) return;
+  p = &pParse->aColCache[SQLITE_N_COLCACHE-1];
+  while(1){
+    if( p->iReg >= iReg && p->iReg < iReg+nReg ) cacheEntryClear(pParse, p);
+    if( p==pParse->aColCache ) break;
+    p--;
   }
 }
 
@@ -2462,7 +2479,6 @@ void sqlite3ExprCachePop(Parse *pParse){
   for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
     if( p->iReg && p->iLevel>pParse->iCacheLevel ){
       cacheEntryClear(pParse, p);
-      p->iReg = 0;
     }
   }
 }
@@ -2597,7 +2613,6 @@ void sqlite3ExprCacheClear(Parse *pParse){
   for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
     if( p->iReg ){
       cacheEntryClear(pParse, p);
-      p->iReg = 0;
     }
   }
 }
@@ -2639,6 +2654,7 @@ static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
 }
 #endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */
 
+
 /*
 ** Convert an expression node to a TK_REGISTER
 */
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index f9f449d967..1b0325254f 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2814,6 +2814,7 @@ struct Parse {
   u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */
   u8 okConstFactor;    /* OK to factor out constants */
   u8 disableLookaside; /* Number of times lookaside has been disabled */
+  u8 nColCache;        /* Number of entries in aColCache[] */
   int aTempReg[8];     /* Holding area for temporary registers */
   int nRangeReg;       /* Size of the temporary register block */
   int iRangeReg;       /* First register in temporary register block */