Use macros to determine if an expression is always true or always false.

FossilOrigin-Name: 6de980a09c3a7adf71f2c9a63a242673b5e1f246e8ee071b26844275f0dad0fc

diff --git a/manifest b/manifest
index b92980907b1fe254829e8c06f36e9c36dc52bc0f..7e497dd6b8b65bc14436029b0d45ba5c96f5de60 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Streamline\sthe\sprocessing\sof\sthe\sAND\soperator.\s\sSlightly\ssmaller\sand\sfaster.
-D 2019-04-19T13:38:34.610
+C Use\smacros\sto\sdetermine\sif\san\sexpression\sis\salways\strue\sor\salways\sfalse.
+D 2019-04-19T16:21:51.905
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -470,7 +470,7 @@ F src/date.c ebe1dc7c8a347117bb02570f1a931c62dd78f4a2b1b516f4837d45b7d6426957
 F src/dbpage.c 135eb3b5e74f9ef74bde5cec2571192c90c86984fa534c88bf4a055076fa19b7
 F src/dbstat.c c12833de69cb655751487d2c5a59607e36be1c58ba1f4bd536609909ad47b319
 F src/delete.c d08c9e01a2664afd12edcfa3a9c6578517e8ff8735f35509582693adbe0edeaf
-F src/expr.c d9b219b2a20f9a99712c24b6c6b21588006260eb3f8bdc96df8262869b58512a
+F src/expr.c 18f8875c247ef5491826619d7ad1d5a67a7a370d76d92066761bd3c015a2d16b
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 0e14d4bef8eac2d87bbd517e492d9084c65008d117823f8922c5e7b2b599bd33
 F src/func.c 2ccf4ae12430b1ae7096be5f0675887e1bd0732828af0ac0f7496339b7c6edee
@@ -523,7 +523,7 @@ F src/shell.c.in 0d1a1abd8f1056ac6b32981442618e988e1e192cec2e904e58c72fcf494c901
 F src/sqlite.h.in 38390767acc1914d58930e03149595ee4710afa4e3c43ab6c3a8aea3f1a6b8cd
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 9ecc93b8493bd20c0c07d52e2ac0ed8bab9b549c7f7955b59869597b650dd8b5
-F src/sqliteInt.h 3a9497a4d7261e348390a1390d00d50f51ebab2ee97335b287447aa9e12bf543
+F src/sqliteInt.h b8d576ae658a3529d2bb72f4ce27892937a2f5cc3b63294250c556007ce112de
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -1818,7 +1818,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 03f2e78899fad99b0a0951b3a408268276954d4cd785389ed9a0192c9217f6fe
-R 4d121f6250fa4d728fb8a46a98d547d3
+P 7713996aa99ce6dd35b5a2db74dd26658fb8d9817169b2a7531cdef6edb41403
+R 8599c4a645fc2e6f1e9b669040f6d312
 U drh
-Z 1c6157db33fa1baf603ced1f230aa369
+Z 635a58ce2bb9d7966c1e1a49c0802a30

diff --git a/manifest.uuid b/manifest.uuid
index 73ca7c5e56a3786f853a13ea9518069a36f73c45..7226259af2b012825e2813f58cacf45c3491d5b8 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-7713996aa99ce6dd35b5a2db74dd26658fb8d9817169b2a7531cdef6edb41403
\ No newline at end of file
+6de980a09c3a7adf71f2c9a63a242673b5e1f246e8ee071b26844275f0dad0fc
\ No newline at end of file

diff --git a/src/expr.c b/src/expr.c
index c9f917ce55cb8447ba4a94e090aa913baba4111c..0484f3b452fb78a9e95a089ad8f8f71d19058ae5 100644 (file)
--- a/src/expr.c
+++ b/src/expr.c
@@ -773,7 +773,7 @@ Expr *sqlite3ExprAlloc(
     pNew->iAgg = -1;
     if( pToken ){
       if( nExtra==0 ){
-        pNew->flags |= EP_IntValue|EP_Leaf;
+        pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
         pNew->u.iValue = iValue;
       }else{
         pNew->u.zToken = (char*)&pNew[1];
@@ -880,33 +880,6 @@ void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
 }
 
