-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
-C Additional\sintarray\stest\scases\sand\stweaks\sto\scomments.
-D 2009-11-10T17:55:48
+C Generate\sVDBE\scode\sfor\sthe\sbuilt-in\sCOALESCE()\sand\sIFNULL()\sfunctions.\s\sThis\nallows\sunused\sarguments\sto\snever\sbe\sevaluated,\swhich\sis\sa\sperformance\swin\swhen\nthe\sunused\sargument\sis\sa\ssubquery.
+D 2009-11-11T00:24:32
F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
F Makefile.in 53f3dfa49f28ab5b80cb083fb7c9051e596bcfa1
F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
F src/complete.c 77016e5a2766cf8b84381397152d2c99ea4b218f
F src/date.c a79c0a8f219370b972e320741f995a3bef9df33f
F src/delete.c ec04635d152debdab70d4b30c5516b59282075ea
-F src/expr.c 11c163003b79f38a5b5100228052aca57b454807
+F src/expr.c be605c60ff84699f3087209f2f86a140a6a5e96c
F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
F src/fkey.c 41219cba186bcf0a053e42327dfa23aaba4f834a
-F src/func.c e536218d193b8d326aab91120bc4c6f28aa2b606
+F src/func.c 5949e2633bb8ff57cc70c1904db171ba23f13537
F src/global.c 271952d199a8cc59d4ce840b3bbbfd2f30c8ba32
F src/hash.c 458488dcc159c301b8e7686280ab209f1fb915af
F src/hash.h 2894c932d84d9f892d4b4023a75e501f83050970
F src/shell.c 360ed53f8672a16b0767bf59e947a9ba7bfe7e21
F src/sqlite.h.in 4464e9772122f0447305d425e04d122b6f1bffec
F src/sqlite3ext.h 69dfb8116af51b84a029cddb3b35062354270c89
-F src/sqliteInt.h 55d26b83d16107804693982028c8b3a075f5a836
+F src/sqliteInt.h ee54fe752ba5672b7ca52bdd0e300c3902103d93
F src/sqliteLimit.h 3afab2291762b5d09ae20c18feb8e9fa935a60a6
F src/status.c e651be6b30d397d86384c6867bc016e4913bcac7
F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 0e7d29253f093d4125ede3cfc478e4bf09aef987
-R 52665a87e5d6f5919cd61ce7e30fc2a5
+P 0c8db5d88ee41dab58d6464283b51f82f7457838
+R 77b5dc144a79987f5b38b3638c59cf4e
U drh
-Z e6118dcdbf5f85120b9d2f449d14ebe3
+Z 3ce600a45d7855e5b1ce1fd4101b7aec
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+30055b257c3c65f8123cad5ac6c62c4c6ca2c900
\ No newline at end of file
sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
break;
}
+
+ /* Attempt a direct implementation of the built-in COALESCE() and
+ ** IFNULL() functions. This avoids unnecessary evalation of
+ ** arguments past the first non-NULL argument.
+ */
+ if( pDef->flags & SQLITE_FUNC_COALESCE ){
+ int endCoalesce = sqlite3VdbeMakeLabel(v);
+ assert( nFarg>=2 );
+ sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
+ for(i=1; i<nFarg; i++){
+ sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
+ sqlite3ExprCacheRemove(pParse, target);
+ sqlite3ExprCachePush(pParse);
+ sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
+ sqlite3ExprCachePop(pParse, 1);
+ }
+ sqlite3VdbeResolveLabel(v, endCoalesce);
+ break;
+ }
+
+
if( pFarg ){
r1 = sqlite3GetTempRange(pParse, nFarg);
sqlite3ExprCachePush(pParse); /* Ticket 2ea2425d34be */
}
}
+
+#if 0 /* This function is never used. */
+/*
+** The COALESCE() and IFNULL() functions used to be implemented as shown
+** here. But now they are implemented as VDBE code so that unused arguments
+** do not have to be computed. This legacy implementation is retained as
+** comment.
+*/
/*
** Implementation of the IFNULL(), NVL(), and COALESCE() functions.
** All three do the same thing. They return the first non-NULL
}
}
}
+#endif /* NOT USED */
+#define ifnullFunc versionFunc /* Substitute function - never called */
/*
** Implementation of random(). Return a random integer.
FUNCTION(upper, 1, 0, 0, upperFunc ),
FUNCTION(lower, 1, 0, 0, lowerFunc ),
FUNCTION(coalesce, 1, 0, 0, 0 ),
- FUNCTION(coalesce, -1, 0, 0, ifnullFunc ),
FUNCTION(coalesce, 0, 0, 0, 0 ),
+/* FUNCTION(coalesce, -1, 0, 0, ifnullFunc ), */
+ {-1,SQLITE_UTF8,SQLITE_FUNC_COALESCE,0,0,ifnullFunc,0,0,"coalesce",0},
FUNCTION(hex, 1, 0, 0, hexFunc ),
- FUNCTION(ifnull, 2, 0, 1, ifnullFunc ),
+/* FUNCTION(ifnull, 2, 0, 0, ifnullFunc ), */
+ {2,SQLITE_UTF8,SQLITE_FUNC_COALESCE,0,0,ifnullFunc,0,0,"ifnull",0},
FUNCTION(random, 0, 0, 0, randomFunc ),
FUNCTION(randomblob, 1, 0, 0, randomBlob ),
FUNCTION(nullif, 2, 0, 1, nullifFunc ),
#define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
#define SQLITE_FUNC_PRIVATE 0x10 /* Allowed for internal use only */
#define SQLITE_FUNC_COUNT 0x20 /* Built-in count(*) aggregate */
+#define SQLITE_FUNC_COALESCE 0x40 /* Built-in coalesce() or ifnull() function */
/*
** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are