 
-/*
-** If the expression is always either TRUE or FALSE (respectively),
-** then return 1.  If one cannot determine the truth value of the
-** expression at compile-time return 0.
-**
-** This is an optimization.  If is OK to return 0 here even if
-** the expression really is always false or false (a false negative).
-** But it is a bug to return 1 if the expression might have different
-** boolean values in different circumstances (a false positive.)
-**
-** Note that if the expression is part of conditional for a
-** LEFT JOIN, then we cannot determine at compile-time whether or not
-** is it true or false, so always return 0.
-*/
-static int exprAlwaysTrue(Expr *p){
-  int v = 0;
-  if( ExprHasProperty(p, EP_FromJoin) ) return 0;
-  if( !sqlite3ExprIsInteger(p, &v) ) return 0;
-  return v!=0;
-}
-static int exprAlwaysFalse(Expr *p){
-  int v = 0;
-  if( ExprHasProperty(p, EP_FromJoin) ) return 0;
-  if( !sqlite3ExprIsInteger(p, &v) ) return 0;
-  return v==0;
-}
-
 /*
 ** Join two expressions using an AND operator.  If either expression is
 ** NULL, then just return the other expression.
@@ -923,7 +896,7 @@ Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
     return pLeft;
   }else if( pParse->nErr || IN_RENAME_OBJECT ){
     return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
-  }else if( exprAlwaysFalse(pLeft) || exprAlwaysFalse(pRight) ){
+  }else if( ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight) ){
     sqlite3ExprDelete(db, pLeft);
     sqlite3ExprDelete(db, pRight);
     return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0);
@@ -1818,6 +1791,7 @@ int sqlite3ExprIdToTrueFalse(Expr *pExpr){
        || sqlite3StrICmp(pExpr->u.zToken, "false")==0)
   ){
     pExpr->op = TK_TRUEFALSE;
+    ExprSetProperty(pExpr, pExpr->u.zToken[4]==0 ? EP_IsTrue : EP_IsFalse);
     return 1;
   }
   return 0;
@@ -4522,9 +4496,9 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
 #endif
     default: {
     default_expr:
-      if( exprAlwaysTrue(pExpr) ){
+      if( ExprAlwaysTrue(pExpr) ){
         sqlite3VdbeGoto(v, dest);
-      }else if( exprAlwaysFalse(pExpr) ){
+      }else if( ExprAlwaysFalse(pExpr) ){
         /* No-op */
       }else{
         r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
@@ -4692,9 +4666,9 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
 #endif
     default: {
     default_expr: 
-      if( exprAlwaysFalse(pExpr) ){
+      if( ExprAlwaysFalse(pExpr) ){
         sqlite3VdbeGoto(v, dest);
-      }else if( exprAlwaysTrue(pExpr) ){
+      }else if( ExprAlwaysTrue(pExpr) ){
         /* no-op */
       }else{
         r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 8868fd3867f9fca743f99badea96eccebd1b0b25..2812433185e89b70421a397f2331514c12bdf083 100644 (file)
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2530,6 +2530,8 @@ struct Expr {
 #define EP_Subrtn   0x2000000 /* Uses Expr.y.sub. TK_IN, _SELECT, or _EXISTS */
 #define EP_Quoted   0x4000000 /* TK_ID was originally quoted */
 #define EP_Static   0x8000000 /* Held in memory not obtained from malloc() */
+#define EP_IsTrue  0x10000000 /* Always has boolean value of TRUE */
+#define EP_IsFalse 0x20000000 /* Always has boolean value of FALSE */
 
 /*
 ** The EP_Propagate mask is a set of properties that automatically propagate
@@ -2545,6 +2547,8 @@ struct Expr {
 #define ExprHasAllProperty(E,P)  (((E)->flags&(P))==(P))
 #define ExprSetProperty(E,P)     (E)->flags|=(P)
 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
+#define ExprAlwaysTrue(E)   (((E)->flags&(EP_FromJoin|EP_IsTrue))==EP_IsTrue)
+#define ExprAlwaysFalse(E)  (((E)->flags&(EP_FromJoin|EP_IsFalse))==EP_IsFalse)
 
 /* The ExprSetVVAProperty() macro is used for Verification, Validation,
 ** and Accreditation only.  It works like ExprSetProperty() during VVA